:root {
    --bg-top: #153428;
    --bg-mid: #1d4a38;
    --bg-bottom: #255d45;
    --panel: rgba(255, 255, 255, 0.06);
    --panel-border: rgba(255, 255, 255, 0.2);
    --text-main: #f3f4f5;
    --text-sub: #a8adb3;
    --accent: #9fc7b2;
    --accent-strong: #f7f8fa;
    --danger: #f06d63;
    --danger-strong: #e35147;
    --light-square: #4f9169;
    --dark-square: #2f6b49;
    --status-ok: #f2f4f8;
    --status-warn: #ff8777;
    --app-height: 100dvh;
    --app-safe-bottom: calc(env(safe-area-inset-bottom, 0px) + var(--browser-safe-bottom-offset, 0px));
    --game-font-family: 'Lilita One', 'Jua', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
    user-select: none;
    -webkit-user-select: none;
}

html {
    height: 100%;
    height: 100dvh;
    height: var(--app-height, 100dvh);
    overflow: hidden;
    touch-action: none;
    overscroll-behavior: none;
    background-color: var(--bg-mid);
    background-image: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-mid) 52%, var(--bg-bottom) 100%);
}

body {
    height: 100%;
    height: 100dvh;
    height: var(--app-height, 100dvh);
    overflow: hidden;
    font-family: var(--game-font-family);
    color: var(--text-main);
    background-color: var(--bg-mid);
    background-image: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-mid) 52%, var(--bg-bottom) 100%);
}

.game-container {
    width: 100%;
    height: 100%;
    height: 100dvh;
    height: var(--app-height, 100dvh);
    position: relative;
    display: flex;
    flex-direction: column;
    padding: env(safe-area-inset-top) env(safe-area-inset-right) var(--app-safe-bottom) env(safe-area-inset-left);
    --controller-inline-size: min(calc(100vw - 16px), 620px);
    --p2-top-strip-gap: 4px;
    --p2-top-edge-gap: 4px;
    --p2-edge-padding-top: 0px;
    --p2-edge-padding-bottom: var(--p2-top-edge-gap);
    --p1-bottom-edge-gap: 4px;
    --top-control-btn-size: 44px;
    --ai-level-btn-size: 30px;
}

.game-container.entry-layout-pending > :not(.entry-start-overlay) {
    visibility: hidden;
    pointer-events: none;
}

.game-container.p2-ai-opponent {
    --p2-edge-padding-top: var(--p2-top-edge-gap);
    --p2-edge-padding-bottom: 0px;
}

.player-section {
    flex: 0 0 auto;
    min-height: 82px;
    padding: 4px 8px;
    display: flex;
    align-items: center;
    justify-content: center;
}

body.global-ad-banner-enabled .player-section {
    min-height: 74px;
    padding-top: 2px;
    padding-bottom: 2px;
}

.opponent-section {
    transform: rotate(180deg);
    align-items: flex-end;
    min-height: 0;
    padding-top: var(--p2-edge-padding-top);
    padding-bottom: var(--p2-edge-padding-bottom);
}

.my-section {
    align-items: flex-end;
    padding-top: 0;
    padding-bottom: var(--p1-bottom-edge-gap);
}

body.global-ad-banner-enabled .opponent-section {
    min-height: 0;
    padding-top: var(--p2-edge-padding-top);
    padding-bottom: var(--p2-edge-padding-bottom);
}

body.global-ad-banner-enabled .my-section {
    padding-top: 0;
    padding-bottom: var(--p1-bottom-edge-gap);
}

.game-container.p2-ai-opponent .opponent-section {
    transform: none;
    align-items: flex-start;
    min-height: 0;
}

.player-card {
    width: var(--controller-inline-size);
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: 14px;
    background: var(--panel);
    border: 1px solid var(--panel-border);
    backdrop-filter: blur(8px);
    transform: translateZ(0);
    transition: background 0.22s ease, border-color 0.22s ease, box-shadow 0.22s ease, opacity 0.22s ease, filter 0.22s ease, transform 0.22s ease;
}

.player-card.is-neutral-side {
    background: linear-gradient(180deg, rgba(118, 127, 138, 0.74) 0%, rgba(89, 97, 107, 0.82) 100%);
    border-color: rgba(205, 213, 225, 0.35);
}

.player-card.is-neutral-side .player-name,
.player-card.is-neutral-side .player-meta {
    color: #f2f5fb;
    text-shadow: 0 1px 2px rgba(12, 14, 19, 0.26);
}

.player-card.is-white-side {
    background: #ffffff;
    border-color: rgba(0, 0, 0, 0.16);
}

.player-card.is-white-side .player-role,
.player-card.is-white-side .player-name,
.player-card.is-white-side .player-meta {
    color: #1d232b;
    text-shadow: none;
}

.player-card.is-black-side {
    background: #000000;
    border-color: rgba(255, 255, 255, 0.18);
}

.player-card.is-black-side .player-role,
.player-card.is-black-side .player-name,
.player-card.is-black-side .player-meta {
    color: #edf2f8;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.35);
}

.player-card.is-active-player {
    border-color: var(--panel-border);
    box-shadow: 0 0 0 1px rgba(236, 255, 245, 0.18), 0 10px 24px rgba(7, 31, 21, 0.24), 0 0 18px rgba(120, 224, 176, 0.2);
    transform: translateY(-3px) scale(1.032);
}

.player-card.is-inactive-player {
    border-color: rgba(145, 153, 165, 0.42);
    box-shadow: inset 0 0 0 1px rgba(17, 21, 27, 0.38);
}

.player-card.is-inactive-player .player-emoji,
.player-card.is-inactive-player .player-name,
.player-card.is-inactive-player .player-meta {
    opacity: 0.4;
}

.player-card.is-inactive-player .player-name,
.player-card.is-inactive-player .player-meta {
    filter: saturate(0.5) brightness(0.85);
}

.player-card.is-inactive-player .ai-elo-wrap,
.player-card.is-inactive-player .ai-elo-label,
.player-card.is-inactive-player .ai-elo-value,
.player-card.is-inactive-player .ai-level-option {
    opacity: 1;
    filter: none;
}

.player-card.is-active-player .player-role,
.player-card.is-active-player .player-name,
.player-card.is-active-player .player-meta {
    text-shadow: 0 1px 4px rgba(31, 22, 14, 0.5);
}

.player-card.is-active-player.is-white-side .player-role,
.player-card.is-active-player.is-white-side .player-name,
.player-card.is-active-player.is-white-side .player-meta {
    text-shadow: none;
}

.player-role {
    display: none;
    grid-column: 1;
}

.player-identity {
    grid-column: 2;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    row-gap: 3px;
    gap: 8px;
    min-width: 0;
    text-align: center;
}

.player-emoji {
    font-size: 1.65rem;
    line-height: 1;
    transition: transform 0.22s ease, opacity 0.22s ease;
}

.player-name {
    font-family: var(--game-font-family);
    font-size: 1rem;
    font-weight: 700;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    text-align: center;
    transition: opacity 0.22s ease, filter 0.22s ease, text-shadow 0.22s ease;
}

