/* style.css - clean, readable dark UI for the DP visualizer */
:root {
    --bg: #0b1020;
    --panel: rgba(255,255,255,0.06);
    --panel-2: rgba(255,255,255,0.08);
    --border: rgba(255,255,255,0.10);
    --text: rgba(255,255,255,0.92);
    --muted: rgba(255,255,255,0.62);
    --accent: #00d9ff; /* cyan */
    --accent2: #ff6b6b; /* coral */
    --good: #2bd97c; /* green */
    --warn: #ffd166; /* amber */

    --shadow: 0 10px 40px rgba(0,0,0,0.35);
    --radius: 16px;
}

* {
    box-sizing: border-box;
}

html, body {
    height: 100%;
}

body {
    margin: 0;
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
    color: var(--text);
    background: radial-gradient(900px 600px at 15% 10%, rgba(0,217,255,0.18), transparent 55%), radial-gradient(900px 600px at 85% 20%, rgba(255,107,107,0.16), transparent 55%), radial-gradient(900px 600px at 50% 100%, rgba(43,217,124,0.10), transparent 60%), var(--bg);
}

.container {
    max-width: 1180px;
    margin: 0 auto;
    padding: 28px 18px 40px;
}

h1 {
    margin: 0;
    font-size: clamp(22px, 2.3vw, 34px);
    letter-spacing: 0.2px;
}

.title-row {
    margin-bottom: 8px;
}

.pill-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 12px;
}

.pill {
    display: inline-flex;
    align-items: center;
    padding: 6px 14px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 600;
    text-decoration: none;
    color: var(--text);
    background: rgba(0, 217, 255, 0.12);
    border: 1px solid rgba(0, 217, 255, 0.35);
    transition: all 0.15s ease;
}

    .pill:hover {
        background: rgba(0, 217, 255, 0.18);
        border-color: rgba(0, 217, 255, 0.55);
        transform: translateY(-1px);
    }

.subtitle {
    margin: 8px 0 18px;
    color: var(--muted);
    font-size: 14px;
}

    .subtitle a {
        color: var(--accent);
        text-decoration: none;
        transition: color 0.15s ease;
    }

        .subtitle a:hover {
            color: rgba(0,217,255,0.8);
            text-decoration: underline;
        }

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 12px;
    align-items: flex-end;
    padding: 14px;
    background: linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.04));
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.control-group {
    flex: 1 1 420px;
    min-width: 280px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

label {
    color: var(--muted);
    font-size: 12px;
}

input[type="text"] {
    width: 100%;
    padding: 10px 12px;
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.14);
    background: rgba(0,0,0,0.25);
    color: var(--text);
    outline: none;
}

    input[type="text"]:focus {
        border-color: rgba(0,217,255,0.45);
        box-shadow: 0 0 0 4px rgba(0,217,255,0.12);
    }

button {
    appearance: none;
    border: 1px solid rgba(255,255,255,0.14);
    background: rgba(255,255,255,0.06);
    color: var(--text);
    padding: 10px 12px;
    border-radius: 12px;
    cursor: pointer;
    transition: transform 0.06s ease, background 0.12s ease, border-color 0.12s ease;
    user-select: none;
    font-weight: 600;
}

    button:hover {
        background: rgba(255,255,255,0.10);
        border-color: rgba(255,255,255,0.22);
    }

    button:active {
        transform: translateY(1px);
    }

.btn-primary {
    border-color: rgba(0,217,255,0.35);
    background: rgba(0,217,255,0.12);
}

    .btn-primary:hover {
        background: rgba(0,217,255,0.18);
    }

.btn-step {
    border-color: rgba(255,209,102,0.35);
    background: rgba(255,209,102,0.12);
}

.btn-secondary {
    border-color: rgba(255,255,255,0.14);
}

.main-content {
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    gap: 14px;
    margin-top: 14px;
}

@media (max-width: 980px) {
    .main-content {
        grid-template-columns: 1fr;
    }
}

.panel {
    background: linear-gradient(180deg, rgba(255,255,255,0.06), rgba(255,255,255,0.04));
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 14px;
}

.panel-title {
    font-weight: 800;
    letter-spacing: 0.2px;
    margin-bottom: 10px;
}

.explanation {
    color: var(--muted);
    font-size: 13px;
    line-height: 1.45;
    padding: 10px 12px;
    background: rgba(0,0,0,0.22);
    border: 1px solid rgba(255,255,255,0.10);
    border-radius: 12px;
}

