/* Genel Stiller */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #1a365d;
    --secondary-color: #2c5282;
    --accent-color: #3182ce;
    --text-color: #2d3748;
    --text-light: #718096;
    --bg-light: #f7fafc;
    --bg-white: #ffffff;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--bg-light);
    font-size: 16px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header - Academic Style */
.header {
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06), 0 1px 3px rgba(0, 0, 0, 0.04);
    padding: 0.75rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 2px solid var(--primary-color);
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--secondary-color) 50%, var(--accent-color) 100%);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo::before {
    content: '';
    width: 2px;
    height: 18px;
    background: linear-gradient(180deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: 2px;
    flex-shrink: 0;
}

.logo h1 {
    font-size: 0.7rem;
    color: var(--primary-color);
    font-weight: 700;
    letter-spacing: 0.3px;
    margin-bottom: 0;
    font-family: 'Inter', sans-serif;
    text-transform: uppercase;
    line-height: 1.2;
}

.nav {
    display: flex;
    gap: 1.25rem;
    align-items: center;
    flex-wrap: wrap;
}

.nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: all 0.3s ease;
    font-size: 0.75rem;
    white-space: nowrap;
    padding: 0.35rem 0.6rem;
    border-radius: 4px;
    position: relative;
}

.nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

.nav a:hover {
    color: var(--primary-color);
    background: rgba(26, 54, 93, 0.05);
}

.nav a:hover::after {
    width: calc(100% - 1.5rem);
}

.nav .btn {
    white-space: nowrap;
    padding: 0.35rem 0.75rem;
    font-size: 0.7rem;
    font-weight: 600;
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(49, 130, 206, 0.2);
}

/* Butonlar */
.btn {
    padding: 0.75rem 1.75rem;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.3s;
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-color) 0%, var(--secondary-color) 100%);
    color: white;
    border: none;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(49, 130, 206, 0.25);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--accent-color) 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(49, 130, 206, 0.35);
}

.btn-primary:active {
    transform: translateY(0);
    box-shadow: 0 2px 8px rgba(49, 130, 206, 0.25);
}

.btn-success {
    background: linear-gradient(135deg, #38a169 0%, #2f855a 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(56, 161, 105, 0.3);
}

.btn-success:hover {
    background: linear-gradient(135deg, #2f855a 0%, #276749 100%);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(56, 161, 105, 0.4);
}

.btn-danger {
    background: linear-gradient(135deg, #e53e3e 0%, #c53030 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(229, 62, 62, 0.3);
}

.btn-danger:hover {
    background: linear-gradient(135deg, #c53030 0%, #9c2626 100%);
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(229, 62, 62, 0.4);
}

.btn-link {
    background: transparent;
    color: var(--accent-color);
    padding: 0.5rem 0;
}

.btn-link:hover {
    text-decoration: underline;
}

/* Hero Section - Academic Style */
.hero-section {
    background-image: url('../images/university-background.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    color: white;
    padding: 6rem 0 5rem;
    min-height: 70vh;
    margin-bottom: 0;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(26, 54, 93, 0.7) 0%, rgba(44, 82, 130, 0.6) 100%);
    z-index: 0;
}

.hero-section::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><path d="M 100 0 L 0 0 0 100" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="1"/></pattern></defs><rect width="100%" height="100%" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
    z-index: 1;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1.25rem;
    letter-spacing: -0.5px;
    line-height: 1.2;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    font-family: 'Inter', sans-serif;
}

.hero-info {
    max-width: 800px;
    margin: 0 auto;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.95;
    margin: 0.4rem 0;
    font-weight: 400;
    letter-spacing: 0.3px;
}

.research-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.625rem;
    justify-content: center;
    margin-top: 1.75rem;
}

.research-tag {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    padding: 0.5rem 1.1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    border: 1px solid rgba(255, 255, 255, 0.25);
    transition: all 0.3s ease;
    cursor: pointer;
    user-select: none;
}

.research-tag:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.research-tag:active {
    transform: translateY(0);
}

/* Popup Styles */
.popup-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(5px);
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.popup-overlay.active {
    opacity: 1;
    visibility: visible;
}

.popup-container {
    background: var(--bg-white);
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 600px;
    width: 100%;
    max-height: 90vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transform: scale(0.9) translateY(20px);
    transition: transform 0.3s ease;
}

.popup-overlay.active .popup-container {
    transform: scale(1) translateY(0);
}

.popup-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-bottom: 2px solid var(--border-color);
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.popup-title {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
}

.popup-close {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    width: 36px;
    height: 36px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    padding: 0;
}

.popup-close:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: rotate(90deg);
}

.popup-close svg {
    width: 20px;
    height: 20px;
}

.popup-content {
    padding: 2rem;
    overflow-y: auto;
    max-height: calc(90vh - 100px);
    line-height: 1.8;
    color: var(--text-color);
}

.popup-content p {
    margin-bottom: 1rem;
    font-size: 1rem;
}

.popup-content ul {
    margin: 1rem 0;
    padding-left: 1.5rem;
}

.popup-content li {
    margin-bottom: 0.75rem;
    font-size: 0.95rem;
    line-height: 1.7;
}

.popup-content li::marker {
    color: var(--accent-color);
}

/* Sections */
.section {
    padding: 4rem 0;
    background: var(--bg-white);
    scroll-margin-top: 80px;
}

.section:nth-child(even) {
    background: var(--bg-light);
}

.section-title {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: var(--primary-color);
    text-align: center;
    letter-spacing: -0.5px;
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--accent-color);
    border-radius: 2px;
}

/* Metrikler */
.metrics-section {
    background: var(--bg-light);
}

.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1100px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .metrics-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    .metrics-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.75rem;
        max-width: 100%;
    }
    
    .metric-card {
        min-width: 0;
    }
    
    .metric-header {
        font-size: 0.95rem;
        padding: 1rem 0.75rem;
    }
    
    .metric-body {
        padding: 1.25rem 0.75rem;
    }
    
    .metric-value {
        font-size: 1.4rem;
    }
    
    .metric-label {
        font-size: 0.85rem;
    }
    
    .metric-item {
        padding: 0.75rem 0;
    }
}

.metric-card {
    background: var(--bg-white);
    border-radius: 12px;
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid var(--border-color);
}

.metric-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.metric-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 1.25rem;
    text-align: center;
    font-weight: 600;
    font-size: 1.1rem;
    letter-spacing: 0.5px;
}

.metric-body {
    padding: 1.5rem;
}

.metric-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.metric-item:last-child {
    border-bottom: none;
}

.metric-label {
    color: var(--text-light);
    font-weight: 500;
    font-size: 0.95rem;
}

.metric-value {
    color: var(--accent-color);
    font-weight: 700;
    font-size: 1.5rem;
}

@media (max-width: 768px) {
    .metric-value {
        font-size: 1.5rem;
    }
    
    .metric-label {
        font-size: 0.9rem;
    }
    
    .metric-header {
        font-size: 1rem;
        padding: 1rem 0.75rem;
    }
    
    .metric-body {
        padding: 1.25rem 1rem;
    }
    
    .metric-item {
        padding: 0.875rem 0;
    }
}

@media (max-width: 480px) {
    .metric-value {
        font-size: 1.4rem;
    }
    
    .metric-label {
        font-size: 0.85rem;
    }
    
    .metric-header {
        font-size: 0.95rem;
        padding: 0.875rem 0.65rem;
    }
    
