:root {
  /* Typography */
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Microsoft YaHei", sans-serif;
  --serif: ui-serif, "Iowan Old Style", "Palatino Linotype", Palatino, "Noto Serif", "Noto Serif CJK SC",
    "Songti SC", "Source Han Serif SC", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  /* Light theme */
  --page-bg: #f3f2ee;
  --paper: #fffdf8;
  --ink: #111827;
  --muted: #6b7280;
  --rule: rgba(17, 24, 39, 0.18);
  --hairline: rgba(17, 24, 39, 0.09);
  --accent: #1d4ed8;
  --accent-ink: #ffffff;
  --focus: rgba(29, 78, 216, 0.35);
  --shadow: 0 16px 48px rgba(0, 0, 0, 0.10);

  --radius: 14px;
  --space-1: 8px;
  --space-2: 12px;
  --space-3: 16px;
  --space-4: 24px;
  --space-5: 32px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --page-bg: #0b0f19;
    --paper: #0f172a;
    --ink: #e5e7eb;
    --muted: #94a3b8;
    --rule: rgba(148, 163, 184, 0.35);
    --hairline: rgba(148, 163, 184, 0.18);
    --accent: #60a5fa;
    --accent-ink: #0b1220;
    --focus: rgba(96, 165, 250, 0.35);
    --shadow: 0 18px 52px rgba(0, 0, 0, 0.28);
  }
}

/* Manual theme override */
html[data-theme="light"] {
  --page-bg: #f3f2ee;
  --paper: #fffdf8;
  --ink: #111827;
  --muted: #6b7280;
  --rule: rgba(17, 24, 39, 0.18);
  --hairline: rgba(17, 24, 39, 0.09);
  --accent: #1d4ed8;
  --accent-ink: #ffffff;
  --focus: rgba(29, 78, 216, 0.35);
  --shadow: 0 16px 48px rgba(0, 0, 0, 0.10);
}

html[data-theme="dark"] {
  --page-bg: #0b0f19;
  --paper: #0f172a;
  --ink: #e5e7eb;
  --muted: #94a3b8;
  --rule: rgba(148, 163, 184, 0.35);
  --hairline: rgba(148, 163, 184, 0.18);
  --accent: #60a5fa;
  --accent-ink: #0b1220;
  --focus: rgba(96, 165, 250, 0.35);
  --shadow: 0 18px 52px rgba(0, 0, 0, 0.28);
}

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--page-bg);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.6;
  padding:
    calc(clamp(14px, 3vw, 28px) + env(safe-area-inset-top)) calc(clamp(14px, 3vw, 28px) + env(safe-area-inset-right)) calc(clamp(14px, 3vw, 28px) + env(safe-area-inset-bottom)) calc(clamp(14px, 3vw, 28px) + env(safe-area-inset-left));
}

a {
  color: inherit;
}

.topbar {
  width: min(920px, 100%);
  margin: 0 auto var(--space-3);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  min-width: 240px;
}

.brand-mark {
  font-family: var(--serif);
  font-weight: 800;
  letter-spacing: 0.02em;
  opacity: 0.8;
}

.brand-name {
  font-weight: 750;
  letter-spacing: -0.01em;
}

.controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.control {
  display: grid;
  grid-template-columns: auto;
  gap: 6px;
}

.control-label {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

select {
  appearance: none;
  border: 1px solid var(--hairline);
  background: color-mix(in srgb, var(--paper), var(--page-bg) 8%);
  color: var(--ink);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 14px;
  line-height: 1.1;
  min-width: 150px;
  outline: none;
}

.page {
  width: min(920px, 100%);
  margin: 0 auto;
}

article.instrument {
  background: var(--paper);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  padding: clamp(18px, 3.6vw, 34px);
  font-family: var(--serif);
  counter-reset: section;
}

.instrument-header {
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--rule);
  margin-bottom: var(--space-4);
}

.kicker {
  margin: 0 0 var(--space-2);
  font-family: var(--sans);
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(22px, 3.4vw, 34px);
  line-height: 1.12;
  letter-spacing: -0.01em;
}

.subtitle {
  margin: 10px 0 0;
  font-size: 15px;
  color: var(--muted);
  font-family: var(--sans);
}

.meta {
  margin-top: var(--space-3);
  display: grid;
  gap: 10px;
  font-family: var(--sans);
  font-size: 14px;
  color: var(--muted);
}

.meta-row {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 12px;
  border-top: 1px dashed var(--hairline);
  padding-top: 10px;
}

.meta-label {
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-size: 12px;
}

