:root {
    --primary: #00d4ff;
    --secondary: #ff6b4a;
    --accent: #a855f7;
    --bg-dark: #0a0e1a;
    --bg-card: rgba(15, 23, 42, 0.6);
    --border: rgba(255, 255, 255, 0.1);
    --text-primary: #ffffff;
    --text-secondary: #8b9dc3;

    --x-color: #ff6b4a;
    --o-color: #00d4ff;
    --x-glow: rgba(255, 107, 74, 0.6);
    --o-glow: rgba(0, 212, 255, 0.6);

    --space-xs: 0.5rem;
    --space-sm: 0.75rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;

    --font-sans: Inter, system-ui, sans-serif;

    --card-bg: rgba(20, 30, 50, 0.8);
    --card-border: rgba(100, 150, 255, 0.2);
    --blur-md: blur(12px);
    --blur-lg: blur(20px);
    --glow-x: 0 0 20px rgba(255, 107, 74, 0.6), 0 0 40px rgba(255, 107, 74, 0.3);
    --glow-o: 0 0 20px rgba(0, 212, 255, 0.6), 0 0 40px rgba(0, 212, 255, 0.3);

    --border-radius: 16px;
    --border-radius-sm: 8px;
    --border-radius-lg: 24px;
    --border-radius-pill: 50px;
    --transition-speed: 0.3s;
    --transition-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
    --cell-size: 100px;
    --gap-size: 12px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-sans);
    background: #0a0e1a;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    position: relative;
    overflow-x: hidden;
    color: var(--text-primary);
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(168, 85, 247, 0.12) 0%, transparent 50%),
        radial-gradient(circle at 80% 50%, rgba(0, 212, 255, 0.12) 0%, transparent 50%),
        linear-gradient(135deg, #0a0e1a 0%, #1a1a2e 50%, #16213e 100%);
    pointer-events: none;
    z-index: 0;
}

.container,
.input-container,
.name-page-leaderboard,
.name-form,
.online-view,
.scoreboard,
.game-area,
.leaderboard-toggle-btn,
.leaderboard-panel,
.modal-content {
    background: var(--bg-card);
    border: 1px solid var(--border);
    backdrop-filter: var(--blur-md);
    border-radius: var(--border-radius);
}

.name-input-screen,
.game-wrapper,
.container,
.input-wrapper,
.input-container {
    position: relative;
    z-index: 1;
}

.name-input-screen {
    min-height: 100vh;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.input-wrapper {
    width: 100%;
    max-width: 920px;
    display: flex;
    align-items: flex-start;
    gap: var(--space-lg);
}

.input-container {
    flex: 1;
    max-width: 520px;
    padding: 20px;
}

.name-page-leaderboard {
    width: 260px;
    padding: var(--space-lg);
}

.header {
    text-align: center;
    margin-bottom: var(--space-lg);
}

.title {
    font-size: clamp(2rem, 5vw, 2.7rem);
    font-weight: 800;
    letter-spacing: 0.03em;
    background: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: var(--space-xs);
}

.mode-selector {
    display: flex;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    border-radius: 50px;
    padding: 4px;
    gap: 4px;
    margin-top: 20px;
    margin-bottom: 20px;
}

.mode-btn {
    flex: 1;
    padding: 0.65rem 1.25rem;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    background: transparent;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.2rem;
}

.mode-btn.active {
    background: linear-gradient(135deg, var(--accent) 0%, var(--primary) 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(168, 85, 247, 0.4);
}

.mode-desc {
    font-size: 0.65rem;
    opacity: 0.8;
    font-weight: 400;
}

.name-form,
.online-view {
    padding: 24px 20px;
}

.input-group {
    margin-bottom: var(--space-lg);
}

.input-label {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.label-mark {
    width: 28px;
    height: 28px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    font-weight: 800;
}

.label-mark.x-mark {
    color: var(--x-color);
    background: rgba(255, 107, 74, 0.15);
}

.label-mark.o-mark {
    color: var(--o-color);
    background: rgba(0, 212, 255, 0.15);
}

