@charset 'utf-8';

:root {
    --pos: #1f5fbf;
    --neg: #d4521c;
    --ink: #1a1a1a;
    --muted: #666;
    --line: #d6d6de;
    --panel: #f6f6f9;
    --navy: navy;
}

* { box-sizing: border-box; }

body {
    margin: 0 auto;
    max-width: 1032px;
    padding: 16px;
    background: #fff;
    color: var(--ink);
    font-family: 'Play', 'Times New Roman', sans-serif;
    line-height: 1.5;
}

a { color: var(--navy); }
h1, h2, h3 { color: var(--navy); }
h1 { margin: 0; font-size: 28pt; }
h2 { margin: 1.6em 0 0.4em; font-size: 20pt; border-bottom: 1px solid var(--line); }
h3 { margin: 1em 0 0.3em; font-size: 13pt; }

.crumbs { font-size: 0.9em; }

.hero { margin-top: 8px; }
.tagline { margin: 0.1em 0 0.6em; font-size: 1.1em; }
.links { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.badges { display: inline-flex; gap: 6px; flex-wrap: wrap; margin-left: 8px; }

/* The playground comes right after the header. */
.playground h2 { margin-top: 0.9em; }
.playground .intro { margin: 0 0 10px; font-size: 0.92em; color: var(--muted); }

a.button {
    display: inline-block;
    padding: 4px 14px;
    border: 1px solid var(--navy);
    border-radius: 4px;
    color: var(--navy);
    text-decoration: none;
}
a.button:hover { background: var(--navy); color: #fff; }

code { font-size: 0.92em; }
pre {
    margin: 0;
    padding: 10px 12px;
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 4px;
    overflow-x: auto;
    font-size: 0.85em;
    line-height: 1.4;
}

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.two-col > div { min-width: 0; }

.algo-grid {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(100%, 420px), 1fr));
    gap: 0 24px;
    font-size: 0.92em;
}
.algo-grid li {
    display: flex;
    gap: 10px;
    justify-content: space-between;
    padding: 3px 0;
    border-bottom: 1px solid var(--line);
}
.algo-grid .algo { font-weight: 700; white-space: nowrap; }
.algo-grid a { text-align: right; }

footer { margin: 32px 0 8px; text-align: center; }

/* ---------------------------------------------------------------- demo */

.demo {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

.board { flex: 0 1 600px; min-width: 0; }

canvas#canvas {
    display: block;
    width: 100%;
    max-width: 600px;
    aspect-ratio: 1;
    border: 1px solid var(--line);
    border-radius: 4px;
    cursor: crosshair;
    touch-action: manipulation;
}

.hint, .muted { color: var(--muted); font-size: 0.9em; }
fieldset .hint { margin: 6px 0 0; font-size: 0.82em; line-height: 1.4; }
#timelineNote { margin: 4px 0 0; font-size: 0.82em; line-height: 1.4; }

/* ---------------------------------------------------------------- timeline */

.timeline { max-width: 600px; margin-top: 4px; }
.timeline[hidden] { display: none; }
.slider-row { display: flex; align-items: center; gap: 10px; }
.slider-row input[type="range"] { flex: 1; accent-color: var(--navy); }
.slider-row button { width: 36px; padding: 4px 0; }
.round-label { min-width: 7.5em; text-align: right; font-variant-numeric: tabular-nums; }
.weights { font-size: 0.9em; white-space: nowrap; }
.chart-head { display: flex; flex-wrap: wrap-reverse; align-items: center; justify-content: space-between; gap: 6px 12px; margin-top: 10px; }
.chart-head h3 { margin: 0; flex: 1 1 100%; font-size: 11pt; }
.chart-head select { width: auto; }
.legend { display: inline-flex; gap: 14px; font-size: 0.85em; color: var(--muted); }
.legend[hidden] { display: none; }
.swatch { display: inline-block; width: 22px; height: 0; margin-right: 6px; vertical-align: middle; border-top: 2px solid var(--train-color, #000080); }
.swatch.test { border-top-color: var(--test-color, #0f7d6b); }
.chart-wrap { position: relative; }
#lossChart {
    display: block;
    width: 100%;
    height: 220px;
    cursor: crosshair;
    touch-action: none;
}
.chart-tip {
    position: absolute;
    pointer-events: none;
    padding: 4px 8px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
    font-size: 0.85em;
    white-space: nowrap;
    font-variant-numeric: tabular-nums;
}

.panel {
    flex: 1 1 300px;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

fieldset {
    margin: 0;
    padding: 10px 12px 12px;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: var(--panel);
}

legend { color: var(--navy); font-weight: 700; padding: 0 4px; }

select, input, button { font: inherit; }
select { width: 100%; padding: 4px; }

/* The opened list of a native <select> ignores web fonts on most systems.
   Customizable selects (Chrome 135+) draw it in the page font; other
   browsers keep the native list. */
@supports (appearance: base-select) {
    select, ::picker(select) { appearance: base-select; }
    select {
        border: 1px solid #aab;
        border-radius: 4px;
        background: #fff;
    }
    ::picker(select) {
        border: 1px solid var(--line);
        border-radius: 4px;
        padding: 4px 0;
        background: #fff;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
    }
    option { padding: 3px 10px; }
    option:hover, option:focus-visible { background: var(--panel); }
    option:checked { color: var(--navy); font-weight: 700; }
}

