:root {
    --ink: #070908;
    --ink-raised: #0d120e;
    --ink-soft: #121a14;
    --ink-inset: #050705;
    --line: rgba(239, 242, 232, .14);
    --line-strong: rgba(239, 242, 232, .27);
    --paper: #f3f0e7;
    --paper-muted: #b7b9ac;
    --paper-dim: #7e857b;
    --signal: #9dff22;
    --signal-soft: rgba(157, 255, 34, .12);
    --signal-mid: rgba(157, 255, 34, .3);
    --danger: #ff776f;
    --board-light: #dfd8c9;
    --board-dark: #243126;
    --board-edge: #0c110d;
    --display: 'Chakra Petch', 'Space Grotesk', system-ui, sans-serif;
    --body: 'Space Grotesk', system-ui, sans-serif;
    --mono: ui-monospace, 'SFMono-Regular', Consolas, monospace;
    --ease: cubic-bezier(.16, 1, .3, 1);
    --max: 1480px;
}

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

html { scroll-behavior: smooth; background: var(--ink); }

body {
    min-height: 100svh;
    margin: 0;
    overflow-x: hidden;
    background: var(--ink);
    color: var(--paper);
    font-family: var(--body);
    font-size: 16px;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; }
button { color: inherit; cursor: pointer; }
button:disabled, select:disabled { cursor: not-allowed; opacity: .48; }
img, svg { display: block; max-width: 100%; }
[hidden] { display: none !important; }

:focus-visible {
    outline: 2px solid var(--signal);
    outline-offset: 3px;
    border-radius: 3px;
}

::selection { background: var(--signal); color: var(--ink); }

.skip-link {
    position: fixed;
    z-index: 100;
    top: 12px;
    left: 12px;
    padding: 10px 14px;
    transform: translateY(-160%);
    background: var(--signal);
    color: var(--ink);
    font: 600 12px var(--mono);
    letter-spacing: .08em;
    text-transform: uppercase;
    transition: transform .2s var(--ease);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
    display: flex;
    align-items: center;
    gap: 34px;
    min-height: 58px;
    padding: 0 clamp(18px, 4vw, 64px);
    border-bottom: 1px solid var(--line);
    background: rgba(7, 9, 8, .96);
}

.brand-lockup { display: inline-flex; align-items: center; gap: 11px; min-width: max-content; }
.brand-lockup img { width: 34px; height: 34px; border-radius: 8px; }
.brand-copy { display: grid; line-height: 1.1; }
.brand-copy strong { color: var(--paper); font: 600 17px var(--display); letter-spacing: -.02em; }
.brand-copy small { margin-top: 4px; color: var(--paper-dim); font: 10px var(--mono); letter-spacing: .13em; text-transform: uppercase; }
.header-context { display: inline-flex; align-items: center; gap: 13px; color: var(--paper-muted); font: 12px var(--mono); letter-spacing: .1em; text-transform: uppercase; }
.header-kicker { color: var(--signal); }
.header-divider { width: 28px; height: 1px; background: var(--line-strong); }
.site-nav { display: inline-flex; align-items: center; gap: 24px; margin-left: auto; color: var(--paper-muted); font: 12px var(--mono); letter-spacing: .05em; }
.site-nav a { transition: color .18s ease; }
.site-nav a:hover { color: var(--signal); }

