/* ==========================================================================
   Fibonacci Test — docs styles
   Aesthetic: refined technical. The spacing scale below is literally the
   Fibonacci sequence (px), the same idea the API computes.
   ========================================================================== */

:root {
    color-scheme: light dark;

    /* Fibonacci spacing scale (px) — the signature system of the site */
    --space-3: 3px;
    --space-5: 5px;
    --space-8: 8px;
    --space-13: 13px;
    --space-21: 21px;
    --space-34: 34px;
    --space-55: 55px;
    --space-89: 89px;

    --content-width: 760px;
    --radius: 10px;
    --radius-sm: 6px;

    --font-display: "Space Grotesk", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;

    /* Light theme (default) */
    --bg: #f6f7f9;
    --surface: #ffffff;
    --surface-sunken: #f1f3f6;
    --ink: #17191e;
    --muted: #59616e;
    --hairline: #e4e7ec;
    --accent: #c4901f;
    --accent-ink: #8a6410;
    --accent-soft: rgb(196 144 31 / 0.12);
    --shadow: 0 1px 2px rgb(15 20 30 / 0.04), 0 12px 32px -18px rgb(15 20 30 / 0.28);
    --danger: #b91c1c;
    --success: #15803d;
    --axis: #c5cbd4;
    /* Chart series; series-1 is the accent darkened to keep 3:1 on --surface */
    --series-1: #b5821a;
    --series-2: #2f6fb3;
    --series-3: #2e8a6a;
    --series-4: #a64d79;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0e1014;
        --surface: #15181e;
        --surface-sunken: #1b1f27;
        --ink: #e7eaef;
        --muted: #9aa3b2;
        --hairline: #262b34;
        --accent: #e0ae4a;
        --accent-ink: #e8bd63;
        --accent-soft: rgb(224 174 74 / 0.14);
        --shadow: 0 1px 2px rgb(0 0 0 / 0.4), 0 20px 44px -24px rgb(0 0 0 / 0.7);
        --danger: #fca5a5;
        --success: #86efac;
        --axis: #3a414d;
        --series-1: #e0ae4a;
        --series-2: #5b9be0;
        --series-3: #4fbf95;
        --series-4: #d27aa8;
    }
}

html[data-theme="light"] {
    --bg: #f6f7f9;
    --surface: #ffffff;
    --surface-sunken: #f1f3f6;
    --ink: #17191e;
    --muted: #59616e;
    --hairline: #e4e7ec;
    --accent: #c4901f;
    --accent-ink: #8a6410;
    --accent-soft: rgb(196 144 31 / 0.12);
    --shadow: 0 1px 2px rgb(15 20 30 / 0.04), 0 12px 32px -18px rgb(15 20 30 / 0.28);
    --danger: #b91c1c;
    --success: #15803d;
    --axis: #c5cbd4;
    /* Chart series; series-1 is the accent darkened to keep 3:1 on --surface */
    --series-1: #b5821a;
    --series-2: #2f6fb3;
    --series-3: #2e8a6a;
    --series-4: #a64d79;
}

html[data-theme="dark"] {
    --bg: #0e1014;
    --surface: #15181e;
    --surface-sunken: #1b1f27;
    --ink: #e7eaef;
    --muted: #9aa3b2;
    --hairline: #262b34;
    --accent: #e0ae4a;
    --accent-ink: #e8bd63;
    --accent-soft: rgb(224 174 74 / 0.14);
    --shadow: 0 1px 2px rgb(0 0 0 / 0.4), 0 20px 44px -24px rgb(0 0 0 / 0.7);
    --danger: #fca5a5;
    --success: #86efac;
    --axis: #3a414d;
    --series-1: #e0ae4a;
    --series-2: #5b9be0;
    --series-3: #4fbf95;
    --series-4: #d27aa8;
}

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

body,
h1,
h2,
h3,
p,
ul,
ol,
li,
figure,
blockquote,
pre {
    margin: 0;
    padding: 0;
}

/* --------------------------------------------------------------------------
   README-style document content
   -------------------------------------------------------------------------- */