.ai-elo-wrap {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: var(--ai-level-btn-size);
    height: var(--ai-level-btn-size);
    border-radius: 50%;
    border: 1px solid transparent;
    background: transparent;
    cursor: pointer;
    --ai-elo-accent: #ef9548;
}

.ai-elo-wrap[data-tier="beginner"] {
    --ai-elo-accent: #47c46a;
}

.ai-elo-wrap[data-tier="intermediate"] {
    --ai-elo-accent: #ef9548;
}

.ai-elo-wrap[data-tier="advanced"] {
    --ai-elo-accent: #e15b52;
}

.ai-elo-label {
    font-family: var(--game-font-family);
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    color: #d8deea;
}

.ai-elo-value {
    border: none;
    background: none;
    margin: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-family: var(--game-font-family);
    font-size: 1.02rem;
    font-weight: 700;
    text-align: center;
    color: #fff7e5;
    cursor: pointer;
    line-height: 1;
    padding: 0;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.46);
    filter: drop-shadow(0 0 4px rgba(255, 226, 164, 0.22));
    transition: transform 0.16s ease, filter 0.18s ease;
}

.ai-elo-value:active {
    transform: scale(0.96);
}

.ai-level-panel {
    position: fixed;
    top: var(--ai-level-panel-top, 88px);
    left: var(--ai-level-panel-left, 50vw);
    width: var(--ai-level-panel-width, 180px);
    height: var(--ai-level-panel-height, 42px);
    z-index: 275;
    min-width: 0;
    max-width: calc(100vw - 16px);
    padding: 5px;
    border-radius: 12px;
    border: 1px solid rgba(231, 238, 248, 0.36);
    background: linear-gradient(180deg, rgba(18, 24, 34, 0.96) 0%, rgba(9, 13, 20, 0.95) 100%);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.32);
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 4px;
    align-items: stretch;
    overflow: hidden;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.ai-level-panel[hidden] {
    display: none !important;
}

.ai-level-option {
    border: 1px solid rgba(228, 235, 244, 0.2);
    border-radius: 8px;
    background: linear-gradient(180deg, rgba(244, 249, 255, 0.11) 0%, rgba(255, 255, 255, 0.03) 100%);
    color: #ecf1fb;
    width: 100%;
    height: 100%;
    min-height: 0;
    min-width: 0;
    padding: 2px 4px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    white-space: nowrap;
    font-family: var(--game-font-family);
    font-size: 0.96rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    line-height: 1;
    cursor: pointer;
    transition: transform 0.15s ease, border-color 0.18s ease, background 0.18s ease, filter 0.18s ease;
}

.ai-level-option.is-selected {
    border-color: rgba(255, 239, 199, 0.82);
    background: linear-gradient(180deg, rgba(154, 113, 58, 0.84) 0%, rgba(110, 78, 38, 0.88) 100%);
    color: #fff1d7;
    box-shadow: inset 0 0 0 1px rgba(255, 239, 205, 0.22);
}

.ai-level-option:active {
    transform: scale(0.96);
}

.player-card.is-active-player .ai-elo-wrap {
    border-color: transparent;
    background: transparent;
}

.game-container:not(.p2-ai-opponent) .ai-elo-wrap {
    display: none !important;
}

.player-card.is-active-player .ai-elo-label,
.player-card.is-active-player .ai-elo-value {
    color: #fff4df;
}

.player-card.is-active-player .player-emoji {
    transform: scale(1.08);
}

.player-card.is-active-player .player-name {
    font-weight: 800;
}

.ai-elo-wrap[data-tier="beginner"] .ai-elo-value {
    filter: drop-shadow(0 0 5px rgba(117, 230, 142, 0.34));
}

.ai-elo-wrap[data-tier="intermediate"] .ai-elo-value {
    filter: drop-shadow(0 0 5px rgba(255, 214, 133, 0.34));
}

.ai-elo-wrap[data-tier="advanced"] .ai-elo-value {
    filter: drop-shadow(0 0 5px rgba(255, 128, 128, 0.34));
}

.player-meta {
    grid-column: 3;
    display: inline-flex;
    align-items: center;
    justify-content: flex-end;
    min-height: 32px;
    font-size: 0.88rem;
    color: var(--text-sub);
    justify-self: end;
    text-align: right;
}

.player-meta.active-turn {
    min-width: auto;
    padding: 0;
    border: none;
    background: none;
    color: inherit;
    font-family: var(--game-font-family);
    font-size: 0.8rem;
    font-weight: 800;
    justify-content: flex-end;
    letter-spacing: 0.12em;
    line-height: 1;
    text-align: right;
    text-shadow: 0 0 8px rgba(238, 255, 246, 0.14);
}

.player-card.is-active-player .player-meta.active-turn {
    text-shadow: none;
}

.player-meta.in-check {
    color: var(--status-warn);
}

.player-meta.deciding-first {
    color: #f6e8cb;
    letter-spacing: 0.06em;
    text-shadow: 0 1px 3px rgba(38, 28, 19, 0.5);
}

.center-section {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding-top: 0;
    gap: 8px;
    --board-max-inline: calc(100vw - env(safe-area-inset-left, 0px) - env(safe-area-inset-right, 0px) - 2px);
    --board-size: var(--board-size-override, min(var(--board-max-inline), max(250px, calc(100dvh - 298px - var(--app-safe-bottom))), 620px));
    --captured-piece-gap: 0px;
    --captured-track-row-gap: 0px;
    --captured-piece-size: 0px;
    --captured-track-max-width: var(--board-size);
    --captured-track-height: 24px;
    --disc-count-size: clamp(0.96rem, calc(var(--board-size) * 0.044), 1.52rem);
    --disc-count-side-padding: clamp(4px, calc(var(--board-size) * 0.016), 12px);
    --disc-count-track-height: max(var(--captured-track-height), calc(var(--disc-count-size) + 8px));
}

.entry-start-overlay {
    position: absolute;
    inset: 0;
    z-index: 260;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.22s ease;
    background: radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.04) 0%, rgba(0, 0, 0, 0.9) 72%);
}

.entry-start-overlay[hidden] {
    display: none !important;
}

.entry-start-overlay.show {
    opacity: 1;
    pointer-events: auto;
}

.turn-announcement {
    position: absolute;
    top: var(--turn-announcement-top, 50%);
    left: var(--turn-announcement-left, 50%);
    transform: translate(-50%, -50%) rotate(var(--turn-announcement-rotation, 0deg)) scale(0.9);
    min-width: clamp(190px, 52vw, 330px);
    max-width: min(88vw, 420px);
    padding: 16px 22px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    border-radius: 14px;
    border: 1px solid rgba(242, 221, 189, 0.92);
    background: linear-gradient(180deg, rgba(247, 233, 207, 0.95) 0%, rgba(174, 141, 95, 0.96) 100%);
    box-shadow: 0 10px 24px rgba(19, 14, 9, 0.36);
    opacity: 0;
    pointer-events: none;
    z-index: 255;
}