.formula {
    margin-top: 10px;
    padding: 10px 12px;
    background: rgba(0,0,0,0.22);
    border: 1px solid rgba(255,255,255,0.10);
    border-radius: 12px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    font-size: 12px;
    color: rgba(255,255,255,0.84);
}

.matrices-display {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 10px;
}

.matrix-box {
    padding: 10px 12px;
    border-radius: 14px;
    background: rgba(0,0,0,0.22);
    border: 1px solid rgba(255,255,255,0.10);
    min-width: 120px;
}

.matrix-name {
    font-weight: 800;
    color: rgba(255,255,255,0.92);
}

.matrix-dims {
    margin-top: 3px;
    color: var(--muted);
    font-size: 12px;
}

.step-info {
    margin-top: 12px;
    padding: 12px;
    background: rgba(0,0,0,0.22);
    border: 1px solid rgba(255,255,255,0.10);
    border-radius: 12px;
}

.step-counter {
    font-weight: 800;
    margin-bottom: 6px;
}

#step-description {
    color: rgba(255,255,255,0.82);
    font-size: 13px;
    line-height: 1.35;
}

    #step-description code {
        font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
        font-size: 12px;
        color: rgba(255,255,255,0.86);
        background: rgba(255,255,255,0.06);
        padding: 2px 6px;
        border-radius: 8px;
        border: 1px solid rgba(255,255,255,0.10);
    }

.result-box {
    margin-top: 12px;
    padding: 12px;
    border-radius: 14px;
    border: 1px solid rgba(43,217,124,0.25);
    background: rgba(43,217,124,0.08);
}

.result-label {
    color: rgba(255,255,255,0.75);
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
}

.result-value {
    font-size: 28px;
    font-weight: 900;
    margin-top: 4px;
    color: rgba(255,255,255,0.95);
}

.parenthesization {
    margin-top: 6px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    font-size: 13px;
    color: rgba(255,255,255,0.90);
    word-break: break-word;
}

.dp-table-container {
    overflow: auto;
    padding: 6px;
    border-radius: 12px;
    background: rgba(0,0,0,0.20);
    border: 1px solid rgba(255,255,255,0.10);
}

.dp-table, .split-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 6px;
    min-width: 520px;
}

    .dp-table th, .split-table th {
        position: sticky;
        top: 0;
        background: rgba(10,16,32,0.92);
        z-index: 2;
        padding: 8px 10px;
        border-radius: 10px;
        text-align: left;
        font-size: 12px;
        color: rgba(255,255,255,0.70);
    }

    .dp-table td, .split-table td {
        padding: 10px 10px;
        border-radius: 12px;
        border: 1px solid rgba(255,255,255,0.10);
        background: rgba(255,255,255,0.05);
        text-align: center;
        font-variant-numeric: tabular-nums;
        color: rgba(255,255,255,0.88);
        min-width: 70px;
    }

        /* cell states */
        .dp-table td.diagonal {
            background: rgba(0,0,0,0.16);
            color: rgba(255,255,255,0.35);
        }

        .dp-table td.current {
            border-color: rgba(0,217,255,0.70);
            box-shadow: 0 0 0 4px rgba(0,217,255,0.14);
        }

        .dp-table td.comparing {
            border-color: rgba(255,209,102,0.70);
            box-shadow: 0 0 0 4px rgba(255,209,102,0.14);
        }

        .dp-table td.computed,
        .split-table td.computed {
            background: rgba(255,255,255,0.08);
            border-color: rgba(255,255,255,0.14);
        }

        .dp-table td.optimal {
            border-color: rgba(43,217,124,0.65);
            box-shadow: 0 0 0 4px rgba(43,217,124,0.14);
        }

/* legend */
.legend {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 14px;
    margin-top: 12px;
    color: rgba(255,255,255,0.75);
    font-size: 12px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.legend-color {
    width: 14px;
    height: 14px;
    border-radius: 4px;
    border: 1px solid rgba(255,255,255,0.16);
}

.color-current {
    background: rgba(0,217,255,0.30);
    border-color: rgba(0,217,255,0.6);
}

.color-comparing {
    background: rgba(255,209,102,0.30);
    border-color: rgba(255,209,102,0.6);
}

.color-computed {
    background: rgba(255,255,255,0.12);
    border-color: rgba(255,255,255,0.22);
}

.color-optimal {
    background: rgba(43,217,124,0.22);
    border-color: rgba(43,217,124,0.55);
}

/* tree panel */
.tree-container {
    overflow: auto;
    padding: 10px;
    border-radius: 12px;
    background: rgba(0,0,0,0.20);
    border: 1px solid rgba(255,255,255,0.10);
}

.tree-svg {
    width: 100%;
    height: auto;
    display: block;
}