/* Base Styles & Variables */
:root {
    --primary-color: #6c5ce7;
    --secondary-color: #a29bfe;
    --accent-color: #fd79a8;
    --text-color: #2d3436;
    --bg-color: #f5f6fa;
    --card-bg: #ffffff;
    --shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    --border-radius: 12px;
}

[data-theme="dark"] {
    --primary-color: #a29bfe;
    --secondary-color: #6c5ce7;
    --text-color: #f5f6fa;
    --bg-color: #2d3436;
    --card-bg: #1e272e;
    --shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: 'Poppins', sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    overflow-x: hidden;
    transition: var(--transition);
}

/* Animated Background */
.animated-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
    z-index: -2;
    opacity: 0.1;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* Particles.js */
#particles-js {
    position: fixed;
    width: 100%;
    height: 100%;
    z-index: -1;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    position: relative;
    z-index: 1;
}

/* Header Styles */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    animation: fadeInDown 1s ease;
}

.logo-container {
    text-align: center;
}

.logo {
    font-family: 'Montserrat', sans-serif;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary-color);
    position: relative;
    display: inline-block;
}

.logo::before {
    content: attr(data-text);
    position: absolute;
    top: 0;
    left: 0;
    width: 0;
    color: var(--accent-color);
    overflow: hidden;
    transition: 1s;
}

.logo:hover::before {
    width: 100%;
}

.tagline {
    font-size: 0.9rem;
    color: var(--secondary-color);
    margin-top: -0.5rem;
}

.back-btn {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.back-btn:hover {
    color: var(--accent-color);
    transform: translateX(-5px);
}

/* Theme Toggle */
.theme-toggle {
    position: relative;
}

.theme-switch {
    display: none;
}

.theme-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 60px;
    height: 30px;
    background: var(--card-bg);
    border-radius: 50px;
    padding: 5px;
    position: relative;
    cursor: pointer;
    box-shadow: var(--shadow);
}

.theme-label i {
    font-size: 14px;
    z-index: 1;
}

.theme-label .fa-sun {
    color: #f39c12;
}

.theme-label .fa-moon {
    color: #f1c40f;
}

.ball {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 26px;
    height: 26px;
    background: var(--primary-color);
    border-radius: 50%;
    transition: transform 0.3s ease;
}

.theme-switch:checked + .theme-label .ball {
    transform: translateX(30px);
}

/* Main Content */
.main-content {
    animation: fadeInUp 1s ease;
}

.main-title {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    text-align: center;
    position: relative;
}

.animate-char {
    background-image: linear-gradient(
        -225deg,
        #6c5ce7 0%,
        #a29bfe 29%,
        #fd79a8 67%,
        #ffeaa7 100%
    );
    background-size: auto auto;
    background-clip: border-box;
    background-size: 200% auto;
    color: #fff;
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: textclip 3s linear infinite;
}

@keyframes textclip {
    to { background-position: 200% center; }
}

/* Class Grid */
.class-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

.class-card {
    perspective: 1000px;
    height: 300px;
}

.class-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.8s;
    transform-style: preserve-3d;
    box-shadow: var(--shadow);
    border-radius: var(--border-radius);
}

.class-card:hover .class-card-inner {
    transform: rotateY(180deg);
}

.class-card-front, .class-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    border-radius: var(--border-radius);
    background: var(--card-bg);
}

.class-card-back {
    transform: rotateY(180deg);
}

.class-number {
    font-size: 5rem;
    font-weight: 800;
    background: linear-gradient(to right, #6c5ce7, #fd79a8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    line-height: 1;
}

.class-name {
    font-size: 1.5rem;
    font-weight: 600;
    margin-top: 1rem;
}

.class-card-back h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.class-card-back ul {
    list-style: none;
    margin-bottom: 1.5rem;
    text-align: left;
}

.class-card-back li {
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.5rem;
}

.class-card-back li::before {
    content: "•";
    color: var(--accent-color);
    position: absolute;
    left: 0;
}

.enter-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.enter-btn:hover {
    background: var(--accent-color);
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

/* Notes Page Specific Styles */
.notes-main {
    margin-top: 2rem;
}

.search-container {
    display: flex;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

#search-input {
    flex: 1;
    padding: 1rem;
    border: 2px solid var(--secondary-color);
    border-radius: var(--border-radius) 0 0 var(--border-radius);
    font-size: 1rem;
    background: var(--card-bg);
    color: var(--text-color);
    transition: var(--transition);
}

#search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.2);
}

#search-btn {
    padding: 0 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
    cursor: pointer;
    transition: var(--transition);
}

#search-btn:hover {
    background: var(--accent-color);
}

.subject-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.tab {
    padding: 0.75rem 1.5rem;
    background: var(--card-bg);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
    box-shadow: var(--shadow);
}

.tab.active {
    background: var(--primary-color);
    color: white;
}

.tab:hover:not(.active) {
    background: var(--secondary-color);
    color: white;
}

.subject-pane {
    display: none;
    animation: fadeIn 0.5s ease;
}

.subject-pane.active {
    display: block;
}

.subject-title {
    font-size: 2rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.chapters-container {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.chapter-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.chapter-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

.chapter-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    cursor: pointer;
    background: var(--primary-color);
    color: white;
}

.expand-btn {
    background: transparent;
    border: none;
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    transition: var(--transition);
}

.chapter-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease;
}

.chapter-card.active .chapter-content {
    max-height: 2000px;
}

.chapter-card.active .expand-btn {
    transform: rotate(180deg);
}

.note-section {
    padding: 1.5rem;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.note-section:last-child {
    border-bottom: none;
}

.note-section h4 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.note-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 1rem;
}

.bookmark-btn, .download-btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

.bookmark-btn {
    background: transparent;
    color: var(--text-color);
}

.bookmark-btn:hover {
    color: var(--accent-color);
}

.download-btn {
    background: var(--secondary-color);
    color: white;
}

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

/* Floating Action Button */
.fab {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 100;
}

.fab-main {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--primary-color);
    color: white;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.fab-main:hover {
    background: var(--accent-color);
    transform: scale(1.1);
}

.fab-options {
    position: absolute;
    bottom: 70px;
    right: 0;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    opacity: 0;
    pointer-events: none;
    transform: translateY(20px);
    transition: var(--transition);
}

.fab:hover .fab-options {
    opacity: 1;
    pointer-events: all;
    transform: translateY(0);
}

.fab-option {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--card-bg);
    color: var(--text-color);
    border: none;
    box-shadow: var(--shadow);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.fab-option:hover {
    background: var(--accent-color);
    color: white;
    transform: scale(1.1);
}

.fab-option::after {
    content: attr(title);
    position: absolute;
    right: 60px;
    white-space: nowrap;
    background: var(--card-bg);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    font-size: 0.9rem;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.fab-option:hover::after {
    opacity: 1;
    right: 70px;
}

/* Footer */
.footer {
    margin-top: 5rem;
    text-align: center;
    padding: 2rem 0;
    animation: fadeIn 1s ease;
}

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

.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
}

.social-links a {
    color: var(--text-color);
    font-size: 1.2rem;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-3px);
}

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

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .header {
        flex-direction: column;
        gap: 1rem;
    }
    
    .class-grid {
        grid-template-columns: 1fr;
    }
    
    .subject-tabs {
        overflow-x: auto;
        padding-bottom: 0.5rem;
    }
    
    .tab {
        white-space: nowrap;
    }
}

/* Print Styles */
@media print {
    .header, .footer, .fab, .search-container, .subject-tabs {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .chapter-content {
        max-height: none !important;
    }
    
    .note-section {
        page-break-inside: avoid;
    }
}