.arena-shell { width: min(var(--max), calc(100% - 36px)); margin: 0 auto; }
.arena-intro { display: grid; grid-template-columns: minmax(0, 1.3fr) minmax(300px, .7fr); gap: clamp(32px, 6vw, 92px); align-items: center; min-height: 145px; padding: 10px 0 9px; }
.eyebrow { margin: 0 0 15px; color: var(--signal); font: 600 11px/1.2 var(--mono); letter-spacing: .13em; text-transform: uppercase; }
.eyebrow-slash { color: var(--paper-dim); padding: 0 3px; }
.signal-dot { display: inline-block; width: 7px; height: 7px; margin-right: 7px; border-radius: 50%; background: var(--signal); box-shadow: 0 0 0 4px var(--signal-soft); vertical-align: 1px; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { font-family: var(--display); font-weight: 600; line-height: 1.02; }
h1 { max-width: 820px; margin-bottom: 7px; color: var(--paper); font-size: clamp(3.25rem, 4vw, 3.7rem); line-height: .88; letter-spacing: -.055em; }
h1 em { color: var(--signal); font-style: normal; }
.intro-lede { max-width: 70ch; margin-bottom: 0; color: var(--paper-muted); font-size: clamp(.84rem, .95vw, .95rem); line-height: 1.35; }
.intro-aside { align-self: end; padding-bottom: 5px; border-top: 1px solid var(--line-strong); }
.aside-label { margin: 8px 0 3px; color: var(--paper-dim); font: 10px var(--mono); letter-spacing: .13em; text-transform: uppercase; }
.quick-start { display: flex; align-items: center; justify-content: space-between; width: 100%; padding: 6px 0 7px; border: 0; border-bottom: 1px solid var(--line); background: transparent; text-align: left; }
.quick-start strong { display: block; color: var(--paper); font: 600 15px var(--display); }
.quick-start small { display: block; margin-top: 1px; color: var(--paper-dim); font-size: 10px; }
.quick-start .arrow { color: var(--signal); font-size: 24px; transition: transform .2s var(--ease); }
.quick-start:hover .arrow { transform: translateX(5px); }
.keyboard-note { margin: 7px 0 0; color: var(--paper-dim); font-size: 10px; line-height: 1.35; }
kbd { display: inline-block; min-width: 20px; padding: 1px 5px; border: 1px solid var(--line-strong); color: var(--paper-muted); font: 10px var(--mono); text-align: center; }

.connection-strip { display: flex; align-items: center; gap: 10px; min-height: 30px; padding: 0 12px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); color: var(--paper-muted); font: 10px var(--mono); letter-spacing: .02em; }
.connection-mark { width: 7px; height: 7px; flex: 0 0 auto; border-radius: 50%; background: var(--paper-dim); }
.connection-strip[data-state="ready"] .connection-mark { background: var(--signal); box-shadow: 0 0 0 4px var(--signal-soft); }
.connection-strip[data-state="error"] .connection-mark { background: var(--danger); }
.connection-strip[data-state="busy"] .connection-mark { background: var(--signal); animation: pulse-mark 1s ease-in-out infinite; }
.connection-strip .text-button { margin-left: auto; }

.mode-bar { display: grid; grid-template-columns: 170px 1fr; gap: 28px; align-items: stretch; padding: 7px 0 6px; border-bottom: 1px solid var(--line); }
.mode-heading { display: flex; gap: 10px; align-items: baseline; color: var(--paper-muted); font: 12px var(--mono); letter-spacing: .08em; text-transform: uppercase; }
.section-index { color: var(--signal); font: 11px var(--mono); letter-spacing: .1em; }
.mode-tabs { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0; }
.mode-tab { min-height: 37px; padding: 2px 16px 3px; border: 0; border-left: 1px solid var(--line); background: transparent; text-align: left; transition: color .2s ease, background .2s ease; }
.mode-tab:hover { background: var(--signal-soft); }
.mode-tab.is-active { background: var(--signal-soft); box-shadow: inset 0 -2px var(--signal); }
.mode-tab-title { display: block; color: var(--paper); font: 600 15px var(--display); }
.mode-tab-note { display: block; margin-top: 4px; color: var(--paper-dim); font-size: 11px; }
.mode-tab.is-active .mode-tab-title { color: var(--signal); }

.arena-grid { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(320px, .65fr); gap: clamp(28px, 5vw, 76px); padding: 0 0 clamp(64px, 8vw, 112px); }
.board-stage { min-width: 0; --board-size: min(100%, 760px, max(440px, calc(100svh - 390px))); }
.board-frame, .player-strip, .board-help, .board-toolbar, .stage-heading { width: var(--board-size); }
.stage-heading, .rail-heading, .section-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; }
.stage-heading { margin-bottom: 8px; }
.stage-heading .eyebrow { margin-bottom: 4px; }
.stage-heading h2 { margin-bottom: 0; font-size: clamp(1.5rem, 2vw, 2rem); letter-spacing: -.045em; }
.status-chip, .live-state { align-self: flex-start; padding: 6px 8px; border: 1px solid var(--line-strong); color: var(--paper-dim); font: 10px var(--mono); letter-spacing: .1em; }
.status-chip[data-state="active"] { border-color: var(--signal-mid); color: var(--signal); }
.status-chip[data-state="terminal"] { border-color: var(--paper-muted); color: var(--paper); }
.status-chip[data-state="error"] { border-color: var(--danger); color: var(--danger); }

