/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #f59e0b;
    --accent-color: #10b981;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #111827;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --text-primary: #f9fafb;
    --text-secondary: #d1d5db;
    --text-light: #9ca3af;
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-dark: #0f172a;
    --border-color: #374151;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.2);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.2);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.4), 0 4px 6px -4px rgb(0 0 0 / 0.3);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.5), 0 8px 10px -6px rgb(0 0 0 / 0.4);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
}

.gradient-text {
    color: var(--secondary-color);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    transform: translateZ(0);
}

.btn:hover {
    transform: translateY(-2px);
}

.btn:active {
    transform: translateY(0);
    transition-duration: 0.1s;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.3);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 2000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-logo i {
    font-size: 2rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #111827;
    font-weight: 500;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    padding: 0.5rem 0;
}

.nav-link:hover {
    color: var(--primary-color);
    transform: translateY(-1px);
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -2px;
    left: 50%;
    background: var(--primary-color);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateX(-50%);
}

.nav-link:hover::after {
    width: 100%;
    left: 0;
    transform: translateX(0);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000"><defs><radialGradient id="a" cx="50%" cy="50%"><stop offset="0%" stop-color="%23ffffff" stop-opacity=".1"/><stop offset="100%" stop-color="%23ffffff" stop-opacity="0"/></radialGradient></defs><circle cx="250" cy="250" r="200" fill="url(%23a)"/><circle cx="750" cy="750" r="300" fill="url(%23a)"/></svg>');
    opacity: 0.1;
    animation: float 20s ease-in-out infinite;
}



@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 100;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.1;
    color: #1f2937;
    z-index: 100;
    position: relative;
}

.hero-description {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    color: #374151;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 3rem;
}

.hero-stats {
    display: flex;
    gap: 2rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--secondary-color);
}

.stat-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
}

.hero-visual {
    position: relative;
    height: 500px;
}

.floating-card {
    position: absolute;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 1rem;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    animation: floating 6s ease-in-out infinite;
}

.floating-card:nth-child(1) {
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.floating-card:nth-child(2) {
    top: 10%;
    right: 20%;
    animation-delay: 1.5s;
}

.floating-card:nth-child(3) {
    bottom: 30%;
    left: 20%;
    animation-delay: 3s;
}

.floating-card:nth-child(4) {
    bottom: 20%;
    right: 10%;
    animation-delay: 4.5s;
}

@keyframes floating {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-15px); }
}

.floating-card i {
    font-size: 2rem;
    color: var(--secondary-color);
}

.floating-card span {
    font-weight: 500;
    font-size: 0.875rem;
}

/* Sections */
section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Profiles Section */
.profiles {
    background-color: var(--bg-secondary);
}

.profiles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.profile-card {
    background: white;
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transform: translateZ(0);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.profile-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.profile-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.profile-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.profile-card:hover .profile-icon {
    transform: rotate(5deg) scale(1.05);
}

.profile-icon i {
    font-size: 2rem;
    color: white;
}

.profile-title {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    min-height: 3rem;
    display: flex;
    align-items: center;
}

.profile-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.profile-card .btn {
    margin-top: auto;
}

.profile-subjects {
    list-style: none;
    margin-bottom: 2rem;
}

.profile-subjects li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.profile-subjects i {
    color: var(--accent-color);
}

/* Years Section */
.years-filter {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 2rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.years-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.year-card {
    background: white;
    border-radius: 0.5rem;
    padding: 2rem 1rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    border: 2px solid transparent;
}

.year-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.year-card:active {
    transform: translateY(-1px);
    transition-duration: 0.1s;
}

.year-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.year-subjects {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    position: relative;
    background-color: white;
    margin: 5% auto;
    padding: 0;
    border-radius: 1rem;
    width: 90%;
    max-width: 800px;
    max-height: 80vh;
    overflow: hidden;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-header {
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg-secondary);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0.5rem;
    border-radius: 0.5rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.modal-close:hover {
    background: var(--border-color);
    color: var(--text-primary);
    transform: scale(1.1);
}

.modal-close:active {
    transform: scale(0.95);
}

.modal-body {
    padding: 2rem;
    overflow-y: auto;
    max-height: 60vh;
}

/* About Section */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

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

.feature {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.feature i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

