:root {
    --bg: #0a0e1a;
    --panel-bg: #0d1424;
    --row-bg: #0a0f1d;
    --border: #1c2438;
    --text: #e7ecf7;
    --text-2: #8892ab;
    --text-dim: #4c5573;
    --accent: #f2a65a;
    --accent-soft: rgba(242,166,90,0.10);
    --easy: #5ec98f;
    --medium: #f2c85a;
    --medium-bg: rgba(242,200,90,0.12);
    --keyword: #7fb0f2;
    --purple: #c792ea;
    --danger: #f2705a;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: 'JetBrains Mono', monospace;
}

.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 40px;
    border-bottom: 1px solid var(--border);
}

.logo {
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 700;
    font-size: 19px;
    color: var(--text);
    text-decoration: none;
}

.navbar { display: flex; gap: 26px; }
.navbar a { color: var(--text-2); text-decoration: none; font-size: 14px; }
.navbar a:hover { color: var(--text); }
.navbar a.active { color: var(--accent); }

.wrap { max-width: 1100px; margin: 0 auto; padding: 48px 24px 100px; }

.crumb { font-size: 12.5px; color: var(--text-dim); margin-bottom: 18px; }
.crumb a { color: var(--text-dim); text-decoration: none; }
.crumb a:hover { color: var(--accent); }

.ptitle-row { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin-bottom: 10px; }

.ptitle-row h1 {
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 700;
    font-size: clamp(22px, 4vw, 34px);
    margin: 0;
}

.diff-badge { font-size: 12px; font-weight: 600; padding: 5px 11px; border-radius: 6px; }
.diff-badge.medium { color: var(--medium); background: var(--medium-bg); }

.topic-badges { display: flex; gap: 8px; margin-bottom: 24px; flex-wrap: wrap; }
.topic-badges span {
    font-size: 11.5px;
    color: var(--text-2);
    border: 1px solid var(--border);
    padding: 4px 9px;
    border-radius: 5px;
}

.card {
    border: 1px solid var(--border);
    border-radius: 12px;
    background: var(--panel-bg);
    margin-bottom: 28px;
    overflow: hidden;
}

.card-title {
    padding: 16px 22px;
    border-bottom: 1px solid var(--border);
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 700;
    font-size: 15px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.card-title::before {
    content: "";
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--accent);
}

.card-body { padding: 20px 22px; font-size: 13.5px; line-height: 1.75; color: var(--text-2); }

.card-body code {
    background: rgba(255,255,255,.06);
    padding: 1px 6px;
    border-radius: 4px;
    color: var(--text);
    font-size: 12.5px;
}

.example {
    margin-top: 12px;
    padding: 12px 14px;
    background: var(--row-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 12.5px;
    color: var(--text-2);
}

.steps-list { margin: 0; padding-left: 20px; display: flex; flex-direction: column; gap: 8px; }
.steps-list li { color: var(--text-2); font-size: 13px; line-height: 1.6; }
.steps-list strong { color: var(--text); }

.switch-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    padding: 14px 22px;
    border-bottom: 1px solid var(--border);
    background: var(--row-bg);
}

.seg {
    display: flex;
    background: var(--panel-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 3px;
    gap: 2px;
}

.seg button {
    background: transparent;
    border: none;
    color: var(--text-2);
    font-family: inherit;
    font-size: 12px;
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.15s ease;
}

.seg button.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }

.seg-title {
    font-size: 11px;
    color: var(--text-dim);
    letter-spacing: 0.05em;
    margin-right: 6px;
    text-transform: uppercase;
    align-self: center;
}

.lang-toggle-group { display: flex; gap: 6px; align-items: center; }

.lang-btn {
    background: var(--panel-bg);
    border: 1px solid var(--border);
    color: var(--text-2);
    font-size: 12px;
    padding: 5px 11px;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
}

.lang-btn.selected { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.lang-btn input { display: none; }

.code-comparison-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 0;
    border-bottom: 1px solid var(--border);
}

.code-pane { border-right: 1px solid var(--border); background: var(--panel-bg); }
.code-pane:last-child { border-right: none; }

.code-pane-header {
    padding: 8px 16px;
    background: var(--row-bg);
    border-bottom: 1px solid var(--border);
    font-size: 11px;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
}

.code-lines { padding: 14px 0; }

.code-line {
    display: flex;
    gap: 12px;
    padding: 2px 16px;
    font-size: 12.5px;
    line-height: 1.8;
    white-space: pre;
    overflow-x: auto;
}

.code-line .ln { color: var(--text-dim); min-width: 18px; text-align: right; user-select: none; }
.code-line.active-line { background: var(--accent-soft); border-left: 3px solid var(--accent); }

/* Simulation */
.sim-visual { padding: 20px 22px; display: flex; flex-direction: column; gap: 16px; }

/* Bar chart stage */
.chart-stage {
    position: relative;
    height: 220px;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    gap: 10px;
    padding-bottom: 44px;
    border-bottom: 1px solid var(--border);
    overflow-x: auto;
    margin-bottom: 4px;
}

.bar-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    flex: 1;
    max-width: 56px;
    min-width: 28px;
}