.doc h2 {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: clamp(1.8rem, 5vw, 2.4rem);
    line-height: 1.1;
    letter-spacing: -0.02em;
    color: var(--ink);
    margin-bottom: var(--space-21);
}

.doc h3 {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1.25rem;
    letter-spacing: -0.01em;
    color: var(--ink);
    margin: var(--space-34) 0 var(--space-13);
    padding-top: var(--space-13);
    border-top: 1px solid var(--hairline);
}

.doc h3:first-of-type {
    padding-top: 0;
    border-top: 0;
}

.doc p {
    margin: var(--space-13) 0;
    color: var(--ink);
}

.doc ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-13);
    margin: var(--space-13) 0;
}

.doc ul li {
    display: inline-flex;
    align-items: center;
    gap: var(--space-8);
    padding: var(--space-8) var(--space-13);
    border: 1px solid var(--hairline);
    border-radius: var(--radius-sm);
    background: var(--surface);
    font-size: 0.92rem;
}

body {
    font-family: var(--font-body);
    line-height: 1.6;
    color: var(--ink);
    background-color: var(--bg);
    -webkit-font-smoothing: antialiased;
}

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

.page {
    max-width: var(--content-width);
    margin: 0 auto;
    padding: var(--space-34) var(--space-21) var(--space-89);
}

/* --------------------------------------------------------------------------
   Site header (built by scripts/siteHeader.js) — sticky, full-bleed
   -------------------------------------------------------------------------- */

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: var(--surface);
    border-bottom: 1px solid var(--hairline);
}

.site-header-inner {
    max-width: var(--content-width);
    margin: 0 auto;
    padding: var(--space-13) var(--space-21);
    display: flex;
    align-items: center;
    gap: var(--space-13) var(--space-21);
    flex-wrap: wrap;
}

.brand {
    display: inline-flex;
    align-items: baseline;
    gap: var(--space-8);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--muted);
    text-decoration: none;
}

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

.brand strong {
    color: var(--ink);
    font-weight: 600;
}

.brand-dot {
    width: var(--space-8);
    height: var(--space-8);
    border-radius: 50%;
    background: var(--accent);
    align-self: center;
}

.site-nav {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-8) var(--space-21);
}

.site-nav a {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 0.92rem;
    color: var(--muted);
    text-decoration: none;
    padding-bottom: 2px;
    border-bottom: 2px solid transparent;
    transition: color 0.15s ease, border-color 0.15s ease;
}

.site-nav a:hover {
    color: var(--ink);
    text-decoration: none;
}

.site-nav a.is-active {
    color: var(--accent-ink);
    border-bottom-color: var(--accent);
}

.site-header-actions {
    display: inline-flex;
    align-items: center;
    gap: var(--space-13);
    margin-left: auto;
}

.site-nav-external {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 0.92rem;
    color: var(--muted);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: var(--space-5);
}

.site-nav-external::after {
    content: "\2197";
    color: var(--accent-ink);
}

.site-nav-external:hover {
    color: var(--ink);
    text-decoration: none;
}

/* --------------------------------------------------------------------------
   Code
   -------------------------------------------------------------------------- */

pre {
    background: var(--surface-sunken);
    border: 1px solid var(--hairline);
    padding: var(--space-13) var(--space-21);
    border-radius: var(--radius-sm);
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 0.86rem;
    line-height: 1.7;
    color: var(--ink);
}

code {
    font-family: var(--font-mono);
    font-size: 0.86em;
}

:not(pre) > code {
    background: var(--accent-soft);
    color: var(--accent-ink);
    padding: 0.12em 0.4em;
    border-radius: 4px;
}

pre code {
    background: transparent;
    color: inherit;
    padding: 0;
    font-size: inherit;
}

/* Copy chip (injected by scripts/copy.js) */
.code-block {
    position: relative;
}

.code-block pre {
    padding-right: 4rem;
}

.copy-chip {
    position: absolute;
    top: var(--space-8);
    right: var(--space-8);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: var(--space-34);
    height: var(--space-34);
    padding: 0;
    border-radius: var(--radius-sm);
    border: 1px solid var(--hairline);
    background: var(--surface);
    color: var(--muted);
    cursor: pointer;
    transition: color 0.15s ease, border-color 0.15s ease;
}