.stats-card {
    background: white;
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
}

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

.stat-item {
    text-align: center;
}

.stat-item i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-item .stat-number {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.stat-item .stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}



/* Footer */
.footer {
    background-color: var(--bg-dark);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-logo i {
    color: var(--secondary-color);
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

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

.footer-section ul li a:hover {
    color: var(--secondary-color);
}

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

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 0.5rem;
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

/* Session Selection Styles */
.session-selection {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.session-info {
    margin-bottom: 3rem;
}

.session-info h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.75rem;
}

.session-info p {
    color: var(--text-secondary);
    font-size: 1.125rem;
    line-height: 1.6;
}

.session-buttons {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
    max-width: 500px;
    margin: 0 auto;
}

.session-btn {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem;
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 1rem;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-align: left;
}

.session-btn:hover {
    border-color: var(--primary-color);
    background: var(--bg-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.session-btn i {
    font-size: 2rem;
    color: var(--primary-color);
    min-width: 40px;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.session-btn:hover i {
    transform: scale(1.1);
}

.session-details {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.session-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.session-subtitle {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Profile Selection Styles */
.profile-selection {
    max-width: 800px;
    margin: 0 auto;
}

.profiles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.profile-btn {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
}

.profile-btn:hover {
    border-color: var(--primary-color);
    background: var(--bg-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.profile-btn i {
    font-size: 2rem;
    color: var(--primary-color);
    min-width: 40px;
}

.profile-details {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.profile-name {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.profile-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.back-button {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.btn-back {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.875rem;
}

.btn-back:hover {
    background: var(--border-color);
    color: var(--text-primary);
}

/* PDF Documents Section */
.session-info-display {
    margin-bottom: 2rem;
}

.session-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--gradient-primary);
    color: white;
    border-radius: 2rem;
    font-weight: 500;
    font-size: 0.875rem;
}

.pdf-documents-section {
    margin-bottom: 3rem;
}

.pdf-documents-section .section-header {
    text-align: left;
    margin-bottom: 2rem;
}

.pdf-documents-section .section-header h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.pdf-documents-section .section-header h3 i {
    color: #dc2626;
}

.pdf-grid {
    display: grid;
    gap: 1.5rem;
}

.pdf-item {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: all 0.3s ease;
}

.pdf-item:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.pdf-icon {
    flex-shrink: 0;
}

.pdf-icon i {
    font-size: 2.5rem;
    color: #dc2626;
}

.pdf-info {
    flex-grow: 1;
}

.pdf-info h5 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.pdf-info p {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    line-height: 1.5;
}

.pdf-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--text-light);
}

.pdf-meta span {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.pdf-actions {
    display: flex;
    gap: 0.5rem;
    flex-shrink: 0;
}

.no-pdfs-message {
    text-align: center;
    padding: 3rem 2rem;
    background: var(--bg-secondary);
    border-radius: 1rem;
    border: 2px dashed var(--border-color);
}

.no-pdfs-icon i {
    font-size: 3rem;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.no-pdfs-message h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.no-pdfs-message p {
    color: var(--text-secondary);
}

/* Placeholder Notice */
.placeholder-notice {
    grid-column: 1 / -1;
    margin-top: 2rem;
    padding: 1rem 1.5rem;
    background: #fef3c7;
    border: 1px solid #f59e0b;
    border-radius: 0.5rem;
    text-align: center;
}

.notice-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    color: #92400e;
}

.notice-content i {
    color: #f59e0b;
}

/* Navigation Section */
.navigation-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.nav-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.nav-buttons .btn-secondary {
    background: var(--primary-color);
    color: white;
    border: 1px solid var(--primary-color);
}

.nav-buttons .btn-secondary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
}

/* Navigation Actions */
.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Dark Mode Toggle */
.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    background: var(--bg-secondary);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    border: 2px solid var(--border-color);
}

.theme-toggle:hover {
    transform: scale(1.1);
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.theme-toggle:active {
    transform: scale(0.95);
}