    .metric-body {
        padding: 1rem 0.75rem;
    }
    
    .metric-item {
        padding: 0.75rem 0;
    }
}

/* Profiller */
.profiles-section {
    background: var(--bg-white);
}

.profiles-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    max-width: 900px;
    margin: 0 auto;
}

.profile-link {
    background: var(--bg-white);
    padding: 1rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    color: var(--text-color);
    box-shadow: var(--shadow);
    transition: all 0.3s;
    display: inline-block;
    border: 2px solid var(--border-color);
    font-weight: 500;
}

.profile-link:hover {
    background: var(--accent-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-color);
}

/* Combined Section - Eğitim ve Deneyim Yan Yana */
.combined-section {
    background: var(--bg-white);
}

.combined-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2.5rem;
    align-items: start;
}

.combined-column {
    display: flex;
    flex-direction: column;
}

.combined-column .section-title {
    margin-bottom: 1.5rem;
    text-align: left;
    font-size: 1.5rem;
}

/* Eğitim */
.education-list {
    max-width: 100%;
    margin: 0;
}

.education-item {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    padding: 1.25rem;
    border-radius: 10px;
    margin-bottom: 1.25rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08), 0 1px 3px rgba(0, 0, 0, 0.05);
    border-left: 3px solid var(--accent-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.education-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
    background: linear-gradient(180deg, var(--accent-color), var(--secondary-color));
    transition: width 0.3s ease;
}

.education-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1), 0 2px 4px rgba(0, 0, 0, 0.06);
}

.education-item:hover::before {
    width: 4px;
}

.education-degree {
    font-size: 0.8rem;
    color: var(--accent-color);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    margin-bottom: 0.5rem;
}

.education-details h3 {
    font-size: 1.1rem;
    color: var(--primary-color);
    margin-bottom: 0.4rem;
    font-weight: 600;
    line-height: 1.3;
}

.education-faculty,
.education-department {
    color: var(--text-light);
    margin: 0.2rem 0;
    font-size: 0.9rem;
    line-height: 1.5;
}

.education-country {
    color: var(--text-light);
    font-size: 0.85rem;
    margin-top: 0.4rem;
}

.education-years {
    color: var(--accent-color);
    font-weight: 600;
    margin-top: 0.4rem;
    font-size: 0.875rem;
}

/* Deneyimler */
.experiences-list {
    max-width: 100%;
    margin: 0;
}

.experience-item {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    padding: 1.25rem;
    border-radius: 10px;
    margin-bottom: 1.25rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08), 0 1px 3px rgba(0, 0, 0, 0.05);
    border-left: 3px solid var(--secondary-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.experience-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
    background: linear-gradient(180deg, var(--secondary-color), var(--primary-color));
    transition: width 0.3s ease;
}

.experience-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1), 0 2px 4px rgba(0, 0, 0, 0.06);
}

.experience-item:hover::before {
    width: 4px;
}

.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.75rem;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.experience-header h3 {
    font-size: 1.1rem;
    color: var(--primary-color);
    font-weight: 600;
    flex: 1;
    line-height: 1.3;
}

.experience-date {
    color: var(--accent-color);
    font-weight: 600;
    font-size: 0.875rem;
    white-space: nowrap;
}

.experience-institution {
    color: var(--text-light);
    font-size: 0.9rem;
    margin: 0.4rem 0;
    font-weight: 500;
    line-height: 1.5;
}

.experience-position {
    color: var(--accent-color);
    font-weight: 500;
    margin: 0.4rem 0;
    font-size: 0.875rem;
    line-height: 1.5;
}

.experience-description {
    color: var(--text-color);
    margin-top: 0.6rem;
    line-height: 1.6;
    font-size: 0.875rem;
}

/* Dersler */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    max-width: 1100px;
    margin: 0 auto;
}

.course-card {
    background: var(--bg-white);
    padding: 1.75rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    border-top: 3px solid var(--accent-color);
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.course-card h3 {
    font-size: 1.15rem;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    font-weight: 600;
}

.course-code {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.course-year {
    color: var(--accent-color);
    font-weight: 500;
    font-size: 0.95rem;
    margin-bottom: 0.75rem;
}

.course-level {
    display: inline-block;
    background: var(--bg-light);
    color: var(--accent-color);
    padding: 0.35rem 0.85rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid var(--border-color);
}

/* Tezler */
.theses-list {
    max-width: 900px;
    margin: 0 auto;
}

.thesis-item {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--accent-color);
    transition: transform 0.3s;
}

.thesis-item:hover {
    transform: translateX(5px);
}

.thesis-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.thesis-header h3 {
    font-size: 1.2rem;
    color: var(--primary-color);
    font-weight: 600;
    flex: 1;
    line-height: 1.4;
}

.thesis-year {
    color: var(--accent-color);
    font-weight: 600;
    font-size: 0.95rem;
    white-space: nowrap;
}

.thesis-student,
.thesis-type {
    color: var(--text-color);
    margin: 0.5rem 0;
    font-size: 0.95rem;
}

.thesis-student strong,
.thesis-type strong {
    color: var(--primary-color);
}

.thesis-institution,
.thesis-department {
    color: var(--text-light);
    font-size: 0.95rem;
    margin: 0.25rem 0;
}

.thesis-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.thesis-link:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Makaleler */
.articles-list {
    max-width: 900px;
    margin: 0 auto;
}

.article-item {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--accent-color);
    transition: transform 0.3s;
}

.article-item:hover {
    transform: translateX(5px);
}

.article-item h3 {
    font-size: 1.2rem;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    font-weight: 600;
    line-height: 1.4;
}

.article-author {
    color: var(--text-light);
    font-size: 0.95rem;
    margin: 0.5rem 0;
}

.article-journal {
    color: var(--accent-color);
    font-weight: 500;
    font-size: 0.95rem;
    margin: 0.5rem 0;
}

.article-date {
    color: var(--text-light);
    font-size: 0.9rem;
    margin: 0.5rem 0;
}

.article-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.article-link:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Çalışmalar */
.works-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
    max-width: 1100px;
    margin: 0 auto;
}

.work-card {
    background: var(--bg-white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid var(--border-color);
}

.work-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.work-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--bg-light);
}

.work-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

.work-card:hover .work-image img {
    transform: scale(1.05);
}

.work-content {
    padding: 1.75rem;
}

.work-content h3 {
    font-size: 1.2rem;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
    font-weight: 600;
    line-height: 1.4;
}

.work-category {
    display: inline-block;
    background: var(--bg-light);
    color: var(--accent-color);
    padding: 0.35rem 0.85rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 0.75rem;
    border: 1px solid var(--border-color);
}

.work-description {
    color: var(--text-color);
    margin: 1rem 0;
    line-height: 1.7;
    font-size: 0.95rem;
}

.work-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.work-link:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}


/* Footer - Modern Academic Style */
.footer {
    background: linear-gradient(180deg, var(--primary-color) 0%, #0f2537 100%);
    color: rgba(255, 255, 255, 0.95);
    padding: 3.5rem 0 1.5rem;
    margin-top: 0;
    position: relative;
    overflow: hidden;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-color) 0%, var(--secondary-color) 50%, var(--accent-color) 100%);
}

.footer-top {
    display: grid;
    grid-template-columns: 1.2fr 1.8fr;
    gap: 3rem;
    margin-bottom: 2.5rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand h3 {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: white;
    letter-spacing: -0.3px;
}

.footer-department {
    font-size: 1rem;
    margin-bottom: 0.25rem;
    opacity: 0.9;
    font-weight: 500;
}

.footer-faculty {
    font-size: 0.9rem;
    opacity: 0.8;
    margin-bottom: 0;
}