.name-input {
    width: 100%;
    padding: 0.9rem 1rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    background: rgba(15, 23, 42, 0.85);
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: all var(--transition-speed) ease;
}

.name-input::placeholder {
    color: rgba(139, 157, 195, 0.7);
}

.name-input:focus {
    border-color: rgba(0, 212, 255, 0.5);
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.15);
}

.start-button,
.reset-button,
.modal-btn {
    border: none;
    cursor: pointer;
    font-weight: 700;
    transition: all var(--transition-speed) ease;
}

.start-button {
    width: 100%;
    padding: 0.95rem var(--space-md);
    border-radius: 12px;
    color: white;
    letter-spacing: 0.02em;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.start-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(118, 75, 162, 0.45);
}

.online-toggle-link,
.copy-btn,
.cancel-btn {
    width: 100%;
    border-radius: 10px;
    padding: 0.75rem 1rem;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-primary);
    cursor: pointer;
}

.online-toggle-link {
    margin-top: var(--space-sm);
}

.waiting-view {
    text-align: center;
    padding: var(--space-2xl) var(--space-xl);
}

.waiting-spinner {
    width: 56px;
    height: 56px;
    border: 4px solid rgba(0, 212, 255, 0.1);
    border-top-color: var(--primary);
    border-radius: 50%;
    margin: 0 auto var(--space-xl);
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.waiting-text {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.room-code-display {
    margin-bottom: var(--space-lg);
}

.room-code-label {
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
}

.room-code-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
}

.room-code-value {
    font-size: 2.5rem;
    font-weight: 800;
    font-family: "Courier New", monospace;
    letter-spacing: 0.3em;
    color: var(--primary);
    text-shadow: var(--glow-o);
}

.game-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-lg);
    max-width: 520px;
    width: 100%;
    margin: 0 auto;
    padding-bottom: 20px;
}

.side-scoreboard {
    display: none;
}

.container {
    width: 100%;
}

.scoreboard {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-md);
    width: 100%;
    background: var(--card-bg);
    backdrop-filter: var(--blur-md);
    border: 1px solid var(--card-border);
    border-radius: var(--border-radius);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    padding: var(--space-md) var(--space-xl);
    margin-bottom: var(--space-md);
}

.score-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    flex: 1;
}

.score-label {
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 600;
}

.score-value {
    font-size: 2.3rem;
    font-weight: 800;
    line-height: 1;
    transition: transform 0.3s ease;
}

.score-value.x-score {
    color: var(--x-color);
    text-shadow: var(--glow-x);
}

.score-value.o-score {
    color: var(--o-color);
    text-shadow: var(--glow-o);
}

.score-value.scored {
    animation: score-bump 0.4s ease-out;
}

@keyframes score-bump {
    0% { transform: scale(1); }
    50% { transform: scale(1.25); }
    100% { transform: scale(1); }
}

.score-divider {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 0 var(--space-md);
}

.vs-text {
    font-size: 1.1rem;
    font-weight: 800;
    color: var(--text-secondary);
    letter-spacing: 2px;
}

.target-score {
    font-size: 0.74rem;
    color: var(--text-secondary);
    opacity: 0.85;
}

.game-area {
    background: var(--card-bg);
    backdrop-filter: var(--blur-md);
    border: 1px solid var(--card-border);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(255, 255, 255, 0.05) inset;
    padding: var(--space-lg);
    width: 100%;
    margin-bottom: var(--space-lg);
}

.status-bar {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: left;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.turn-indicator {
    display: inline-flex;
    align-items: center;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-secondary);
    padding: var(--space-xs) var(--space-lg);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius-pill);
    white-space: nowrap;
    transition: all var(--transition-speed) ease;
    animation: subtle-pulse 2s ease-in-out infinite;
}

@keyframes subtle-pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.8;
        transform: scale(0.98);
    }
}

