:root {
    --nord0: #2e3440;
    --nord1: #232832;
    --nord2: #232936;
    --nord3: #3b4252;
    --nord4: #d8dee9;
    --nord5: #e5e9f0;
    --nord6: #eceff4;
    --nord7: #8fbcbb;
    --nord8: #88c0d0;
    --nord9: #81a1c1;
    --nord10: #5e81ac;
}
body {
    background: linear-gradient(135deg, var(--nord0) 0%, var(--nord1) 100%);
    font-family: 'Inter', Arial, sans-serif;
    color: var(--nord5);
    margin: 0;
    min-height: 100vh;
}
header {
    background: var(--nord0);
    color: var(--nord6);
    padding: 2rem 0 1.2rem 0;
    text-align: center;
    box-shadow: 0 4px 20px 0 rgba(30, 34, 40, 0.28);
    margin-bottom: 2.5rem;
}
header h1 {
    font-size: 2.3rem;
    font-weight: 700;
    margin: 0 0 0.5rem 0;
    letter-spacing: 1px;
    color: var(--nord6);
    text-shadow: 0 2px 8px rgba(30,34,40,0.45);
}
header p {
    font-size: 1.15rem;
    font-weight: 400;
    color: var(--nord4);
    margin: 0.2rem 0 0 0;
}
.grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 5px;
    max-width: 700px;
    margin: 0 auto;
    padding: 0 10px;
}
.cell {
    aspect-ratio: 1;
    background-color: var(--nord1);
    border: 2.5px solid var(--nord3);
    cursor: pointer;
    background-size: cover;
    background-position: center;
    box-shadow: 0 2px 12px 0 rgba(30, 34, 40, 0.38);
    transition: border 0.2s, box-shadow 0.2s, transform 0.15s, background-color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    color: var(--nord5);
    font-weight: 500;
    text-shadow: 0 2px 8px rgba(30,34,40,0.55);
    overflow: hidden;
}
.cell:hover {
    border-color: var(--nord8);
    box-shadow: 0 6px 24px 0 rgba(30, 34, 40, 0.48);
    background-color: var(--nord2);
    transform: scale(1.03);
}
@media (max-width: 700px) {
    .grid {
        max-width: 98vw;
        gap: 6px;
    }
}
.powered-by {
    text-align: center;
    margin-top: 1.6rem;
    font-size: 0.98rem;
    color: var(--nord4);
    opacity: 0.65;
    letter-spacing: 0.02em;
    font-weight: 400;
}
.powered-by a {
    color: var(--nord8);
    text-decoration: none;
    border-bottom: 1px dotted var(--nord8);
    transition: color 0.2s, border-bottom-color 0.2s;
}
.powered-by a:hover {
    color: var(--nord10);
    border-bottom-color: var(--nord10);
}
/* Mobile friendly enhancements */
@media (max-width: 700px) {
    .grid {
        max-width: 98vw;
        gap: 6px;
        grid-template-columns: repeat(3, 1fr);
        padding: 0 5px;
    }
    header h1 {
        font-size: 1.8rem;
    }
    header p {
        font-size: 1rem;
        padding: 0 10px;
    }
    .cell {
        font-size: 0.9rem;
        border-width: 2px;
    }
}
@media (max-width: 400px) {
    .grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 5px;
    }
    .cell {
        font-size: 0.85rem;
    }
    header h1 {
        font-size: 1.5rem;
    }
    header p {
        font-size: 0.9rem;
    }
}

.other-3x3 {
    text-align: center;
    margin-top: 1.2rem;
    font-size: 1.03rem;
    color: var(--nord4);
    opacity: 0.85;
    letter-spacing: 0.01em;
    font-weight: 400;
}
.other-3x3 a {
    color: var(--nord7);
    text-decoration: none;
    border-bottom: 1px dashed var(--nord7);
    transition: color 0.2s, border-bottom-color 0.2s;
}
.other-3x3 a:hover {
    color: var(--nord8);
    border-bottom-color: var(--nord8);
}