.turn-announcement.p2-perspective {
    --turn-announcement-rotation: 180deg;
}

.turn-announcement.show {
    animation: chess-turn-announce 1.45s ease-out forwards;
}

.turn-announcement-emoji {
    font-size: 2rem;
    line-height: 1;
}

.turn-announcement-text {
    font-family: var(--game-font-family);
    font-size: clamp(0.95rem, 3.6vw, 1.08rem);
    font-weight: 700;
    color: #2f2112;
    letter-spacing: 0.04em;
    text-shadow: 0 1px 0 rgba(255, 255, 255, 0.42);
}

.entry-start-btn {
    position: absolute;
    left: var(--entry-start-btn-left, 50%);
    top: var(--entry-start-btn-top, 50%);
    transform: translate(-50%, -50%);
    overflow: hidden;
    min-width: clamp(180px, 46vw, 300px);
    min-height: clamp(66px, 11dvh, 88px);
    padding: 0 24px;
    border-radius: 18px;
    border: none;
    background: linear-gradient(180deg, rgba(246, 247, 249, 0.96) 0%, rgba(136, 141, 149, 0.96) 100%);
    color: #111315;
    font-family: var(--game-font-family);
    font-size: clamp(1.34rem, 5.3vw, 1.92rem);
    letter-spacing: 0.5px;
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.24), 0 8px 20px rgba(0, 0, 0, 0.5);
    cursor: pointer;
    pointer-events: none;
    opacity: 0;
    animation: entry-start-pulse 1.5s ease-in-out infinite;
}

.entry-start-btn[data-positioned="1"] {
    pointer-events: auto;
    opacity: 1;
}

.entry-start-btn > span {
    position: relative;
    z-index: 2;
}

.entry-start-btn::after {
    content: '';
    position: absolute;
    top: -45%;
    left: -68%;
    width: 46%;
    height: 190%;
    transform: skewX(-18deg);
    background: linear-gradient(
        90deg,
        rgba(255, 255, 255, 0) 0%,
        rgba(255, 255, 255, 0.52) 50%,
        rgba(255, 255, 255, 0) 100%
    );
    z-index: 1;
    pointer-events: none;
    animation: entry-start-sweep 2.4s linear infinite;
}

.entry-start-btn:active {
    transform: translate(-50%, -50%) scale(0.98);
}

.top-strip {
    width: var(--controller-inline-size);
    margin-top: var(--p2-top-strip-gap);
    padding: 0 clamp(4px, calc(var(--controller-inline-size) * 0.015), 12px);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: clamp(6px, calc(var(--controller-inline-size) * 0.018), 14px);
}

.captured-zone {
    width: var(--board-size);
    min-height: calc(var(--captured-track-height) + 2px);
    padding: 0 8px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.captured-zone-top {
    margin-top: auto;
}

.captured-zone-bottom {
    margin-bottom: auto;
}

.captured-track {
    width: min(100%, var(--captured-track-max-width));
    min-height: var(--captured-track-height);
    max-height: var(--captured-track-height);
    padding: 2px 0;
    display: flex;
    align-items: flex-start;
    align-content: flex-start;
    flex-wrap: wrap;
    row-gap: var(--captured-track-row-gap);
    column-gap: var(--captured-piece-gap);
    overflow: hidden;
    scrollbar-width: none;
}

.game-container.captured-single-row .center-section {
    --captured-piece-gap: 2px;
    --captured-track-row-gap: 0px;
    --captured-piece-size: clamp(17px, calc((var(--board-size) - 54px) / 15), 28px);
    --captured-track-max-width: calc((var(--captured-piece-size) * 15) + (var(--captured-piece-gap) * 14));
    --captured-track-height: calc(var(--captured-piece-size) + 2px);
}

.game-container.captured-single-row .captured-track {
    flex-wrap: nowrap;
    align-content: center;
    align-items: center;
    row-gap: 0;
}

.captured-track.p2-perspective {
    transform: rotate(180deg);
}

.captured-track::-webkit-scrollbar {
    display: none;
}

.disc-count-track {
    width: 100%;
    min-height: var(--disc-count-track-height);
    max-height: var(--disc-count-track-height);
    padding: 0 var(--disc-count-side-padding);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: nowrap;
    row-gap: 0;
    column-gap: 0;
}

.disc-count-track[hidden] {
    display: none !important;
}

.disc-count-label {
    width: 100%;
    font-family: var(--game-font-family);
    font-size: var(--disc-count-size);
    font-weight: 700;
    letter-spacing: 0.015em;
    line-height: 1.05;
    color: #def2e7;
    text-shadow: 0 1px 2px rgba(10, 62, 38, 0.4);
    white-space: nowrap;
}

.disc-count-label.align-left {
    text-align: left;
}

.disc-count-label.align-right {
    text-align: right;
}

/* Keep screen-right alignment even when the top track is rotated for P2 perspective. */
.disc-count-track.p2-perspective .disc-count-label.align-right {
    text-align: left;
}

.disc-token {
    display: inline-block;
    width: 1.08em;
    text-align: center;
    font-weight: 800;
}

.disc-token.black {
    color: #000000;
    text-shadow: none;
}

.disc-token.white {
    color: #ffffff;
    text-shadow: none;
}

.captured-piece {
    flex: 0 0 auto;
    width: var(--captured-piece-size);
    height: var(--captured-piece-size);
    display: flex;
    align-items: center;
    justify-content: center;
}

.captured-piece-image {
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
    object-position: center;
}

.captured-piece.captured-white .captured-piece-image {
    filter: drop-shadow(0 1px 1px rgba(0, 0, 0, 0.42));
}

.captured-piece.captured-black .captured-piece-image {
    filter: drop-shadow(0 0 1px rgba(255, 255, 255, 0.86)) drop-shadow(0 1px 1px rgba(0, 0, 0, 0.35));
}

.piece-image[hidden],
.captured-piece-image[hidden],
.promotion-piece-image[hidden] {
    display: none !important;
}

.icon-group {
    display: flex;
    align-items: center;
    gap: clamp(4px, calc(var(--controller-inline-size) * 0.011), 10px);
}

.icon-btn {
    width: var(--top-control-btn-size);
    height: var(--top-control-btn-size);
    border: 2px solid rgba(255, 255, 255, 0.45);
    border-radius: 50%;
    background: rgba(8, 8, 8, 0.86);
    color: var(--accent-strong);
    font-size: 1.12rem;
    line-height: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

#rules-btn {
    background: linear-gradient(180deg, rgba(177, 183, 193, 0.95) 0%, rgba(116, 123, 134, 0.94) 100%);
    border-color: rgba(230, 234, 242, 0.72);
    color: #f7f8fb;
}

.entry-start-overlay.show ~ .center-section #rules-btn,
.entry-start-overlay.show ~ .center-section #home-btn-container {
    position: relative;
    z-index: 270;
}

.entry-start-overlay.show ~ .player-section .player-identity {
    position: relative;
    z-index: 272;
    pointer-events: auto;
}

.entry-start-overlay.show ~ .player-section .ai-elo-wrap {
    z-index: 273;
    pointer-events: auto;
}