.theme-toggle .icon-sun {
    display: block;
}

.theme-toggle .icon-moon {
    display: none;
}

[data-theme="dark"] .theme-toggle .icon-sun {
    display: none;
}

[data-theme="dark"] .theme-toggle .icon-moon {
    display: block;
}

/* Dark Mode Specific Styles */
[data-theme="dark"] .profile-card,
[data-theme="dark"] .year-card,
[data-theme="dark"] .session-btn {
    background: var(--bg-secondary);
    border-color: var(--border-color);
}

[data-theme="dark"] .modal-content {
    background: var(--bg-secondary);
}

[data-theme="dark"] .modal-header {
    background: var(--bg-dark);
    border-color: var(--border-color);
}

[data-theme="dark"] .hero {
    background: linear-gradient(135deg, #1e1b4b 0%, #312e81 100%);
}

[data-theme="dark"] .hero-title {
    color: #f9fafb;
}

[data-theme="dark"] .header {
    background: rgba(17, 24, 39, 0.95);
    border-color: var(--border-color);
}

[data-theme="dark"] .nav-link {
    color: #f9fafb;
}

[data-theme="dark"] .btn-secondary {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.1);
}

[data-theme="dark"] .btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
}

[data-theme="dark"] .nav-buttons .btn-secondary {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

[data-theme="dark"] .nav-buttons .btn-secondary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
}

/* Dark Mode Modal Elements */
[data-theme="dark"] .year-btn,
[data-theme="dark"] .profile-btn,
[data-theme="dark"] .session-option {
    background: var(--bg-secondary);
    border-color: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] .year-btn:hover,
[data-theme="dark"] .profile-btn:hover,
[data-theme="dark"] .session-option:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

[data-theme="dark"] .filter-btn {
    background: var(--bg-secondary);
    border-color: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] .filter-btn.active,
[data-theme="dark"] .filter-btn:hover {
    background: var(--primary-color);
    color: white;
}

/* Dark Mode PDF Pages */
[data-theme="dark"] .solutions-page {
    background-color: var(--bg-primary);
}

[data-theme="dark"] .solutions-header {
    background: var(--bg-secondary);
    border-color: var(--border-color);
}

[data-theme="dark"] .solutions-content {
    background: var(--bg-secondary);
}

[data-theme="dark"] .pdf-item {
    background: var(--bg-secondary);
    border-color: var(--border-color);
}

[data-theme="dark"] .pdf-item:hover {
    border-color: var(--primary-color);
}

[data-theme="dark"] .no-pdfs-message {
    background: var(--bg-dark);
    border-color: var(--border-color);
}

[data-theme="dark"] .placeholder-notice {
    background: rgba(245, 158, 11, 0.1);
    border-color: rgba(245, 158, 11, 0.3);
}

[data-theme="dark"] .breadcrumb a {
    color: var(--primary-color);
}

/* Smooth theme transitions */
html {
    transition: background-color 0.3s ease;
}

body,
.profile-card,
.year-card,
.session-btn,
.modal-content,
.header {
    transition: all 0.3s ease;
}

/* Responsive Design for PDF Section */
@media (max-width: 768px) {
    .pdf-item {
        flex-direction: column;
        text-align: center;
        gap: 1rem;
    }

    .pdf-actions {
        width: 100%;
        justify-content: center;
    }

    .pdf-meta {
        justify-content: center;
        flex-wrap: wrap;
    }

    .nav-buttons {
        flex-direction: column;
        align-items: center;
    }

    .sessions-grid {
        gap: 0.5rem;
    }

    .session-option {
        padding: 0.75rem;
        gap: 0.75rem;
    }

    .session-option i {
        font-size: 1rem;
    }

    .session-header {
        flex-direction: column;
        text-align: center;
        gap: 0.5rem;
    }

    .session-badge {
        margin-left: 0;
    }
}

@media (max-width: 480px) {
    .pdf-documents-section .section-header h3 {
        font-size: 1.25rem;
    }

    .pdf-icon i {
        font-size: 2rem;
    }

    .session-badge {
        padding: 0.375rem 0.75rem;
        font-size: 0.8125rem;
    }
}

/* Subtle Animations */
body {
    animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* Smooth transitions for interactive elements */
.profile-icon {
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.profile-card:hover .profile-icon {
    transform: rotate(5deg) scale(1.05);
}

