/* --- Global Styles & CSS Variables (SOFT & PROFESSIONAL PALETTE) --- */
:root {
    --bg-light-gray: #f8f9fa;
    --border-cool-gray: #dee2e6;
    --text-muted-navy: #3d5a80;
    --accent-magenta: #e03669;
    --text-bright: #ffffff;
    --heading-font: 'Roboto Slab', serif;
    --body-font: 'Open Sans', sans-serif;
}

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

body {
    font-family: var(--body-font);
    line-height: 1.7;
    background-color: var(--bg-light-gray);
    color: var(--text-muted-navy);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    color: var(--accent-magenta);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #b32b54; /* Darker magenta on hover */
}

h1, h2, h3 {
    font-family: var(--heading-font);
    color: var(--text-muted-navy);
}

/* --- New Floating Header --- */
header {
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 95%;
    max-width: 1200px;
    z-index: 100;
    padding: 15px 30px;
    
    background-color: rgba(255, 255, 255, 0.7); /* Light transparent background */
    backdrop-filter: blur(10px);
    
    border: 1px solid var(--border-cool-gray);
    border-radius: 15px;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0;
}

header .logo {
    font-size: 1.5rem;
    font-family: var(--heading-font);
    color: var(--text-muted-navy);
    font-weight: bold;
}

header nav ul {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 30px;
}

header nav ul li a {
    color: var(--text-muted-navy);
    font-weight: bold;
    font-size: 1rem;
    padding-bottom: 5px;
    transition: all 0.3s ease;
}

header nav ul li a:hover {
    color: var(--accent-magenta);
}

.header-btn.btn-highlight {
    background-color: var(--text-muted-navy);
    color: var(--text-bright);
    padding: 8px 18px;
    border-radius: 8px;
    font-weight: bold;
    transition: all 0.3s ease;
}

.header-btn.btn-highlight:hover {
    background-color: var(--accent-magenta);
}


/* --- General Page & Component Styles --- */
.page-header {
    background-color: var(--text-bright);
    padding: 40px 0;
    text-align: center;
    border-bottom: 1px solid var(--border-cool-gray);
}

.page-header.dark-bg-header {
    background-color: var(--bg-light-gray);
    padding-top: 150px;
    padding-bottom: 40px;
    border-bottom: none;
}

.page-header h1 {
    font-size: 2.8rem;
    margin-bottom: 10px;
}

.page-header p {
    opacity: 0.8;
}

.btn {
    display: inline-block;
    background-color: var(--accent-magenta);
    color: var(--text-bright);
    padding: 10px 20px;
    border-radius: 5px;
    font-weight: bold;
}

.btn:hover {
    background-color: #b32b54;
}

/* --- Homepage (Hero with Particles) Styles --- */
.hero {
    background-color: var(--text-muted-navy);
    color: var(--text-bright);
    text-align: center;
    position: relative;
    overflow: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

#particles-js {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: 3.2rem;
    color: var(--text-bright);
    margin-bottom: 15px;
}

.hero p {
    font-size: 1.25rem;
    max-width: 750px;
    margin: 0 auto 30px;
    opacity: 0.9;
}

/* --- FUTURISTIC CTA BUTTON --- */
.cta-button {
    display: inline-block;
    position: relative;
    overflow: hidden;
    
    background: var(--accent-magenta);
    color: var(--text-bright);
    padding: 18px 40px;
    border-radius: 10px;
    font-weight: bold;
    font-size: 1.2rem;
    transition: all 0.4s ease;
    border: none;
    box-shadow: 0 5px 25px rgba(224, 54, 105, 0.4);
}

.cta-button:hover {
    transform: translateY(-4px) scale(1.05);
    background-color: #b32b54;
    box-shadow: 0 10px 35px rgba(224, 54, 105, 0.5);
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 75%;
    height: 100%;
    background: linear-gradient(120deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transform: skewX(-25deg);
    transition: left 0.8s ease;
}

.cta-button:hover::before {
    left: 150%;
}


/* --- Resources Page (Selection Grid) --- */
.year-selection-grid {
    padding: 60px 0 80px 0;
    background-color: var(--bg-light-gray);
}

.year-selection-grid .container {
    display: flex;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
}

.selection-card {
    background-color: var(--text-bright);
    border: 1px solid var(--border-cool-gray);
    border-radius: 15px;
    padding: 30px;
    text-align: center;
    max-width: 400px;
    width: 100%;
    color: var(--text-muted-navy);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
}

.selection-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
    border-color: var(--accent-magenta);
}

.selection-card .card-icon {
    font-size: 3.5rem;
    color: var(--accent-magenta);
    margin-bottom: 20px;
}