.entry-start-overlay.show ~ .player-section .ai-level-panel {
    z-index: 274;
}

.entry-start-overlay.show ~ .player-section {
    position: relative;
    z-index: 271;
}

.entry-start-overlay.show ~ .player-section .player-card {
    position: relative;
    z-index: 271;
    border-color: transparent;
    background: transparent;
    box-shadow: none;
    backdrop-filter: none;
}

.entry-start-overlay.show ~ .player-section .player-role,
.entry-start-overlay.show ~ .player-section .player-meta {
    visibility: hidden;
    pointer-events: none;
}

.icon-btn.danger {
    border-color: rgba(240, 109, 99, 0.6);
    color: #ffd8d3;
}

.icon-btn:active {
    transform: scale(0.95);
}

.hold-btn-container {
    position: relative;
    width: var(--top-control-btn-size);
    height: var(--top-control-btn-size);
    cursor: pointer;
}

.hold-btn-progress {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.hold-btn-bg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.24);
    stroke-width: 3;
}

.hold-btn-fill {
    fill: none;
    stroke-width: 3;
    stroke-linecap: round;
    stroke-dasharray: 126;
    stroke-dashoffset: 126;
}

.home-btn-fill {
    stroke: #53c46f;
}

.undo-btn-fill {
    stroke: #53c46f;
}

.surrender-btn-fill {
    stroke: #53c46f;
}

.hold-btn-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 1.12rem;
    line-height: 1;
}

.board-shell {
    width: var(--board-size);
    aspect-ratio: 1 / 1;
    position: relative;
    padding: 7px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    background: linear-gradient(180deg, rgba(146, 223, 180, 0.28) 0%, rgba(16, 51, 34, 0.88) 100%);
    box-shadow: 0 14px 30px rgba(0, 0, 0, 0.4);
}

.chess-board {
    width: 100%;
    height: 100%;
    display: grid;
    grid-template-columns: repeat(8, minmax(0, 1fr));
    grid-template-rows: repeat(8, minmax(0, 1fr));
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid rgba(0, 0, 0, 0.34);
}

.chess-board.rotated {
    transform: rotate(180deg);
}

.chess-board.rotated .piece {
    transform: rotate(180deg);
}

.piece.p2-owned-piece {
    transform: rotate(180deg);
}

.chess-board.rotated .piece.p2-owned-piece {
    transform: rotate(0deg);
}

.chess-board.rotated .coord-rank,
.chess-board.rotated .coord-file {
    transform: rotate(180deg);
}

.square {
    position: relative;
    border: none;
    appearance: none;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    aspect-ratio: 1 / 1;
    touch-action: manipulation;
}

.square.light {
    background: var(--light-square);
}

.square.dark {
    background: var(--dark-square);
}

.square.selected {
    box-shadow:
        inset 0 0 0 3px rgba(225, 255, 191, 0.88),
        inset 0 0 0 6px rgba(28, 68, 45, 0.34);
}

.square.last-from,
.square.last-to {
    box-shadow: inset 0 0 0 3px rgba(206, 240, 181, 0.84);
}

.square.last-to .piece.last-moved-piece .piece-image {
    filter: drop-shadow(0 0 6px rgba(209, 255, 187, 0.62));
}

.square.legal::after,
.square.legal.capture::after {
    content: '';
    position: absolute;
    inset: auto;
    pointer-events: none;
}

.square.legal::after {
    width: 26%;
    height: 26%;
    border-radius: 50%;
    border: 2px solid rgba(214, 247, 198, 0.94);
    background: rgba(178, 228, 146, 0.82);
    box-shadow:
        inset 0 1px 0 rgba(235, 255, 226, 0.35),
        0 0 0 1px rgba(36, 78, 53, 0.52),
        0 2px 6px rgba(0, 0, 0, 0.3);
}

.square.legal.capture::after {
    width: 78%;
    height: 78%;
    border-radius: 50%;
    border: 2px solid rgba(90, 63, 37, 0.82);
    background: radial-gradient(
        circle,
        rgba(0, 0, 0, 0) 56%,
        rgba(188, 152, 103, 0.24) 57%,
        rgba(188, 152, 103, 0.24) 66%,
        rgba(0, 0, 0, 0) 67%
    );
    box-shadow:
        inset 0 0 0 1px rgba(246, 231, 202, 0.84),
        inset 0 0 0 5px rgba(124, 86, 50, 0.42),
        0 0 0 1px rgba(246, 229, 198, 0.64),
        0 2px 7px rgba(44, 28, 16, 0.36);
}

.square.in-check {
    box-shadow: inset 0 0 0 4px rgba(211, 55, 55, 0.9);
}

.square-skill-popup {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -100%) rotate(var(--square-popup-rotation, 0deg)) scale(0.9);
    min-width: 72px;
    max-width: 170px;
    padding: 4px 9px;
    border-radius: 9px;
    border: 1px solid rgba(226, 203, 167, 0.92);
    background: linear-gradient(180deg, rgba(248, 235, 208, 0.96) 0%, rgba(146, 108, 64, 0.95) 100%);
    box-shadow: 0 8px 14px rgba(21, 15, 9, 0.35);
    color: #2a1d10;
    font-family: var(--game-font-family);
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    text-align: center;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    z-index: 18;
}

.square-skill-popup.p2-perspective {
    --square-popup-rotation: 180deg;
}

.square-skill-popup.show {
    animation: chess-skill-popup 1.2s ease-out forwards;
}

.piece {
    width: 80%;
    height: 80%;
    pointer-events: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.piece-disc {
    width: 84%;
    height: 84%;
    border-radius: 50%;
    display: block;
    transform: translateZ(0);
}

.piece-disc.black {
    background: radial-gradient(circle at 32% 28%, #4e5662 0%, #262e39 38%, #111821 78%);
    border: 1px solid rgba(207, 220, 232, 0.22);
    box-shadow:
        inset 0 1px 1px rgba(255, 255, 255, 0.12),
        0 2px 5px rgba(0, 0, 0, 0.45);
}

.piece-disc.white {
    background: radial-gradient(circle at 32% 28%, #ffffff 0%, #edf2f8 45%, #cfd8e3 85%);
    border: 1px solid rgba(26, 35, 45, 0.22);
    box-shadow:
        inset 0 1px 1px rgba(255, 255, 255, 0.9),
        0 2px 5px rgba(17, 24, 33, 0.3);
}

.piece.drag-origin {
    opacity: 0;
}

.piece-image {
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
    object-position: center;
}

.chess-drag-piece {
    position: fixed;
    left: 0;
    top: 0;
    width: 46px;
    height: 46px;
    transform: translate(-50%, -50%);
    pointer-events: none;
    z-index: 320;
    opacity: 0;
}

.chess-drag-piece.show {
    opacity: 1;
}

.chess-drag-piece.p2-piece {
    transform: translate(-50%, -50%) rotate(180deg);
}

.chess-drag-piece-image {
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
    object-position: center;
}