/* Enhanced focus states */
.btn:focus,
.profile-card:focus,
.year-card:focus,
.session-btn:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Subtle loading state */
.loading {
    opacity: 0.7;
    pointer-events: none;
}

/* Animations and Interactions */
.profile-card,
.year-card,
.btn {
    will-change: transform;
}

/* Smooth scrolling for all browsers */
html {
    scroll-behavior: smooth;
}

/* Focus states for accessibility */
.btn:focus,
input:focus,
textarea:focus,
.nav-link:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Loading animation */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* Solutions Modal Styles */
.profile-solutions,
.year-solutions {
    text-align: center;
}

.profile-header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.profile-header i {
    font-size: 2rem;
    color: var(--primary-color);
}

.years-selection,
.profiles-selection {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 1rem;
    margin: 2rem 0;
}

.year-btn,
.profile-btn {
    padding: 1rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.year-btn:hover,
.profile-btn:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.profile-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    min-height: 80px;
    justify-content: center;
}

.profile-btn i {
    font-size: 1.5rem;
}

.sessions-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.75rem;
    margin-top: 1rem;
}

.session-option {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 0.75rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.session-option:hover {
    border-color: var(--primary-color);
    background: var(--bg-secondary);
    transform: translateY(-2px);
}

.session-option i {
    font-size: 1.25rem;
    color: var(--primary-color);
}

.session-option span {
    font-weight: 500;
    color: var(--text-primary);
}

.session-badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    background: var(--primary-color);
    color: white;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 500;
    margin-left: 1rem;
}

.session-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.session-header i {
    font-size: 2rem;
    color: var(--primary-color);
}

.session-header h3 {
    margin: 0;
}

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

.btn-back {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.875rem;
    text-decoration: none;
}

.btn-back:hover {
    background: var(--border-color);
    color: var(--text-primary);
    transform: translateY(-1px);
}

/* Solutions Content */
.solutions-content {
    max-width: none;
}

.solutions-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.solutions-header h3 {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.subjects-list {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.subject-section {
    background: var(--bg-secondary);
    border-radius: 1rem;
    padding: 1.5rem;
}

.subject-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.problems-list {
    display: grid;
    gap: 1rem;
}

.problem-card {
    background: white;
    border-radius: 0.5rem;
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
    border-left: 4px solid var(--primary-color);
}

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

.problem-header h5 {
    margin: 0;
    color: var(--text-primary);
}

.difficulty {
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.difficulty-usor {
    background: #d1fae5;
    color: #047857;
}

.difficulty-mediu {
    background: #fef3c7;
    color: #d97706;
}

.difficulty-dificil {
    background: #fee2e2;
    color: #dc2626;
}

.btn-danger {
    background: #dc2626;
    color: white;
    border-color: #dc2626;
}

.btn-danger:hover {
    background: #b91c1c;
    border-color: #b91c1c;
}

.problem-description {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Problem Solution Styles */
.problem-solution {
    max-width: none;
}

.problem-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

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

.problem-statement,
.problem-solution-content {
    margin-bottom: 2rem;
    padding: 1.5rem;
    border-radius: 0.5rem;
}

.problem-statement {
    background: #f0f9ff;
    border-left: 4px solid #0ea5e9;
}

.problem-solution-content {
    background: #f0fdf4;
    border-left: 4px solid #10b981;
}

.problem-statement h4,
.problem-solution-content h4 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.problem-solution-content h4 {
    color: #047857;
}

.problem-statement h4 {
    color: #0369a1;
}

.problem-solution-content ul {
    margin: 1rem 0;
    padding-left: 2rem;
}

.problem-solution-content li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

.problem-solution-content p {
    margin-bottom: 1rem;
    line-height: 1.7;
}

.problem-solution-content strong {
    color: var(--text-primary);
    font-weight: 600;
}

.solution-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

/* No solutions state */
.no-solutions {
    text-align: center;
    padding: 3rem 2rem;
}

.no-solutions i {
    font-size: 4rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.no-solutions h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.no-solutions p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.6;
}

/* Loading spinner */
.loading-spinner {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

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

/* Print styles */
@media print {
    .modal-header,
    .solution-actions,
    .problem-meta {
        display: none !important;
    }
    