.player-strip { display: flex; align-items: center; gap: 9px; max-width: 760px; min-height: 36px; padding: 4px 10px; border: 1px solid var(--line); background: var(--ink-raised); }
.player-strip-top { border-bottom: 0; }
.player-strip-bottom { border-top: 0; }
.player-mark { display: grid; place-items: center; width: 25px; height: 25px; border: 1px solid var(--line-strong); color: var(--paper); font-size: 17px; line-height: 1; }
.player-mark-dark { background: var(--ink); }
.player-mark-light { background: var(--paper); color: var(--ink); }
.player-info { display: grid; min-width: 0; }
.player-info strong { overflow: hidden; color: var(--paper); font: 600 13px var(--display); text-overflow: ellipsis; white-space: nowrap; }
.player-info small { overflow: hidden; color: var(--paper-dim); font: 9px var(--mono); letter-spacing: .04em; text-overflow: ellipsis; white-space: nowrap; }
.turn-indicator { margin-left: auto; color: var(--signal); font: 10px var(--mono); letter-spacing: .12em; }

.board-frame { position: relative; max-width: 760px; padding: 10px; border: 1px solid var(--line-strong); background: var(--board-edge); box-shadow: 0 22px 58px rgba(0, 0, 0, .32); }
.board-frame::before, .board-frame::after { position: absolute; z-index: 1; width: 16px; height: 16px; border-color: var(--signal); content: ''; pointer-events: none; }
.board-frame::before { top: -1px; left: -1px; border-top: 2px solid; border-left: 2px solid; }
.board-frame::after { right: -1px; bottom: -1px; border-right: 2px solid; border-bottom: 2px solid; }
.chessboard { display: grid; grid-template-columns: repeat(8, minmax(0, 1fr)); grid-template-rows: repeat(8, minmax(0, 1fr)); width: 100%; overflow: hidden; aspect-ratio: 1; background: var(--board-dark); }
.square { position: relative; display: grid; place-items: center; min-width: 0; min-height: 0; padding: 0; border: 0; background: var(--board-dark); color: var(--ink); transition: filter .18s ease, box-shadow .18s ease; }
.square.is-light { background: var(--board-light); }
.square:hover { filter: brightness(1.08); }
.square.is-selected { box-shadow: inset 0 0 0 4px var(--signal); z-index: 2; }
.square.is-last { box-shadow: inset 0 0 0 4px rgba(157, 255, 34, .34); }
.square.is-last.is-selected { box-shadow: inset 0 0 0 4px var(--signal); }
.square.is-legal::after { position: absolute; width: 20%; height: 20%; border-radius: 50%; background: var(--signal); box-shadow: 0 0 0 5px rgba(7, 9, 8, .16); content: ''; }
.square.is-capture::after { width: 68%; height: 68%; border: 4px solid var(--signal); background: transparent; box-shadow: none; }
.square.is-check { box-shadow: inset 0 0 0 5px var(--danger); }
.square.is-check .piece-svg { animation: check-flash 1.3s ease-in-out infinite; }
.piece-svg { position: absolute; z-index: 1; inset: 6%; width: 88%; height: 88%; overflow: visible; pointer-events: none; user-select: none; }
.piece-body { stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.piece-detail { fill: none; stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
.piece-svg.is-white { --piece-fill: #fffdf5; --piece-outline: #172019; --piece-detail: #172019; }
.piece-svg.is-black { --piece-fill: #18221c; --piece-outline: #e4e9d9; --piece-detail: #cdd7c6; }
.piece-body { fill: var(--piece-fill); stroke: var(--piece-outline); }
.piece-detail { stroke: var(--piece-detail); }
.square-coord { position: absolute; z-index: 2; left: 4px; top: 3px; color: #344036; font: 600 10px var(--mono); line-height: 1; pointer-events: none; }
.square:not(.is-light) .square-coord { color: #e2e7d8; }
.square-coord.file { left: auto; top: auto; bottom: 3px; right: 4px; }
.square[aria-disabled="true"] { cursor: default; }
.board-help { max-width: 760px; margin: 11px 0 0; color: var(--paper-dim); font-size: 11px; }
.board-toolbar { display: flex; flex-wrap: wrap; gap: 7px; max-width: 760px; padding-top: 19px; }
.toolbar-button, .button, .text-button { border: 1px solid var(--line-strong); background: transparent; transition: border-color .18s ease, color .18s ease, background .18s ease, transform .18s var(--ease); }
.toolbar-button { min-height: 34px; padding: 0 11px; color: var(--paper-muted); font: 11px var(--mono); }
.toolbar-button:hover, .text-button:hover { border-color: var(--signal-mid); color: var(--signal); }
.toolbar-button-danger:hover { border-color: var(--danger); color: var(--danger); }