.copy-chip:hover {
    color: var(--accent-ink);
    border-color: var(--accent);
}

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

.copy-chip.is-copied {
    color: var(--success);
    border-color: var(--success);
}

.copy-icon {
    width: 1rem;
    height: 1rem;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.copy-icon-check {
    display: none;
}

.copy-chip.is-copied .copy-icon-clipboard {
    display: none;
}

.copy-chip.is-copied .copy-icon-check {
    display: block;
}

.io-note {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--muted);
    margin: var(--space-8) 0 var(--space-5);
}

/* --------------------------------------------------------------------------
   Links
   -------------------------------------------------------------------------- */

a {
    color: var(--accent-ink);
    text-decoration: underline;
    text-underline-offset: 0.15em;
    text-decoration-thickness: 1px;
    text-decoration-color: color-mix(in srgb, var(--accent-ink) 40%, transparent);
    transition: color 0.15s ease, text-decoration-color 0.15s ease;
}

a:hover {
    text-decoration-color: currentColor;
}

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

/* External links get the same outbound arrow as the header's GitHub link.
   inline-block keeps the arrow out of the link's underline. */
.ext-link::after {
    content: "\2197";
    display: inline-block;
    margin-left: 2px;
    color: var(--accent-ink);
    text-decoration: none;
}

/* --------------------------------------------------------------------------
   Theme toggle (markup created by scripts/theme.js)
   -------------------------------------------------------------------------- */

.theme-toggle {
    border: 1px solid var(--hairline);
    background: var(--surface);
    color: var(--ink);
    border-radius: var(--radius-sm);
    width: var(--space-34);
    height: var(--space-34);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: border-color 0.15s ease, color 0.15s ease;
}

.theme-toggle:hover {
    color: var(--accent-ink);
    border-color: var(--accent);
}

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

.theme-icon {
    width: 1.1rem;
    height: 1.1rem;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.theme-icon-sun,
.theme-icon-moon {
    display: none;
}

.theme-toggle[data-next-theme="light"] .theme-icon-sun {
    display: block;
}

.theme-toggle[data-next-theme="dark"] .theme-icon-moon {
    display: block;
}

/* --------------------------------------------------------------------------
   Fibonacci calculator page
   -------------------------------------------------------------------------- */

.fibonacci-form {
    margin-top: var(--space-21);
    display: grid;
    gap: var(--space-13);
    max-width: 22rem;
}

.fibonacci-form label {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--muted);
}

.fibonacci-form input {
    font: inherit;
    font-family: var(--font-mono);
    border-radius: var(--radius-sm);
    border: 1px solid var(--hairline);
    background: var(--surface);
    color: var(--ink);
    padding: var(--space-13);
    width: 100%;
}

.fibonacci-form input:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 1px;
    border-color: var(--accent);
}

.input-with-loader {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.input-with-loader input {
    flex: 1;
}

.fibonacci-form button {
    font-family: var(--font-display);
    font-weight: 500;
    font-size: 0.95rem;
    cursor: pointer;
    border-radius: var(--radius-sm);
    border: 1px solid var(--accent);
    background: var(--accent);
    color: #17140b;
    padding: var(--space-13) var(--space-21);
    justify-self: start;
    transition: background-color 0.15s ease, border-color 0.15s ease, transform 0.12s ease;
}

.fibonacci-form button:hover:not(:disabled) {
    background: var(--accent-ink);
    border-color: var(--accent-ink);
    transform: translateY(-1px);
}

.fibonacci-form button:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.fibonacci-form button:disabled {
    opacity: 0.55;
    cursor: not-allowed;
}

.status-message,
.error-message {
    margin-top: var(--space-13);
    min-height: 1.5rem;
    font-family: var(--font-mono);
    font-size: 0.86rem;
}

.status-message {
    color: var(--muted);
}

.error-message {
    color: var(--danger);
}

.result-panel {
    margin-top: var(--space-21);
    border: 1px solid var(--hairline);
    border-radius: var(--radius);
    background: var(--surface);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.result-panel h3 {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--muted);
    padding: var(--space-13) var(--space-21);
    border-bottom: 1px solid var(--hairline);
    background: var(--surface-sunken);
}

