:root {
    --bg-deep: #1A1A2E;
    --bg-card: rgba(13, 27, 62, 0.7);
    --chemistry: #2E7D32;
    --physics: #2196F3;
    --geography: #FF9800;
    --history: #9C27B0;
    --countries: #0097A7;
    --biology: #E63946;
    --astronomy: #7E57C2;
    --gold: #FFD700;
    --text-primary: #FFFFFF;
    --text-secondary: #90A4AE;
    --font-heading: 'Fredoka', cursive;
    --font-body: 'Nunito', sans-serif;
}

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

body {
    font-family: var(--font-body);
    background-color: var(--bg-deep);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 5%;
    background: rgba(26, 26, 46, 0.8);
    backdrop-filter: blur(10px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 100;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    color: var(--gold);
    text-decoration: none;
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    margin-left: 2rem;
    font-weight: 700;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--chemistry);
}

/* Hero Section */
.hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 100vh;
    padding: 6rem 5% 2rem;
    background: radial-gradient(circle at top right, rgba(0, 229, 255, 0.15), transparent 40%),
                radial-gradient(circle at bottom left, rgba(179, 136, 255, 0.15), transparent 40%);
    position: relative; /* anchor for Evo */
}

.hero-content {
    max-width: 50%;
}

.hero h1 {
    font-family: var(--font-heading);
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 1.5rem;
}

.highlight {
    background: linear-gradient(90deg, var(--chemistry), var(--physics));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
}

.btn-primary {
    display: inline-block;
    background: var(--gold);
    color: #000;
    padding: 1rem 2.5rem;
    border-radius: 999px;
    font-weight: 800;
    text-decoration: none;
    font-size: 1.1rem;
    transition: transform 0.3s, box-shadow 0.3s;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(255, 215, 0, 0.3);
}

/* Phone Mockup */
.hero-visual {
    position: relative;
    width: 40%;
    display: flex;
    justify-content: center;
}

.phone-mockup {
    width: 300px;
    height: 600px;
    background: #000;
    border-radius: 40px;
    border: 10px solid #333;
    position: relative;
    overflow: hidden;
    box-shadow: 0 25px 50px rgba(0,0,0,0.5);
    animation: float 6s ease-in-out infinite;
}

.notch {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 25px;
    background: #333;
    border-bottom-left-radius: 20px;
    border-bottom-right-radius: 20px;
    z-index: 10;
}

.screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, #0D1B3E, var(--bg-deep) 60%);
    padding: 32px 12px 8px;
    overflow: hidden;
    color: var(--text-primary);
    font-size: 11px;
    position: relative;
}

.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.app-header h2 {
    font-family: var(--font-heading);
    font-size: 13px;
    color: #fff;
}

.profile-bubble {
    width: 24px; height: 24px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--chemistry), var(--physics));
    display: flex; align-items: center; justify-content: center;
    font-size: 11px;
    border: 1.5px solid rgba(255,255,255,0.3);
}

.xp-bar {
    display: flex; align-items: center; gap: 6px;
    background: rgba(255,255,255,0.08);
    border-radius: 999px;
    padding: 4px 10px;
    margin-bottom: 10px;
    font-size: 9px;
}
.xp-bar .xp-label { color: var(--text-secondary); font-weight: 700; }
.xp-bar .xp-track {
    flex: 1;
    height: 5px;
    background: rgba(255,255,255,0.1);
    border-radius: 999px;
    overflow: hidden;
}
.xp-bar .xp-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--gold), var(--geography));
    border-radius: 999px;
}
.xp-bar .xp-value { color: var(--gold); font-weight: 800; font-size: 10px; }

.section-label {
    font-size: 9px;
    font-weight: 800;
    color: var(--text-secondary);
    margin: 2px 0 6px;
    letter-spacing: 0.5px;
}

/* 2×2 grid of subject cards (hub) */
.subjects-grid-mini {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
    margin-bottom: 6px;
}