.coord-rank,
.coord-file {
    position: absolute;
    font-family: var(--game-font-family);
    font-size: 0.54rem;
    font-weight: 700;
    opacity: 1;
    transition: opacity 0.16s ease;
    pointer-events: none;
}

.chess-board:not(.show-coords) .coord-rank,
.chess-board:not(.show-coords) .coord-file {
    opacity: 0;
}

.coord-rank {
    top: 3px;
    left: 3px;
}

.coord-file {
    right: 3px;
    bottom: 3px;
}

.square.light .coord-rank,
.square.light .coord-file {
    color: rgba(26, 26, 26, 0.58);
}

.square.dark .coord-rank,
.square.dark .coord-file {
    color: rgba(232, 236, 242, 0.62);
}

.rules-overlay,
.promotion-overlay,
.surrender-overlay {
    position: fixed;
    inset: 0;
    z-index: 220;
    display: none;
    align-items: center;
    justify-content: center;
    background: rgba(3, 8, 13, 0.9);
    padding: 20px;
}

.checkmate-confirm-overlay {
    position: fixed;
    inset: 0;
    z-index: 220;
    display: none;
    pointer-events: none;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background: transparent !important;
}

#game-over {
    display: none;
}

#game-over.shared-game-over {
    display: flex;
}

.rules-overlay.show,
.promotion-overlay.show,
.surrender-overlay.show,
.checkmate-confirm-overlay.show {
    display: flex;
}

#rules-overlay {
    z-index: 280;
}

.rules-stack {
    width: min(94vw, 440px);
    display: grid;
    gap: 10px;
}

.rules-overlay:not(.dual-layout) .rules-content-p2 {
    display: none;
}

.rules-overlay.dual-layout .rules-stack {
    max-height: calc(100dvh - 40px);
    overflow-y: auto;
    padding-right: 2px;
}

.rules-overlay.dual-layout .rules-content-p2 {
    transform: rotate(180deg);
}

.rules-content,
.promotion-panel,
.surrender-content {
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.42);
    background: linear-gradient(180deg, #171717 0%, #0d0d0d 100%);
    box-shadow: 0 18px 38px rgba(0, 0, 0, 0.5);
    padding: 16px 16px 14px;
}

.rules-content {
    width: 100%;
}

.promotion-panel,
.surrender-content {
    width: min(94vw, 420px);
}

.rules-content h2,
.promotion-panel h2,
.surrender-content h2 {
    color: var(--accent-strong);
    margin-bottom: 10px;
    font-family: var(--game-font-family);
    text-align: center;
    font-size: clamp(1.02rem, 3.6vw, 1.16rem);
}

.rules-content ul {
    list-style: none;
    display: grid;
    gap: 8px;
    font-size: clamp(0.85rem, 3vw, 0.92rem);
    line-height: 1.45;
    color: #d9dce1;
    margin: 0;
    padding: 0;
}

.rules-content li {
    padding-left: 9px;
    border-left: 2px solid rgba(255, 255, 255, 0.62);
}

.close-rules-btn {
    margin-top: 14px;
    width: 100%;
    border: none;
    border-radius: 10px;
    padding: 11px 12px;
    font-family: var(--game-font-family);
    font-size: 0.98rem;
    color: #101214;
    background: linear-gradient(180deg, #f3f5f8 0%, #9197a0 100%);
    cursor: pointer;
}

.close-rules-btn:active {
    transform: scale(0.98);
}

.promotion-buttons {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
}

.promotion-btn {
    border: 1px solid rgba(255, 255, 255, 0.45);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.08);
    color: #f6f8fb;
    padding: 11px 10px;
    font-family: var(--game-font-family);
    font-size: 1rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    cursor: pointer;
}

.promotion-overlay.black-promotion-theme .promotion-panel {
    border-color: rgba(33, 43, 55, 0.28);
    background: linear-gradient(180deg, #f2f4f7 0%, #cdd4dd 100%);
}

.promotion-overlay.black-promotion-theme .promotion-panel h2 {
    color: #1e2731;
    text-shadow: none;
}

.promotion-overlay.black-promotion-theme .promotion-btn {
    border-color: rgba(32, 43, 56, 0.28);
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.92) 0%, rgba(227, 233, 240, 0.92) 100%);
    color: #1f2730;
}

.promotion-piece-image {
    width: 28px;
    height: 28px;
    display: block;
    object-fit: cover;
    object-position: center;
}

.promotion-btn:active {
    transform: scale(0.98);
}

.surrender-content {
    border-color: rgba(240, 109, 99, 0.65);
}

.checkmate-confirm-content {
    width: min(86vw, 340px);
    pointer-events: auto;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.5);
    background: linear-gradient(180deg, rgba(23, 23, 23, 0.72) 0%, rgba(13, 13, 13, 0.72) 100%);
    backdrop-filter: blur(2px);
    box-shadow: 0 18px 38px rgba(0, 0, 0, 0.5);
    padding: 18px;
    text-align: center;
}

.checkmate-confirm-overlay.is-stalemate .checkmate-confirm-content {
    border-color: rgba(174, 196, 220, 0.56);
    background: linear-gradient(180deg, rgba(29, 38, 52, 0.82) 0%, rgba(18, 25, 36, 0.84) 100%);
    box-shadow: 0 18px 40px rgba(8, 13, 20, 0.62);
}

.promotion-overlay.p2-perspective .promotion-panel,
.surrender-overlay.p2-perspective .surrender-content,
.checkmate-confirm-overlay.p2-perspective .checkmate-confirm-content {
    transform: rotate(180deg);
}

.checkmate-confirm-actions {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
}

.checkmate-confirm-icon {
    font-size: 2.4rem;
    line-height: 1;
    margin-bottom: 8px;
}

.checkmate-confirm-overlay.is-stalemate .checkmate-confirm-icon {
    color: #d7e6f8;
    text-shadow: 0 0 12px rgba(173, 198, 228, 0.35);
}

.checkmate-confirm-content h2 {
    color: var(--accent-strong);
    margin-bottom: 8px;
    font-family: var(--game-font-family);
}

.checkmate-confirm-overlay.is-stalemate .checkmate-confirm-content h2 {
    color: #dce8f7;
}

.checkmate-confirm-desc {
    color: #d5dae1;
    font-size: 0.95rem;
    margin-bottom: 14px;
}

.checkmate-confirm-overlay.is-stalemate .checkmate-confirm-desc {
    color: #c7d3e2;
}

.checkmate-confirm-btn {
    width: 100%;
    border: none;
    border-radius: 10px;
    padding: 11px 12px;
    font-family: var(--game-font-family);
    font-size: 1rem;
    color: #111315;
    background: linear-gradient(180deg, #f0f2f6 0%, #8d939c 100%);
    cursor: pointer;
}

.checkmate-confirm-overlay.is-stalemate .checkmate-confirm-btn {
    color: #172534;
    background: linear-gradient(180deg, #e9f2fb 0%, #9eb4ca 100%);
}

