:root {
    --primary-color: #6366f1;
    --text-color: #1e293b;
    --bg-color: #ffffff;
    --nav-bg: rgba(255, 255, 255, 0.8);
    --nav-border: rgba(0, 0, 0, 0.1);
    --hover-color: #4f46e5;
}

[data-theme="dark"] {
    --text-color: #e2e8f0;
    --bg-color: #0f172a;
    --nav-bg: rgba(15, 23, 42, 0.8);
    --nav-border: rgba(255, 255, 255, 0.1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease;
}

/* Navbar Styles */
.navbar-custom {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 70px;
    padding: 0 2rem;
    background: var(--nav-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--nav-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    z-index: 1000;
}

/* Logo Styles */
.nav-brand {
    display: flex;
    align-items: center;
    gap: 1rem;
}
.btn-cse{
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    position: relative;
    left: 50%;
    top: -2rem;
    transform: translateX(-50%);
    transition: all 0.3s ease;
}

.logo {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-text {
    color: white;
    font-size: 1.5rem;
    font-weight: bold;
}

.brand-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
}

/* Navigation Links */
.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.nav-link:hover {
    color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
}

.nav-link.active {
    color: var(--primary-color);
    background: rgba(99, 102, 241, 0.1);
}

.nav-link i {
    font-size: 1.25rem;
}

/* Action Buttons */
.nav-actions {
    display: flex;
    gap: 1rem;
}

.theme-toggle, .menu-toggle {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.theme-toggle:hover, .menu-toggle:hover {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 300px;
    height: 100vh;
    background: var(--bg-color);
    padding: 2rem;
    transition: right 0.3s ease;
    z-index: 1001;
}

.mobile-menu.active {
    right: 0;
    box-shadow: -5px 0 30px rgba(0, 0, 0, 0.1);
}

.menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.close-menu {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.5rem;
    cursor: pointer;
}

.menu-links {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.menu-link {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    padding: 1rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.menu-link:hover {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
}

.menu-link.active {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .navbar-custom {
        padding: 0 1rem;
    }
}

@media (min-width: 769px) {
    .menu-toggle {
        display: none;
    }
}

/* Animations */
@keyframes slideIn {
    from {
        transform: translateX(100%);
    }
    to {
        transform: translateX(0);
    }
}

/* Enhanced Hover Effects */
.nav-link, .menu-link {
    position: relative;
    overflow: hidden;
}

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

.nav-link:hover::after, .menu-link:hover::after {
    width: 80%;
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Better Touch Interactions */
@media (hover: none) {
    .nav-link:active, .menu-link:active {
        background: rgba(99, 102, 241, 0.2);
    }
}

/* Semester Section Styles */
.semester-section {
    padding: 4rem 2rem;
}
.btn-cse{
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 5rem ;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    position: relative;
}
.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-color);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 4px;
    background: var(--primary-color);
    border-radius: 2px;
}


.semester-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    padding: 1rem;
}

.semester-card {
    position: relative;
    background: linear-gradient(145deg, var(--bg-color), var(--bg-secondary));
    border: 1px solid rgba(var(--primary-rgb), 0.1);
    border-radius: 15px;
    overflow: hidden;
    transition: all 0.3s ease;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.semester-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    background: linear-gradient(145deg, var(--bg-secondary), var(--bg-color));
}

.card-content {
    padding: 2rem;
    text-align: center;
}

.semester-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-color);
    border-radius: 50%;
}

.semester-icon i {
    font-size: 1.8rem;
    color: white;
}

.semester-card h3 {
    font-size: 1.5rem;
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.semester-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

.semester-progress {
    margin: 1rem 0;
}

.progress-bar {
    width: 100%;
    height: 6px;
    background: rgba(var(--primary-rgb), 0.1);
    border-radius: 3px;
    overflow: hidden;
}

.progress {
    height: 100%;
    background: var(--primary-color);
    border-radius: 3px;
    transition: width 0.5s ease;
}

.progress-text {
    display: block;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
    text-align: right;
}

.semester-stats {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin: 1rem 0;
}

.stat {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.stat i {
    color: var(--primary-color);
}

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

.view-btn, .download-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.view-btn {
    background: var(--primary-color);
    color: white;
    flex-grow: 1;
}