.hub-card {
    position: relative;
    border-radius: 10px;
    padding: 7px 8px;
    color: #fff;
    display: flex;
    flex-direction: column;
    gap: 1px;
    min-height: 60px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.25);
}
.hub-card .emoji { font-size: 18px; }
.hub-card .hub-card-name {
    font-size: 11px;
    font-weight: 800;
    line-height: 1.1;
}
.hub-card .hub-card-meta {
    font-size: 8.5px;
    opacity: 0.8;
}
.hub-card .free-badge,
.hub-card .lock-badge {
    position: absolute;
    top: 5px; right: 5px;
    font-size: 8px;
    font-weight: 800;
    padding: 1px 5px;
    border-radius: 999px;
    background: rgba(255,255,255,0.25);
}
.hub-card .lock-badge {
    background: rgba(0,0,0,0.4);
    width: 14px; height: 14px;
    padding: 0;
    display: flex; align-items: center; justify-content: center;
}

.hub-card.chemistry { background: linear-gradient(135deg, #2E7D32, #1B5E20); }
.hub-card.physics   { background: linear-gradient(135deg, #2196F3, #1565C0); opacity: 0.55; }
.hub-card.biology   { background: linear-gradient(135deg, #E63946, #A4161A); opacity: 0.55; }
.hub-card.astronomy { background: linear-gradient(135deg, #7E57C2, #4527A0); opacity: 0.55; }

/* Wide card row */
.hub-wide {
    display: flex;
    align-items: center;
    gap: 8px;
    border-radius: 10px;
    padding: 5px 10px;
    margin-bottom: 5px;
    color: #fff;
    opacity: 0.55;
    box-shadow: 0 3px 10px rgba(0,0,0,0.2);
    min-height: 32px;
}
.hub-wide .emoji { font-size: 14px; }
.hub-wide > div { flex: 1; line-height: 1.1; }
.hub-wide .lock-badge {
    background: rgba(0,0,0,0.4);
    width: 14px; height: 14px;
    border-radius: 999px;
    font-size: 8px;
    display: flex; align-items: center; justify-content: center;
}
.hub-wide.geography { background: linear-gradient(135deg, #FF9800, #E65100); }
.hub-wide.history   { background: linear-gradient(135deg, #9C27B0, #6A1B9A); }
.hub-wide.countries { background: linear-gradient(135deg, #0097A7, #00637A); }

.unlock-cta {
    background: var(--gold);
    color: #000;
    text-align: center;
    border-radius: 999px;
    padding: 6px 10px;
    font-weight: 800;
    font-size: 10px;
    margin: 4px 0 6px;
    box-shadow: 0 4px 12px rgba(255, 215, 0, 0.3);
}

.bottom-nav {
    position: absolute;
    bottom: 0; left: 0; right: 0;
    background: rgba(13, 27, 62, 0.95);
    border-top: 1px solid rgba(255,255,255,0.08);
    padding: 6px 10px 12px;
    display: flex;
    justify-content: space-around;
    font-size: 14px;
}
.bottom-nav .nav-item { opacity: 0.4; }
.bottom-nav .nav-item.active { opacity: 1; filter: drop-shadow(0 0 3px var(--gold)); }

@keyframes float {
    0% { transform: translateY(0px); }
    100% { transform: translateY(-20px); }
}

/* Features Section */
.features {
    padding: 5rem 5%;
    text-align: center;
}

.section-title {
    margin-bottom: 4rem;
}

.section-title h2 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

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

.feature-card {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 24px;
    border: 1px solid rgba(255,255,255,0.05);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-card .icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

/* Legal Pages */
.legal-container {
    max-width: 800px;
    margin: 8rem auto 4rem;
    padding: 0 5%;
}

.legal-container h1 {
    font-family: var(--font-heading);
    font-size: 3rem;
    margin-bottom: 2rem;
    color: var(--chemistry);
}

.legal-container h2 {
    font-family: var(--font-heading);
    margin: 2rem 0 1rem;
}

.legal-container p, .legal-container li {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

/* Footer */
footer {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 4rem 5% 2rem;
    margin-top: 4rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    margin-bottom: 2rem;
}