.player-mark {
    font-size: 1.15rem;
    font-weight: 800;
}

.online-indicator {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: 0.4rem var(--space-md);
    background: rgba(107, 203, 119, 0.15);
    border: 1px solid rgba(107, 203, 119, 0.4);
    border-radius: 50px;
    font-size: 0.85rem;
    color: #6bcb77;
}

.online-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #6bcb77;
}

.online-dot.disconnected {
    background: var(--secondary);
}

.board {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--gap-size);
    margin: 0 auto var(--space-lg);
    max-width: calc(var(--cell-size) * 3 + var(--gap-size) * 2);
}

.cell {
    width: var(--cell-size);
    height: var(--cell-size);
    background: rgba(15, 23, 42, 0.8);
    border: 2px solid rgba(255, 255, 255, 0.08);
    border-radius: 14px;
    font-size: 2.5rem;
    font-weight: 800;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
}

.cell:hover:not(:disabled) {
    background: rgba(30, 50, 80, 0.9);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

.cell:disabled {
    cursor: not-allowed;
}

.cell.x {
    color: var(--x-color);
    text-shadow: var(--glow-x);
}

.cell.o {
    color: var(--o-color);
    text-shadow: var(--glow-o);
}

.cell.winner {
    animation: winner-pulse 0.8s ease-in-out infinite;
}

@keyframes winner-pulse {
    0%, 100% { transform: scale(1); box-shadow: 0 0 20px rgba(255, 215, 0, 0.3); }
    50% { transform: scale(1.06); box-shadow: 0 0 40px rgba(255, 215, 0, 0.6); }
}

.cell.marked {
    animation: scaleIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.result-message {
    min-height: 1.8rem;
    text-align: center;
    margin-bottom: var(--space-md);
    font-size: 1.2rem;
    font-weight: 700;
    opacity: 0;
    transform: translateY(-8px);
    transition: all var(--transition-speed) ease;
}

.result-message.show {
    opacity: 1;
    transform: translateY(0);
}

.result-message.winner {
    color: var(--x-color);
    text-shadow: var(--glow-x);
}

.result-message.draw {
    color: var(--text-secondary);
}

.countdown-display,
.match-winner-display {
    text-align: center;
    margin-bottom: var(--space-md);
    padding: var(--space-md);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
}

.countdown-number {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
}

.winner-name {
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--secondary);
}

.new-match-countdown {
    margin-top: var(--space-xs);
}

.button-group {
    display: flex;
    gap: var(--space-md);
    width: 100%;
}

.reset-button {
    flex: 1;
    padding: 0.9rem var(--space-md);
    font-size: 0.95rem;
    color: white;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px;
    letter-spacing: 0.5px;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.reset-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(118, 75, 162, 0.5);
    filter: brightness(1.1);
}

.reset-button.secondary {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    box-shadow: none;
}

.reset-button.secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.2);
    box-shadow: 0 4px 15px rgba(255, 255, 255, 0.05);
}

.footer {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.82rem;
    margin-top: var(--space-md);
    padding: var(--space-md) 20px;
    width: 100%;
}

.leaderboard-toggle {
    width: 100%;
    position: relative;
}

.leaderboard-toggle-btn {
    width: 100%;
    padding: var(--space-md) var(--space-xl);
    background: var(--card-bg);
    backdrop-filter: var(--blur-md);
    border: 1px solid var(--card-border);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: all var(--transition-speed) ease;
    letter-spacing: 0.5px;
}

.leaderboard-toggle-btn:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.leaderboard-toggle-btn:active {
    transform: translateY(0);
}

.toggle-arrow {
    transition: transform var(--transition-speed) var(--transition-bounce);
    display: inline-block;
    font-size: 0.75rem;
}

.leaderboard-toggle-btn.open .toggle-arrow {
    transform: rotate(180deg);
}

.leaderboard-panel {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    background: var(--card-bg);
    backdrop-filter: var(--blur-md);
    border: 1px solid var(--card-border);
    border-top: none;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
}

.leaderboard-panel.open {
    max-height: 500px;
    overflow-y: auto;
    padding: 20px;
}

.leaderboard-panel.open::-webkit-scrollbar {
    width: 6px;
}

.leaderboard-panel.open::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 3px;
}

