/* ===== Design Tokens ===== */
:root {
    --bg: #0a0a0f;
    --bg-subtle: #101018;
    --surface: rgba(255, 255, 255, 0.04);
    --surface-hover: rgba(255, 255, 255, 0.07);
    --surface-strong: rgba(255, 255, 255, 0.06);
    --border: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
    --text: #ececf1;
    --text-secondary: #8e8ea0;
    --text-tertiary: #565669;
    --brand: #10b981;
    --brand-dim: rgba(16, 185, 129, 0.15);
    --brand-glow: rgba(16, 185, 129, 0.3);
    --accent: #f59e0b;
    --accent-dim: rgba(245, 158, 11, 0.12);
    --purple: #a78bfa;
    --purple-dim: rgba(167, 139, 250, 0.12);
    --blue: #60a5fa;
    --blue-dim: rgba(96, 165, 250, 0.12);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 24px 64px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(16, 185, 129, 0.08);
    --radius-sm: 12px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-pill: 999px;
    --font-display: "Space Grotesk", "Noto Sans SC", sans-serif;
    --font-body: "Noto Sans SC", "Inter", sans-serif;
    --font-mono: "JetBrains Mono", "Fira Code", monospace;
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    margin: 0;
    font-family: var(--font-body);
    color: var(--text);
    background: var(--bg);
    overflow-x: hidden;
}

/* subtle mesh gradient background */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    background:
        radial-gradient(ellipse 80% 50% at 20% 0%, rgba(16, 185, 129, 0.08), transparent),
        radial-gradient(ellipse 60% 40% at 80% 10%, rgba(167, 139, 250, 0.06), transparent),
        radial-gradient(ellipse 50% 60% at 50% 100%, rgba(245, 158, 11, 0.04), transparent);
}

a {
    color: inherit;
    text-decoration: none;
}

img {
    display: block;
    max-width: 100%;
}

/* ===== Layout ===== */
.page-shell {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.nav-inner,
.footer-inner {
    width: min(1600px, calc(100% - 64px));
    margin: 0 auto;
}

.hero-inner,
.section-inner {
    width: calc(100% - 80px);
    max-width: 1600px;
    margin: 0 auto;
}

/* ===== Navigation ===== */
.site-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(20px) saturate(1.4);
    -webkit-backdrop-filter: blur(20px) saturate(1.4);
    background: rgba(10, 10, 15, 0.75);
    border-bottom: 1px solid var(--border);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 16px 0;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    font-family: var(--font-display);
    font-weight: 700;
    letter-spacing: -0.03em;
    transition: opacity 0.2s;
}

.brand:hover {
    opacity: 0.8;
}

.brand-logo {
    width: 34px;
    height: 34px;
}

.brand-text {
    font-size: 1.15rem;
    background: linear-gradient(135deg, var(--text), var(--brand));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    transition: color 0.2s, background 0.2s;
}

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

.nav-links a:last-child {
    color: var(--brand);
    background: var(--brand-dim);
    font-weight: 600;
}

.nav-links a:last-child:hover {
    background: rgba(16, 185, 129, 0.22);
}

.nav-links .friend-link-lc {
    color: #818cf8;
}

.nav-links .friend-link-lc:hover {
    color: #14b8a6;
    background: rgba(129, 140, 248, 0.08);
}

.nav-toggle {
    display: none;
    border: 0;
    background: transparent;
    padding: 8px;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: background 0.2s;
}

.nav-toggle:hover {
    background: var(--surface-hover);
}

.nav-toggle span {
    display: block;
    width: 20px;
    height: 2px;
    margin: 4px 0;
    background: var(--text);
    border-radius: 1px;
    transition: transform 0.3s var(--ease-out), opacity 0.2s;
}

/* ===== Hero ===== */
.hero {
    padding: 68px 0 64px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero-inner {
    max-width: 1600px;
    position: relative;
    z-index: 1;
}

.hero-copy {
    padding: 0;
    background: none;
    border: none;
    border-radius: 0;
}

.hero-decoration {
    position: absolute;
    right: -60px;
    top: 50%;
    transform: translateY(-50%) rotate(-5deg);
    opacity: 0.55;
    pointer-events: none;
}