.brand h3 {
    font-family: var(--font-heading);
    color: var(--gold);
    font-size: 1.5rem;
}

.footer-links a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    margin-bottom: 0.5rem;
}

.footer-links a:hover {
    color: var(--text-primary);
}

.copyright {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Hero meta line */
.hero-meta {
    margin-top: 1.25rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* CTA group + store badges (brand-accurate approximations) */
.cta-group {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-top: 0.5rem;
}

.store-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: #000;
    color: #fff;
    border: 1px solid rgba(255,255,255,0.18);
    border-radius: 10px;
    padding: 8px 16px;
    text-decoration: none;
    transition: transform 0.2s, border-color 0.2s;
    min-width: 180px;
    height: 56px;
    box-sizing: border-box;
}

.store-badge:hover {
    transform: translateY(-2px);
    border-color: rgba(255,255,255,0.45);
}

.store-badge-icon {
    width: 28px;
    height: 28px;
    flex-shrink: 0;
}

.store-badge-text {
    display: flex;
    flex-direction: column;
    line-height: 1.1;
}

.store-badge-small {
    font-size: 0.65rem;
    font-weight: 500;
    color: rgba(255,255,255,0.85);
    letter-spacing: 0.02em;
}

.store-badge-large {
    font-size: 1.15rem;
    font-weight: 700;
    color: #fff;
    letter-spacing: -0.01em;
}

/* Subjects section */
.subjects-section {
    padding: 4rem 5% 2rem;
    text-align: center;
}

.subjects-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    max-width: 900px;
    margin: 0 auto;
}

.subject-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: color-mix(in srgb, var(--c) 15%, transparent);
    color: var(--c);
    border: 1.5px solid color-mix(in srgb, var(--c) 40%, transparent);
    border-radius: 999px;
    padding: 0.6rem 1.2rem;
    font-weight: 700;
    font-size: 1rem;
    transition: transform 0.2s;
}

.subject-pill:hover { transform: translateY(-3px); }
.subject-pill span { font-size: 1.25rem; }

/* Pricing — moved from inline */
.pricing-section {
    padding: 4rem 5%;
    text-align: center;
    background: rgba(255,255,255,0.02);
}

.pricing-card {
    background: var(--bg-card);
    border: 2px solid var(--gold);
    border-radius: 24px;
    padding: 3rem;
    max-width: 500px;
    margin: 0 auto;
    box-shadow: 0 10px 30px rgba(255,215,0,0.1);
}

.pricing-card h3 {
    font-family: var(--font-heading);
    font-size: 2rem;
    color: var(--gold);
    margin-bottom: 1rem;
}

.price {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
}

.price-suffix {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 400;
}

.pricing-card ul {
    list-style: none;
    margin-bottom: 2rem;
    text-align: left;
}

.pricing-card li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.pricing-card li::before {
    content: '✨';
    margin-right: 10px;
}

.btn-block {
    display: block;
    width: 100%;
    margin-top: 1rem;
    box-sizing: border-box;
    text-align: center;
}

/* Support section */
.support-section {
    padding: 4rem 5%;
    text-align: center;
}

.support-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
    max-width: 1000px;
    margin: 0 auto;
}

.support-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 18px;
    border: 1px solid rgba(255,255,255,0.06);
}

.support-card h3 {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
}

.support-card a {
    color: var(--gold);
    text-decoration: none;
    word-break: break-word;
}

.support-card a:hover {
    text-decoration: underline;
}

/* ─── Evo the Robot — mascot presence ───────────────────── */

/* Evo is anchored to .hero (the section), peeking out from the right
 * side of the phone mockup. He's tilted toward the phone (-8deg) so he
 * reads as part of the app's world, not floating in empty space. */
.evo-hero {
    position: absolute;
    bottom: 12%;
    right: 4%;       /* hugs the right edge near the phone */
    width: 100px;
    height: 100px;
    animation: evo-bob 3.5s ease-in-out infinite;
    filter: drop-shadow(0 8px 18px rgba(0, 0, 0, 0.4));
    z-index: 2;
}