.checkmate-confirm-btn:active {
    transform: scale(0.98);
}

.checkmate-board-view-btn {
    width: 100%;
    border: none;
    border-radius: 10px;
    padding: 11px 12px;
    font-family: var(--game-font-family);
    font-size: 1rem;
    color: #f0f4fa;
    background: rgba(255, 255, 255, 0.16);
    cursor: pointer;
}

.checkmate-confirm-overlay.is-stalemate .checkmate-board-view-btn {
    color: #e6eef9;
    background: rgba(188, 210, 235, 0.22);
}

.checkmate-board-view-btn:active {
    transform: scale(0.98);
}

.checkmate-return-btn {
    display: none;
    position: fixed;
    left: 50%;
    bottom: max(16px, var(--app-safe-bottom));
    transform: translateX(-50%);
    border: none;
    border-radius: 999px;
    padding: 10px 16px;
    font-family: var(--game-font-family);
    font-size: 0.95rem;
    color: #111315;
    background: linear-gradient(180deg, #f0f2f6 0%, #8d939c 100%);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.35);
    cursor: pointer;
}

.checkmate-confirm-overlay.is-stalemate .checkmate-return-btn {
    color: #172534;
    background: linear-gradient(180deg, #e9f2fb 0%, #9eb4ca 100%);
}

.checkmate-confirm-overlay.p2-perspective .checkmate-return-btn {
    top: max(16px, env(safe-area-inset-top));
    bottom: auto;
    transform: translateX(-50%) rotate(180deg);
}

.checkmate-confirm-overlay.board-view .checkmate-confirm-content {
    display: none;
}

.checkmate-confirm-overlay.board-view {
    pointer-events: none;
}

.checkmate-confirm-overlay.board-view .checkmate-return-btn {
    display: block;
    pointer-events: auto;
}

.surrender-icon {
    font-size: 2.6rem;
    line-height: 1;
    text-align: center;
    margin-bottom: 10px;
}

.surrender-warning {
    color: #cfd6de;
    font-size: 0.9rem;
    margin-bottom: 14px;
    text-align: center;
}

.surrender-buttons {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
}

.surrender-cancel-btn,
.surrender-confirm-btn {
    border: none;
    border-radius: 10px;
    font-family: var(--game-font-family);
    font-size: 0.98rem;
    padding: 11px 12px;
    cursor: pointer;
}

.surrender-cancel-btn {
    background: rgba(255, 255, 255, 0.15);
    color: #f2f4f7;
}

.surrender-confirm-btn {
    background: linear-gradient(180deg, var(--danger) 0%, var(--danger-strong) 100%);
    color: #fff;
}

.surrender-cancel-btn:active,
.surrender-confirm-btn:active {
    transform: scale(0.98);
}

.shared-game-over #winner-score {
    display: block;
    margin: -10px 0 14px;
    color: #d5dae1;
    font-size: 0.98rem;
    font-family: var(--game-font-family);
}

#game-over .game-over-board-view-btn {
    display: block;
    width: 100%;
    max-width: 250px;
    margin: 6px auto 10px;
    padding: 10px 16px;
    border: 1px solid rgba(255, 255, 255, 0.34);
    border-radius: 999px;
    font-family: var(--game-font-family);
    font-size: 0.93rem;
    color: #eaf0f7;
    background: rgba(255, 255, 255, 0.1);
    cursor: pointer;
}

#game-over .game-over-board-view-btn:active {
    transform: scale(0.98);
}

#game-over .game-over-return-btn {
    display: none;
    position: fixed;
    left: 50%;
    bottom: max(16px, var(--app-safe-bottom));
    transform: translateX(-50%);
    border: none;
    border-radius: 999px;
    padding: 10px 16px;
    font-family: var(--game-font-family);
    font-size: 0.95rem;
    color: #101214;
    background: linear-gradient(180deg, #f3f5f8 0%, #9197a0 100%);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.35);
    cursor: pointer;
}

#game-over .game-over-return-btn:active {
    transform: translateX(-50%) scale(0.98);
}

#game-over.board-view {
    background: transparent;
    pointer-events: none;
}

#game-over.board-view .game-over-content {
    display: none;
}

#game-over.board-view .game-over-return-btn {
    display: block;
    pointer-events: auto;
}

#home-btn-container.board-view-disabled,
#surrender-btn-container.board-view-disabled {
    opacity: 0.45;
    filter: saturate(0.75);
    pointer-events: none;
}

@media (max-width: 900px) and (hover: none) {
    .player-section {
        min-height: 64px;
        padding-top: 2px;
        padding-bottom: 2px;
        padding-left: 6px;
        padding-right: 6px;
    }

    .opponent-section {
        min-height: 0;
        padding-top: var(--p2-edge-padding-top);
        padding-bottom: var(--p2-edge-padding-bottom);
    }

    .my-section {
        padding-top: 0;
        padding-bottom: var(--p1-bottom-edge-gap);
    }

    body.global-ad-banner-enabled .player-section {
        min-height: 58px;
        padding-top: 1px;
        padding-bottom: 1px;
    }

    body.global-ad-banner-enabled .opponent-section {
        min-height: 0;
        padding-top: var(--p2-edge-padding-top);
        padding-bottom: var(--p2-edge-padding-bottom);
    }

    body.global-ad-banner-enabled .my-section {
        padding-top: 0;
        padding-bottom: var(--p1-bottom-edge-gap);
    }

    .player-card {
        padding: 8px 9px;
        gap: 8px;
    }

    .center-section {
        justify-content: flex-start;
        padding-top: 0;
        --board-size: var(--board-size-override, min(var(--board-max-inline), max(220px, calc(100dvh - 292px - var(--app-safe-bottom))), 620px));
        --captured-piece-gap: 3px;
        --captured-piece-size: clamp(20px, calc((var(--board-size) - 64px) / 13), 32px);
    }

    .top-strip {
        margin-top: var(--p2-top-strip-gap);
        padding: 0 clamp(3px, calc(var(--controller-inline-size) * 0.012), 8px);
    }

    .captured-zone {
        padding: 0 3px;
    }

    .icon-btn {
        width: var(--top-control-btn-size);
        height: var(--top-control-btn-size);
    }

    .hold-btn-container {
        width: var(--top-control-btn-size);
        height: var(--top-control-btn-size);
    }
}

@media (max-height: 760px) {
    .player-section {
        min-height: 68px;
        padding: 3px 6px;
    }

    .opponent-section {
        min-height: 0;
        padding-top: var(--p2-edge-padding-top);
        padding-bottom: var(--p2-edge-padding-bottom);
    }

    .my-section {
        padding-top: 0;
        padding-bottom: var(--p1-bottom-edge-gap);
    }

    body.global-ad-banner-enabled .player-section {
        min-height: 62px;
        padding-top: 2px;
        padding-bottom: 2px;
    }

    body.global-ad-banner-enabled .opponent-section {
        min-height: 0;
        padding-top: var(--p2-edge-padding-top);
        padding-bottom: var(--p2-edge-padding-bottom);
    }

    body.global-ad-banner-enabled .my-section {
        padding-top: 0;
        padding-bottom: var(--p1-bottom-edge-gap);
    }