.presets {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
}
.presets button {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    padding: 4px;
    font-size: 0.75em;
    line-height: 1.2;
}
.presets canvas {
    width: 100%;
    aspect-ratio: 1;
    border: 1px solid var(--line);
    border-radius: 3px;
    background: #fff;
}
.presets button:hover canvas { border-color: var(--navy); }

.row { display: flex; gap: 6px; margin-top: 8px; align-items: center; flex-wrap: wrap; }

.classes { gap: 14px; font-weight: 700; }
.classes .split { display: inline-flex; gap: 10px; margin-left: auto; font-weight: 400; }
.view-row { justify-content: space-between; font-size: 0.9em; }
.view-row select { width: auto; margin-left: 6px; }

/* Cyberpunk: crisp neon accents on the light page. */
.playground[data-theme="cyberpunk"] canvas#canvas {
    border-color: rgba(122, 0, 255, 0.45);
    box-shadow: 0 0 14px rgba(122, 0, 255, 0.14);
}
.playground[data-theme="cyberpunk"] .board h3 { color: #7a00ff; }
.playground[data-theme="cyberpunk"] .slider-row input[type="range"] { accent-color: #7a00ff; }
.playground[data-theme="cyberpunk"] .presets canvas { border-color: rgba(122, 0, 255, 0.3); }

/* Cyberpunk (dark): the board (plot, slider, loss chart) on a dark panel
   with neon accents; the controls keep the page style. */
.playground[data-theme="cyberpunk-dark"] .board {
    background: #0a0b1a;
    color: #d6d9f5;
    padding: 10px;
    border-radius: 6px;
    box-shadow: 0 0 0 1px rgba(0, 240, 255, 0.25), 0 0 18px rgba(185, 103, 255, 0.18);
}
.playground[data-theme="cyberpunk-dark"] canvas#canvas { border-color: rgba(0, 240, 255, 0.35); }
.playground[data-theme="cyberpunk-dark"] .board h3 { color: #f9f871; }
.playground[data-theme="cyberpunk-dark"] .board .muted,
.playground[data-theme="cyberpunk-dark"] .board .legend,
.playground[data-theme="cyberpunk-dark"] #timelineNote { color: #8b90b8; }
.playground[data-theme="cyberpunk-dark"] .slider-row input[type="range"] { accent-color: #f9f871; }
.playground[data-theme="cyberpunk-dark"] .board button,
.playground[data-theme="cyberpunk-dark"] .board select {
    background: #14162e;
    color: #d6d9f5;
    border-color: rgba(0, 240, 255, 0.4);
}
.playground[data-theme="cyberpunk-dark"] .chart-tip {
    background: #14162e;
    color: #d6d9f5;
    border-color: rgba(0, 240, 255, 0.4);
}
.playground[data-theme="cyberpunk-dark"] .presets canvas { background: #0a0b1a; border-color: rgba(0, 240, 255, 0.3); }
.classes .muted { font-weight: 400; }
.classes .pos { color: var(--pos); }
.classes .neg { color: var(--neg); }

.param, .lparam {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    margin-top: 8px;
}
p.lparam { display: block; margin: 8px 0 0; }
.param input, .lparam input { width: 90px; padding: 2px 4px; }
.param select, .lparam select { width: auto; }
.param[hidden], .lparam[hidden] { display: none; }

button {
    padding: 4px 12px;
    border: 1px solid #aab;
    border-radius: 4px;
    background: #fff;
    color: var(--ink);
    cursor: pointer;
}
button:hover:not(:disabled) { border-color: var(--navy); }
button:disabled { opacity: 0.5; cursor: default; }
button.primary {
    background: var(--navy);
    border-color: var(--navy);
    color: #fff;
    padding: 6px 24px;
}

.actions { display: flex; gap: 8px; align-items: center; }
.auto { margin-left: auto; }

.status {
    min-height: 3em;
    padding: 8px 12px;
    border-left: 4px solid var(--line);
    background: var(--panel);
    font-size: 0.95em;
}
.status.error { border-left-color: #c0392b; color: #8e2a1f; }
.status.ok { border-left-color: var(--navy); }

/* Fit the playground in one laptop screen: the board's side follows the
   viewport height, leaving room for the slider and the loss chart. */
#playground { scroll-margin-top: 8px; }
@media (min-width: 761px) {
    /* Fits once the "Playground" heading is scrolled to the top: the
       heading and intro take about 75 px above the board. */
    .board { flex: 0 0 auto; width: min(600px, max(300px, calc(100vh - 385px))); }
    #lossChart { height: clamp(110px, 17vh, 220px); }
}
/* Wide screens: presets in one row, algorithm and weak learner side by side. */
@media (min-width: 1100px) {
    .panel {
        display: grid;
        grid-template-columns: 1fr 1fr;
        align-items: start;
        gap: 10px;
    }
    .panel > fieldset:first-child, .panel > .actions, .panel > .status { grid-column: 1 / -1; }
    .presets { grid-template-columns: repeat(8, 1fr); }
}

@media (max-width: 760px) {
    h1 { font-size: 26pt; }
    .two-col { grid-template-columns: 1fr; gap: 0; }
    .demo { flex-direction: column; }
    .board, .panel { flex: none; width: 100%; }
}