/* ---------- Design tokens ---------- */

:root {
    --color-bg: #fafafa;
    --color-surface: #ffffff;
    --color-border: #e4e4e4;
    --color-text: #171717;
    --color-text-muted: #666666;
    --color-accent: #4f46e5;
    --color-accent-soft: rgba(79, 70, 229, 0.08);
    --syntax-keyword: #7c3aed;
    --syntax-string: #15803d;
    --syntax-fn: #b45309;
    --syntax-comment: #8a8a8a;
    --font-mono: ui-monospace, "Cascadia Code", "JetBrains Mono", Menlo, monospace;
    --radius: 8px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #111111;
        --color-surface: #181818;
        --color-border: #2a2a2a;
        --color-text: #ededed;
        --color-text-muted: #a0a0a0;
        --color-accent: #818cf8;
        --color-accent-soft: rgba(129, 140, 248, 0.12);
        --syntax-keyword: #a78bfa;
        --syntax-string: #4ade80;
        --syntax-fn: #fbbf24;
        --syntax-comment: #787878;
    }
}

/* ---------- Base ---------- */

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-bg);
    -webkit-font-smoothing: antialiased;
}

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

a:hover {
    text-decoration: underline;
}

code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    padding: 0.15em 0.4em;
    border-radius: 5px;
    color: var(--color-accent);
    background: var(--color-accent-soft);
}

/* ---------- Layout ---------- */

.site {
    max-width: 44rem;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    min-height: 100dvh;
}

.main {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4rem;
    padding: 3.5rem 0 4rem;
}

/* ---------- Header ---------- */

.header {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 1.1rem 0;
    border-bottom: 1px solid var(--color-border);
}

.brand {
    font-weight: 650;
    letter-spacing: -0.01em;
    color: var(--color-text);
}

.brand:hover {
    text-decoration: none;
}

.badge {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    padding: 0.15em 0.55em;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    color: var(--color-text-muted);
}

.nav {
    margin-left: auto;
    display: flex;
    gap: 1.25rem;
    font-size: 0.9rem;
}

.nav a {
    color: var(--color-text-muted);
}

.nav a:hover,
.nav a[aria-current="page"] {
    color: var(--color-text);
    text-decoration: none;
}

/* ---------- Hero ---------- */

.hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    text-align: center;
}

.title {
    margin: 0;
    font-size: clamp(2.25rem, 5vw, 3rem);
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--color-accent);
}

.tagline {
    margin: 0;
    font-size: 1.125rem;
    color: var(--color-text-muted);
    max-width: 34rem;
}

.tagline .no-need {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.95em;
    font-weight: 500;
    padding: 0.1em 0.45em;
    border-radius: 5px;
    color: var(--color-accent);
    background: var(--color-accent-soft);
}

/* Entrance: rises in from below */
.tagline .no-need.word-in {
    animation: word-in 0.25s ease;
}

@keyframes word-in {
    from {
        opacity: 0;
        transform: translateY(0.5em);
    }
    to {
        opacity: 1;
        transform: none;
    }
}

/* Exit: added by the word-cycle script before each swap; duration must
   match the exit delay in index.html */
.tagline .no-need.word-out {
    animation: word-out 0.2s ease forwards;
}

@keyframes word-out {
    to {
        opacity: 0;
        transform: translateY(-0.5em);
    }
}

.hero-actions {
    display: flex;
    gap: 0.75rem;
    margin-top: 0.75rem;
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.55em 1.3em;
    border-radius: var(--radius);
    border: 1px solid var(--color-border);
    color: var(--color-text);
    background: var(--color-surface);
    transition: border-color 0.15s ease;
}

.btn:hover {
    border-color: var(--color-accent);
    text-decoration: none;
}

.btn.primary {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: #ffffff;
}

.btn.primary:hover {
    opacity: 0.9;
}

/* ---------- Sections ---------- */

.section {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.section > h2 {
    margin: 0;
    font-size: 1.35rem;
    letter-spacing: -0.015em;
}

.section > p {
    margin: 0;
    color: var(--color-text-muted);
}

/* ---------- Feature list ---------- */

.features {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
    gap: 0.75rem;
}

.features li {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 0.9rem 1.1rem;
}

.features strong {
    display: block;
    font-weight: 600;
    margin-bottom: 0.15rem;
}

.features span {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

/* ---------- Cards & code ---------- */

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

.example {
    overflow: hidden;
}

.example-preview {
    display: flex;
    justify-content: center;
    padding: 2.5rem 1.5rem;
    border-bottom: 1px solid var(--color-border);
}

.example .code-block {
    margin: 0;
    border: none;
    border-radius: 0;
}

.example-preview button {
    font: inherit;
    font-weight: 500;
    font-variant-numeric: tabular-nums;
    padding: 0.6em 1.4em;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background: var(--color-bg);
    color: var(--color-text);
    cursor: pointer;
    transition: border-color 0.15s ease;
}

.example-preview button:hover {
    border-color: var(--color-accent);
}

.example-preview button:active {
    background: var(--color-accent-soft);
}

.code-block {
    margin: 0;
    padding: 1.25rem 1.5rem;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    overflow-x: auto;
}

.code-block code {
    display: block;
    padding: 0;
    background: none;
    color: var(--color-text);
    font-family: var(--font-mono);
    font-size: 0.85rem;
    line-height: 1.7;
}

.tok-kw { color: var(--syntax-keyword); }
.tok-str { color: var(--syntax-string); }
.tok-fn { color: var(--syntax-fn); }
.tok-cmt { color: var(--syntax-comment); }
.tok-cls { color: var(--color-text); font-weight: 600; }

.hint {
    margin: 0;
    font-size: 0.85rem;
    color: var(--color-text-muted);
    text-align: center;
}

/* ---------- Docs ---------- */

.doc {
    display: flex;
    flex-direction: column;
    gap: 3rem;
    padding: 3rem 0 4rem;
    flex: 1;
}

.doc-header h1 {
    margin: 0 0 0.5rem;
    font-size: 2rem;
    letter-spacing: -0.02em;
}

.doc-header p {
    margin: 0;
    color: var(--color-text-muted);
}

.doc ul.toc {
    margin: 1.25rem 0 0;
    padding: 0;
    list-style: none;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 0.5rem;
    font-size: 0.85rem;
}

.toc a {
    display: inline-block;
    padding: 0.25em 0.8em;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    color: var(--color-text-muted);
}

.toc a:hover {
    color: var(--color-text);
    border-color: var(--color-accent);
    text-decoration: none;
}

.doc section {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    scroll-margin-top: 1.5rem;
}

.doc h2 {
    margin: 0;
    padding-bottom: 0.4rem;
    font-size: 1.35rem;
    letter-spacing: -0.015em;
    border-bottom: 1px solid var(--color-border);
}

.doc p,
.doc ul,
.doc ol {
    margin: 0;
}

.doc ul,
.doc ol {
    padding-left: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

/* ---------- Footer ---------- */

.footer {
    padding: 1.25rem 0;
    border-top: 1px solid var(--color-border);
    font-size: 0.85rem;
    color: var(--color-text-muted);
    text-align: center;
}

.footer p {
    margin: 0;
}

/* ---------- Accessibility ---------- */

:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}