/* ═══════════════════════════════════════════════════════════
   Tic Tac Toe — Dark Theme Stylesheet
   Matching the Java Swing version's color palette
   ═══════════════════════════════════════════════════════════ */

/* ─── CSS Variables ────────────────────────────────────── */
:root {
    --bg-dark: #1a1a2e;
    --bg-card: #16213e;
    --bg-cell: #0f3d62;
    --bg-cell-hover: #1a557f;
    --color-x: #00d4ff;
    --color-o: #ff006e;
    --color-win: #00ff87;
    --text-primary: #e9ecef;
    --text-secondary: #adb5bd;
    --btn-active: #00d4ff;
    --btn-inactive: #2d2d44;
    --transition-speed: 0.2s;
}

/* ─── Reset & Base ─────────────────────────────────────── */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    overflow-x: hidden;
}

/* Subtle animated gradient background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(0, 212, 255, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(255, 0, 110, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 80%, rgba(0, 255, 135, 0.04) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

/* ─── Container ────────────────────────────────────────── */
.container {
    position: relative;
    z-index: 1;
    max-width: 440px;
    width: 100%;
    text-align: center;
}

/* ─── Title ────────────────────────────────────────────── */
.title {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: 4px;
    margin-bottom: 4px;
    background: linear-gradient(135deg, var(--color-x), var(--color-o));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
    font-weight: 400;
}

/* ─── Score Panel ──────────────────────────────────────── */
.score-panel {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-bottom: 20px;
}

.score-card {
    background: var(--bg-card);
    border-radius: 14px;
    padding: 14px 8px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    transition: transform var(--transition-speed);
}

.score-card:hover {
    transform: translateY(-2px);
}

.score-label {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 1.5px;
    text-transform: uppercase;
}

.score-value {
    font-size: 1.6rem;
    font-weight: 800;
}

.score-x { color: var(--color-x); }
.score-o { color: var(--color-o); }
.score-draw { color: var(--text-secondary); }

/* ─── Difficulty Panel ─────────────────────────────────── */
.difficulty-panel {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-bottom: 20px;
}

.pill-btn {
    font-family: 'Inter', sans-serif;
    font-size: 0.8rem;
    font-weight: 700;
    padding: 8px 22px;
    border: none;
    border-radius: 50px;
    background: var(--btn-inactive);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-speed);
    letter-spacing: 0.5px;
}

.pill-btn:hover {
    filter: brightness(1.3);
    transform: translateY(-1px);
}

.pill-btn.active {
    background: var(--btn-active);
    color: var(--bg-dark);
    box-shadow: 0 0 16px rgba(0, 212, 255, 0.35);
}

/* ─── Game Board ───────────────────────────────────────── */
.board {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    padding: 0 10px;
    margin-bottom: 20px;
}

.cell {
    aspect-ratio: 1;
    border: none;
    border-radius: 16px;
    background: var(--bg-cell);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    font-size: 3rem;
    font-weight: 800;
    cursor: pointer;
    transition: all var(--transition-speed);
    position: relative;
    overflow: hidden;
    outline: none;
}

.cell:hover:not(.taken):not(.game-over) {
    background: var(--bg-cell-hover);
    transform: scale(1.04);
}

.cell:hover:not(.taken):not(.game-over)::after {
    content: 'X';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: rgba(0, 212, 255, 0.15);
    font-size: 3rem;
    font-weight: 800;
    pointer-events: none;
}

.cell.x {
    color: var(--color-x);
    text-shadow: 0 0 20px rgba(0, 212, 255, 0.4);
}

.cell.o {
    color: var(--color-o);
    text-shadow: 0 0 20px rgba(255, 0, 110, 0.4);
}

.cell.winning {
    background: rgba(0, 255, 135, 0.15);
    box-shadow: 0 0 20px rgba(0, 255, 135, 0.3), inset 0 0 20px rgba(0, 255, 135, 0.1);
    animation: winPulse 1.2s ease-in-out infinite;
}

.cell.taken, .cell.game-over {
    cursor: default;
}

@keyframes winPulse {
    0%, 100% { box-shadow: 0 0 15px rgba(0, 255, 135, 0.25); }
    50% { box-shadow: 0 0 30px rgba(0, 255, 135, 0.5), inset 0 0 15px rgba(0, 255, 135, 0.15); }
}

/* ─── Cell Place Animation ─────────────────────────────── */
@keyframes popIn {
    0% { transform: scale(0); opacity: 0; }
    60% { transform: scale(1.2); }
    100% { transform: scale(1); opacity: 1; }
}

.cell.animate-mark {
    animation: popIn 0.3s ease-out;
}

/* ─── Status ───────────────────────────────────────────── */
.status {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 16px;
    min-height: 1.5em;
    transition: color var(--transition-speed);
}

.status.win { color: var(--color-win); }
.status.lose { color: var(--color-o); }

/* ─── New Game Button ──────────────────────────────────── */
.new-game-btn {
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    font-weight: 700;
    padding: 12px 32px;
    border: none;
    border-radius: 50px;
    background: var(--btn-inactive);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-speed);
    margin-bottom: 24px;
}

.new-game-btn:hover {
    background: var(--btn-active);
    color: var(--bg-dark);
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
    transform: translateY(-2px);
}

/* ─── Modal ────────────────────────────────────────────── */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(6px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
}

.modal-overlay.show {
    opacity: 1;
    pointer-events: all;
}

.modal {
    background: var(--bg-card);
    border-radius: 24px;
    padding: 36px 40px;
    text-align: center;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    transform: scale(0.9);
    transition: transform 0.3s;
    max-width: 340px;
    width: 90%;
}

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

.modal-message {
    font-size: 1.4rem;
    font-weight: 800;
    margin-bottom: 24px;
    line-height: 1.4;
}

.modal-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
}

.modal-btn {
    padding: 10px 28px;
    font-size: 0.85rem;
}

.modal-btn.rematch {
    background: var(--btn-active);
    color: var(--bg-dark);
    box-shadow: 0 0 16px rgba(0, 212, 255, 0.35);
}

/* ─── Footer ───────────────────────────────────────────── */
.footer {
    font-size: 0.75rem;
    color: var(--text-secondary);
    opacity: 0.6;
}

.footer a {
    color: var(--color-x);
    text-decoration: none;
    font-weight: 600;
}

.footer a:hover {
    text-decoration: underline;
}

/* ─── Responsive ───────────────────────────────────────── */
@media (max-width: 480px) {
    .title { font-size: 1.6rem; letter-spacing: 3px; }
    .cell { font-size: 2.4rem; border-radius: 12px; }
    .cell:hover:not(.taken):not(.game-over)::after { font-size: 2.4rem; }
    .board { gap: 8px; padding: 0 4px; }
    .score-card { padding: 10px 6px; border-radius: 10px; }
    .score-value { font-size: 1.3rem; }
    .modal { padding: 28px 24px; }
}