/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg: #0a0a0a;
    --surface: #141414;
    --surface-2: #1a1a1a;
    --border: #222;
    --text: #f0f0f0;
    --text-secondary: #888;
    --accent: #9199ff;
    --accent-warm: #f99d9f;
    --accent-glow: rgba(145, 153, 255, 0.15);
    --radius: 12px;
    --radius-lg: 20px;
    --max-width: 960px;
}

html {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    -webkit-font-smoothing: antialiased;
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
}

/* Nav */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    background: rgba(10, 10, 10, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text);
}

.logo-mark {
    font-weight: 700;
    font-size: 14px;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--accent), var(--accent-warm));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    border: 1px solid var(--border);
    padding: 4px 8px;
    border-radius: 6px;
}

.logo-text {
    font-weight: 600;
    font-size: 15px;
    letter-spacing: -0.01em;
}

.nav-cta {
    font-size: 13px;
    font-weight: 600;
    color: var(--bg);
    background: var(--text);
    padding: 8px 18px;
    border-radius: 8px;
    text-decoration: none;
    transition: opacity 0.2s;
}

.nav-cta:hover {
    opacity: 0.85;
}

/* Sections */
main {
    padding-top: 60px;
}

section {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 80px 24px;
}

.section-label {
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--accent);
    margin-bottom: 16px;
}

h2 {
    font-size: clamp(28px, 5vw, 40px);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.15;
    margin-bottom: 16px;
}

.section-sub {
    font-size: 17px;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 560px;
    margin-bottom: 48px;
}

/* Hero */
.hero {
    padding-top: 140px;
    padding-bottom: 100px;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero-badge {
    font-size: 13px;
    font-weight: 500;
    color: var(--accent);
    background: var(--accent-glow);
    border: 1px solid rgba(145, 153, 255, 0.2);
    padding: 6px 16px;
    border-radius: 100px;
    margin-bottom: 28px;
}

.hero h1 {
    font-size: clamp(40px, 8vw, 72px);
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1.05;
    margin-bottom: 24px;
}

.gradient-text {
    background: linear-gradient(135deg, var(--accent), var(--accent-warm));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-sub {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.65;
    max-width: 520px;
    margin-bottom: 40px;
}

.hero-cta {
    display: flex;
    gap: 12px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-family: inherit;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    font-size: 16px;
    color: #fff;
    background: linear-gradient(135deg, var(--accent), #7a83f0);
    padding: 14px 28px;
    border-radius: 12px;
    box-shadow: 0 0 30px rgba(145, 153, 255, 0.2);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 0 40px rgba(145, 153, 255, 0.35);
}

.btn-lg {
    font-size: 18px;
    padding: 16px 36px;
    border-radius: 14px;
}

/* Task Grid */
.task-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

.task-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    transition: border-color 0.2s;
}

.task-card:hover {
    border-color: #333;
}

.task-icon {
    font-size: 24px;
    margin-bottom: 14px;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
}

.task-icon.morning { background: rgba(255, 180, 50, 0.12); }
.task-icon.evening { background: rgba(249, 157, 159, 0.12); }
.task-icon.night { background: rgba(145, 153, 255, 0.12); }

.task-card h3 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 6px;
    letter-spacing: -0.01em;
}

.task-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Optional section */
.optional {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 40px;
    padding-bottom: 40px;
}

.optional .section-sub {
    margin-bottom: 0;
}

/* Science Grid */
.science-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.science-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px;
}

.science-card h3 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
    letter-spacing: -0.01em;
}

.science-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.55;
}

/* Features */
.feature-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.feature-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
}

.feature-icon {
    font-size: 24px;
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-2);
    border-radius: 10px;
}

.feature-item h3 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 4px;
    letter-spacing: -0.01em;
}

.feature-item p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Final CTA */
.final-cta {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding-top: 60px;
    padding-bottom: 100px;
}

.final-cta h2 {
    margin-bottom: 12px;
}

.final-cta p {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

/* Footer */
footer {
    border-top: 1px solid var(--border);
    padding: 40px 24px;
}

.footer-content {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 500;
    font-size: 14px;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    font-size: 13px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

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

.footer-copy {
    font-size: 12px;
    color: #555;
    width: 100%;
    text-align: center;
    margin-top: 8px;
}

/* Responsive */
@media (max-width: 768px) {
    .task-grid {
        grid-template-columns: 1fr;
    }

    .science-grid {
        grid-template-columns: 1fr;
    }

    .feature-list {
        grid-template-columns: 1fr;
    }

    .hero {
        padding-top: 110px;
        padding-bottom: 60px;
    }

    section {
        padding: 60px 20px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .task-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}