.hero-decoration .hero-card {
    width: 380px;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 14px;
    border-radius: var(--radius-pill);
    background: var(--brand-dim);
    color: var(--brand);
    font-size: 0.82rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    border: 1px solid rgba(16, 185, 129, 0.2);
    margin-bottom: 8px;
}

.hero h1 {
    margin: 12px 0 18px;
    font-family: var(--font-display);
    font-size: clamp(3rem, 7vw, 5.5rem);
    font-weight: 700;
    line-height: 1.02;
    letter-spacing: -0.04em;
}

.hero h1 span {
    background: linear-gradient(135deg, var(--brand), #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    margin: 0 auto 32px;
    max-width: 680px;
    color: var(--text-secondary);
    font-size: 1.12rem;
    line-height: 1.85;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin: 0 0 40px;
    justify-content: center;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 46px;
    padding: 0 22px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.92rem;
    transition: all 0.25s var(--ease-out);
    cursor: pointer;
    border: none;
}

.button-primary {
    color: #fff;
    background: linear-gradient(135deg, var(--brand), #059669);
    box-shadow: 0 0 24px rgba(16, 185, 129, 0.25), var(--shadow-sm);
}

.button-primary:hover {
    box-shadow: 0 0 32px rgba(16, 185, 129, 0.35), var(--shadow-md);
    transform: translateY(-2px);
}

.button-secondary {
    color: var(--text-secondary);
    border: 1px solid var(--border);
    background: var(--surface);
}

.button-secondary:hover {
    color: var(--text);
    border-color: var(--border-hover);
    background: var(--surface-hover);
    transform: translateY(-2px);
}

.hero-meta {
    display: inline-grid;
    grid-template-columns: repeat(3, auto);
    gap: 16px;
    padding: 0;
    margin: 0;
    list-style: none;
}

.hero-meta li {
    padding: 16px;
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.055);
    border: 1px solid rgba(255, 255, 255, 0.12);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04);
    transition: border-color 0.3s, background 0.3s, transform 0.3s;
}

.hero-meta li:hover {
    border-color: rgba(255, 255, 255, 0.22);
    background: rgba(255, 255, 255, 0.075);
    transform: translateY(-2px);
}

.hero-meta strong {
    display: block;
    margin-bottom: 4px;
    font-family: var(--font-display);
    font-size: 1.1rem;
    color: var(--text);
}

.hero-meta span {
    color: var(--text-tertiary);
    font-size: 0.84rem;
    line-height: 1.5;
}

/* hero right card */
.hero-card {
    position: relative;
    padding: 28px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(12px);
    overflow: hidden;
}

.hero-card::after {
    content: "";
    position: absolute;
    inset: auto -60px -80px auto;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(167, 139, 250, 0.08), transparent 60%);
    pointer-events: none;
}

/* ===== Terminal ===== */
.terminal {
    position: relative;
    z-index: 1;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.06);
    background: #0d0d12;
    color: #e4e4ec;
    box-shadow: var(--shadow-lg);
}

.terminal-top {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 14px 16px;
    background: rgba(255, 255, 255, 0.03);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.terminal-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #3b3b4f;
}

.terminal-dot:nth-child(1) {
    background: #ef4444;
}

.terminal-dot:nth-child(2) {
    background: #f59e0b;
}

.terminal-dot:nth-child(3) {
    background: #10b981;
}

.terminal-title {
    margin-left: auto;
    color: var(--text-tertiary);
    font-size: 0.8rem;
    font-family: var(--font-mono);
}

.terminal-body {
    padding: 20px;
    font-family: var(--font-mono);
    font-size: 0.88rem;
    line-height: 1.9;
}

.terminal-body div {
    opacity: 0.7;
}

.terminal-body div:has(.prompt) {
    opacity: 1;
}

.prompt {
    color: var(--brand);
}

.terminal-note {
    margin-top: 20px;
    color: var(--text-tertiary);
    font-size: 0.92rem;
    line-height: 1.7;
}

/* ===== Sections ===== */
.section {
    padding: 48px 0;
}

.section-heading {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    gap: 8px;
    margin-bottom: 32px;
}

