:root {
  color-scheme: light dark;
  --bg: #f7f8fc;
  --card: #ffffff;
  --text: #0f172a;
  --muted: rgba(15, 23, 42, 0.7);
  --border: rgba(15, 23, 42, 0.14);
  --shadow: 0 10px 28px rgba(15, 23, 42, 0.08);
  --accent: #2563eb;
  --accent2: #10b981;
  --ring: rgba(37, 99, 235, 0.32);
  --code-bg: #0b1220;
  --code-text: #e2e8f0;
  --radius: 14px;
  --max: 1040px;
}

html[data-theme="dark"] {
  --bg: #0b1020;
  --card: rgba(255, 255, 255, 0.06);
  --text: #e6edf6;
  --muted: rgba(230, 237, 246, 0.72);
  --border: rgba(255, 255, 255, 0.14);
  --shadow: 0 18px 44px rgba(0, 0, 0, 0.45);
  --accent: #60a5fa;
  --accent2: #34d399;
  --ring: rgba(96, 165, 250, 0.35);
  --code-bg: rgba(0, 0, 0, 0.42);
  --code-text: #e6edf6;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Arial, sans-serif;
  color: var(--text);
  line-height: 1.55;
  background:
    radial-gradient(1200px 500px at 15% 0%, rgba(37, 99, 235, 0.12), transparent 55%),
    radial-gradient(900px 400px at 80% 10%, rgba(16, 185, 129, 0.12), transparent 60%),
    var(--bg);
}

.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 18px;
}

a {
  color: inherit;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 0.95em;
}

.muted {
  color: var(--muted);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  background: color-mix(in oklab, var(--bg), transparent 10%);
  backdrop-filter: blur(10px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 0 10px;
}

.brand .title {
  font-weight: 850;
  letter-spacing: 0.2px;
  font-size: 16px;
}

.brand .subtitle {
  margin-top: 4px;
  font-size: 12px;
  color: var(--muted);
}

.header-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: flex-end;
}

.btn {
  border: 1px solid color-mix(in oklab, var(--accent), transparent 65%);
  background: var(--accent);
  background: linear-gradient(180deg, color-mix(in oklab, var(--accent), #fff 8%), var(--accent));
  color: #ffffff;
  border-radius: 12px;
  padding: 10px 12px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 120ms ease, box-shadow 120ms ease, opacity 120ms ease;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 18px rgba(37, 99, 235, 0.18);
}

.btn:active {
  transform: translateY(0);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}

.btn.small {
  padding: 8px 10px;
  font-size: 12px;
  border-radius: 10px;
}

.btn.ghost {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
}

.btn.ghost:hover {
  background: rgba(37, 99, 235, 0.1);
  box-shadow: none;
}

.progress-wrap {
  padding: 8px 0 14px;
}

.progress-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.progress-text {
  display: flex;
  gap: 10px;
  align-items: center;
  font-size: 12.5px;
  color: var(--muted);
}

.dot {
  opacity: 0.6;
}

.progress-tip {
  font-size: 12px;
  color: var(--muted);
}

.progress-bar {
  margin-top: 8px;
  height: 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--card);
  background: color-mix(in oklab, var(--card), transparent 25%);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width 220ms ease;
}

main.container {
  padding-top: 18px;
  padding-bottom: 64px;
  display: grid;
  gap: 16px;
}

.card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
  background: color-mix(in oklab, var(--card), transparent 5%);
  box-shadow: var(--shadow);
  padding: 16px;
}

.intro h1 {
  margin: 0;
  font-size: 20px;
}

.card h2 {
  margin: 0;
  font-size: 18px;
}

.step-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.checkbox {
  display: inline-flex;
  align-items: flex-start;
  gap: 10px;
  user-select: none;
  font-size: 14px;
  color: var(--muted);
}

.checkbox.small {
  font-size: 13px;
}

.checkbox input {
  margin-top: 2px;
}

.bullets {
  margin: 10px 0 0;
  padding-left: 18px;
  display: grid;
  gap: 6px;
}

.bullets.compact {
  gap: 4px;
}

.choices {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 10px;
  margin-top: 12px;
}