.download-btn {
    background: rgba(var(--primary-rgb), 0.1);
    color: var(--primary-color);
    padding: 0.5rem;
    border-radius: 5px;
}

.view-btn:hover, .download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(var(--primary-rgb), 0.2);
}

/* Dark Theme Adjustments */
[data-theme='dark'] .semester-card {
    background: linear-gradient(145deg, var(--bg-secondary), var(--bg-color));
}

/* Animations */
@keyframes cardPulse {
    0% { transform: scale(1) translateY(-5px); }
    50% { transform: scale(1.02) translateY(-5px); }
    100% { transform: scale(1) translateY(-5px); }
}

.semester-card:hover {
    animation: cardPulse 1s infinite;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .semester-section {
        padding: 3rem 1rem;
    }
    
    .section-title {
        margin-top: 3rem;
        font-size: 2rem;
    }
    
    .semester-grid {
        gap: 1.5rem;
    }
    
    .card-content {
        padding: 1.5rem;
    }
    
    .semester-stats {
        flex-direction: column;
        align-items: center;
        gap: 0.5rem;
    }
    
    .card-footer {
        flex-direction: column;
    }
    
    .view-btn, .download-btn {
        width: 100%;
        justify-content: center;
    }
}

/* Semester Details Page Styles */
.semester-details-section {
    padding: 6rem 2rem 4rem;
}
.aisemester-details-section {
    padding: 6rem 2rem 4rem ;
    position: relative;
    top: -4rem;
}
.back-button {
    margin-bottom: 2rem;
}

.btn-back {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.btn-back:hover {
    background: rgba(var(--primary-rgb), 0.1);
    color: var(--primary-color);
    transform: translateX(-5px);
}

.semester-header {
    margin-bottom: 3rem;
    text-align: center;
}

.semester-title h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.semester-number {
    color: var(--primary-color);
}

.semester-subtitle {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.semester-meta {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 1rem;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.meta-item i {
    color: var(--primary-color);
    font-size: 1.2rem;
}

/* Subject Cards */
.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.subject-card {
    background: var(--bg-color);
    border-radius: 15px;
    padding: 1.5rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.subject-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.subject-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.subject-header h3 {
    font-size: 1.3rem;
    color: var(--text-color);
    margin: 0;
}

.credit-badge {
    background: rgba(var(--primary-rgb), 0.1);
    color: var(--primary-color);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

.subject-content {
    margin-bottom: 1.5rem;
}

.subject-content p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.subject-meta {
    display: flex;
    gap: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.subject-meta span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.subject-meta i {
    color: var(--primary-color);
}

.subject-footer {
    display: flex;
    gap: 1rem;
}

.btn-syllabus, .btn-resources {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.btn-syllabus {
    background: var(--primary-color);
    color: white;
    flex-grow: 1;
}
.btn-syllabus a{
    background: var(--primary-color);
    color: white;
    flex-grow: 1;
    text-decoration: none;
}

.btn-resources {
    background: rgba(var(--primary-rgb), 0.1);
    color: var(--primary-color);
}
.btn-resources a{
    background: rgba(var(--primary-rgb), 0.1);
    color: var(--primary-color);
    text-decoration: none;
}

.btn-syllabus:hover, .btn-resources:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(var(--primary-rgb), 0.2);
}

/* Semester Summary */
.semester-summary {
    margin-top: 4rem;
}

.semester-summary h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--text-color);
}

.summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.summary-card {
    background: var(--bg-color);
    border-radius: 15px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.summary-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.summary-card i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.summary-card h4 {
    color: var(--text-color);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.summary-card p {
    color: var(--text-secondary);
    font-size: 1.2rem;
    font-weight: 500;
    margin: 0;
}

/* Dark Theme Adjustments */
[data-theme='dark'] .subject-card,
[data-theme='dark'] .summary-card {
    background: var(--bg-secondary);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .semester-details-section {
        padding: 5rem 1rem 3rem;
    }
.aisemester-details-section {
        padding: 5rem 1rem 3rem;
    }
    .semester-title h1 {
        font-size: 2.5rem;
    }

    .semester-meta {
        flex-direction: column;
        gap: 1rem;
    }

    .subjects-grid {
        gap: 1.5rem;
    }

    .summary-grid {
        gap: 1.5rem;
    }
}