.evo-bubble-hero {
    position: absolute;
    bottom: calc(12% + 110px); /* sits just above Evo */
    right: 9%;                 /* offset left of Evo so tail points down-right at him */
    background: #fff;
    color: #1B4332;
    font-family: var(--font-body);
    font-weight: 700;
    font-size: 0.85rem;
    padding: 10px 14px;
    border-radius: 14px;
    max-width: 200px;
    text-align: center;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
    line-height: 1.3;
    z-index: 2;
    animation: evo-bubble-fade 6s ease-in-out infinite;
}
.evo-bubble-hero::after {
    content: '';
    position: absolute;
    bottom: -8px;
    right: 18px;     /* tail on the right side, pointing down at Evo */
    width: 0;
    height: 0;
    border-top: 8px solid #fff;
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
}

@keyframes evo-bob {
    0%, 100% { transform: translateY(0) rotate(-8deg); }
    50%      { transform: translateY(-12px) rotate(-8deg); }
}

@keyframes evo-bubble-fade {
    0%, 5%   { opacity: 0; transform: scale(0.9); }
    10%, 90% { opacity: 1; transform: scale(1); }
    100%     { opacity: 0; transform: scale(0.9); }
}

/* Features card: Evo's portrait replaces the generic 🤖 emoji */
.evo-feature-card {
    text-align: center;
}
.evo-feature-img {
    width: 96px;
    height: 96px;
    margin: 0 auto 1rem;
    display: block;
    filter: drop-shadow(0 6px 14px rgba(76, 175, 80, 0.25));
    animation: evo-bob 4s ease-in-out infinite;
}

/* Hide hero Evo on small screens — would crowd the layout */
@media (max-width: 900px) {
    .evo-hero, .evo-bubble-hero { display: none; }
}

/* ─── Carousel section ───────────────────────────────────── */
.carousel-section {
    padding: 4rem 0 3rem;
    text-align: center;
    background: linear-gradient(180deg, transparent, rgba(255,255,255,0.02));
    overflow: hidden;
}

.carousel-section .section-title { padding: 0 5%; }

.carousel-wrap {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
}

.carousel {
    display: flex;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    scroll-behavior: smooth;
    scrollbar-width: none;
    /* Each slide takes 100% of the carousel width — only one visible at a time */
}
.carousel::-webkit-scrollbar { display: none; }

/* Each slide = one subject. Background tinted in subject color. */
.carousel-slide {
    flex: 0 0 100%;
    scroll-snap-align: center;
    padding: 2rem 1rem 1rem;
    border-radius: 24px;
    margin: 0 1rem;
    position: relative;
}

.subject-themed.theme-chemistry {
    background:
        radial-gradient(ellipse at top, rgba(46, 125, 50, 0.18), transparent 60%),
        linear-gradient(180deg, rgba(46, 125, 50, 0.08), rgba(13, 27, 62, 0.4));
    border: 1px solid rgba(46, 125, 50, 0.25);
}
.subject-themed.theme-physics {
    background:
        radial-gradient(ellipse at top, rgba(33, 150, 243, 0.18), transparent 60%),
        linear-gradient(180deg, rgba(33, 150, 243, 0.08), rgba(13, 27, 62, 0.4));
    border: 1px solid rgba(33, 150, 243, 0.25);
}
.subject-themed.theme-astronomy {
    background:
        radial-gradient(ellipse at top, rgba(126, 87, 194, 0.20), transparent 60%),
        linear-gradient(180deg, rgba(126, 87, 194, 0.10), rgba(13, 27, 62, 0.4));
    border: 1px solid rgba(126, 87, 194, 0.25);
}

.slide-tag {
    display: inline-block;
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 700;
    padding: 0.4rem 1rem;
    border-radius: 999px;
    background: rgba(255,255,255,0.08);
    margin-bottom: 1.5rem;
}
.theme-chemistry .slide-tag { color: #A5D6A7; border: 1px solid rgba(46, 125, 50, 0.3); }
.theme-physics .slide-tag   { color: #90CAF9; border: 1px solid rgba(33, 150, 243, 0.3); }
.theme-astronomy .slide-tag { color: #D1C4E9; border: 1px solid rgba(126, 87, 194, 0.3); }

