:root {
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-color: #1e293b;
    --accent-color: #3b82f6;
    --cell-hidden: #e2e8f0;
    --cell-revealed: #f8fafc;
    --cell-border: #cbd5e1;
    --mine-bg: #fee2e2;
    --flag-color: #ef4444;
}

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

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

.container {
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    text-align: center;
}

h1 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--accent-color);
}

.difficulty-selector {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 25px;
}

.diff-btn {
    padding: 8px 16px;
    border: 1px solid var(--cell-border);
    background: white;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.9rem;
}

.diff-btn.active {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

.status-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #f1f5f9;
    padding: 15px 25px;
    border-radius: 12px;
    margin-bottom: 25px;
}

.status-item span {
    font-family: 'Courier New', Courier, monospace;
    font-size: 1.8rem;
    font-weight: bold;
    color: #0f172a;
    display: block;
}

.status-item p {
    font-size: 0.75rem;
    color: #64748b;
    text-transform: uppercase;
    letter-spacing: 1px;
}

#reset-btn {
    font-size: 2rem;
    background: none;
    border: none;
    cursor: pointer;
    transition: transform 0.1s;
}

#reset-btn:active {
    transform: scale(0.9);
}

.board {
    display: grid;
    gap: 4px;
    background-color: var(--cell-border);
    border: 4px solid var(--cell-border);
    border-radius: 8px;
    margin: 0 auto;
    user-select: none;
    overflow: auto;
    max-width: 90vw;
}

.cell {
    width: 30px;
    height: 30px;
    background-color: var(--cell-hidden);
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    font-size: 1.1rem;
    cursor: pointer;
    border-radius: 2px;
    transition: background-color 0.1s;
}

.cell:hover:not(.revealed):not(.flagged) {
    background-color: #d1d5db;
}

.cell.revealed {
    background-color: var(--cell-revealed);
    cursor: default;
}

.cell.mine {
    background-color: var(--mine-bg);
}

.cell.flagged {
    color: var(--flag-color);
}

/* Number Colors */
.n1 { color: #2563eb; }
.n2 { color: #16a34a; }
.n3 { color: #dc2626; }
.n4 { color: #7c3aed; }
.n5 { color: #92400e; }
.n6 { color: #0891b2; }
.n7 { color: #1e293b; }
.n8 { color: #64748b; }

.instructions {
    margin-top: 25px;
    color: #64748b;
    font-size: 0.9rem;
}

/* Responsive adjustments */
@media (max-width: 500px) {
    .cell {
        width: 25px;
        height: 25px;
        font-size: 0.9rem;
    }
}