:root {
    color-scheme: dark;
    --page: #101310;
    --ink: #ecefe9;
    --muted: #a7afa6;
    --panel: #171b17;
    --panel-2: #1d221d;
    --line: #394039;
    --line-strong: #707970;
    --board: #11673e;
    --board-dark: #0d4a30;
    --accent: #8b2f23;
    --accent-text: #d28677;
    --focus: #f0c27a;
    --gold: #b28b45;
    --shadow: none;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    color: var(--ink);
    font-family: "Yu Gothic", "Hiragino Sans", "Meiryo", system-ui, sans-serif;
    background: var(--page);
}

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

button,
input,
select {
    font: inherit;
}

button {
    min-height: 44px;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: var(--panel-2);
    color: var(--ink);
    cursor: pointer;
}

select {
    width: 100%;
    min-height: 44px;
    padding: 0 10px;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: var(--panel-2);
    color: var(--ink);
}

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

button:hover {
    border-color: var(--accent-text);
}

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

.skip-link {
    position: absolute;
    top: 0.75rem;
    left: 0.75rem;
    z-index: 1000;
    transform: translateY(-200%);
    padding: 0.7rem 0.9rem;
    border: 2px solid var(--focus);
    border-radius: 4px;
    background: var(--panel);
    color: var(--ink);
    font-weight: 700;
}

.skip-link:focus-visible {
    position: relative;
    top: auto;
    left: auto;
    display: inline-block;
    margin: 0.75rem;
    transform: none;
    outline: 3px solid var(--focus);
    outline-offset: 3px;
}

.shell {
    width: min(1160px, calc(100% - 28px));
    margin: 0 auto;
    padding: 22px 0 42px;
}

.header {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 16px;
    align-items: start;
    margin-bottom: 18px;
}

.back-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: fit-content;
    justify-self: start;
    min-width: 74px;
    min-height: 44px;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: var(--panel);
    color: var(--muted);
}

.eyebrow {
    margin: 0 0 6px;
    color: var(--accent-text);
    font-size: 0.74rem;
    font-weight: 800;
    letter-spacing: 0;
    text-transform: uppercase;
}

h1,
h2,
p {
    margin-top: 0;
}

h1 {
    margin-bottom: 8px;
    font-size: clamp(2.2rem, 5vw, 4rem);
    line-height: 1;
    letter-spacing: 0;
}

h2 {
    margin-bottom: 10px;
    font-size: 0.98rem;
}

.lead {
    max-width: 34rem;
    margin: 0;
    color: var(--muted);
    line-height: 1.7;
}

.layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(292px, 360px);
    gap: 18px;
    align-items: start;
}

.board-panel,
.panel {
    border: 1px solid var(--line);
    border-radius: 6px;
    background: var(--panel);
    box-shadow: var(--shadow);
}

.board-panel {
    min-width: 0;
    padding: clamp(10px, 2vw, 18px);
    overflow: hidden;
}

#boardCanvas {
    display: block;
    width: 100%;
    max-width: 640px;
    min-width: 0;
    margin-inline: auto;
    aspect-ratio: 1 / 1;
    height: auto;
    border: 10px solid #2b2218;
    border-radius: 4px;
    background: var(--board);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.18);
}

.side {
    min-width: 0;
    display: grid;
    gap: 12px;
}

.panel {
    min-width: 0;
    padding: 15px;
}

.status-text,
.winner-text,
.note p,
.ranking-head span,
.ranking-list .entry span,
.ranking-list .empty,
.submit-status {
    color: var(--muted);
}

.status-text {
    min-height: 1.6em;
    margin-bottom: 12px;
    line-height: 1.55;
}

.winner-text {
    min-height: 1.4em;
    margin-bottom: 12px;
    color: var(--accent-text);
    font-weight: 800;
    line-height: 1.55;
}

.score-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.score-grid div {
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: var(--panel-2);
}

.score-grid span {
    display: block;
    min-height: 1.35em;
    color: var(--muted);
    font-size: 0.82rem;
}

.score-grid strong {
    display: block;
    margin-top: 4px;
    font-size: 1.8rem;
    line-height: 1;
}

.clock-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
    margin: 16px 0;
    padding: 12px 0;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.clock-grid span {
    display: block;
    color: var(--muted);
    font-size: 0.82rem;
}

.clock-grid strong {
    display: block;
    margin-top: 3px;
    font-size: 1.4rem;
    font-variant-numeric: tabular-nums;
}

.clock-grid strong.is-low-time {
    color: var(--accent-text);
}

.controls {
    display: grid;
    gap: 11px;
}

.segmented {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
}

.side-choice {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.difficulty-button.is-active,
.side-button.is-active {
    border-color: var(--accent-text);
    background: #2b2218;
    color: #fffaf1;
}

#newGameButton {
    border-color: var(--line-strong);
    background: var(--accent);
    color: #fff;
    font-weight: 800;
}

.ranking-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.ranking-head h2 {
    flex-shrink: 0;
    white-space: nowrap;
}

.ranking-rule {
    margin: 0 0 8px;
    color: var(--muted);
    font-size: 0.84rem;
}

.ranking-list {
    display: grid;
    gap: 8px;
    margin: 0;
    padding-left: 1.35rem;
}

.ranking-list li {
    padding: 8px 0;
    border-top: 1px solid var(--line);
}

.ranking-list .entry {
    display: grid;
    gap: 3px;
}

.ranking-list .entry strong {
    color: var(--ink);
}

.ranking-list .entry span {
    font-size: 0.84rem;
}

.score-form {
    display: grid;
    gap: 8px;
    margin-top: 14px;
}

.score-form[hidden] {
    display: none;
}

.submit-row {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 8px;
}

.submit-row input {
    min-width: 0;
    min-height: 44px;
    padding: 0 10px;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: var(--panel-2);
    color: var(--ink);
}

.note p {
    margin-bottom: 0;
    line-height: 1.7;
}

@media (max-width: 900px) {
    .layout {
        grid-template-columns: minmax(0, 1fr);
    }

    .side {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 640px) {
    .shell {
        width: min(100% - 18px, 520px);
        padding-top: 14px;
    }

    .header,
    .side {
        grid-template-columns: 1fr;
    }

    .segmented,
    .side-choice {
        grid-template-columns: 1fr;
    }

    .board-panel {
        padding: 8px;
    }

    #boardCanvas {
        border-width: 6px;
    }

    .score-grid,
    .submit-row {
        grid-template-columns: 1fr;
    }

    h1 {
        font-size: clamp(2rem, 12vw, 3rem);
    }
}

.board-panel,
.panel { border-radius: 0; background: transparent; box-shadow: none; }
.board-panel { border: 0; padding: 0; }
.panel { border-left: 0; border-right: 0; }
.score-grid div { border-radius: 0; background: transparent; }
.difficulty-button,
.side-button,
#newGameButton,
.submit-row button,
.submit-row input { border-radius: 0; }
.ranking-list li { background: transparent; }


#boardCanvas:focus-visible {
    outline: 3px solid var(--gold);
    outline-offset: 4px;
}

.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;
}