    .problem-solution {
        box-shadow: none !important;
        border: none !important;
    }
    
    .problem-statement,
    .problem-solution-content {
        border: 1px solid #000 !important;
        background: none !important;
    }
}

/* Additional responsive styles for modal */
@media (max-width: 768px) {
    .years-selection,
    .profiles-selection {
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    }
    
    .problem-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .problem-meta {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .solution-actions {
        flex-direction: column;
    }
}

/* Solutions Page Styles */
.solutions-page {
    min-height: 100vh;
    padding-top: 90px;
    background-color: var(--bg-secondary);
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 2rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.breadcrumb a {
    color: var(--primary-color);
    text-decoration: none;
}

.breadcrumb a:hover {
    text-decoration: underline;
}

.breadcrumb i {
    font-size: 0.75rem;
    color: var(--text-light);
}

.solutions-header {
    background: white;
    border-radius: 1rem;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.profile-info {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.profile-icon-large {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.profile-icon-large i {
    font-size: 2.5rem;
    color: white;
}

.profile-details h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

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

.profile-meta {
    display: flex;
    gap: 1rem;
}

.meta-tag {
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border-radius: 2rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.solutions-content {
    background: white;
    border-radius: 1rem;
    padding: 3rem;
    box-shadow: var(--shadow-md);
}

.content-message {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.message-icon {
    width: 100px;
    height: 100px;
    background: var(--gradient-secondary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 2rem;
}

.message-icon i {
    font-size: 3rem;
    color: white;
}

.content-message h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.content-message > p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    line-height: 1.6;
}

.coming-soon-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 0.5rem;
    border-left: 4px solid var(--primary-color);
}

.feature-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.feature-item span {
    font-weight: 500;
    color: var(--text-primary);
}

.action-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 4rem;
}

.btn-accent {
    background: var(--gradient-accent);
    color: white;
    border: none;
}

.btn-accent:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Mobile Navigation */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--bg-primary);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-md);
        padding: 2rem 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-menu li {
        margin: 1rem 0;
    }
    
    .nav-actions {
        gap: 0.5rem;
    }
    
    .theme-toggle {
        width: 35px;
        height: 35px;
        font-size: 0.875rem;
    }
}

/* Dark Mode Additional Elements */
[data-theme="dark"] .footer {
    background-color: var(--bg-dark);
}

[data-theme="dark"] .section-header,
[data-theme="dark"] .about-content {
    color: var(--text-primary);
}

[data-theme="dark"] .stats-card,
[data-theme="dark"] .feature-item {
    background: var(--bg-secondary);
    border-color: var(--border-color);
}

[data-theme="dark"] .profiles {
    background-color: var(--bg-primary);
}

[data-theme="dark"] .years {
    background-color: var(--bg-secondary);
}

[data-theme="dark"] .about {
    background-color: var(--bg-primary);
}

/* Dark Mode Form Elements */
[data-theme="dark"] input,
[data-theme="dark"] textarea,
[data-theme="dark"] select {
    background: var(--bg-secondary);
    border-color: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] input:focus,
[data-theme="dark"] textarea:focus,
[data-theme="dark"] select:focus {
    border-color: var(--primary-color);
    background: var(--bg-primary);
}

/* Dark Mode Session Badge */
[data-theme="dark"] .session-badge {
    background: var(--primary-color);
    color: white;
}

/* Dark Mode Meta Tags and Badges */
[data-theme="dark"] .meta-tag,
[data-theme="dark"] .profile-meta .meta-tag {
    background: var(--bg-dark);
    border-color: var(--border-color);
    color: var(--text-secondary);
}

/* Dark Mode Coming Soon Features */
[data-theme="dark"] .coming-soon-features .feature-item {
    background: var(--bg-dark);
    border-left-color: var(--primary-color);
}

[data-theme="dark"] .message-icon {
    opacity: 0.9;
}

/* Dark Mode Scrollbar for Firefox */
[data-theme="dark"] * {
    scrollbar-color: var(--primary-color) var(--bg-secondary);
}

/* Dark Mode Selection */
[data-theme="dark"] ::selection {
    background: var(--primary-color);
    color: white;
}