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

:root {
    --ocean: #0a1628;
    --ocean-light: #132240;
    --ocean-mid: #1a3158;
    --accent: #00b4d8;
    --accent-hover: #0096c7;
    --hit: #e63946;
    --miss: #8d99ae;
    --ship: #4a6fa5;
    --ship-hover: #5c85c4;
    --sunk: #9d0208;
    --text: #edf2f4;
    --text-dim: #8d99ae;
    --success: #2ec4b6;
    --grid-line: #2a4a7f;
    --cell-bg: #0d2137;
    --cell-hover: #1a3a5c;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--ocean);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Screens */
.screen { display: none; width: 100%; }
.screen.active { display: flex; justify-content: center; align-items: center; min-height: 100vh; }

/* Lobby */
.lobby-container {
    text-align: center;
    padding: 2rem;
}

.lobby-container h1 {
    font-size: 3rem;
    margin-bottom: 0.25rem;
    letter-spacing: 2px;
}

.subtitle {
    color: var(--text-dim);
    margin-bottom: 2.5rem;
    font-size: 1.1rem;
}

.lobby-buttons {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.divider {
    color: var(--text-dim);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.join-form {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.join-form input {
    padding: 0.75rem 1rem;
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 3px;
    text-align: center;
    background: var(--ocean-light);
    border: 2px solid var(--ocean-mid);
    color: var(--text);
    border-radius: 8px;
    width: 180px;
    outline: none;
    transition: border-color 0.2s;
}

.join-form input:focus {
    border-color: var(--accent);
}

/* Buttons */
.btn {
    padding: 0.75rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: var(--accent);
    color: var(--ocean);
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--ocean-mid);
    color: var(--text);
}

.btn-secondary:hover {
    background: var(--ship);
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.hidden { display: none !important; }

/* Error */
.error-message {
    color: var(--hit);
    margin-top: 1rem;
    font-size: 0.9rem;
}

/* Waiting */
.waiting-container {
    text-align: center;
    padding: 2rem;
}

.game-code-display {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin: 1.5rem 0;
}

.game-code-display span {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: 8px;
    color: var(--accent);
    background: var(--ocean-light);
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    border: 2px solid var(--ocean-mid);
    font-family: 'Consolas', 'Courier New', monospace;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--ocean-mid);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 2rem auto 0;
}

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

/* Board */
.board {
    display: grid;
    grid-template-columns: 30px repeat(10, 1fr);
    grid-template-rows: 30px repeat(10, 1fr);
    gap: 2px;
    background: var(--grid-line);
    border: 2px solid var(--grid-line);
    border-radius: 4px;
    width: 372px;
    height: 372px;
    user-select: none;
    position: relative;
}

.board-small {
    width: 340px;
    height: 340px;
}

.board-label {
    text-align: center;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 0.85rem;
}

.board-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 1.5rem 0;
}

.cell {
    background: var(--cell-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background 0.15s;
    font-size: 0.7rem;
    font-weight: 600;
}

.cell:hover {
    background: var(--cell-hover);
}

.cell-header {
    background: var(--ocean-light);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-dim);
    cursor: default;
}

.cell-corner {
    background: var(--ocean-light);
    cursor: default;
}

.cell-ship {
    background: var(--ship);
}

.cell-hit {
    background: var(--hit);
}

.cell-hit::after {
    content: '✕';
    font-size: 1.1rem;
    color: white;
}

.cell-miss {
    background: var(--ocean-mid);
}

.cell-miss::after {
    content: '•';
    font-size: 1.4rem;
    color: var(--miss);
}

.cell-sunk {
    background: var(--sunk);
}

.cell-sunk::after {
    content: '✕';
    font-size: 1.1rem;
    color: white;
}

.cell-preview {
    background: var(--ship-hover);
}

.cell-preview-invalid {
    background: var(--hit);
    opacity: 0.5;
}

.cell.no-hover:hover {
    background: var(--cell-bg);
    cursor: default;
}

.cell-ship.no-hover:hover {
    background: var(--ship);
    cursor: default;
}

.cell-hit.no-hover:hover, .cell-miss.no-hover:hover, .cell-sunk.no-hover:hover {
    cursor: default;
}

/* Ship graphic overlays */
.ship-overlay {
    position: absolute;
    pointer-events: none;
    z-index: 1;
}

.cell-hit, .cell-miss, .cell-sunk {
    position: relative;
    z-index: 2;
}

/* Setup */
.setup-container {
    text-align: center;
    padding: 1.5rem;
}

.setup-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin: 1rem 0;
}

#orientation-label {
    color: var(--text-dim);
    font-size: 0.9rem;
}

.ship-list {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin: 1rem 0;
    flex-wrap: wrap;
}

.ship-item {
    padding: 0.4rem 0.8rem;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    background: var(--ocean-mid);
    color: var(--text-dim);
}

.ship-item.placed {
    background: var(--ship);
    color: var(--text);
}

.ship-item.current {
    background: var(--accent);
    color: var(--ocean);
}

/* Battle */
.battle-container {
    text-align: center;
    padding: 1rem;
}

.boards-row {
    display: flex;
    gap: 2rem;
    justify-content: center;
    flex-wrap: wrap;
    margin: 1rem 0;
}

.board-section {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.turn-indicator {
    font-size: 1.2rem;
    font-weight: 700;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 0.5rem;
}

.turn-indicator.my-turn {
    background: var(--accent);
    color: var(--ocean);
}

.turn-indicator.opponent-turn {
    background: var(--ocean-mid);
    color: var(--text-dim);
}

.battle-log {
    max-height: 120px;
    overflow-y: auto;
    margin-top: 1rem;
    padding: 0.75rem;
    background: var(--ocean-light);
    border-radius: 8px;
    font-size: 0.8rem;
    color: var(--text-dim);
    max-width: 720px;
    margin-left: auto;
    margin-right: auto;
    text-align: left;
}

.battle-log p {
    margin: 0.2rem 0;
}

.battle-log .log-hit { color: var(--hit); }
.battle-log .log-miss { color: var(--miss); }
.battle-log .log-sunk { color: #ff6b6b; font-weight: 600; }

/* Game Over */
.gameover-container {
    text-align: center;
    padding: 2rem;
}

.gameover-container h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.gameover-container .win { color: var(--success); }
.gameover-container .lose { color: var(--hit); }

.gameover-container p {
    color: var(--text-dim);
    margin-bottom: 2rem;
}

/* Leave button */
.btn-leave {
    margin-top: 1.5rem;
}

/* Responsive */
@media (max-width: 768px) {
    .board { width: 320px; height: 320px; }
    .board-small { width: 290px; height: 290px; }
    .boards-row { gap: 1rem; }
    .lobby-container h1 { font-size: 2rem; }
}