.arena-rail { min-width: 0; }
.rail-section { padding: 0 0 27px; margin-bottom: 28px; border-bottom: 1px solid var(--line); }
.rail-heading h2 { margin: 0; color: var(--paper); font-size: 1.65rem; letter-spacing: -.04em; }
.rail-code { color: var(--signal); font: 11px var(--mono); letter-spacing: .08em; }
.setup-form { margin-top: 24px; }
.setup-options { display: grid; grid-template-columns: 1fr; gap: 7px; margin-bottom: 18px; }
.setup-form label { color: var(--paper-muted); font: 11px var(--mono); letter-spacing: .04em; }
.setup-form select { width: 100%; min-height: 42px; padding: 0 35px 0 11px; border: 1px solid var(--line-strong); border-radius: 0; outline: 0; appearance: auto; background: var(--ink); color: var(--paper); font-size: 13px; }
.setup-form select:hover, .setup-form select:focus { border-color: var(--signal-mid); }
.field-note { margin: 4px 0 0; color: var(--paper-dim); font-size: 11px; line-height: 1.55; }
.field-note-strong { color: var(--paper-muted); }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 10px; min-height: 40px; padding: 0 15px; font: 600 11px var(--mono); letter-spacing: .04em; }
.button:hover { transform: translateY(-1px); }
.button-primary { border-color: var(--signal); background: var(--signal); color: var(--ink); }
.button-primary:hover { border-color: #c1ff7b; background: #c1ff7b; }
.button-quiet { background: var(--ink-soft); color: var(--paper-muted); }
.button-quiet:hover { background: var(--signal-soft); }
.setup-form .button { width: 100%; }
.resume-note { margin: 17px 0 0; padding: 10px; border-left: 2px solid var(--signal); background: var(--signal-soft); color: var(--paper-muted); font-size: 11px; }

.live-state { border-color: var(--line); color: var(--paper-dim); }
.live-state[data-state="active"] { border-color: var(--signal-mid); color: var(--signal); }
.live-state[data-state="terminal"] { border-color: var(--paper-muted); color: var(--paper); }
.live-copy { margin: 18px 0; color: var(--paper-muted); font-size: 13px; line-height: 1.55; }
.live-actions { display: flex; flex-wrap: wrap; gap: 8px; }
.war-progress { display: grid; gap: 8px; margin-top: 18px; color: var(--paper-dim); font: 10px var(--mono); }
.war-progress-line { display: block; height: 3px; background: var(--line); }
.war-progress-line span { display: block; width: 0; height: 100%; background: var(--signal); transition: width .3s var(--ease); }

.empty-state, .loading-state { padding: 14px 0; color: var(--paper-dim); font-size: 12px; }
.move-ledger { max-height: 250px; padding: 0; margin: 20px 0 0; overflow: auto; list-style: none; }
.move-row { display: grid; grid-template-columns: 32px minmax(0, 1fr) minmax(0, 1fr); min-height: 35px; border-top: 1px solid var(--line); }
.move-number, .move-button { display: flex; align-items: center; }
.move-number { color: var(--paper-dim); font: 10px var(--mono); }
.move-button { min-width: 0; padding: 0 7px; border: 0; border-left: 1px solid var(--line); background: transparent; color: var(--paper-muted); text-align: left; }
.move-button:hover, .move-button.is-active { background: var(--signal-soft); color: var(--signal); }
.move-san { overflow: hidden; font: 13px var(--mono); text-overflow: ellipsis; white-space: nowrap; }
.move-source { display: block; overflow: hidden; color: var(--paper-dim); font: 9px var(--mono); text-overflow: ellipsis; white-space: nowrap; }
.replay-controls { margin-top: 18px; padding-top: 15px; border-top: 1px solid var(--line); }
.replay-heading, .replay-buttons { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.replay-heading { color: var(--paper-muted); font: 10px var(--mono); letter-spacing: .06em; text-transform: uppercase; }
.replay-heading output { color: var(--signal); }
.replay-controls input { width: 100%; margin: 12px 0 8px; accent-color: var(--signal); }
.replay-buttons .text-button { border: 0; padding: 4px 0; color: var(--paper-dim); font-size: 10px; }