.footer-links {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.footer-column h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: white;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.875rem;
}

.footer-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-column ul li {
    margin-bottom: 0.75rem;
}

.footer-column ul li a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-column ul li a:hover {
    color: white;
    padding-left: 0.25rem;
}

.footer-contact-link {
    display: inline-flex;
    align-items: flex-start;
    gap: 0.5rem;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    font-size: 0.9rem;
    line-height: 1.6;
    transition: all 0.3s ease;
}

.footer-contact-link svg {
    flex-shrink: 0;
    margin-top: 0.2rem;
    opacity: 0.8;
}

.footer-contact-link:hover {
    color: white;
}

.footer-contact-link:hover svg {
    opacity: 1;
}

.footer-social {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-social h4 {
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: white;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.social-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    font-size: 0.875rem;
    padding: 0.6rem 1rem;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 6px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.social-link:hover {
    background: rgba(255, 255, 255, 0.15);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    border-color: rgba(255, 255, 255, 0.2);
}

.social-link svg {
    flex-shrink: 0;
    opacity: 0.9;
}

.social-link:hover svg {
    opacity: 1;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    padding-top: 1.5rem;
}

.footer-copyright p {
    margin: 0;
    font-size: 0.875rem;
    opacity: 0.8;
    color: rgba(255, 255, 255, 0.8);
}

.footer-design p {
    margin: 0;
    font-size: 0.875rem;
    opacity: 0.7;
    color: rgba(255, 255, 255, 0.7);
    font-style: italic;
}

.footer-design a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: all 0.3s ease;
}

.footer-design a:hover {
    color: rgba(255, 255, 255, 0.9);
    opacity: 1;
}

/* Login Page */
.login-page {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    padding: 20px;
}

.login-container {
    width: 100%;
    max-width: 450px;
}

.login-box {
    background: var(--bg-white);
    padding: 3rem 2.5rem;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    width: 100%;
}

.login-box h1 {
    text-align: center;
    margin-bottom: 2.5rem;
    color: var(--primary-color);
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.login-form {
    width: 100%;
}

.form-group {
    margin-bottom: 1.75rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.75rem;
    color: var(--text-color);
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.3px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 1rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s;
    background: var(--bg-white);
    color: var(--text-color);
    box-sizing: border-box;
}

.form-group input::placeholder {
    color: var(--text-light);
    opacity: 0.6;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.1);
    transform: translateY(-1px);
}

.form-group input:hover {
    border-color: var(--secondary-color);
}

.form-submit {
    margin-top: 2rem;
    margin-bottom: 0;
    text-align: center;
}

.btn-login {
    width: 100%;
    padding: 1rem 2rem;
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    border-radius: 8px;
    transition: all 0.3s;
    box-shadow: 0 4px 12px rgba(49, 130, 206, 0.3);
}

.btn-login:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(49, 130, 206, 0.4);
}

.btn-login:active {
    transform: translateY(0);
}

.login-footer {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.login-footer a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    font-size: 0.95rem;
}

.login-footer a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Alert Messages */
.alert {
    padding: 1rem 1.25rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
    line-height: 1.6;
    word-wrap: break-word;
}

.alert-error {
    background: #fed7d7;
    color: #c53030;
    border: 1px solid #fc8181;
}

.alert-success {
    background: #c6f6d5;
    color: #22543d;
    border: 1px solid #68d391;
}

.alert a {
    color: inherit;
    text-decoration: underline;
    font-weight: 600;
}

/* Admin Panel Styles */
.admin-wrapper {
    display: flex;
    min-height: 100vh;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.admin-sidebar {
    width: 220px;
    background: linear-gradient(180deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 0;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    display: flex;
    flex-direction: column;
}

/* Student Sidebar - Same as Admin */
.student-sidebar {
    width: 220px;
    background: linear-gradient(180deg, var(--primary-color) 0%, var(--secondary-color) 100%);
}

.student-sidebar .sidebar-header h2 {
    font-size: 1.1rem;
}

.student-sidebar ul.sidebar-menu li a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
    font-size: 0.875rem;
    border-radius: 8px;
    position: relative;
    margin-bottom: 0.25rem;
}

.student-sidebar ul.sidebar-menu li a svg {
    flex-shrink: 0;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.student-sidebar ul.sidebar-menu li a span {
    flex: 1;
}

.student-sidebar ul.sidebar-menu li a:hover {
    background: rgba(255, 255, 255, 0.12);
    color: white;
    transform: translateX(4px);
}

.student-sidebar ul.sidebar-menu li a:hover svg {
    opacity: 1;
}

.student-sidebar ul.sidebar-menu li a.active {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.student-sidebar ul.sidebar-menu li a.active svg {
    opacity: 1;
}

.notification-badge {
    background: linear-gradient(135deg, #e53e3e 0%, #c53030 100%);
    color: white;
    padding: 0.2rem 0.5rem;
    border-radius: 10px;
    font-size: 0.7rem;
    font-weight: 700;
    margin-left: auto;
    box-shadow: 0 2px 6px rgba(229, 62, 62, 0.4);
    animation: pulse-badge 2s infinite;
    min-width: 20px;
    text-align: center;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    line-height: 1.2;
    flex-shrink: 0;
}

@keyframes pulse-badge {
    0%, 100% { 
        opacity: 1;
        transform: scale(1);
    }
    50% { 
        opacity: 0.85;
        transform: scale(1.08);
    }
}

.admin-sidebar::-webkit-scrollbar {
    width: 6px;
}

.admin-sidebar::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.1);
}

.admin-sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
}

.sidebar-header {
    padding: 1.5rem 1rem;
    background: rgba(0, 0, 0, 0.2);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    position: sticky;
    top: 0;
    z-index: 10;
    backdrop-filter: blur(10px);
}

.admin-sidebar h2 {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 700;
    letter-spacing: -0.3px;
    text-align: center;
    color: white;
}

.sidebar-menu {
    list-style: none;
    padding: 0.75rem 0;
    margin: 0;
    flex: 1;
}

.admin-sidebar ul.sidebar-menu li {
    margin: 0.15rem 0.5rem;
}

.admin-sidebar ul.sidebar-menu li a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
    font-size: 0.875rem;
    border-radius: 8px;
    position: relative;
    margin-bottom: 0.25rem;
}

.admin-sidebar ul.sidebar-menu li a svg {
    flex-shrink: 0;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.admin-sidebar ul.sidebar-menu li a span {
    flex: 1;
}

.admin-sidebar ul.sidebar-menu li a:hover {
    background: rgba(255, 255, 255, 0.12);
    color: white;
    transform: translateX(4px);
}

.admin-sidebar ul.sidebar-menu li a:hover svg {
    opacity: 1;
}

.admin-sidebar ul.sidebar-menu li a.active {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.admin-sidebar ul.sidebar-menu li a.active svg {
    opacity: 1;
}

.sidebar-footer {
    padding: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin-top: auto;
    background: rgba(0, 0, 0, 0.1);
}

.sidebar-brand-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 500;
    padding: 0.5rem;
    border-radius: 6px;
    transition: all 0.3s ease;
    justify-content: center;
}

.sidebar-brand-link:hover {
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

.sidebar-brand-link svg {
    flex-shrink: 0;
    opacity: 0.8;
}

.sidebar-brand-link:hover svg {
    opacity: 1;
}

.admin-content {
    margin-left: 220px;
    flex: 1;
    padding: 2rem;
    min-height: 100vh;
}

/* Student sidebar override */
.student-sidebar ~ .admin-content {
    margin-left: 200px;
}