    .player-card {
        padding: 8px 10px;
    }

    .center-section {
        justify-content: flex-start;
        padding-top: 0;
        --board-size: var(--board-size-override, min(var(--board-max-inline), max(220px, calc(100dvh - 294px - var(--app-safe-bottom))), 580px));
    }

    .icon-btn {
        width: var(--top-control-btn-size);
        height: var(--top-control-btn-size);
    }

    .hold-btn-container {
        width: var(--top-control-btn-size);
        height: var(--top-control-btn-size);
    }
}

.game-container.layout-tight .player-section {
    min-height: 56px;
    padding-top: 1px;
    padding-bottom: 1px;
}

.game-container.layout-tight .opponent-section {
    min-height: 0;
    padding-top: var(--p2-edge-padding-top);
    padding-bottom: var(--p2-edge-padding-bottom);
}

.game-container.layout-tight .my-section {
    padding-top: 0;
    padding-bottom: var(--p1-bottom-edge-gap);
}

body.global-ad-banner-enabled .game-container.layout-tight .player-section {
    min-height: 52px;
    padding-top: 0;
    padding-bottom: 0;
}

body.global-ad-banner-enabled .game-container.layout-tight .opponent-section {
    min-height: 0;
    padding-top: var(--p2-edge-padding-top);
    padding-bottom: var(--p2-edge-padding-bottom);
}

body.global-ad-banner-enabled .game-container.layout-tight .my-section {
    padding-bottom: var(--p1-bottom-edge-gap);
}

.game-container.layout-tight .player-card {
    padding: 7px 8px;
    gap: 7px;
}

.game-container.layout-tight .center-section {
    gap: 6px;
    --captured-piece-gap: 3px;
    --captured-piece-size: clamp(19px, calc((var(--board-size) - 66px) / 13), 30px);
}

.game-container.layout-tight .top-strip {
    margin-top: var(--p2-top-strip-gap);
    padding: 0 clamp(2px, calc(var(--controller-inline-size) * 0.01), 6px);
}

.game-container.layout-tight .captured-zone {
    padding: 0 2px;
}

.game-container.layout-tight .icon-btn {
    width: var(--top-control-btn-size);
    height: var(--top-control-btn-size);
}

.game-container.layout-tight .hold-btn-container {
    width: var(--top-control-btn-size);
    height: var(--top-control-btn-size);
}

.game-container.layout-ultra-tight .player-section {
    min-height: 50px;
    padding-top: 0;
    padding-bottom: 0;
}

.game-container.layout-ultra-tight .opponent-section {
    min-height: 0;
    padding-top: var(--p2-edge-padding-top);
    padding-bottom: var(--p2-edge-padding-bottom);
}

.game-container.layout-ultra-tight .my-section {
    padding-bottom: var(--p1-bottom-edge-gap);
}

body.global-ad-banner-enabled .game-container.layout-ultra-tight .player-section {
    min-height: 48px;
    padding-top: 0;
    padding-bottom: 0;
}

body.global-ad-banner-enabled .game-container.layout-ultra-tight .opponent-section {
    min-height: 0;
    padding-top: var(--p2-edge-padding-top);
    padding-bottom: var(--p2-edge-padding-bottom);
}

.game-container.layout-ultra-tight .player-card {
    padding: 6px 7px;
    gap: 6px;
    border-radius: 12px;
}

.game-container.layout-ultra-tight .player-emoji {
    font-size: 1.45rem;
}

.game-container.layout-ultra-tight .player-name {
    font-size: 0.92rem;
}

.game-container.layout-ultra-tight .player-meta {
    font-size: 0.78rem;
}

.game-container.layout-ultra-tight .center-section {
    gap: 4px;
    --captured-piece-gap: 2px;
    --captured-piece-size: clamp(17px, calc((var(--board-size) - 72px) / 13), 28px);
}

.game-container.layout-ultra-tight .top-strip {
    margin-top: var(--p2-top-strip-gap);
    padding: 0 clamp(1px, calc(var(--controller-inline-size) * 0.008), 4px);
}

.game-container.layout-ultra-tight .captured-zone {
    min-height: calc(var(--captured-track-height) + 1px);
    padding: 0 1px;
}

.game-container.layout-ultra-tight .icon-btn {
    width: var(--top-control-btn-size);
    height: var(--top-control-btn-size);
}

.game-container.layout-ultra-tight .hold-btn-container {
    width: var(--top-control-btn-size);
    height: var(--top-control-btn-size);
}

@media (hover: hover) and (pointer: fine) {
    .icon-btn:hover,
    .hold-btn-container:hover,
    .promotion-btn:hover,
    .close-rules-btn:hover,
    .surrender-cancel-btn:hover,
    .surrender-confirm-btn:hover,
    .checkmate-confirm-btn:hover,
    .checkmate-board-view-btn:hover,
    .checkmate-return-btn:hover {
        filter: brightness(1.08);
    }
}

@keyframes entry-start-pulse {
    0% {
        box-shadow: 0 0 16px rgba(255, 255, 255, 0.16), 0 8px 20px rgba(0, 0, 0, 0.45);
    }

    50% {
        box-shadow: 0 0 24px rgba(255, 255, 255, 0.36), 0 10px 22px rgba(0, 0, 0, 0.56);
    }

    100% {
        box-shadow: 0 0 16px rgba(255, 255, 255, 0.16), 0 8px 20px rgba(0, 0, 0, 0.45);
    }
}

@keyframes entry-start-sweep {
    0% {
        left: -70%;
    }

    100% {
        left: 132%;
    }
}

@keyframes chess-turn-announce {
    0% {
        opacity: 0;
        transform: translate(-50%, -50%) rotate(var(--turn-announcement-rotation, 0deg)) scale(0.82);
    }

    16% {
        opacity: 1;
        transform: translate(-50%, -50%) rotate(var(--turn-announcement-rotation, 0deg)) scale(1.03);
    }

    68% {
        opacity: 1;
        transform: translate(-50%, -50%) rotate(var(--turn-announcement-rotation, 0deg)) scale(1);
    }

    100% {
        opacity: 0;
        transform: translate(-50%, -50%) rotate(var(--turn-announcement-rotation, 0deg)) scale(0.95);
    }
}

@keyframes chess-skill-popup {
    0% {
        opacity: 0;
        transform: translate(-50%, -92%) rotate(var(--square-popup-rotation, 0deg)) scale(0.88);
    }

    18% {
        opacity: 1;
        transform: translate(-50%, -118%) rotate(var(--square-popup-rotation, 0deg)) scale(1.02);
    }

    72% {
        opacity: 1;
        transform: translate(-50%, -126%) rotate(var(--square-popup-rotation, 0deg)) scale(1);
    }

    100% {
        opacity: 0;
        transform: translate(-50%, -138%) rotate(var(--square-popup-rotation, 0deg)) scale(0.97);
    }
}