.choice-card {
  position: relative;
  display: grid;
  gap: 6px;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
  cursor: pointer;
  user-select: none;
  background: var(--card);
  background: color-mix(in oklab, var(--card), transparent 8%);
}

.choice-card input {
  position: absolute;
  top: 12px;
  right: 12px;
  accent-color: var(--accent);
}

.choice-card:has(input:checked) {
  border-color: color-mix(in oklab, var(--accent), transparent 35%);
  box-shadow: 0 0 0 4px var(--ring);
}

.choice-title {
  padding-right: 34px;
  font-weight: 820;
}

.choice-meta {
  padding-right: 34px;
  font-size: 12.5px;
  color: var(--muted);
}

.choice-desc {
  padding-right: 34px;
  font-size: 13px;
  color: var(--muted);
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 12px;
}

.panel {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
  background: var(--card);
  background: color-mix(in oklab, var(--card), transparent 8%);
}

.panel h3 {
  margin: 0 0 10px;
  font-size: 15px;
}

.form {
  display: grid;
  gap: 12px;
}

label {
  display: grid;
  gap: 6px;
  font-size: 13px;
  color: var(--muted);
}

input[type="text"],
select,
textarea {
  width: 100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--card);
  background: color-mix(in oklab, var(--card), transparent 6%);
  color: var(--text);
  font-size: 14px;
  outline: none;
}

textarea {
  resize: vertical;
}

input[type="text"]:focus,
select:focus,
textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--ring);
}

.row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 12px;
}

.output {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 12.5px;
  line-height: 1.45;
  white-space: pre;
}

.result {
  margin-top: 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  padding: 12px;
  background: rgba(37, 99, 235, 0.08);
  background: color-mix(in oklab, var(--accent), transparent 92%);
}

.result-title {
  font-size: 12px;
  color: var(--muted);
}

.result-main {
  margin-top: 6px;
  font-weight: 820;
  font-size: 14px;
}

.result-detail {
  margin-top: 6px;
  font-size: 12.5px;
  color: var(--muted);
}

.callout {
  margin-top: 12px;
  border: 1px solid rgba(37, 99, 235, 0.35);
  border-radius: 12px;
  padding: 12px;
  background: rgba(37, 99, 235, 0.08);
  background: color-mix(in oklab, var(--accent), transparent 92%);
}

.callout-title {
  font-size: 13px;
  font-weight: 800;
  margin-bottom: 8px;
}

.details {
  margin-top: 10px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--card);
  background: color-mix(in oklab, var(--card), transparent 6%);
  padding: 10px 12px;
}

.details > summary {
  cursor: pointer;
  font-weight: 800;
  color: var(--text);
  list-style: none;
}

.details > summary::-webkit-details-marker {
  display: none;
}

.details > summary::after {
  content: "▼";
  float: right;
  color: var(--muted);
  font-size: 12px;
  margin-top: 2px;
}

.details[open] > summary::after {
  content: "▲";
}

.details-body {
  margin-top: 10px;
}

.code {
  margin: 10px 0 0;
  border-radius: 12px;
  padding: 12px;
  border: 1px solid var(--border);
  background: var(--code-bg);
  color: var(--code-text);
  overflow: auto;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px;
  margin-top: 12px;
}

.link-card {
  display: grid;
  gap: 6px;
  padding: 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--card);
  background: color-mix(in oklab, var(--card), transparent 8%);
}

.link-card:hover {
  text-decoration: none;
  border-color: color-mix(in oklab, var(--accent), transparent 50%);
  box-shadow: 0 10px 18px rgba(37, 99, 235, 0.12);
}

.link-title {
  font-weight: 820;
}

.link-desc {
  color: var(--muted);
  font-size: 13px;
}

.steps {
  margin: 10px 0 0;
  padding-left: 20px;
  display: grid;
  gap: 6px;
}

.footer {
  text-align: center;
  padding: 18px 0 10px;
}

@media (max-width: 860px) {
  .split {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 620px) {
  .header-inner {
    align-items: flex-start;
  }
  .header-actions {
    justify-content: flex-start;
  }
}