.bar {
    width: 100%;
    background: var(--row-bg);
    border: 1px solid var(--border);
    border-radius: 4px 4px 0 0;
    transition: background 0.25s, border-color 0.25s, height 0.3s;
}

.bar.min-bar {
    background: rgba(94,201,143,.18);
    border-color: var(--easy);
}

.bar.current {
    background: rgba(242,166,90,.18);
    border-color: var(--accent);
}

.bar.done {
    background: rgba(94,201,143,.12);
    border-color: var(--easy);
}

.bar-value {
    margin-top: 6px;
    font-size: 12px;
    font-weight: 600;
    color: var(--text);
}

.bar-idx {
    position: absolute;
    bottom: -20px;
    font-size: 10px;
    color: var(--text-dim);
}

.delta-label {
    position: absolute;
    top: -22px;
    font-size: 11px;
    font-weight: 600;
    color: var(--accent);
    white-space: nowrap;
}

/* Info panel chips */
.info-panel {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    padding: 10px 14px;
    background: var(--row-bg);
    border: 1px dashed var(--border);
    border-radius: 8px;
    min-height: 44px;
    align-items: center;
}

.info-chip {
    font-size: 12px;
    padding: 4px 9px;
    border-radius: 6px;
    background: var(--accent-soft);
    color: var(--accent);
    border: 1px solid rgba(242,166,90,.3);
}

.info-chip.ok {
    background: rgba(94,201,143,.10);
    color: var(--easy);
    border-color: rgba(94,201,143,.3);
}

.info-empty { color: var(--text-dim); font-size: 12px; }

.desc-line {
    min-height: 38px;
    font-size: 13px;
    color: var(--text);
    padding: 10px 14px;
    background: var(--row-bg);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.desc-line.win {
    border-color: var(--easy);
    color: var(--easy);
    background: rgba(94,201,143,.08);
}

.controls-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 22px;
    border-top: 1px solid var(--border);
    background: var(--row-bg);
    flex-wrap: wrap;
}

.controls-row button {
    width: 34px;
    height: 34px;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--panel-bg);
    color: var(--text);
    cursor: pointer;
    font-family: inherit;
    font-size: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.controls-row button:hover { border-color: var(--accent); color: var(--accent); }
.controls-row button.play { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); }

.step-count { font-size: 12px; color: var(--text-dim); margin-left: auto; }

.progress-track { flex: 1; min-width: 100px; height: 4px; background: var(--border); border-radius: 2px; margin: 0 8px; }
.progress-fill { height: 100%; background: var(--accent); border-radius: 2px; transition: width .2s ease; }

/* Complexity */
.complexity-body { padding: 22px; }

.complexity-badges { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 20px; }

.cbadge {
    flex: 1;
    min-width: 150px;
    padding: 12px 16px;
    background: var(--row-bg);
    border: 1px solid var(--border);
    border-radius: 10px;
}

.cbadge .label { font-size: 11px; color: var(--text-dim); letter-spacing: .06em; margin-bottom: 4px; }
.cbadge .value { font-family: 'Space Grotesk', sans-serif; font-size: 18px; font-weight: 700; color: var(--accent); }

.chart-wrap { background: var(--row-bg); border: 1px solid var(--border); border-radius: 10px; padding: 18px; }

.chart-legend { display: flex; gap: 18px; font-size: 11.5px; color: var(--text-2); margin-top: 12px; flex-wrap: wrap; }
.chart-legend span { display: flex; align-items: center; gap: 6px; }
.swatch { width: 10px; height: 10px; border-radius: 2px; }

table.compare { width: 100%; border-collapse: collapse; font-size: 13px; }
table.compare th, table.compare td { padding: 12px 16px; text-align: left; border-bottom: 1px solid var(--border); }
table.compare th { color: var(--text-dim); font-size: 11px; letter-spacing: .06em; font-weight: 600; }
table.compare td { color: var(--text-2); }
table.compare td.hl { color: var(--accent); font-weight: 600; }
table.compare tr:last-child td { border-bottom: none; }

.hamburger { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; z-index: 1001; padding: 5px; }
.hamburger span { width: 24px; height: 2px; background: var(--text); transition: all 0.3s ease; }
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width:760px) {
    .hamburger { display: flex; }
    .navbar { position: fixed; top: 0; right: -100%; width: 240px; height: 100vh; background: var(--panel-bg); border-left: 1px solid var(--border); flex-direction: column; justify-content: center; align-items: flex-start; padding: 40px 30px; gap: 16px; transition: right 0.35s ease; z-index: 999; }
    .navbar.nav-open { right: 0; }
    .header { padding: 16px 20px; }
    .wrap { padding: 80px 16px 100px; }
    .code-comparison-grid { grid-template-columns: 1fr; }
    .code-pane { border-right: none; border-bottom: 1px solid var(--border); }
    .complexity-badges { flex-direction: column; }
    .code-line { font-size: 11px; white-space: pre-wrap; word-break: break-all; }
    .desc-line, .example { word-wrap: break-word; }
    .cbadge .value { font-size: 14px; }
}