.leaderboard-panel.open::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

.leaderboard-panel.open::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

.leaderboard-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.scoreboard-title {
    text-align: center;
    margin-bottom: var(--space-md);
    font-size: 1.05rem;
}

.leaderboard-entry {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm);
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    background: rgba(15, 23, 42, 0.65);
}

.leaderboard-rank {
    width: 28px;
    height: 28px;
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 0.85rem;
    color: #0f172a;
    background: #94a3b8;
}

.leaderboard-rank.rank-1 { background: #fbbf24; }
.leaderboard-rank.rank-2 { background: #cbd5e1; }
.leaderboard-rank.rank-3 { background: #d97706; }

.leaderboard-player {
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.leaderboard-wins {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.empty-message {
    text-align: center;
    color: var(--text-secondary);
    opacity: 0.85;
    padding: var(--space-sm) 0;
}

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-speed) ease;
}

.modal-overlay.show {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    width: min(92vw, 420px);
    padding: var(--space-xl);
    transform: scale(0.96);
    transition: transform var(--transition-speed) ease;
}

.modal-overlay.show .modal-content {
    transform: scale(1);
}

.modal-title {
    margin-bottom: var(--space-sm);
}

.modal-message {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.modal-actions {
    display: flex;
    gap: var(--space-sm);
}

.modal-btn {
    flex: 1;
    border-radius: 10px;
    padding: 0.85rem;
    color: white;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.modal-btn.cancel {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--border);
}

#confetti-canvas {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.scoreboard {
    animation: slideInUp 0.5s ease-out backwards;
}

.game-area {
    animation: slideInUp 0.5s ease-out 0.1s backwards;
}

.leaderboard-toggle {
    animation: slideInUp 0.5s ease-out 0.2s backwards;
}

.score-card {
    animation: slideInUp 0.4s ease-out backwards;
}

.score-card:nth-child(1) {
    animation-delay: 0.15s;
}

.score-card:nth-child(2) {
    animation-delay: 0.2s;
}

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.85); }
    to { opacity: 1; transform: scale(1); }
}

.cell:focus,
.reset-button:focus,
.name-input:focus,
.start-button:focus,
.modal-btn:focus,
.leaderboard-toggle-btn:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

@media (max-width: 1024px) {
    .input-wrapper {
        max-width: 640px;
        flex-direction: column;
        align-items: center;
    }

    .name-page-leaderboard {
        width: 100%;
        max-width: 520px;
    }
}

@media (max-width: 768px) {
    :root {
        --cell-size: 86px;
        --gap-size: 10px;
    }

    .game-area {
        padding: var(--space-lg);
    }

    .status-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .turn-indicator {
        justify-content: center;
    }

    .online-indicator {
        margin-left: 0;
        justify-content: center;
    }

    .button-group {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    :root {
        --cell-size: 76px;
        --gap-size: 8px;
    }

    body {
        padding: 14px;
    }

    .game-wrapper {
        padding: var(--space-md);
        gap: var(--space-md);
    }

    .name-form,
    .online-view {
        padding: var(--space-md);
    }

    .game-area {
        padding: var(--space-md);
    }

    .scoreboard {
        padding: var(--space-sm) var(--space-md);
        gap: var(--space-sm);
        flex-direction: column;
    }

    .status-bar {
        flex-direction: column;
        gap: var(--space-sm);
        margin-bottom: var(--space-md);
        align-items: center;
    }

    .turn-indicator {
        font-size: 0.85rem;
        padding: var(--space-xs) var(--space-md);
    }

    .leaderboard-toggle-btn {
        padding: var(--space-sm) var(--space-md);
        font-size: 0.9rem;
    }

    .score-value {
        font-size: 2rem;
    }

    .cell {
        width: 80px;
        height: 80px;
        font-size: 2rem;
    }

    .room-code-value {
        font-size: 1.7rem;
        letter-spacing: 0.18em;
    }
}

@media (max-width: 375px) {
    :root {
        --cell-size: 70px;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}