/* Notification badge in sidebar */
.admin-sidebar .notification-badge {
    background: linear-gradient(135deg, #e53e3e 0%, #c53030 100%);
    color: white;
    padding: 0.2rem 0.5rem;
    border-radius: 10px;
    font-size: 0.7rem;
    font-weight: 700;
    margin-left: auto;
    box-shadow: 0 2px 6px rgba(229, 62, 62, 0.4);
    animation: pulse-badge 2s infinite;
    min-width: 20px;
    text-align: center;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.admin-sidebar ul li a {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Mobile Menu Toggle Button */
.mobile-menu-toggle {
    display: none;
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1001;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border: none;
    padding: 0.75rem;
    border-radius: 8px;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    transition: all 0.3s ease;
}

.mobile-menu-toggle:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.mobile-menu-toggle svg {
    width: 24px;
    height: 24px;
}

/* Sidebar Overlay for Mobile */
.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.sidebar-overlay.active {
    display: block;
    opacity: 1;
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .admin-sidebar,
    .student-sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        z-index: 1000;
    }
    
    .admin-sidebar.active,
    .student-sidebar.active {
        transform: translateX(0);
    }
    
    .admin-sidebar.active {
        transform: translateX(0);
    }
    
    .admin-content {
        margin-left: 0;
        padding-top: 4rem;
    }
    
    .student-sidebar ~ .admin-content {
        margin-left: 0;
    }
    
    /* Student sidebar responsive */
    .student-sidebar {
        width: 100% !important;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }
    
    .student-sidebar.active {
        transform: translateX(0);
    }
    
    .student-sidebar h2 {
        font-size: 1rem;
        padding: 1rem 1.25rem !important;
    }
    
    .student-sidebar ul li a {
        padding: 0.875rem 1.25rem !important;
        font-size: 0.9rem !important;
    }
    
    .student-sidebar .notification-badge {
        font-size: 0.65rem;
        padding: 0.15rem 0.4rem;
        min-width: 18px;
    }
    
    /* Message content responsive */
    .message-content {
        padding: 1rem;
    }
    
    .message-bubble {
        padding: 0.875rem 1rem;
        font-size: 0.9rem;
    }
    
    .message-input-area textarea {
        font-size: 0.9rem;
        padding: 0.75rem;
        min-height: 100px;
    }
    
    .message-input-area .btn {
        width: 100%;
        padding: 0.875rem 1.5rem;
        font-size: 0.9rem;
        justify-content: center;
    }
    
    .message-bubble {
        max-width: 90%;
    }
    
    .student-dashboard .stats-grid {
        grid-template-columns: 1fr !important;
        gap: 1rem;
    }
    
    .grade-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .grade-item .subject {
        font-size: 1.1rem;
    }
    
    .admin-header h1 {
        font-size: 1.3rem;
        line-height: 1.3;
    }
    
    .admin-header span {
        font-size: 0.85rem;
    }

.admin-header {
        padding: 1.25rem 1rem;
    }
    
    .admin-header h1 {
        font-size: 1.35rem;
    }
    
    .admin-header span {
        font-size: 0.85rem;
    }
    
    .table-container {
        overflow-x: auto;
    }
    
    table {
        min-width: 600px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .admin-sidebar .notification-badge {
        font-size: 0.65rem;
        padding: 0.15rem 0.4rem;
        min-width: 18px;
    }
    
    .quick-actions-grid {
        display: grid;
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .quick-action-btn {
        text-align: center;
        padding: 1rem;
        border-radius: 8px;
        font-weight: 600;
        transition: all 0.3s ease;
        width: 100%;
    }
    
    .quick-action-messages {
        background: linear-gradient(135deg, #16a085 0%, #138d75 100%);
        color: white;
    }
}

/* Quick Actions Grid */
.quick-actions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.25rem;
}

.quick-action-btn {
    text-align: center;
    padding: 1rem;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.quick-action-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.quick-action-messages {
    background: linear-gradient(135deg, #16a085 0%, #138d75 100%);
    color: white;
}

.admin-header {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    padding: 1.75rem 2rem;
    margin-bottom: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-left: 5px solid var(--accent-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.admin-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-color), var(--secondary-color));
    opacity: 0.3;
}

.admin-header:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.12);
}

.admin-header h1 {
    color: var(--primary-color);
    font-size: 1.85rem;
    font-weight: 700;
    margin: 0;
    letter-spacing: -0.5px;
    position: relative;
    z-index: 1;
}

.admin-header span {
    color: var(--text-light);
    font-size: 0.95rem;
    font-weight: 500;
    position: relative;
    z-index: 1;
}

/* Tables */
.table-container {
    background: var(--bg-white);
    padding: 0;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.table-container:hover {
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.12);
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 0;
}

table th,
table td {
    padding: 1.25rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

table th {
    background: linear-gradient(180deg, #f8fafc 0%, #e2e8f0 100%);
    font-weight: 700;
    color: var(--primary-color);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    position: sticky;
    top: 0;
    z-index: 10;
    padding: 1.5rem 1rem;
}

table tbody tr {
    transition: all 0.25s ease;
    border-left: 3px solid transparent;
}

table tbody tr:hover {
    background: linear-gradient(90deg, #f8fafc 0%, #ffffff 100%);
    border-left-color: var(--accent-color);
    transform: translateX(3px);
    box-shadow: -3px 0 10px rgba(49, 130, 206, 0.1);
}

table tbody tr:last-child td {
    border-bottom: none;
}

table td {
    color: var(--text-color);
    font-size: 0.95rem;
}

/* Forms */
.form-container {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    max-width: 900px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.form-container:hover {
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.12);
}

.form-container h2 {
    color: var(--primary-color);
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 3px solid var(--accent-color);
    position: relative;
}

.form-container h2::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--secondary-color);
}

.form-actions {
    margin-top: 2rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    padding-top: 1.5rem;
    border-top: 2px solid var(--border-color);
}

/* Admin Dashboard Cards */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.dashboard-card {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    border-top: 5px solid var(--accent-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.dashboard-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: linear-gradient(90deg, var(--accent-color), var(--secondary-color));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.dashboard-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.dashboard-card:hover::before {
    transform: scaleX(1);
}

.dashboard-card h2 {
    color: var(--primary-color);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
    position: relative;
}

.dashboard-card h3 {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.8px;
}

.dashboard-card p {
    font-size: 2.5rem;
    font-weight: 800;
    margin: 0;
    background: linear-gradient(135deg, var(--accent-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -1px;
}

/* Bulk Actions */
.bulk-actions {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    margin-bottom: 2rem;
    border: 2px dashed var(--accent-color);
    transition: all 0.3s ease;
    position: relative;
}

.bulk-actions::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-color), var(--secondary-color));
    opacity: 0.5;
}

.bulk-actions:hover {
    border-color: var(--secondary-color);
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.12);
    transform: translateY(-2px);
}

.bulk-actions h3 {
    color: var(--primary-color);
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    font-weight: 700;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--accent-color);
}

.bulk-actions h4 {
    color: var(--primary-color);
    font-size: 1.1rem;
    margin-bottom: 1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.bulk-actions h4::before {
    content: '▸';
    color: var(--accent-color);
    font-size: 1.2rem;
}

.checkbox-group {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1.5rem;
    max-height: 250px;
    overflow-y: auto;
    padding: 1.5rem;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.checkbox-group::-webkit-scrollbar {
    width: 8px;
}

.checkbox-group::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.05);
    border-radius: 4px;
}

