/* CSS Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #64748b;
    --background: #0f172a;
    --surface: #1e293b;
    --surface-light: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --player-x: #f472b6;
    --player-o: #22d3ee;
    --draw-color: #fbbf24;
    --success: #22c55e;
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
header {
    text-align: center;
    padding: 20px 0;
}

header h1 {
    font-size: 2.5rem;
    background: linear-gradient(135deg, var(--player-x), var(--player-o));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
    letter-spacing: 2px;
}

/* Main Content */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

/* Mode Selection */
.mode-selection {
    text-align: center;
    animation: fadeIn 0.5s ease;
}

.mode-selection h2 {
    font-size: 1.5rem;
    margin-bottom: 30px;
    color: var(--text-secondary);
}

.mode-buttons {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.mode-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 30px 40px;
    background: var(--surface);
    border: 2px solid var(--surface-light);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-primary);
}

.mode-btn:hover {
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.2);
}

.mode-icon {
    font-size: 3rem;
}

.mode-text {
    font-size: 1.1rem;
    font-weight: 600;
}

/* Game Area */
.game-area {
    width: 100%;
    animation: fadeIn 0.5s ease;
}

/* Scoreboard */
.scoreboard {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 20px;
}

.score-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 15px 25px;
    background: var(--surface);
    border-radius: var(--border-radius);
    min-width: 100px;
}

.score-card.player-x {
    border-bottom: 3px solid var(--player-x);
}

.score-card.player-o {
    border-bottom: 3px solid var(--player-o);
}

.score-card.draws {
    border-bottom: 3px solid var(--draw-color);
}

.player-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.score {
    font-size: 1.8rem;
    font-weight: 700;
}

.player-x .score {
    color: var(--player-x);
}

.player-o .score {
    color: var(--player-o);
}

.draws .score {
    color: var(--draw-color);
}

/* Turn Display */
.turn-display {
    text-align: center;
    margin-bottom: 20px;
    padding: 10px 20px;
    background: var(--surface);
    border-radius: var(--border-radius);
}

#turnIndicator {
    font-size: 1.2rem;
    font-weight: 600;
}

.turn-display.player-x-turn #turnIndicator {
    color: var(--player-x);
}

.turn-display.player-o-turn #turnIndicator {
    color: var(--player-o);
}

/* Game Board */
.board {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    max-width: 350px;
    margin: 0 auto 30px;
    padding: 15px;
    background: var(--surface);
    border-radius: var(--border-radius);
}

.cell {
    aspect-ratio: 1;
    background: var(--surface-light);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    user-select: none;
}

.cell:hover:not(.taken) {
    background: #475569;
    transform: scale(1.05);
}

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

.cell.x {
    color: var(--player-x);
    text-shadow: 0 0 20px rgba(244, 114, 182, 0.5);
}

.cell.o {
    color: var(--player-o);
    text-shadow: 0 0 20px rgba(34, 211, 238, 0.5);
}

.cell.winner {
    animation: pulse 0.5s ease infinite alternate;
    background: var(--surface);
}

@keyframes pulse {
    from {
        transform: scale(1);
    }
    to {
        transform: scale(1.1);
    }
}

/* Game Controls */
.game-controls {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.control-btn {
    padding: 12px 24px;
    background: var(--primary-color);
    color: var(--text-primary);
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.control-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
}

.control-btn.secondary {
    background: var(--secondary-color);
}

.control-btn.secondary:hover {
    background: #475569;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background: var(--surface);
    padding: 40px;
    border-radius: var(--border-radius);
    text-align: center;
    max-width: 400px;
    width: 90%;
    animation: scaleIn 0.3s ease;
}

.modal-content h2 {
    font-size: 1.8rem;
    margin-bottom: 30px;
}

.modal-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.modal-btn {
    padding: 12px 30px;
    background: var(--primary-color);
    color: var(--text-primary);
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.modal-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
}

.modal-btn.secondary {
    background: var(--secondary-color);
}

.modal-btn.secondary:hover {
    background: #475569;
}

/* Footer */
footer {
    text-align: center;
    padding: 20px;
    margin-top: auto;
}

footer a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: var(--transition);
}

footer a:hover {
    color: var(--primary-color);
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes scaleIn {
    from {
        transform: scale(0.8);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

@keyframes cellPop {
    0% {
        transform: scale(0);
    }
    50% {
        transform: scale(1.2);
    }
    100% {
        transform: scale(1);
    }
}

.cell.animate {
    animation: cellPop 0.3s ease;
}

/* Responsive Design */
@media (max-width: 480px) {
    .container {
        padding: 15px;
    }

    header h1 {
        font-size: 2rem;
    }

    .mode-btn {
        padding: 20px 30px;
    }

    .mode-icon {
        font-size: 2.5rem;
    }

    .scoreboard {
        gap: 10px;
    }

    .score-card {
        padding: 10px 15px;
        min-width: 80px;
    }

    .score {
        font-size: 1.5rem;
    }

    .board {
        max-width: 280px;
        gap: 8px;
        padding: 10px;
    }

    .cell {
        font-size: 2.5rem;
    }

    .game-controls {
        gap: 8px;
    }

    .control-btn {
        padding: 10px 18px;
        font-size: 0.9rem;
    }

    .modal-content {
        padding: 30px 20px;
    }

    .modal-content h2 {
        font-size: 1.5rem;
    }
}

@media (max-width: 360px) {
    .board {
        max-width: 240px;
    }

    .cell {
        font-size: 2rem;
    }

    .score-card {
        min-width: 70px;
        padding: 8px 12px;
    }

    .player-label {
        font-size: 0.75rem;
    }
}