.selection-card h2 {
    font-size: 1.8rem;
    margin-bottom: 10px;
}

.selection-card p {
    font-size: 1rem;
    opacity: 0.8;
    margin-bottom: 25px;
}

.selection-card .card-proceed {
    font-weight: bold;
    color: var(--accent-magenta);
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: color 0.3s ease, transform 0.3s ease;
}

.selection-card:hover .card-proceed {
    color: #b32b54;
    transform: translateX(5px);
}


/* --- Class Pages --- */
.resources-content {
    padding: 60px 0;
    background-color: var(--bg-light-gray);
}

.syllabus-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--text-bright);
    border: 1px solid var(--border-cool-gray);
    padding: 20px 25px;
    border-radius: 12px;
    max-width: 800px;
    margin: 0 auto 40px auto;
    transition: all 0.3s ease;
}

.syllabus-bar:hover {
    border-color: var(--accent-magenta);
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
}

.syllabus-bar .syllabus-title {
    font-family: var(--heading-font);
    font-size: 1.6rem;
}

.syllabus-bar .syllabus-icon {
    font-size: 1.8rem;
    color: var(--accent-magenta);
}

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

.accordion-item {
    border: 1px solid var(--border-cool-gray);
    border-radius: 5px;
    margin-bottom: 10px;
    overflow: hidden;
    background-color: var(--text-bright);
}

.accordion-header {
    width: 100%;
    background-color: transparent;
    border: none;
    padding: 20px;
    font-size: 1.5rem;
    font-family: var(--heading-font);
    cursor: pointer;
    text-align: left;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.accordion-header:hover {
    background-color: #f1f3f5;
}

.accordion-header .arrow {
    font-size: 1.2rem;
    transition: transform 0.3s ease;
    color: var(--accent-magenta);
}

.accordion-header.active .arrow {
    transform: rotate(180deg);
}

.accordion-content {
    background-color: transparent;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.chapter-table {
    padding: 10px 20px 20px 20px;
}

.table-header, .table-row {
    display: grid;
    grid-template-columns: 40px 1fr 60px 60px 60px;
    gap: 20px;
    align-items: center;
    text-align: center;
}

.table-header {
    padding: 0 15px 15px 15px;
    border-bottom: 1px solid var(--border-cool-gray);
    text-transform: uppercase;
    font-weight: bold;
    font-size: 0.8rem;
    letter-spacing: 1px;
    opacity: 0.7;
}

.table-row {
    padding: 15px;
    border-bottom: 1px solid var(--border-cool-gray);
}
.table-row:last-child {
    border-bottom: none;
}

.table-header span:nth-child(2),
.table-row .chapter-name {
    text-align: left;
}

.chapter-number {
    font-family: var(--heading-font);
    font-size: 1.2rem;
}

.chapter-name {
    font-size: 1.1rem;
    font-weight: bold;
}

.chapter-links-item {
    font-size: 1.5rem;
    color: var(--accent-magenta);
    transition: transform 0.3s ease, color 0.3s ease;
}

.chapter-links-item:hover {
    transform: scale(1.2);
    color: #b32b54;
}

/* --- Chapter Detail Page --- */
.chapter-header {
    background-color: var(--text-bright);
    padding: 120px 0 40px 0;
    text-align: center;
}

.chapter-header h1 {
    font-size: 3rem;
    margin-bottom: 5px;
}

.chapter-content {
    padding: 60px 0;
    background: var(--bg-light-gray);
}

.video-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    max-width: 100%;
    background: #000;
    margin-bottom: 40px;
    border-radius: 8px;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.resources-box {
    background-color: var(--text-bright);
    border: 1px solid var(--border-cool-gray);
    border-radius: 8px;
    padding: 30px;
    text-align: center;
}

.resources-box h2 {
    font-size: 1.8rem;
    margin-bottom: 25px;
}

.resource-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
}

.resource-button {
    display: inline-block;
    background-color: var(--accent-magenta);
    color: var(--text-bright);
    padding: 15px 30px;
    border-radius: 5px;
    font-weight: bold;
    font-size: 1.1rem;
    transition: all 0.3s ease;
}

.resource-button:hover {
    background-color: #b32b54;
    transform: translateY(-3px);
}

.chapter-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 50px;
    padding-top: 20px;
    border-top: 1px solid var(--border-cool-gray);
}

.chapter-nav a {
    font-weight: bold;
    font-size: 1.1rem;
}

/* --- Footer --- */
footer {
    background-color: var(--text-bright);
    color: var(--text-muted-navy);
    opacity: 0.8;
    padding: 40px 0;
    position: relative;
    z-index: 10;
    border-top: 1px solid var(--border-cool-gray);
}

footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

footer a {
    color: var(--accent-magenta);
    font-weight: bold;
}