.checkbox-group::-webkit-scrollbar-thumb {
    background: var(--accent-color);
    border-radius: 4px;
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1.25rem;
    background: white;
    border-radius: 8px;
    border: 2px solid var(--border-color);
    cursor: pointer;
    transition: all 0.25s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.checkbox-item:hover {
    border-color: var(--accent-color);
    background: linear-gradient(135deg, #f0f7ff 0%, #e6f2ff 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(49, 130, 206, 0.15);
}

.checkbox-item:has(input:checked) {
    border-color: var(--accent-color);
    background: linear-gradient(135deg, #e6f2ff 0%, #d0e7ff 100%);
    box-shadow: 0 4px 12px rgba(49, 130, 206, 0.2);
}

.checkbox-item input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--accent-color);
}

.checkbox-item label {
    margin: 0;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-color);
}

.select-all-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid var(--border-color);
    flex-wrap: wrap;
}

/* Messages */
.messages-container {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 1.5rem;
    height: calc(100vh - 200px);
    min-height: 600px;
}

.messages-list {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    overflow-y: auto;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.messages-list:hover {
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.12);
}

.messages-list::-webkit-scrollbar {
    width: 8px;
}

.messages-list::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.05);
}

.messages-list::-webkit-scrollbar-thumb {
    background: var(--accent-color);
    border-radius: 4px;
}

.message-item {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
    transition: all 0.25s ease;
    position: relative;
    display: flex;
    align-items: center;
    gap: 1rem;
    text-decoration: none;
    color: inherit;
}

.message-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--accent-color);
    transform: scaleY(0);
    transition: transform 0.25s ease;
}

.message-item:hover {
    background: linear-gradient(90deg, rgba(49, 130, 206, 0.05) 0%, rgba(255, 255, 255, 0.05) 100%);
}

.message-item:hover::before {
    transform: scaleY(1);
}

.message-item.active {
    background: linear-gradient(90deg, rgba(49, 130, 206, 0.1) 0%, rgba(255, 255, 255, 0.1) 100%);
    border-left: 3px solid var(--accent-color);
    font-weight: 600;
}

.message-item.active::before {
    transform: scaleY(1);
}

.message-item.unread {
    background: linear-gradient(90deg, rgba(255, 193, 7, 0.08) 0%, rgba(255, 255, 255, 0.05) 100%);
}

.message-item.unread::before {
    background: #f39c12;
    transform: scaleY(1);
}

/* Message item avatar and content */
.message-item-avatar {
    flex-shrink: 0;
}

.avatar-circle {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-color), var(--secondary-color));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    box-shadow: 0 2px 6px rgba(49, 130, 206, 0.3);
}

.avatar-circle-large {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-color), var(--secondary-color));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.5rem;
    box-shadow: 0 3px 8px rgba(49, 130, 206, 0.3);
    flex-shrink: 0;
}

.message-item-content {
    flex: 1;
    min-width: 0;
}

.message-item-content .message-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.25rem;
    gap: 0.5rem;
}

.message-item-content .message-sender {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 0.95rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.message-item-content .message-preview {
    font-size: 0.85rem;
    color: var(--text-light);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.notification-badge-small {
    background: linear-gradient(135deg, #e53e3e 0%, #c53030 100%);
    color: white;
    padding: 0.2rem 0.5rem;
    border-radius: 10px;
    font-size: 0.7rem;
    font-weight: 700;
    box-shadow: 0 2px 4px rgba(229, 62, 62, 0.3);
    min-width: 20px;
    text-align: center;
    flex-shrink: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.message-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.5rem;
    gap: 1rem;
}

.message-sender {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1rem;
}

.message-time {
    font-size: 0.8rem;
    color: var(--text-light);
    white-space: nowrap;
}

.message-preview {
    font-size: 0.85rem;
    color: var(--text-color);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.message-content {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    padding: 2rem;
    overflow-y: auto;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.message-content:hover {
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.12);
}

.message-content::-webkit-scrollbar {
    width: 8px;
}

.message-content::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.05);
}

.message-content::-webkit-scrollbar-thumb {
    background: var(--accent-color);
    border-radius: 4px;
}

.message-bubble {
    padding: 1.25rem 1.5rem;
    border-radius: 16px;
    margin-bottom: 1.25rem;
    max-width: 75%;
    word-wrap: break-word;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    animation: slideIn 0.3s ease;
    position: relative;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message-bubble.sent {
    background: linear-gradient(135deg, var(--accent-color) 0%, var(--secondary-color) 100%);
    color: white;
    margin-left: auto;
    border-bottom-right-radius: 4px;
    box-shadow: 0 4px 12px rgba(49, 130, 206, 0.3);
}

.message-bubble.received {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    color: var(--text-color);
    border-bottom-left-radius: 4px;
    border: 1px solid var(--border-color);
}

.message-bubble-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.75rem;
    font-size: 0.85rem;
    opacity: 0.9;
    font-weight: 600;
}

.message-input-area {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
}

.message-input-area textarea {
    width: 100%;
    min-height: 120px;
    padding: 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    font-family: inherit;
    font-size: 0.95rem;
    resize: vertical;
    transition: all 0.3s ease;
    background: var(--bg-white);
}

.message-input-area textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(49, 130, 206, 0.1);
    transform: translateY(-2px);
}

/* Student Panel */
.student-dashboard {
    max-width: 1100px;
    margin: 0 auto;
}

.student-dashboard .dashboard-card {
    background: linear-gradient(135deg, var(--bg-white) 0%, #f8fafc 100%);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    margin-bottom: 2rem;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.student-dashboard .dashboard-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-color), var(--secondary-color));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.student-dashboard .dashboard-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.student-dashboard .dashboard-card:hover::before {
    transform: scaleX(1);
}

.student-dashboard .dashboard-card h2 {
    color: var(--primary-color);
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 3px solid var(--accent-color);
    font-size: 1.6rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    position: relative;
}

.student-dashboard .dashboard-card h2::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 80px;
    height: 3px;
    background: var(--secondary-color);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-light);
}

.empty-state-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    color: var(--text-light);
    opacity: 0.5;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(49, 130, 206, 0.1), rgba(44, 82, 130, 0.1));
    border-radius: 50%;
}

.empty-state h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.empty-state p {
    font-size: 0.95rem;
    color: var(--text-light);
    margin: 0;
}

/* Grades List */
.grades-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.grade-item {
    padding: 1.75rem;
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    border-radius: 12px;
    border-left: 4px solid var(--accent-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.grade-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--accent-color), var(--secondary-color));
    transition: width 0.3s ease;
}

.grade-item:hover {
    transform: translateX(4px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

.grade-item:hover::before {
    width: 6px;
}

.grade-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    gap: 1rem;
    flex-wrap: wrap;
}

.grade-item .subject {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1.3rem;
    margin: 0;
    flex: 1;
}

.grade-badge {
    display: inline-flex;
    align-items: center;
    background: linear-gradient(135deg, #38a169 0%, #2f855a 100%);
    color: white;
    padding: 0.5rem 1.25rem;
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.95rem;
    box-shadow: 0 2px 8px rgba(56, 161, 105, 0.3);
    transition: all 0.3s ease;
    white-space: nowrap;
}

.grade-badge:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(56, 161, 105, 0.4);
}

.grade-notes {
    margin-top: 1rem;
    padding: 1.25rem;
    background: rgba(49, 130, 206, 0.05);
    border-radius: 8px;
    border-left: 3px solid var(--accent-color);
}

