:root {
    --bg-color: #1c232b;
    --grid-color: #3c465a;
    --p1-color: #ff6b6b;
    --p1-territory: rgba(100, 30, 30, 0.6);
    --p1-territory-border: rgba(255, 107, 107, 0.3);
    --p2-color: #6bb2ff;
    --p2-territory: rgba(30, 60, 100, 0.6);
    --p2-territory-border: rgba(107, 178, 255, 0.3);
    --highlight: #ffd700;
    --text-color: #f0f0f0;
    --btn-color: #4682b4;
    --btn-hover: #64a0d2;
    --cell-size: 50px;
    --gap-size: 4px;
}

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

body {
    font-family: 'Segoe UI', 'Microsoft YaHei', system-ui, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
}

.app-shell {
    width: 100%;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.loading-text,
.loading-error {
    color: var(--text-color);
    font-size: 1.1rem;
}

.loading-error {
    color: #ff6b6b;
}

.screen-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-color);
    z-index: 200;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    transition: opacity 0.3s;
}

.hidden {
    display: none !important;
}

.menu-card {
    background: #2c3e50;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
    text-align: center;
    width: 90%;
    max-width: 400px;
    border: 1px solid #4a6075;
}

.menu-card .rules {
    margin-top: 25px;
    padding: 15px;
    background: #1c232b;
    border: 1px solid #4a6075;
    border-radius: 10px;
    font-size: 0.85rem;
    text-align: left;
    line-height: 1.4;
}
.menu-card .rules h2 {
    margin: 0 0 10px;
    font-size: 1.1rem;
    color: var(--highlight);
}
.menu-card .rules ul {
    margin: 0;
    padding-left: 18px;
}
.menu-card .rules li {
    margin: 4px 0;
}

h1 {
    margin: 0 0 30px 0;
    font-size: 2rem;
    color: var(--text-color);
}

h2 {
    margin-top: 0;
    color: var(--highlight);
}

.menu-btn {
    display: block;
    width: 100%;
    padding: 15px;
    margin: 10px 0;
    border: none;
    border-radius: 8px;
    background: var(--btn-color);
    color: white;
    font-size: 1.1rem;
    cursor: pointer;
    transition: transform 0.1s, background 0.2s;
}

.menu-btn:hover {
    background: var(--btn-hover);
    transform: scale(1.02);
}

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

.menu-btn.secondary {
    background: #4a5568;
}

input.room-input {
    width: 100%;
    padding: 15px;
    margin: 10px 0 20px;
    border-radius: 8px;
    border: 2px solid #4a6075;
    background: #1c232b;
    color: white;
    font-size: 1.1rem;
    text-align: center;
}

.status-bar {
    display: flex;
    justify-content: space-between;
    width: 100%;
    max-width: 500px;
    margin-bottom: 15px;
    background: rgba(0, 0, 0, 0.2);
    padding: 10px 20px;
    border-radius: 12px;
    font-weight: bold;
}

.player-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 5px 12px;
    border-radius: 20px;
    transition: all 0.3s ease;
    opacity: 0.5;
}

.player-indicator.active {
    background: rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
    opacity: 1;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    display: inline-block;
}

.p1-text {
    color: var(--p1-color);
}

.p2-text {
    color: var(--p2-color);
}

.dot.p1 {
    background: var(--p1-color);
}

.dot.p2 {
    background: var(--p2-color);
}

.board-container {
    position: relative;
    padding: 10px;
    background: #252d38;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.board {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: var(--gap-size);
    background-color: var(--grid-color);
    border: 2px solid var(--grid-color);
}

.cell {
    width: var(--cell-size);
    height: var(--cell-size);
    background-color: var(--bg-color);
    position: relative;
    cursor: pointer;
    transition: background-color 0.2s;
}

.cell:not(.has-piece):hover {
    background-color: #2a3544;
}

.cell::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    width: 70%;
    height: 70%;
    border-radius: 50%;
    transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.4);
}

.cell.p1::after {
    background-color: var(--p1-color);
    transform: translate(-50%, -50%) scale(1);
}

.cell.p2::after {
    background-color: var(--p2-color);
    transform: translate(-50%, -50%) scale(1);
}

.cell.territory-p1 {
    background-color: var(--p1-territory);
    box-shadow: inset 0 0 0 1px var(--p1-territory-border);
}

.cell.territory-p2 {
    background-color: var(--p2-territory);
    box-shadow: inset 0 0 0 1px var(--p2-territory-border);
}

.cell.last-move::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border: 2px solid var(--highlight);
    border-radius: 4px;
    animation: pulse 1.5s infinite;
    pointer-events: none;
    z-index: 10;
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

.info-panel {
    margin-top: 20px;
    text-align: center;
    font-size: 1.1rem;
}

.moves-left {
    margin-top: 10px;
    font-size: 0.9rem;
    color: #888;
}

.back-btn {
    position: absolute;
    top: 20px;
    left: 20px;
    background: none;
    border: 1px solid #4a6075;
    color: #888;
    padding: 5px 15px;
    border-radius: 5px;
    cursor: pointer;
}

@media (max-width: 600px) {
    :root {
        --cell-size: 9vw;
        --gap-size: 2px;
    }

    .status-bar {
        flex-direction: column;
        align-items: center;
        gap: 10px;
    }
}

.floating-btn {
    position: fixed;
    right: 20px;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
    transition: all 0.3s;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 8px;
}

.github-btn {
    bottom: 80px;
    background: #24292e;
}

.github-btn:hover {
    background: #343a40;
    transform: scale(1.05) translateY(-2px);
}

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

.export-btn {
    bottom: 20px;
    background: #27ae60;
}

.export-btn:hover {
    background: #2ecc71;
    transform: scale(1.05) translateY(-2px);
}

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