/* Othello board overrides */
.othello-board {
    width: 100%;
    height: 100%;
    display: grid;
    grid-template-columns: repeat(8, minmax(0, 1fr));
    grid-template-rows: repeat(8, minmax(0, 1fr));
    border-radius: 8px;
    overflow: hidden;
    border: 2px solid rgba(6, 28, 17, 0.55);
    background: #00853d;
}

.othello-board.rotated {
    transform: rotate(180deg);
}

.othello-board .square {
    position: relative;
    border: 1px solid rgba(8, 28, 18, 0.58);
    appearance: none;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    aspect-ratio: 1 / 1;
    touch-action: manipulation;
    background: #00853d;
}

.othello-board .square.selected {
    box-shadow:
        inset 0 0 0 2px rgba(219, 255, 170, 0.9),
        inset 0 0 0 4px rgba(24, 68, 42, 0.42);
}

.othello-board .square.last-to {
    box-shadow: inset 0 0 0 2px rgba(197, 255, 146, 0.86);
}

.othello-board .square.legal::after {
    content: '';
    position: absolute;
    width: 22%;
    height: 22%;
    border-radius: 50%;
    border: 2px solid rgba(228, 255, 203, 0.84);
    background: rgba(210, 255, 174, 0.52);
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.35);
    pointer-events: none;
}

.coord-rank,
.coord-file {
    display: none !important;
}

.piece-disc {
    width: 93%;
    height: 93%;
    --disc-front-bg: #000000;
    --disc-front-ring: #000000;
    --disc-back-bg: #ffffff;
    --disc-back-ring: #ffffff;
    border-radius: 50%;
    display: block;
    position: relative;
    transform: rotateY(0deg);
    transform-style: preserve-3d;
    -webkit-backface-visibility: visible;
    backface-visibility: visible;
    will-change: transform;
}

.othello-board .piece {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    perspective: 520px;
    transform-style: preserve-3d;
}

.othello-board .piece.has-piece {
    opacity: 1;
}

.piece-disc .disc-face {
    position: absolute;
    inset: 0;
    border-radius: 50%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
}

.piece-disc .front-face {
    transform: rotateY(0deg);
    background: var(--disc-front-bg);
    border: none;
    box-shadow: none;
}

.piece-disc .back-face {
    transform: rotateY(180deg);
    background: var(--disc-back-bg);
    border: none;
    box-shadow: none;
}

.piece-disc.is-white {
    transform: rotateY(180deg);
}

.piece-disc.is-flipping {
    transition: transform var(--disc-flip-duration, 560ms) cubic-bezier(0.2, 0.72, 0.2, 1);
}

.piece-disc:not(.is-flipping) {
    transition: none;
}

/* Othello green theme base */
:root {
    --bg-top: #0b2f2b;
    --bg-mid: #155046;
    --bg-bottom: #236459;
    --accent: #96ebc3;
    --accent-strong: #ecfff5;
    --panel: rgba(17, 84, 56, 0.44);
    --panel-border: rgba(166, 242, 208, 0.34);
}

body {
    background:
        radial-gradient(circle at 16% 14%, rgba(170, 236, 211, 0.2) 0%, rgba(170, 236, 211, 0) 42%),
        radial-gradient(circle at 84% 86%, rgba(118, 199, 168, 0.18) 0%, rgba(118, 199, 168, 0) 40%),
        linear-gradient(180deg, #0b2f2b 0%, #155046 48%, #236459 100%);
}

.player-card {
    background: linear-gradient(180deg, rgba(25, 101, 68, 0.72) 0%, rgba(14, 69, 45, 0.78) 100%);
    border-color: rgba(166, 242, 208, 0.34);
}

.player-card.is-neutral-side {
    background: linear-gradient(180deg, rgba(47, 126, 88, 0.82) 0%, rgba(21, 83, 55, 0.86) 100%);
    border-color: rgba(188, 255, 225, 0.42);
}

.player-card.is-active-player {
    border-color: rgba(216, 255, 237, 0.9);
    box-shadow: 0 0 0 1px rgba(222, 255, 240, 0.28), 0 12px 28px rgba(8, 43, 28, 0.3), 0 0 24px rgba(90, 214, 150, 0.36);
}

.player-card.is-active-player.is-black-side {
    border-color: rgba(61, 69, 79, 0.96);
    box-shadow: 0 0 0 1px rgba(56, 71, 63, 0.28), 0 12px 28px rgba(7, 31, 21, 0.32), 0 0 24px rgba(90, 214, 150, 0.28);
}

.player-card.is-inactive-player {
    border-color: rgba(18, 87, 57, 0.82);
    box-shadow: inset 0 0 0 1px rgba(9, 50, 33, 0.56);
}

.player-card.is-inactive-player.is-white-side {
    background: linear-gradient(180deg, rgba(236, 239, 244, 0.98) 0%, rgba(214, 220, 228, 0.98) 100%);
    border-color: rgba(192, 200, 210, 0.94);
    box-shadow: inset 0 0 0 1px rgba(247, 249, 252, 0.68);
}

.player-card.is-inactive-player.is-black-side {
    background: linear-gradient(180deg, rgba(46, 50, 56, 0.96) 0%, rgba(19, 22, 26, 0.99) 100%);
    border-color: rgba(49, 54, 60, 0.86);
    box-shadow: inset 0 0 0 1px rgba(4, 6, 8, 0.62);
}

.entry-start-btn {
    border-color: transparent;
    background: linear-gradient(180deg, rgba(66, 212, 142, 0.98) 0%, rgba(28, 146, 92, 0.98) 100%);
    color: #111315;
    box-shadow: 0 0 20px rgba(35, 141, 93, 0.36), 0 8px 20px rgba(9, 52, 33, 0.5);
}

.top-strip .icon-btn,
.top-strip #rules-btn {
    border-color: rgba(171, 244, 206, 0.52);
    background: linear-gradient(180deg, rgba(32, 118, 78, 0.96) 0%, rgba(19, 82, 54, 0.96) 100%);
    color: #edfff5;
}

.hold-btn-bg {
    stroke: rgba(170, 244, 206, 0.22);
}

.board-shell {
    border-color: rgba(171, 244, 206, 0.34);
    background: linear-gradient(180deg, rgba(41, 126, 86, 0.46) 0%, rgba(20, 78, 52, 0.9) 100%);
    box-shadow: 0 14px 30px rgba(8, 56, 35, 0.44);
}

.disc-count-label {
    color: #f1fff8;
    text-shadow: 0 1px 2px rgba(10, 62, 38, 0.46);
}

.rules-content,
.surrender-content {
    border-color: rgba(168, 239, 203, 0.4);
    background: linear-gradient(180deg, rgba(20, 90, 60, 0.94) 0%, rgba(10, 58, 38, 0.97) 100%);
}

.rules-content h2,
.surrender-content h2 {
    color: #eefff7;
}

.rules-content ul,
.surrender-warning {
    color: #ddf7ea;
}

.rules-content li {
    border-left-color: rgba(179, 245, 211, 0.66);
}

.close-rules-btn {
    color: #f2fff8;
    background: linear-gradient(180deg, rgba(53, 201, 132, 0.97) 0%, rgba(24, 137, 86, 0.98) 100%);
}