.grade-notes p {
    margin: 0;
    color: var(--text-color);
    line-height: 1.7;
    font-size: 0.95rem;
}

.grade-footer {
    margin-top: 1.25rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-light);
}

.grade-footer svg {
    width: 16px;
    height: 16px;
    opacity: 0.6;
}

/* GitHub List */
.github-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.github-item {
    padding: 1.75rem;
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    border-radius: 12px;
    border-left: 4px solid #9b59b6;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.github-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, #9b59b6, #8e44ad);
    transition: width 0.3s ease;
}

.github-item:hover {
    transform: translateX(4px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

.github-item:hover::before {
    width: 6px;
}

.github-header {
    margin-bottom: 1rem;
}

.github-header h3 {
    margin: 0;
    font-size: 1.1rem;
}

.github-link {
    color: var(--accent-color);
    text-decoration: none;
    word-break: break-all;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
}

.github-link svg:first-child {
    flex-shrink: 0;
    color: #9b59b6;
}

.github-link span {
    flex: 1;
    min-width: 0;
}

.github-link .external-icon {
    flex-shrink: 0;
    opacity: 0.6;
    transition: all 0.3s ease;
}

.github-link:hover {
    color: var(--secondary-color);
}

.github-link:hover .external-icon {
    opacity: 1;
    transform: translate(2px, -2px);
}

.github-description {
    margin-top: 1rem;
    padding: 1.25rem;
    background: rgba(155, 89, 182, 0.05);
    border-radius: 8px;
    border-left: 3px solid #9b59b6;
}

.github-description p {
    margin: 0;
    color: var(--text-color);
    line-height: 1.7;
    font-size: 0.95rem;
}

.github-footer {
    margin-top: 1.25rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-light);
}

.github-footer svg {
    width: 16px;
    height: 16px;
    opacity: 0.6;
}

/* Student Panel Responsive */
@media (max-width: 768px) {
    .student-dashboard {
        max-width: 100%;
    }

    .student-dashboard .stats-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .student-dashboard .dashboard-card {
        padding: 1.5rem;
    }

    .student-dashboard .dashboard-card h2 {
        font-size: 1.3rem;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .grade-item,
    .github-item {
        padding: 1.25rem;
    }

    .grade-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }

    .grade-item .subject {
        font-size: 1.1rem;
    }

    .grade-badge {
        align-self: flex-start;
    }

    .github-link {
        flex-wrap: wrap;
    }

    .github-link span {
        width: 100%;
        word-break: break-all;
    }

    .empty-state {
        padding: 2.5rem 1.5rem;
    }

    .empty-state-icon {
        width: 60px;
        height: 60px;
    }

    .empty-state-icon svg {
        width: 48px;
        height: 48px;
    }

    .empty-state h3 {
        font-size: 1.1rem;
    }

    .empty-state p {
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .student-dashboard .dashboard-card {
        padding: 1.25rem;
    }

    .student-dashboard .dashboard-card h2 {
        font-size: 1.2rem;
        margin-bottom: 1.5rem;
        flex-direction: column;
        align-items: flex-start;
    }

    .student-dashboard .dashboard-card h2 > span {
        width: 3px;
        height: 20px;
    }

    .student-dashboard .stats-grid {
        gap: 0.75rem;
    }

    .student-dashboard .dashboard-card h3 {
        font-size: 0.8rem;
    }

    .student-dashboard .dashboard-card p {
        font-size: 1.5rem;
    }

    .grade-item,
    .github-item {
        padding: 1rem;
        margin-bottom: 1rem;
        border-left-width: 3px;
    }

    .grade-item::before,
    .github-item::before {
        width: 3px;
    }

    .grade-item:hover::before,
    .github-item:hover::before {
        width: 4px;
    }

    .grade-item .subject {
        font-size: 1rem;
        line-height: 1.4;
    }

    .grade-badge {
        padding: 0.4rem 0.9rem;
        font-size: 0.85rem;
    }

    .grade-notes,
    .github-description {
        padding: 0.875rem;
        margin-top: 0.875rem;
    }

    .grade-notes p,
    .github-description p {
        font-size: 0.875rem;
        line-height: 1.6;
    }

    .grade-footer,
    .github-footer {
        font-size: 0.75rem;
        margin-top: 0.875rem;
        padding-top: 0.75rem;
        flex-wrap: wrap;
    }

    .grade-footer svg,
    .github-footer svg {
        width: 14px;
        height: 14px;
    }

    .github-link {
        font-size: 0.875rem;
        gap: 0.5rem;
    }

    .github-link svg:first-child {
        width: 18px;
        height: 18px;
    }

    .github-link .external-icon {
        width: 14px;
        height: 14px;
    }

    .empty-state {
        padding: 2rem 1rem;
    }

    .empty-state-icon {
        width: 50px;
        height: 50px;
        margin-bottom: 1rem;
    }

    .empty-state-icon svg {
        width: 40px;
        height: 40px;
    }

    .empty-state h3 {
        font-size: 1rem;
        margin-bottom: 0.5rem;
    }

    .empty-state p {
        font-size: 0.85rem;
    }

    /* Header responsive */
    .header {
        padding: 0.6rem 0;
    }
    
    .header::before {
        height: 2px;
    }
    
    .logo h1 {
        font-size: 0.85rem;
    }
    
    .logo::before {
        height: 24px;
        width: 3px;
    }
    
    .nav {
        gap: 0.75rem;
    }
    
    .nav a {
        font-size: 0.7rem;
        padding: 0.3rem 0.5rem;
    }
    
    .nav .btn {
        padding: 0.4rem 0.85rem;
        font-size: 0.7rem;
    }
    
    .admin-header h1 {
        font-size: 1.25rem;
        line-height: 1.4;
    }

    .admin-header span {
        font-size: 0.85rem;
    }
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .logo {
        flex-shrink: 0;
    }
    
    .logo h1 {
        font-size: 0.7rem;
    }
    
    .logo::before {
        width: 2px;
        height: 16px;
    }
    
    .nav {
        flex: 1;
        justify-content: flex-end;
        gap: 0.4rem;
        flex-wrap: wrap;
    }
    
    .nav a {
        font-size: 0.75rem;
        padding: 0.35rem 0.6rem;
    }
    
    .nav .btn {
        padding: 0.45rem 0.9rem;
        font-size: 0.75rem;
    }
    
    .hero-section {
        padding: 4rem 0 3rem;
        min-height: 60vh;
        background-attachment: scroll;
    }
    
    .hero-title {
        font-size: 1.75rem;
        margin-bottom: 1rem;
    }
    
    .hero-subtitle {
        font-size: 0.95rem;
        margin: 0.3rem 0;
    }
    
    .research-tags {
        margin-top: 1.5rem;
        gap: 0.5rem;
    }
    
    .research-tag {
        font-size: 0.8rem;
        padding: 0.4rem 0.9rem;
    }
    
    /* Popup Responsive */
    .popup-container {
        max-width: 90%;
        max-height: 85vh;
    }
    
    .popup-header {
        padding: 1.25rem 1.5rem;
    }
    
    .popup-title {
        font-size: 1.3rem;
    }
    
    .popup-content {
        padding: 1.75rem;
        max-height: calc(85vh - 90px);
    }
    
    .section {
        padding: 2.5rem 0;
        scroll-margin-top: 70px;
    }
    
    .section-title {
        font-size: 1.5rem;
        margin-bottom: 2rem;
    }
    
    .section-title::after {
        width: 40px;
        height: 3px;
    }
    
    .admin-sidebar {
        width: 100%;
        position: relative;
        height: auto;
        box-shadow: none;
    }
    