.arena-context { padding: 0 0 clamp(72px, 10vw, 144px); border-top: 1px solid var(--line); }
.context-heading { display: flex; gap: 19px; align-items: baseline; padding: 28px 0 27px; }
.context-heading h2 { margin: 0; font-size: clamp(2rem, 4vw, 3.9rem); letter-spacing: -.05em; }
.context-list { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.context-list article { min-height: 185px; padding: 18px 22px 22px 0; border-right: 1px solid var(--line); }
.context-list article + article { padding-left: 22px; }
.context-list article:last-child { border-right: 0; }
.context-number { color: var(--signal); font: 11px var(--mono); }
.context-list h3 { margin: 25px 0 9px; color: var(--paper); font-size: 1.35rem; letter-spacing: -.03em; }
.context-list p { max-width: 25ch; margin-bottom: 0; color: var(--paper-muted); font-size: 12px; line-height: 1.55; }

.intel-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 clamp(32px, 6vw, 98px); padding-bottom: 110px; }
.intel-section { min-width: 0; padding: 27px 0 45px; border-top: 1px solid var(--line); }
.section-heading { margin-bottom: 25px; }
.section-heading h2 { margin: 0; color: var(--paper); font-size: clamp(1.7rem, 3vw, 2.6rem); letter-spacing: -.045em; }
.section-heading .section-index { padding-top: 6px; }
.bot-list, .feed-list, .leaderboard-list { min-height: 58px; }
.bot-entry, .feed-entry, .leader-entry { display: grid; grid-template-columns: 36px minmax(0, 1fr) auto; gap: 12px; align-items: center; min-height: 64px; padding: 9px 0; border-top: 1px solid var(--line); }
.entry-mark { display: grid; place-items: center; width: 30px; height: 30px; border: 1px solid var(--line-strong); color: var(--signal); font: 16px var(--display); }
.entry-main { min-width: 0; }
.entry-main strong { display: block; overflow: hidden; color: var(--paper); font: 600 15px var(--display); text-overflow: ellipsis; white-space: nowrap; }
.entry-main small { display: block; overflow: hidden; margin-top: 2px; color: var(--paper-dim); font-size: 11px; text-overflow: ellipsis; white-space: nowrap; }
.entry-tag { color: var(--paper-dim); font: 9px var(--mono); letter-spacing: .08em; text-align: right; text-transform: uppercase; }
.entry-tag.is-ready { color: var(--signal); }
.entry-tag.is-gated { color: var(--paper-muted); }
.feed-entry { grid-template-columns: minmax(0, 1fr) auto; }
.feed-entry .entry-mark { display: none; }
.feed-action { padding: 5px 0; border: 0; color: var(--signal); font: 10px var(--mono); }
.feed-action:hover { text-decoration: underline; }
.leader-entry { grid-template-columns: 32px minmax(0, 1fr) auto; }
.leader-rank { color: var(--signal); font: 11px var(--mono); }
.leader-score { color: var(--paper-muted); font: 12px var(--mono); }
.no-data { padding: 15px 0; border-top: 1px solid var(--line); color: var(--paper-dim); font-size: 12px; }

.site-footer { display: flex; flex-wrap: wrap; gap: 16px 28px; align-items: center; padding: 26px clamp(18px, 4vw, 64px) 34px; border-top: 1px solid var(--line); color: var(--paper-dim); font: 10px var(--mono); letter-spacing: .04em; }
.site-footer span:first-child { color: var(--paper-muted); }
.site-footer a:hover { color: var(--signal); }
.site-footer a:first-of-type { margin-left: auto; }