.result-body {
    padding: var(--space-21);
}

.result-row {
    display: flex;
    gap: var(--space-13);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    padding: var(--space-5) 0;
}

.result-row .result-key {
    color: var(--muted);
    min-width: 5.5rem;
}

.result-row .result-value {
    color: var(--ink);
}

.result-fibonacci {
    margin-top: var(--space-13);
    max-width: 100%;
    background: var(--surface-sunken);
    border: 1px solid var(--hairline);
    border-radius: var(--radius-sm);
    padding: var(--space-13);
    font-family: var(--font-mono);
    font-size: 0.88rem;
    color: var(--accent-ink);
    overflow-wrap: anywhere;
    white-space: pre-wrap;
    word-break: break-word;
}

.checking-loader {
    width: 1rem;
    height: 1rem;
    border: 2px solid var(--hairline);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.75s linear infinite;
    flex: none;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* --------------------------------------------------------------------------
   Benchmark report (benchmarks/report.html, rendered by benchmarks/report/)
   Everything is scoped under .bench so generic elements stay untouched.
   -------------------------------------------------------------------------- */

.bench .bench-subtitle {
    margin-top: calc(-1 * var(--space-13));
    color: var(--muted);
}

.bench .bench-meta {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-8);
    margin: var(--space-13) 0 0;
}

.bench .bench-meta li {
    display: inline-flex;
    align-items: center;
    gap: var(--space-8);
    padding: var(--space-5) var(--space-13);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    background: var(--surface);
}

.bench .bench-meta + .bench-meta {
    margin-top: var(--space-8);
}

.bench-meta-label {
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-size: 0.72rem;
}

.bench-meta-value {
    color: var(--ink);
    font-weight: 500;
}

.bench-status-dot {
    width: var(--space-8);
    height: var(--space-8);
    border-radius: 50%;
    flex: none;
}

.bench .bench-lead {
    margin-top: 0;
    color: var(--muted);
    font-size: 0.92rem;
}

/* Panels share the calculator's .result-panel look: shadow + sunken title strip */
.bench-panel {
    border: 1px solid var(--hairline);
    border-radius: var(--radius);
    background: var(--surface);
    box-shadow: var(--shadow);
}

/* No overflow: hidden on the panel (it would clip chart tooltips), so the
   title strip rounds its own top corners. */
.bench-panel-title {
    display: flex;
    align-items: center;
    gap: var(--space-8);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--muted);
    padding: var(--space-13) var(--space-21);
    border-bottom: 1px solid var(--hairline);
    border-radius: calc(var(--radius) - 1px) calc(var(--radius) - 1px) 0 0;
    background: var(--surface-sunken);
}

.bench-panel-body {
    padding: var(--space-21);
}

.bench .bench-panel-note {
    margin: 0 0 var(--space-13);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--muted);
}

.bench-units {
    margin-top: var(--space-21);
}

.bench-tiles {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-13);
    margin-top: var(--space-34);
}

.bench-tile {
    flex: 1 1 13rem;
    padding: var(--space-21);
}

.bench-tile-hero {
    flex-basis: 100%;
    border-color: var(--accent);
    background: linear-gradient(var(--accent-soft), var(--accent-soft)), var(--surface);
}

.bench-tile-label {
    display: flex;
    align-items: center;
    gap: var(--space-8);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--muted);
}

.bench-tile-value {
    margin-top: var(--space-5);
    font-family: var(--font-display);
    font-weight: 600;
    font-size: 1.9rem;
    line-height: 1.2;
    letter-spacing: -0.02em;
    font-variant-numeric: tabular-nums;
    color: var(--ink);
}

.bench-tile-hero .bench-tile-value {
    font-size: clamp(2rem, 7vw, 2.6rem);
    color: var(--accent-ink);
}

.bench-tile-note {
    margin-top: var(--space-3);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--muted);
}

.bench-swatch {
    display: inline-block;
    width: 0.65rem;
    height: 0.65rem;
    border-radius: 3px;
    flex: none;
}

