:root {
    --prishthabhumi-varna: #060b1a;
    --tala-varna: rgba(255, 255, 255, 0.05);
    --prathamika-varna: #00d4ff;
    --mukhya-pathya: #f8fafc;
    --manda-pathya: #cbd5e1;
    --sima-varna: rgba(255, 255, 255, 0.1);
    --sparsha-varna: yellow;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--prishthabhumi-varna);
    color: var(--mukhya-pathya);
    line-height: 1.6;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 900px;
    width: 100%;
    padding: 40px 20px;
}

p.subtitle {
    font-size: 1.2rem;
    color: var(--manda-pathya);
}

section {
    background-color: var(--tala-varna);
    border-radius: 16px;
    padding: 30px;
    margin-bottom: 30px;
    backdrop-filter: blur(10px);
    border: 1px solid var(--sima-varna);
    transition: transform 0.3s ease;
}

section:hover {
    transform: translateY(-5px);
    border-color: rgba(0, 212, 255, 0.3);
}

h2 {
    font-size: 1.8rem;
    color: var(--prathamika-varna);
    margin-top: 0;
    border-bottom: 1px solid var(--sima-varna);
    padding-bottom: 10px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

ul {
    list-style-type: none;
    padding-left: 0;
}

li {
    margin-bottom: 15px;
    position: relative;
    padding-left: 25px;
}

li::before {
    content: "▹";
    position: absolute;
    left: 0;
    color: var(--prathamika-varna);
    font-size: 1.2rem;
    top: -2px;
}

.topic-title {
    font-weight: 600;
    font-size: 1.1rem;
}

.sub-topics {
    color: var(--manda-pathya);
    margin-top: 5px;
    font-size: 0.95rem;
    padding-left: 0;
}

.sub-topics li {
    padding-left: 15px;
    margin-bottom: 5px;
}

.sub-topics li::before {
    content: "-";
    font-size: 1rem;
    color: var(--manda-pathya);
}

a {
    color: var(--prathamika-varna);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--sparsha-varna);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background-color: transparent;
    color: var(--mukhya-pathya);
    padding: 8px 16px;
    border-radius: 4px;
    border: 1px solid var(--sima-varna);
    margin-top: 10px;
    font-size: 0.85rem;
    transition: all 0.2s ease;
}

.btn:hover {
    background-color: var(--prathamika-varna);
    color: #060b1a;
    border-color: var(--prathamika-varna);
    text-decoration: none;
}

.card-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
}

.card {
    background-color: var(--tala-varna);
    border: 1px solid var(--sima-varna);
    border-radius: 12px;
    padding: 20px;
    transition: all 0.3s ease;
}

.card:hover {
    border-color: var(--prathamika-varna);
    box-shadow: 0 0 15px rgba(0, 212, 255, 0.15);
}

.card h3 {
    margin-top: 0;
    font-size: 1.2rem;
    color: var(--mukhya-pathya);
}

/* Arattai Floating Button */
.arattai-float {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.5);
    z-index: 1000;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    background-color: var(--tala-varna);
}

.arattai-float:hover {
    transform: scale(1.1);
    box-shadow: 0 0 15px rgba(0, 212, 255, 0.4);
}

.arattai-icon {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
}

/* --- Footer Section --- */
.site-footer {
    background: #030610;
    padding: 40px 5% 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.footer-content {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    max-width: 1200px;
    margin: 0 auto;
    margin-bottom: 30px;
    gap: 20px;
}

.footer-section {
    min-width: 200px;
    margin-bottom: 20px;
    text-align: left;
}

.footer-section h4 {
    color: #00d4ff;
    font-size: 1.2rem;
    margin-bottom: 15px;
}

.footer-section p, .footer-section a {
    color: #cbd5e1;
    text-decoration: none;
    line-height: 1.6;
    display: block;
}

.footer-section a:hover {
    color: #fff;
    text-decoration: underline;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 20px;
    color: #888;
    font-size: 0.9rem;
    text-align: center;
}