.text-button { padding: 5px 0; border: 0; color: var(--paper-muted); font: 11px var(--mono); }
.dialog-backdrop { position: fixed; z-index: 50; inset: 0; display: grid; place-items: center; padding: 18px; background: rgba(2, 4, 3, .8); }
.dialog-panel { width: min(100%, 420px); padding: 28px; border: 1px solid var(--line-strong); border-top: 2px solid var(--signal); background: var(--ink-raised); box-shadow: 0 24px 70px rgba(0, 0, 0, .55); }
.dialog-panel h2 { margin-bottom: 12px; font-size: 2rem; letter-spacing: -.04em; }
.dialog-panel p:not(.eyebrow) { color: var(--paper-muted); font-size: 13px; }
.promotion-options { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin: 20px 0 13px; }
.promotion-button { display: grid; place-items: center; min-height: 70px; border: 1px solid var(--line-strong); background: var(--ink); }
.promotion-button:hover { border-color: var(--signal); background: var(--signal-soft); }
.promotion-button .piece-svg { position: relative; inset: auto; width: 56px; height: 56px; }
.toast { position: fixed; z-index: 70; right: 18px; bottom: 18px; max-width: min(400px, calc(100vw - 36px)); padding: 11px 14px; border: 1px solid var(--signal-mid); background: var(--ink-raised); color: var(--paper); font-size: 12px; opacity: 0; pointer-events: none; transform: translateY(10px); transition: opacity .2s ease, transform .2s var(--ease); }
.toast.is-visible { opacity: 1; transform: translateY(0); }
.toast.is-error { border-color: var(--danger); }

@keyframes pulse-mark { 50% { opacity: .45; } }
@keyframes check-flash { 50% { filter: drop-shadow(0 0 8px rgba(255, 119, 111, .8)); } }

@media (max-width: 1050px) {
    .arena-grid { grid-template-columns: minmax(0, 1fr); }
    .board-stage { --board-size: min(100%, 660px); }
    .stage-heading { margin-right: auto; margin-left: auto; }
    .arena-rail { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 28px; }
    .setup-section { grid-column: 1 / -1; }
    .live-section, .ledger-section { margin-bottom: 0; }
    .board-frame, .player-strip, .board-help, .board-toolbar { margin-right: auto; margin-left: auto; }
}

@media (max-width: 760px) {
    .site-header { flex-wrap: wrap; gap: 8px 20px; min-height: 68px; padding-top: 12px; padding-bottom: 12px; }
    .header-context { order: 3; width: 100%; }
    .site-nav { gap: 14px; }
    .site-nav a:not(:last-child) { display: none; }
    .arena-shell { width: min(var(--max), calc(100% - 24px)); }
    .arena-intro { grid-template-columns: 1fr; gap: 10px; min-height: 0; padding: 16px 0 12px; }
    .arena-intro .eyebrow { margin-bottom: 8px; font-size: 9px; }
    h1 { font-size: clamp(2rem, 8vw, 3rem); line-height: .98; }
    .intro-lede { font-size: 12px; }
    .intro-aside { padding-bottom: 0; }
    .aside-label, .keyboard-note { display: none; }
    .quick-start { min-height: 44px; padding: 4px 0; }
    .quick-start small { display: none; }
    .mode-bar { display: block; padding-top: 6px; }
    .mode-heading { display: none; }
    .mode-tabs { grid-template-columns: repeat(2, minmax(0, 1fr)); border-top: 1px solid var(--line); }
    .mode-tab { min-height: 44px; padding: 8px 10px 8px 0; border-bottom: 1px solid var(--line); }
    .mode-tab-title { font-size: 14px; }
    .mode-tab-note { display: none; }
    .mode-tab:nth-child(odd) { border-left: 0; }
    .mode-tab:nth-child(even) { padding-left: 12px; }
    .arena-grid { padding-top: 12px; gap: 30px; }
    .stage-heading h2 { font-size: 1.35rem; }
    .board-frame { padding: 5px; }
    .board-frame::before, .board-frame::after { width: 11px; height: 11px; }
    .square-coord { left: 3px; top: 3px; font-size: 9px; }
    .square-coord.file { left: auto; top: auto; right: 3px; bottom: 3px; }
    .board-toolbar { gap: 5px; }
    .toolbar-button { flex: 1 1 auto; padding-right: 8px; padding-left: 8px; }
    .arena-rail { display: block; }
    .live-section, .ledger-section { margin-bottom: 28px; }
    .context-list { grid-template-columns: repeat(2, 1fr); }
    .context-list article:nth-child(2) { border-right: 0; }
    .context-list article:nth-child(3), .context-list article:nth-child(4) { border-top: 1px solid var(--line); }
    .context-list article:nth-child(3) { padding-left: 0; }
    .context-list article:nth-child(4) { padding-left: 22px; }
    .intel-grid { display: block; padding-bottom: 65px; }
    .intel-section { padding-bottom: 35px; }
    .site-footer { display: grid; gap: 9px; }
    .site-footer a:first-of-type { margin-left: 0; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; scroll-behavior: auto !important; transition-duration: .01ms !important; }
}