/* Landing Page - Human Body Explorer */

:root {
    --l-bg: #1a1a2e;
    --l-bg-alt: #16213e;
    --l-card: #1e2a45;
    --l-primary: #4A90D9;
    --l-primary-dark: #3A7BC8;
    --l-secondary: #5CB85C;
    --l-accent: #F5A623;
    --l-text: #eaeaea;
    --l-text-muted: #a0a0b8;
    --l-border: #2a2a4a;
    --l-radius: 16px;
    --l-radius-sm: 10px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--l-bg);
    color: var(--l-text);
    line-height: 1.6;
    overflow-x: hidden;
}

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

/* ==================== NAV ==================== */

.landing-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: rgba(26, 26, 46, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--l-border);
    transition: background 0.3s;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--l-text);
}

.nav-logo span {
    font-size: 1.5rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: var(--l-text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
}

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

.nav-cta {
    background: var(--l-primary);
    color: #fff !important;
    padding: 0.5rem 1.25rem;
    border-radius: var(--l-radius-sm);
    font-weight: 600;
    transition: background 0.2s, transform 0.2s;
}

.nav-cta:hover {
    background: var(--l-primary-dark);
    transform: translateY(-1px);
}

.nav-hamburger {
    display: none;
    background: none;
    border: none;
    color: var(--l-text);
    font-size: 1.5rem;
    cursor: pointer;
}

/* ==================== HERO ==================== */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 6rem 2rem 4rem;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(74, 144, 217, 0.12) 0%, transparent 60%),
        radial-gradient(ellipse at 80% 50%, rgba(92, 184, 92, 0.08) 0%, transparent 60%),
        radial-gradient(ellipse at 50% 0%, rgba(245, 166, 35, 0.06) 0%, transparent 50%),
        var(--l-bg);
}

.hero-content {
    max-width: 720px;
}

.hero-badge {
    display: inline-block;
    background: rgba(74, 144, 217, 0.15);
    color: var(--l-primary);
    padding: 0.4rem 1rem;
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(74, 144, 217, 0.25);
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 1.25rem;
    background: linear-gradient(135deg, #fff 0%, #a0c4f0 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero h1 .emoji {
    -webkit-text-fill-color: initial;
}

.hero p {
    font-size: 1.2rem;
    color: var(--l-text-muted);
    max-width: 540px;
    margin: 0 auto 2.5rem;
}

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

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--l-primary);
    color: #fff;
    padding: 0.9rem 2rem;
    border-radius: var(--l-radius-sm);
    font-size: 1.05rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 20px rgba(74, 144, 217, 0.3);
}

.btn-primary:hover {
    background: var(--l-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 28px rgba(74, 144, 217, 0.4);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: transparent;
    color: var(--l-text);
    padding: 0.9rem 2rem;
    border-radius: var(--l-radius-sm);
    font-size: 1.05rem;
    font-weight: 600;
    border: 1px solid var(--l-border);
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s;
}

.btn-secondary:hover {
    background: var(--l-card);
    border-color: var(--l-text-muted);
}

.hero-stats {
    display: flex;
    gap: 3rem;
    justify-content: center;
    margin-top: 3.5rem;
    padding-top: 2.5rem;
    border-top: 1px solid var(--l-border);
}

.hero-stat .number {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--l-primary);
}

.hero-stat .label {
    font-size: 0.85rem;
    color: var(--l-text-muted);
}

/* ==================== SECTIONS ==================== */

section {
    padding: 5rem 2rem;
}

.section-title {
    text-align: center;
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.section-subtitle {
    text-align: center;
    color: var(--l-text-muted);
    font-size: 1.05rem;
    margin-bottom: 3.5rem;
    max-width: 560px;
    margin-left: auto;
    margin-right: auto;
}

/* ==================== FEATURES ==================== */

.features {
    background: var(--l-bg-alt);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    max-width: 1000px;
    margin: 0 auto;
}

.feature-card {
    background: var(--l-card);
    border: 1px solid var(--l-border);
    border-radius: var(--l-radius);
    padding: 2rem 1.5rem;
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.feature-card .badge {
    display: inline-block;
    background: rgba(245, 166, 35, 0.15);
    color: var(--l-accent);
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 700;
    vertical-align: middle;
    margin-left: 0.35rem;
}

.feature-card p {
    font-size: 0.9rem;
    color: var(--l-text-muted);
    line-height: 1.5;
}