/* Row of 3 phones inside each slide */
.phone-row {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ─── Smaller phone mockup used inside the carousel ─────── */
.phone-mockup-mini {
    width: 220px;
    height: 460px;
    animation: none;
    background: #000;
    border-radius: 32px;
    border: 8px solid #333;
    position: relative;
    overflow: hidden;
    box-shadow: 0 20px 40px rgba(0,0,0,0.5);
}
.phone-mockup-mini .notch {
    width: 90px;
    height: 18px;
}

/* Lesson screen layout — mirrors the actual app's lesson_screen.dart:
 *   • Top: back arrow + progress bar + N/5 (theme-coloured)
 *   • Subject tier pill
 *   • Topic title
 *   • White lesson card with body text + gold "Key Concept" highlight
 *   • Bottom: subject-themed Start Quiz button
 */
.lesson-screen {
    padding: 28px 10px 12px;
    font-size: 10px;
    color: #fff;
    display: flex;
    flex-direction: column;
    background: #FFFFFF !important;  /* actual app screens are light-themed */
}

/* Top progress bar row (replaces the dark "lesson-header" of the previous version) */
.lesson-topbar {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 0 4px 8px;
    border-bottom: 1px solid #ECEFF1;
    margin-bottom: 10px;
}
.lesson-topbar .back-arrow { font-size: 16px; color: #1A1A2E; }
.lesson-topbar .progress-track {
    flex: 1;
    height: 5px;
    background: #ECEFF1;
    border-radius: 999px;
    overflow: hidden;
}
.lesson-topbar .progress-fill {
    height: 100%;
    border-radius: 999px;
    width: 40%;
}
.lesson-topbar .progress-count {
    font-size: 9px;
    font-weight: 700;
}

.tier-pill {
    display: inline-block;
    align-self: flex-start;
    font-size: 9px;
    font-weight: 800;
    padding: 4px 9px;
    border-radius: 8px;
    margin-bottom: 8px;
    letter-spacing: 0.3px;
}
/* Subject-themed tier pills — matches lesson_screen.dart's
 * subjectMeta.primaryColor.withValues(alpha: 0.15) + darkColor text. */
.theme-chemistry-bg .tier-pill { background: rgba(46, 125, 50, 0.15); color: #1B5E20; border: 1px solid rgba(46, 125, 50, 0.3); }
.theme-physics-bg .tier-pill   { background: rgba(33, 150, 243, 0.15); color: #1565C0; border: 1px solid rgba(33, 150, 243, 0.3); }
.theme-astronomy-bg .tier-pill { background: rgba(126, 87, 194, 0.15); color: #4527A0; border: 1px solid rgba(126, 87, 194, 0.3); }

.lesson-topic-title {
    font-family: var(--font-heading);
    font-size: 15px;
    font-weight: 700;
    margin: 4px 4px 10px;
    color: #1A1A2E;
    line-height: 1.15;
}

/* Evo row (small Evo with speech bubble, matches actual app) */
.evo-row {
    display: flex;
    align-items: center;
    gap: 6px;
    margin: 0 4px 8px;
}
.evo-row img {
    width: 28px; height: 28px; flex-shrink: 0;
}
.evo-row .evo-bubble-mini {
    flex: 1;
    background: #fff;
    border: 1px solid #E0E0E0;
    border-radius: 8px;
    padding: 4px 7px;
    font-size: 8.5px;
    font-weight: 700;
    color: #1B4332;
    line-height: 1.25;
}

/* White content card (like lesson_screen.dart's body container) */
.lesson-card {
    background: #FFFFFF;
    border: 1px solid #ECEFF1;
    border-radius: 12px;
    padding: 10px;
    margin: 0 4px 10px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.03);
    flex: 1;
}
.lesson-text {
    font-size: 9.5px;
    line-height: 1.4;
    color: #1A1A2E;
    margin-bottom: 8px;
}

