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

:root {
    --bg: #0d0d0d;
    --surface: #161616;
    --border: #2a2a2a;
    --accent: #00e5a0;
    --accent2: #00b37a;
    --text: #e8e8e8;
    --muted: #666;
    --mono: 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Inter', system-ui, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 32px;
    padding: 40px 20px;
}

header {
    text-align: center;
}

header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--accent);
}

header p {
    font-size: 0.85rem;
    color: var(--muted);
    margin-top: 6px;
}

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 28px;
    width: 100%;
    max-width: 720px;
}

.input-row {
    display: flex;
    gap: 12px;
    align-items: center;
}

.format-row {
    display: flex;
    gap: 16px;
    align-items: center;
    margin-top: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.format-row label {
    font-size: 0.85rem;
    color: var(--text);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
}

input[type="text"] {
    flex: 1;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 2.5rem;
    text-align: center;
    padding: 10px 16px;
    outline: none;
    transition: border-color 0.2s;
    font-family: 'Noto Serif SC', serif;
    max-width: 100px;
}

input[type="text"]:focus {
    border-color: var(--accent);
}

label {
    font-size: 0.8rem;
    color: var(--muted);
    flex: 1;
}

.btn {
    background: var(--accent);
    color: #000;
    border: none;
    border-radius: 8px;
    padding: 12px 22px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

.btn:hover {
    background: var(--accent2);
}

.btn:active {
    transform: scale(0.97);
}

.preview-row {
    display: flex;
    gap: 28px;
    margin-top: 28px;
    flex-wrap: wrap;
    align-items: flex-start;
}

.preview-section {
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: center;
}

.section-label {
    font-size: 0.72rem;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

canvas {
    border: 1px solid var(--border);
    border-radius: 6px;
    image-rendering: pixelated;
}

#matrix-grid {
    display: grid;
    grid-template-columns: repeat(32, 4px);
    grid-template-rows: repeat(32, 4px);
    gap: 1.5px;
}

.cell {
    width: 4px;
    height: 4px;
    border-radius: 1px;
    transition: background 0.05s;
}

.cell.on {
    background: var(--accent);
}

.cell.off {
    background: #1e1e1e;
}

.code-section {
    margin-top: 24px;
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.copy-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--muted);
    border-radius: 6px;
    padding: 5px 12px;
    font-size: 0.75rem;
    cursor: pointer;
    transition: color 0.2s, border-color 0.2s;
}

.copy-btn:hover {
    color: var(--accent);
    border-color: var(--accent);
}

.copy-btn.copied {
    color: var(--accent);
    border-color: var(--accent);
}

pre {
    background: #0a0a0a;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
    font-family: var(--mono);
    font-size: 0.72rem;
    line-height: 1.6;
    overflow-x: auto;
    color: #c8fae0;
    white-space: pre;
}

.empty-hint {
    text-align: center;
    color: var(--muted);
    font-size: 0.85rem;
    padding: 40px 0;
}