    .sidebar-header {
        padding: 1.25rem 1rem;
    }
    
    .admin-sidebar h2 {
        font-size: 1rem;
    }

    .sidebar-menu {
        padding: 0.5rem 0;
    }

    .admin-sidebar ul.sidebar-menu li {
        margin: 0.1rem 0.25rem;
    }

    .admin-sidebar ul.sidebar-menu li a {
        padding: 0.7rem 0.875rem;
        font-size: 0.85rem;
    }

    .admin-sidebar ul.sidebar-menu li a svg {
        width: 16px;
        height: 16px;
    }

    .sidebar-footer {
        padding: 0.875rem;
    }

    .sidebar-brand-link {
        font-size: 0.75rem;
        padding: 0.4rem;
    }

    .messages-container {
        grid-template-columns: 1fr;
        height: auto;
    }

    .messages-list {
        max-height: 400px;
        margin-bottom: 1.5rem;
    }
    
    .admin-content {
        margin-left: 0;
        padding: 1rem;
    }
    
    .admin-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
        padding: 1.25rem 1rem;
    }
    
    .admin-header h1 {
        font-size: 1.35rem;
        line-height: 1.3;
    }

    .admin-header span {
        font-size: 0.9rem;
    }
    
    /* Table responsive */
    .table-container {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    
    table {
        min-width: 600px;
        font-size: 0.875rem;
    }
    
    table th,
    table td {
        padding: 0.875rem 0.75rem;
    }
    
    /* Form responsive */
    .form-group {
        margin-bottom: 1rem;
    }
    
    .form-group label {
        font-size: 0.9rem;
        margin-bottom: 0.5rem;
    }
    
    .form-group input,
    .form-group textarea,
    .form-group select {
        font-size: 0.9rem;
        padding: 0.75rem;
    }
    
    /* Button responsive */
    .btn {
        padding: 0.7rem 1.5rem;
        font-size: 0.9rem;
    }
    
    /* Card responsive */
    .dashboard-card {
        padding: 1.25rem;
    }
    
    .dashboard-card h2,
    .dashboard-card h3 {
        font-size: 1.1rem;
    }
    
    /* Stats grid responsive */
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    /* Alert responsive */
    .alert {
        padding: 1rem;
        font-size: 0.9rem;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.875rem;
    }

    /* Student dashboard specific */
    .student-dashboard .stats-grid {
        grid-template-columns: 1fr !important;
        gap: 0.75rem;
    }
    
    .student-dashboard .dashboard-card {
        padding: 1.25rem;
    }
    
    .student-dashboard .dashboard-card h3 {
        font-size: 0.8rem;
    }
    
    .student-dashboard .dashboard-card p {
        font-size: 1.5rem;
    }
    
    .grade-item {
        padding: 1rem;
        margin-bottom: 1rem;
    }
    
    .grade-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .grade-item .subject {
        font-size: 1rem;
        line-height: 1.4;
    }
    
    .grade-badge {
        align-self: flex-start;
        font-size: 0.9rem;
        padding: 0.35rem 0.75rem;
    }
    
    .message-content {
        padding: 1rem;
        max-width: 100%;
    }
    
    .message-bubble {
        max-width: 90%;
        padding: 0.875rem 1rem;
        font-size: 0.85rem;
    }
    
    .message-bubble-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
        font-size: 0.8rem;
    }
    
    .message-input-area textarea {
        min-height: 100px;
        font-size: 0.9rem;
    }
    
    .message-input-area .btn {
        width: 100%;
        padding: 0.875rem 1.5rem;
        font-size: 0.9rem;
        justify-content: center;
    }
    
    .admin-header h1 {
        font-size: 1.2rem;
        line-height: 1.3;
    }
    
    .admin-header span {
        font-size: 0.8rem;
    }
    
    .dashboard-card {
        padding: 1.25rem;
    }
    
    .dashboard-card h2 {
        font-size: 1.3rem;
    }
    
    .dashboard-card h3 {
        font-size: 0.85rem;
    }
    
    .dashboard-card p {
        font-size: 1.75rem;
    }
    
    .messages-container {
        grid-template-columns: 1fr;
        height: auto;
    }
    
    .messages-list {
        max-height: 400px;
        margin-bottom: 1.5rem;
    }

    .message-item {
        padding: 0.875rem 1rem;
    }

    .avatar-circle {
        width: 36px;
        height: 36px;
        font-size: 0.9rem;
    }

    .message-item-content .message-sender {
        font-size: 0.9rem;
    }

    .message-item-content .message-preview {
        font-size: 0.8rem;
    }
    
    /* Table responsive */
    .table-container {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    
    table {
        min-width: 600px;
        font-size: 0.875rem;
    }
    
    table th,
    table td {
        padding: 0.875rem 0.75rem;
    }
    
    /* Form responsive */
    .form-group {
        margin-bottom: 1rem;
    }
    
    .form-group label {
        font-size: 0.9rem;
        margin-bottom: 0.5rem;
    }
    
    .form-group input,
    .form-group textarea,
    .form-group select {
        font-size: 0.9rem;
        padding: 0.75rem;
    }
    
    /* Button responsive */
    .btn {
        padding: 0.7rem 1.5rem;
        font-size: 0.9rem;
    }
    
    /* Alert responsive */
    .alert {
        padding: 1rem;
        font-size: 0.9rem;
    }
    
    .bulk-actions {
        margin-bottom: 1.5rem;
        padding: 1.25rem;
    }
    
    .bulk-actions h3 {
        font-size: 1.1rem;
    }
    
    .bulk-actions h4 {
        font-size: 1rem;
    }
    
    .checkbox-group {
        max-height: 150px;
        padding: 0.75rem;
    }
    
    .checkbox-item {
        padding: 0.4rem 0.75rem;
        font-size: 0.85rem;
    }
    
    .select-all-actions {
        flex-wrap: wrap;
        gap: 0.5rem;
    }
    
    .select-all-actions .btn {
        padding: 0.4rem 0.75rem;
        font-size: 0.8rem;
    }
    
    table {
        font-size: 0.9rem;
    }
    
    table th,
    table td {
        padding: 0.75rem 0.5rem;
    }
    
    table th:first-child,
    table td:first-child {
        width: auto;
        padding-left: 0.75rem;
    }
    
    table td:last-child {
        padding-right: 0.75rem;
    }
    
    table td .btn {
        padding: 0.3rem 0.6rem;
        font-size: 0.8rem;
        margin: 0.2rem 0;
    }
    
    .table-container {
        overflow-x: auto;
    }
    
    .form-container {
        padding: 1.5rem;
    }
    
    .header {
        padding: 1rem 0;
    }
    
    .header-content {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
    
    .logo h1 {
        font-size: 0.8rem;
    }
    
    .logo::before {
        width: 2px;
        height: 18px;
    }
    
    .nav {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 0.5rem;
        width: 100%;
        justify-content: flex-start;
    }
    
    .nav a {
        font-size: 0.9rem;
        padding: 0.25rem 0;
    }
    
    .nav .btn {
        padding: 0.6rem 1.25rem;
        font-size: 0.85rem;
    }
    
    .metrics-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .metric-card {
        margin: 0 auto;
        max-width: 100%;
    }
    
    .profiles-grid {
        flex-direction: column;
        gap: 0.75rem;
    }
    
    .profile-link {
        width: 100%;
        text-align: center;
        padding: 0.875rem 1.5rem;
    }
    
