:root {
    --parchment-bg: #f4ecd8;
    --parchment-dark: #d4a373;
    --text-color: #5d4037;
    --accent-color: #8d6e63;
    --gold: #ffd700;
    --tile-bg: #e0d5c1;
    --tile-revealed: white;
    --body-bg: #2c2c2c;
}

body.dark-mode {
    --parchment-bg: #2c2c2c;
    --parchment-dark: #1a1a1a;
    --text-color: #e4e6eb;
    --accent-color: #a0a0a0;
    --tile-bg: #3a3b3c;
    --tile-revealed: #242526;
    --body-bg: #18191a;
}

body {
    margin: 0;
    font-family: 'Pretendard', sans-serif;
    background-color: var(--body-bg);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    transition: background-color 0.3s, color 0.3s;
}

.game-container {
    width: 90%;
    max-width: 600px;
    background-color: var(--parchment-bg);
    background-image: radial-gradient(circle at 50% 50%, transparent 80%, rgba(0,0,0,0.05)),
                      repeating-linear-gradient(rgba(0,0,0,0.01) 0px, rgba(0,0,0,0.01) 1px, transparent 1px, transparent 2px);
    border-radius: 8px;
    padding: 30px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.5), inset 0 0 100px rgba(141, 110, 99, 0.2);
    position: relative;
    border: 15px solid transparent;
    border-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="50" height="50" viewBox="0 0 50 50"><rect width="50" height="50" fill="%23d4a373"/><path d="M0 0L50 50M50 0L0 50" stroke="%238d6e63" stroke-width="2"/></svg>') 30 stretch;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

.back-link {
    text-decoration: none;
    color: var(--accent-color);
    font-size: 0.9rem;
    font-weight: bold;
}

h1 {
    font-size: 2.2rem;
    margin: 10px 0;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.1);
}

.screen {
    transition: opacity 0.3s ease;
}

.hidden {
    display: none;
    opacity: 0;
}

/* Setup Screen */
.difficulty-options {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-top: 30px;
}

.diff-btn {
    background: var(--tile-revealed);
    border: 2px solid var(--parchment-dark);
    padding: 20px;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-color);
}

.diff-btn:hover {
    background: var(--parchment-dark);
    color: white;
    transform: translateY(-3px);
}

.diff-btn .level {
    font-size: 1.5rem;
    font-weight: 800;
}

.diff-btn .desc {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* Game Screen */
.game-info {
    display: flex;
    justify-content: space-around;
    background: rgba(212, 163, 115, 0.2);
    padding: 15px;
    border-radius: 10px;
    margin-bottom: 25px;
}

.info-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.info-item .label {
    font-size: 0.8rem;
    font-weight: bold;
}

.info-item .value {
    font-size: 1.4rem;
    font-weight: 800;
    color: #a0522d;
}

body.dark-mode .info-item .value {
    color: var(--gold);
}

.grid {
    display: grid;
    gap: 8px;
    margin: 0 auto 30px;
    max-width: 100%;
}

.tile {
    aspect-ratio: 1/1;
    background: var(--tile-bg);
    border: 1px solid rgba(0,0,0,0.1);
    border-radius: 4px;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    transition: all 0.2s;
    box-shadow: inset 0 -3px 0 rgba(0,0,0,0.1);
}

.tile:hover:not(.revealed) {
    background: var(--parchment-dark);
    transform: scale(1.05);
}

.tile.revealed {
    cursor: default;
    background: var(--tile-revealed);
    box-shadow: none;
}

.tile.revealed.empty { background: var(--tile-bg); opacity: 0.5; }
.tile.revealed.coin { background: #fff9c4; animation: pop 0.3s ease; color: #333; }
.tile.revealed.gem { background: #e1f5fe; animation: pop 0.4s ease; border: 2px solid #03a9f4; color: #333; }
.tile.revealed.chest { background: #fff3e0; animation: bounce 0.5s ease; border: 2px solid #ff9800; font-size: 2rem; color: #333; }

@keyframes pop {
    0% { transform: scale(0); }
    80% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

@keyframes bounce {
    0% { transform: translateY(0); }
    30% { transform: translateY(-10px); }
    50% { transform: translateY(0); }
    70% { transform: translateY(-5px); }
    100% { transform: translateY(0); }
}

#reset-btn {
    width: 100%;
    padding: 12px;
    background: none;
    border: 2px solid var(--accent-color);
    color: var(--accent-color);
    font-weight: bold;
    border-radius: 8px;
    cursor: pointer;
}

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

.modal-content {
    background: var(--parchment-bg);
    padding: 40px;
    border-radius: 20px;
    text-align: center;
    max-width: 300px;
    color: var(--text-color);
}

.modal-content h2 { font-size: 2rem; margin-bottom: 20px; }
.result-stats { font-size: 1.2rem; margin-bottom: 30px; }
#new-record { color: #e67e22; font-weight: bold; }

#modal-close-btn {
    width: 100%;
    padding: 15px;
    background: var(--parchment-dark);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
}