.section-heading h2 {
    margin: 0;
    font-family: var(--font-display);
    font-size: clamp(1.8rem, 3.5vw, 2.8rem);
    font-weight: 700;
    letter-spacing: -0.04em;
    background: linear-gradient(135deg, var(--text), var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-heading p {
    margin: 0;
    max-width: 760px;
    color: var(--text-tertiary);
    line-height: 1.7;
    font-size: 0.95rem;
}

/* ===== Intro Cards ===== */
.section-card {
    padding: 0;
    background: none;
    border: none;
    border-radius: 0;
}

.intro-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.intro-card {
    padding: 24px;
    background: var(--surface-strong);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: border-color 0.3s, transform 0.3s var(--ease-out);
}

.intro-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.intro-card h3 {
    margin: 0 0 10px;
    font-size: 1.05rem;
    font-family: var(--font-display);
    color: var(--text);
}

.intro-card p {
    margin: 0;
    color: var(--text-tertiary);
    line-height: 1.75;
    font-size: 0.92rem;
}

/* ===== Roadmap ===== */
.roadmap-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.roadmap-grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.roadmap-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 14px;
}

.roadmap-badge {
    font-size: 0.72rem;
    font-weight: 600;
    font-family: var(--font-mono);
    padding: 3px 8px;
    border-radius: var(--radius-pill);
    letter-spacing: 0.02em;
}

.badge-done {
    color: var(--brand);
    background: var(--brand-dim);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.badge-todo {
    color: var(--text-tertiary);
    background: var(--surface);
    border: 1px solid var(--border);
}

.roadmap-card-muted {
    opacity: 0.6;
}

.roadmap-card-muted:hover {
    opacity: 1;
}

.roadmap-card {
    padding: 28px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: border-color 0.35s, transform 0.35s var(--ease-out), box-shadow 0.35s;
    position: relative;
    overflow: hidden;
}

.roadmap-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--brand), transparent);
    opacity: 0;
    transition: opacity 0.3s;
}

.roadmap-card:hover {
    border-color: rgba(16, 185, 129, 0.25);
    transform: translateY(-3px);
    box-shadow: var(--shadow-glow);
}

.roadmap-card:hover::before {
    opacity: 1;
}

.roadmap-card:nth-child(2)::before {
    background: linear-gradient(90deg, var(--purple), transparent);
}

.roadmap-card:nth-child(2):hover {
    border-color: rgba(167, 139, 250, 0.25);
    box-shadow: 0 0 40px rgba(167, 139, 250, 0.08);
}

.roadmap-card:nth-child(3)::before {
    background: linear-gradient(90deg, var(--blue), transparent);
}

.roadmap-card:nth-child(3):hover {
    border-color: rgba(96, 165, 250, 0.25);
    box-shadow: 0 0 40px rgba(96, 165, 250, 0.08);
}

.roadmap-card:nth-child(4)::before {
    background: linear-gradient(90deg, var(--accent), transparent);
}

.roadmap-card:nth-child(4):hover {
    border-color: rgba(245, 158, 11, 0.25);
    box-shadow: 0 0 40px rgba(245, 158, 11, 0.08);
}

.roadmap-card:nth-child(5)::before {
    background: linear-gradient(90deg, #f472b6, transparent);
}

.roadmap-card:nth-child(5):hover {
    border-color: rgba(244, 114, 182, 0.25);
    box-shadow: 0 0 40px rgba(244, 114, 182, 0.08);
}

.roadmap-card:nth-child(6)::before {
    background: linear-gradient(90deg, #38bdf8, transparent);
}

.roadmap-card:nth-child(6):hover {
    border-color: rgba(56, 189, 248, 0.25);
    box-shadow: 0 0 40px rgba(56, 189, 248, 0.08);
}

.roadmap-index {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    background: var(--brand-dim);
    color: var(--brand);
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 0.88rem;
    margin-bottom: 16px;
}

.roadmap-card:nth-child(2) .roadmap-index {
    background: var(--purple-dim);
    color: var(--purple);
}

.roadmap-card:nth-child(3) .roadmap-index {
    background: var(--blue-dim);
    color: var(--blue);
}

.roadmap-card:nth-child(4) .roadmap-index {
    background: var(--accent-dim);
    color: var(--accent);
}