/* Gold "Key Concept" highlight — matches lesson_screen.dart's #FFF8E1 box */
.key-concept {
    background: #FFF8E1;
    border: 1px solid rgba(255, 215, 0, 0.4);
    border-radius: 6px;
    padding: 6px 8px;
    font-size: 8.5px;
    color: #F9A825;
    line-height: 1.3;
    font-weight: 700;
}

.start-quiz-cta {
    text-align: center;
    border-radius: 999px;
    padding: 10px 14px;
    font-weight: 800;
    font-size: 11px;
    color: #fff;
    box-shadow: 0 4px 14px rgba(0,0,0,0.15);
    margin: 0 4px;
}
.theme-chemistry-bg .start-quiz-cta { background: #2E7D32; box-shadow: 0 4px 14px rgba(46, 125, 50, 0.4); }
.theme-physics-bg .start-quiz-cta   { background: #2196F3; box-shadow: 0 4px 14px rgba(33, 150, 243, 0.4); }
.theme-astronomy-bg .start-quiz-cta { background: #7E57C2; box-shadow: 0 4px 14px rgba(126, 87, 194, 0.4); }

/* Theme-coloured progress fill */
.theme-chemistry-bg .progress-fill { background: linear-gradient(90deg, #2E7D32, #1B5E20); }
.theme-physics-bg .progress-fill   { background: linear-gradient(90deg, #2196F3, #1565C0); }
.theme-astronomy-bg .progress-fill { background: linear-gradient(90deg, #7E57C2, #4527A0); }
.theme-chemistry-bg .progress-count { color: #1B5E20; }
.theme-physics-bg .progress-count   { color: #1565C0; }
.theme-astronomy-bg .progress-count { color: #4527A0; }

/* Carousel arrows */
.carousel-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px; height: 44px;
    border-radius: 50%;
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.15);
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
    z-index: 5;
    transition: background 0.2s, transform 0.2s;
    display: flex; align-items: center; justify-content: center;
}
.carousel-arrow:hover { background: var(--gold); color: #000; transform: translateY(-50%) scale(1.05); }
.carousel-prev { left: 12px; }
.carousel-next { right: 12px; }

/* Carousel dots — emoji bullets so it's clear which subject each represents */
.carousel-dots {
    display: flex;
    justify-content: center;
    gap: 14px;
    margin-top: 1.5rem;
}
.carousel-dots .dot {
    width: 44px; height: 44px;
    border-radius: 50%;
    border: 2px solid rgba(255,255,255,0.15);
    background: rgba(255,255,255,0.04);
    cursor: pointer;
    transition: all 0.25s;
    padding: 0;
    display: flex; align-items: center; justify-content: center;
    font-size: 18px;
}
.carousel-dots .dot:hover { transform: translateY(-2px); }
.carousel-dots .dot.active {
    background: var(--gold);
    border-color: var(--gold);
    transform: scale(1.1);
    box-shadow: 0 6px 18px rgba(255, 215, 0, 0.35);
}
.carousel-dots .dot.active .dot-emoji { filter: drop-shadow(0 1px 2px rgba(0,0,0,0.4)); }

/* Responsive */
@media (max-width: 768px) {
    .hero {
        flex-direction: column;
        text-align: center;
        padding-top: 8rem;
    }
    .hero-content {
        max-width: 100%;
        margin-bottom: 4rem;
    }
    .hero-visual {
        width: 100%;
    }
    .hero h1 { font-size: 2.5rem; }
    .cta-group { justify-content: center; }
    .footer-content { flex-direction: column; gap: 2rem; }
    .nav-links a { margin-left: 1rem; font-size: 0.9rem; }
    .carousel-arrow { display: none; }
    .phone-row { gap: 12px; }
    .phone-mockup-mini { width: 180px; height: 380px; }
    .lesson-screen { padding: 24px 10px 10px; font-size: 9px; }
    .lesson-topic-title { font-size: 14px; }
}

@media (max-width: 600px) {
    .phone-row { flex-direction: column; align-items: center; }
    .phone-mockup-mini { width: 220px; height: 460px; }
}