.bench-line-key {
    display: inline-block;
    width: 0.9rem;
    height: 2px;
    border-radius: 1px;
    flex: none;
}

.bench-chart {
    position: relative;
    width: 100%;
}

.bench-chart svg {
    display: block;
    width: 100%;
    overflow: visible;
}

.bench-chart text {
    font-family: var(--font-mono);
    font-size: 11px;
    fill: var(--muted);
    font-variant-numeric: tabular-nums;
}

.bench-chart .bench-row-label {
    font-family: var(--font-display);
    font-size: 13px;
    font-weight: 500;
    fill: var(--ink);
}

.bench-chart .bench-value-label {
    fill: var(--ink);
}

.bench-grid line {
    stroke: var(--hairline);
    stroke-width: 1;
}

.bench-baseline {
    stroke: var(--axis);
    stroke-width: 1;
}

.bench-hit {
    fill: transparent;
}

.bench-hit:focus {
    outline: none;
}

.bench-focus-ring {
    opacity: 0;
    fill: none;
    stroke: var(--accent);
    stroke-width: 1;
}

.bench-hit:focus-visible + .bench-focus-ring,
.bench-focus-ring.is-active {
    opacity: 1;
}

.bench-legend {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-8) var(--space-21);
    margin-top: var(--space-13);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--muted);
}

.bench-legend span {
    display: inline-flex;
    align-items: center;
    gap: var(--space-5);
}

.bench-multiples {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr));
    gap: var(--space-13);
}

.bench-tooltip {
    position: absolute;
    z-index: 2;
    pointer-events: none;
    padding: var(--space-8) var(--space-13);
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--muted);
    white-space: nowrap;
    opacity: 0;
    transition: opacity 80ms ease;
}

.bench-tooltip.is-visible {
    opacity: 1;
}

.bench-tooltip strong {
    display: block;
    font-size: 0.86rem;
    font-weight: 600;
    color: var(--ink);
    font-variant-numeric: tabular-nums;
}

.bench-table-wrap {
    overflow-x: auto;
}

.bench-table {
    width: 100%;
    border-collapse: collapse;
    font-family: var(--font-mono);
    font-size: 0.8rem;
}

.bench-table th,
.bench-table td {
    padding: var(--space-8) var(--space-13);
    text-align: right;
    white-space: nowrap;
    border-bottom: 1px solid var(--hairline);
}

.bench-table th {
    font-weight: 500;
    font-size: 0.7rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--muted);
    background: var(--surface-sunken);
}

.bench-table td {
    color: var(--ink);
    font-variant-numeric: tabular-nums;
}

.bench-table th:first-child,
.bench-table td:first-child {
    text-align: left;
}

.bench-table tbody tr:last-child td {
    border-bottom: 0;
}

.bench-units-table th,
.bench-units-table td {
    text-align: left;
}

.bench-units-table td:first-child {
    color: var(--accent-ink);
    font-weight: 600;
}

.bench-name-cell {
    display: inline-flex;
    align-items: center;
    gap: var(--space-8);
    font-family: var(--font-display);
    font-weight: 500;
}

.bench-flag {
    display: inline-block;
    margin-left: var(--space-8);
    padding: 0 var(--space-5);
    border-radius: 4px;
    background: var(--accent-soft);
    color: var(--accent-ink);
    font-size: 0.7rem;
}

.bench .bench-footer {
    margin-top: var(--space-34);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--muted);
}

/* --------------------------------------------------------------------------
   Responsive & motion
   -------------------------------------------------------------------------- */

@media (max-width: 600px) {
    .page {
        padding: var(--space-21) var(--space-13) var(--space-55);
    }

    .site-header-inner {
        padding: var(--space-13);
        gap: var(--space-8) var(--space-13);
    }

    /* Row 1: brand + actions. Row 2: full-width, wrapping nav. */
    .site-header-actions {
        order: 2;
        margin-left: auto;
    }

    .site-nav {
        order: 3;
        flex-basis: 100%;
        gap: var(--space-8) var(--space-13);
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.001ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.001ms !important;
    }
}