/* ==================== HOW IT WORKS ==================== */

.how-it-works {
    background: var(--l-bg);
}

.steps {
    display: flex;
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
    justify-content: center;
}

.step {
    flex: 1;
    text-align: center;
    max-width: 260px;
    position: relative;
}

.step-number {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--l-primary), var(--l-primary-dark));
    color: #fff;
    font-size: 1.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.25rem;
    box-shadow: 0 4px 16px rgba(74, 144, 217, 0.3);
}

.step h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.step p {
    font-size: 0.9rem;
    color: var(--l-text-muted);
}

/* Connector arrows between steps */
.step:not(:last-child)::after {
    content: '';
    position: absolute;
    top: 28px;
    right: -1rem;
    width: 2rem;
    height: 2px;
    background: var(--l-border);
}

/* ==================== SCREENSHOTS ==================== */

.screenshots {
    background: var(--l-bg-alt);
}

.screenshots-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    max-width: 900px;
    margin: 0 auto;
}

.screenshot-placeholder {
    aspect-ratio: 9 / 16;
    background: var(--l-card);
    border: 1px dashed var(--l-border);
    border-radius: var(--l-radius);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--l-text-muted);
    font-size: 0.85rem;
    gap: 0.5rem;
}

.screenshot-placeholder .icon {
    font-size: 2rem;
    opacity: 0.5;
}

/* ==================== FAQ ==================== */

.faq {
    background: var(--l-bg);
}

.faq-list {
    max-width: 700px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.faq-item {
    background: var(--l-card);
    border: 1px solid var(--l-border);
    border-radius: var(--l-radius-sm);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    color: var(--l-text);
    padding: 1.25rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.2s;
}

.faq-question:hover {
    background: rgba(255, 255, 255, 0.03);
}

.faq-question .arrow {
    font-size: 0.8rem;
    transition: transform 0.3s;
    color: var(--l-text-muted);
}

.faq-item.open .faq-question .arrow {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.open .faq-answer {
    max-height: 200px;
}

.faq-answer p {
    padding: 0 1.5rem 1.25rem;
    color: var(--l-text-muted);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ==================== CTA ==================== */

.cta-section {
    background:
        radial-gradient(ellipse at 50% 50%, rgba(74, 144, 217, 0.1) 0%, transparent 60%),
        var(--l-bg-alt);
    text-align: center;
    padding: 5rem 2rem;
}

.cta-section h2 {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.cta-section p {
    color: var(--l-text-muted);
    margin-bottom: 2.5rem;
    font-size: 1.05rem;
}

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

.store-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    background: var(--l-card);
    border: 1px solid var(--l-border);
    color: var(--l-text);
    padding: 0.75rem 1.5rem;
    border-radius: var(--l-radius-sm);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s;
}

.store-btn:hover {
    background: var(--l-bg);
    border-color: var(--l-text-muted);
}

.store-btn .store-icon {
    font-size: 1.5rem;
}

/* ==================== FOOTER ==================== */

.landing-footer {
    background: var(--l-bg);
    border-top: 1px solid var(--l-border);
    padding: 2.5rem 2rem;
    text-align: center;
    color: var(--l-text-muted);
    font-size: 0.85rem;
}

.landing-footer a {
    color: var(--l-text-muted);
    transition: color 0.2s;
}

.landing-footer a:hover {
    color: var(--l-text);
}

.footer-links {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    margin-bottom: 1rem;
}

/* ==================== ANIMATIONS ==================== */

.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==================== RESPONSIVE ==================== */

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .nav-hamburger {
        display: block;
    }

    .nav-links.open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(26, 26, 46, 0.97);
        padding: 1.5rem 2rem;
        gap: 1rem;
        border-bottom: 1px solid var(--l-border);
    }

    .hero h1 {
        font-size: 2.25rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .hero-stats {
        gap: 1.5rem;
    }

    .hero-stat .number {
        font-size: 1.35rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
    }

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

    .step:not(:last-child)::after {
        display: none;
    }

    .screenshots-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

@media (max-width: 480px) {
    .hero {
        padding: 5rem 1.25rem 3rem;
    }

    .hero h1 {
        font-size: 1.85rem;
    }

    section {
        padding: 3.5rem 1.25rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }

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

    .screenshots-grid {
        grid-template-columns: 1fr;
        max-width: 250px;
        margin: 0 auto;
    }
}