.roadmap-card h3 {
    margin: 0 0 10px;
    font-size: 1.08rem;
    font-family: var(--font-mono);
    color: var(--text);
}

.roadmap-card p {
    margin: 0;
    color: var(--text-tertiary);
    line-height: 1.75;
    font-size: 0.92rem;
}

/* ===== Module Grid ===== */
.module-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.module-card {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 24px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: border-color 0.3s, transform 0.3s var(--ease-out);
}

.module-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.module-kicker {
    color: var(--brand);
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-family: var(--font-mono);
}

.module-card:nth-child(2) .module-kicker { color: var(--purple); }
.module-card:nth-child(3) .module-kicker { color: var(--blue); }
.module-card:nth-child(4) .module-kicker { color: var(--accent); }
.module-card:nth-child(5) .module-kicker { color: #f472b6; }
.module-card:nth-child(6) .module-kicker { color: #38bdf8; }

.module-card h3 {
    margin: 0;
    font-size: 1.05rem;
    color: var(--text);
}

.module-card p {
    margin: 0;
    color: var(--text-tertiary);
    line-height: 1.7;
    font-size: 0.9rem;
}

/* ===== Section Footer ===== */
.section-footer {
    margin-top: 20px;
    color: var(--text-tertiary);
    font-size: 0.92rem;
}

/* ===== Stats ===== */
.section-stats {
    padding: 32px 0;
}

.stats-grid {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0;
    padding: 28px 40px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 0 40px;
    text-align: center;
}

.stat-num {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.04em;
    background: linear-gradient(135deg, var(--text), var(--brand));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.82rem;
    color: var(--text-tertiary);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--border);
    flex-shrink: 0;
}

/* ===== Footer ===== */
.site-footer {
    margin-top: auto;
    padding: 32px 0 40px;
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
    flex-wrap: wrap;
}

.footer-desc {
    color: var(--text-tertiary);
    font-size: 0.82rem;
    line-height: 1.5;
}

.footer-right {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-shrink: 0;
}

.footer-link {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.82rem;
    padding: 5px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-pill);
    transition: color 0.15s, border-color 0.15s, background 0.15s;
}

.footer-link:hover {
    color: var(--brand);
    border-color: rgba(16, 185, 129, 0.4);
    background: var(--brand-dim);
}

/* ===== Responsive ===== */
@media (max-width: 960px) {
    .intro-grid,
    .module-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .roadmap-grid,
    .roadmap-grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }

    .stats-grid {
        gap: 0;
        padding: 20px 16px;
    }

    .stat-item {
        padding: 0 20px;
    }

    .section-heading {
        flex-direction: column;
        align-items: flex-start;
    }

    .footer-inner {
        flex-direction: column;
    }

    .hero-meta {
        grid-template-columns: repeat(3, 1fr);
    }

    .hero-decoration {
        display: none;
    }
}

@media (max-width: 640px) {
    .nav-inner {
        flex-wrap: wrap;
    }

    .nav-toggle {
        display: block;
    }

    .nav-links {
        display: none;
        width: 100%;
        flex-direction: column;
        align-items: stretch;
        gap: 4px;
        padding-top: 12px;
    }

    .nav-links.is-open {
        display: flex;
    }

    .nav-inner,
    .hero-inner,
    .section-inner,
    .footer-inner {
        width: calc(100% - 32px);
    }

    .hero {
        padding: 40px 0 32px;
    }

    .hero h1 {
        font-size: 2.4rem;
    }

    .hero-meta {
        grid-template-columns: 1fr;
    }

    .intro-grid,
    .module-grid,
    .roadmap-grid-3 {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        flex-wrap: wrap;
        gap: 16px;
        justify-content: center;
    }

    .stat-divider {
        display: none;
    }

    .section {
        padding: 32px 0;
    }
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-copy {
    animation: fadeInUp 0.6s var(--ease-out) both;
}

.section {
    animation: fadeInUp 0.5s var(--ease-out) both;
}

#audience { animation-delay: 0.15s; }
#roadmap { animation-delay: 0.2s; }
#modules { animation-delay: 0.25s; }

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg);
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.18);
}