    .combined-content {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }
    
    .combined-column .section-title {
        margin-bottom: 1.5rem;
    }
    
    .education-list,
    .experiences-list,
    .theses-list,
    .articles-list {
        margin: 0;
    }
    
    .education-item,
    .experience-item,
    .thesis-item,
    .article-item {
        padding: 1.5rem;
        margin-bottom: 1rem;
    }
    
    .courses-grid,
    .works-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .work-card {
        margin: 0;
    }
    
    .work-image {
        height: 180px;
    }
    
    .work-content {
        padding: 1.5rem;
    }
    
    .experience-header,
    .thesis-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
    
    .experience-date,
    .thesis-year {
        align-self: flex-start;
    }
    
    .contact-info {
        text-align: left;
    }
    
    .footer {
        padding: 2.5rem 0 1.5rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .footer {
        padding: 2.5rem 0 1.25rem;
    }
    
    .footer-top {
        grid-template-columns: 1fr;
        gap: 2rem;
        margin-bottom: 2rem;
        padding-bottom: 1.5rem;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .footer-brand h3 {
        font-size: 1.2rem;
    }
    
    .footer-department {
        font-size: 0.95rem;
    }
    
    .footer-faculty {
        font-size: 0.85rem;
    }
    
    .footer-column h4 {
        font-size: 0.8rem;
    }
    
    .footer-column ul li a,
    .footer-contact-link {
        font-size: 0.85rem;
    }
    
    .social-links {
        gap: 0.75rem;
    }
    
    .social-link {
        padding: 0.5rem 0.875rem;
        font-size: 0.8rem;
    }
    
    .social-link span {
        display: none;
    }
    
    .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
        text-align: left;
    }
    
    .footer-copyright p,
    .footer-design p {
        font-size: 0.8rem;
    }
    
    .container {
        padding: 0 16px;
    }
    
    .btn {
        padding: 0.65rem 1.5rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .hero-section {
        padding: 3rem 0 2.5rem;
        min-height: 50vh;
    }
    
    .hero-title {
        font-size: 1.75rem;
        line-height: 1.3;
    }
    
    /* Popup Mobile */
    .popup-container {
        max-width: 100%;
        max-height: 90vh;
        border-radius: 12px 12px 0 0;
        margin-top: auto;
    }
    
    .popup-header {
        padding: 1rem 1.25rem;
    }
    
    .popup-title {
        font-size: 1.1rem;
    }
    
    .popup-close {
        width: 28px;
        height: 28px;
    }
    
    .popup-content {
        padding: 1.25rem;
        max-height: calc(90vh - 80px);
    }
    
    .popup-content p {
        font-size: 0.9rem;
    }
    
    .popup-content ul {
        padding-left: 1.25rem;
    }
    
    .popup-content li {
        font-size: 0.85rem;
        margin-bottom: 0.5rem;
    }
    
    .hero-subtitle {
        font-size: 0.9rem;
    }
    
    .research-tags {
        margin-top: 1rem;
    }
    
    .research-tag {
        font-size: 0.8rem;
        padding: 0.35rem 0.85rem;
    }
    
    .section {
        padding: 2rem 0;
    }
    
    .section-title {
        font-size: 1.35rem;
        margin-bottom: 1.5rem;
    }
    
    .metric-header {
        font-size: 0.95rem;
        padding: 0.875rem 0.65rem;
    }
    
    .metric-body {
        padding: 1rem 0.75rem;
    }
    
    .metric-value {
        font-size: 1.4rem;
    }
    
    .metric-label {
        font-size: 0.85rem;
    }
    
    .metric-item {
        padding: 0.75rem 0;
    }
    
    .metric-item {
        padding: 1.25rem 0;
    }
    
    .education-item,
    .experience-item,
    .thesis-item,
    .article-item {
        padding: 1.25rem;
    }
    
    .education-item h3,
    .experience-header h3,
    .thesis-header h3,
    .article-item h3,
    .work-content h3 {
        font-size: 1.05rem;
    }
    
    .course-card {
        padding: 1.5rem;
    }
    
    .course-card h3 {
        font-size: 1.05rem;
    }
    
    .work-content {
        padding: 1.25rem;
    }
    
    .logo h1 {
        font-size: 0.6rem;
    }
    
    .logo::before {
        width: 2px;
        height: 12px;
    }
    
    .nav {
        gap: 0.35rem;
        width: 100%;
        justify-content: flex-start;
    }
    
    .nav a {
        font-size: 0.65rem;
        padding: 0.25rem 0.45rem;
    }
    
    .nav .btn {
        padding: 0.3rem 0.6rem;
        font-size: 0.65rem;
    }
    
    .footer {
        padding: 2rem 0 1.25rem;
    }
    
    .footer-section h3 {
        font-size: 1rem;
    }
    
    .footer-item p {
        font-size: 0.9rem;
    }
    
    .footer-copyright p {
        font-size: 0.85rem;
    }
    
    /* Login Page Mobile */
    .login-page {
        padding: 15px;
        align-items: flex-start;
        padding-top: 40px;
    }
    
    .login-container {
        max-width: 100%;
    }
    
    .login-box {
        padding: 2rem 1.5rem;
        border-radius: 12px;
    }
    
    .login-box h1 {
        font-size: 1.75rem;
        margin-bottom: 2rem;
    }
    
    .form-group {
        margin-bottom: 1.5rem;
    }
    
    .form-group label {
        font-size: 0.9rem;
        margin-bottom: 0.6rem;
    }
    
    .form-group input,
    .form-group textarea,
    .form-group select {
        padding: 0.9rem 1.1rem;
        font-size: 1rem;
    }
    
    .btn-login {
        padding: 0.9rem 1.5rem;
        font-size: 1rem;
    }
    
    .login-footer {
        margin-top: 1.5rem;
        padding-top: 1.25rem;
    }
}

@media (max-width: 480px) {
    .login-page {
        padding: 10px;
        padding-top: 30px;
    }
    
    .login-box {
        padding: 1.75rem 1.25rem;
        border-radius: 10px;
    }
    
    .login-box h1 {
        font-size: 1.5rem;
        margin-bottom: 1.75rem;
    }
    
    .form-group {
        margin-bottom: 1.25rem;
    }
    
    .form-group input,
    .form-group textarea,
    .form-group select {
        padding: 0.85rem 1rem;
        font-size: 0.95rem;
    }
    
    .btn-login {
        padding: 0.85rem 1.25rem;
        font-size: 0.95rem;
    }
    
    .alert {
        padding: 0.875rem 1rem;
        font-size: 0.9rem;
        margin-bottom: 1.25rem;
    }
    
    .admin-sidebar {
        padding: 0;
    }
    
    .sidebar-header {
        padding: 1rem 0.875rem;
    }
    
    .admin-sidebar h2 {
        font-size: 0.95rem;
    }
    
    .admin-sidebar ul.sidebar-menu li a {
        padding: 0.65rem 0.75rem;
        font-size: 0.8rem;
    }

    .admin-sidebar ul.sidebar-menu li a svg {
        width: 14px;
        height: 14px;
    }

    .sidebar-footer {
        padding: 0.75rem;
    }

    .sidebar-brand-link {
        font-size: 0.7rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .dashboard-card h3 {
        font-size: 0.8rem;
    }
    
    .dashboard-card p {
        font-size: 1.5rem;
    }
    
    .messages-container {
        grid-template-columns: 1fr;
    }
    
    .message-bubble {
        max-width: 85%;
        padding: 0.875rem 1rem;
    }
    
    .message-input-area textarea {
        min-height: 80px;
    }
}