.sec {
  padding: 0;
  margin: 0 0 var(--space-4);
}

.sec > h2 {
  margin: 0 0 var(--space-2);
  font-size: 15px;
  font-family: var(--sans);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding-top: var(--space-2);
  border-top: 1px solid var(--rule);
}

.sec > h2::before {
  counter-increment: section;
  content: counter(section) ". ";
  color: var(--muted);
  margin-right: 4px;
}

.sec p {
  margin: 0 0 var(--space-2);
  font-size: 16px;
}

.bullet {
  margin: 0;
  padding-left: 20px;
}

.bullet li {
  margin: 0 0 8px;
}

.muted {
  color: var(--muted);
  font-family: var(--sans);
  font-size: 14px;
}

.mono {
  font-family: var(--mono);
  font-size: 13px;
  word-break: break-all;
}

/* Execution (form) */
form {
  margin-top: var(--space-3);
  font-family: var(--sans);
}

.field {
  display: block;
  margin: 0 0 var(--space-3);
}

label {
  display: block;
  font-weight: 650;
  margin-bottom: 8px;
  font-family: var(--sans);
}

input[type="text"],
textarea {
  width: 100%;
  border: 1px solid var(--hairline);
  background: color-mix(in srgb, var(--paper), var(--page-bg) 8%);
  color: var(--ink);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 16px;
  line-height: 1.35;
  outline: none;
  font-family: var(--sans);
}

textarea {
  resize: vertical;
  min-height: 120px;
}

input[type="text"] {
  border-radius: 0;
  border: none;
  border-bottom: 1px solid var(--rule);
  background: transparent;
  padding: 10px 4px;
}

input[type="text"]::placeholder,
textarea::placeholder {
  color: color-mix(in srgb, var(--muted), var(--ink) 25%);
}

.checkbox-row {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 12px;
  border: 1px solid var(--hairline);
  border-radius: 10px;
  background: color-mix(in srgb, var(--paper), var(--page-bg) 8%);
  margin: 0 0 var(--space-3);
  font-family: var(--sans);
}

.checkbox-row input[type="checkbox"] {
  width: 18px;
  height: 18px;
  margin: 2px 0 0;
  flex: 0 0 auto;
}

.checkbox-row label {
  margin: 0;
  font-weight: 500;
}

.actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

button {
  border: 1px solid color-mix(in srgb, var(--accent), #000 12%);
  background: var(--accent);
  color: var(--accent-ink);
  border-radius: 10px;
  padding: 12px 14px;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  width: 100%;
  font-family: var(--sans);
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.cache-controls {
  margin-top: var(--space-2);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: flex-end;
}

.cache-controls .control {
  min-width: 100%;
  display: flex;
  flex-direction: column;
}

.cache-controls .control-label {
  display: block;
  margin-bottom: 4px;
}

.cache-controls .control select {
  min-width: min(360px, 100%);
  width: 100%;
}

.cache-controls button {
  width: auto;
  padding: 10px 12px;
  font-size: 14px;
  align-self: flex-end;
}

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

input[type="text"]:focus-visible,
textarea:focus-visible,
select:focus-visible,
button:focus-visible,
a:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
}

/* Receipt */
.receipt-intro {
  margin-bottom: var(--space-3);
}

.receipt-grid {
  margin: 0;
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 10px 14px;
  padding: var(--space-3);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  background: color-mix(in srgb, var(--paper), var(--page-bg) 6%);
  font-family: var(--sans);
}

.receipt-grid dt {
  margin: 0;
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding-top: 2px;
}

.receipt-grid dd {
  margin: 0;
  min-width: 0;
}

.downloads {
  margin-top: var(--space-3);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
  font-family: var(--sans);
}

.download-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 12px;
  border-radius: 999px;
  border: 1px solid var(--hairline);
  text-decoration: none;
  color: var(--ink);
  background: color-mix(in srgb, var(--paper), var(--page-bg) 10%);
  font-weight: 650;
}

.error {
  color: #b91c1c;
  font-family: var(--sans);
  font-size: 14px;
  margin: 10px 0 0;
}

.codeblock {
  margin: var(--space-2) 0 0;
  padding: var(--space-3);
  border-radius: 12px;
  border: 1px solid var(--hairline);
  background: color-mix(in srgb, var(--paper), var(--page-bg) 6%);
  font-family: var(--mono);
  font-size: 13px;
  overflow-x: auto;
  white-space: pre;
  line-height: 1.45;
}

.verify-result {
  white-space: pre-wrap;
  word-break: break-word;
}

@media (max-width: 520px) {
  .meta-row {
    grid-template-columns: 1fr;
  }

  .receipt-grid {
    grid-template-columns: 1fr;
  }

  select {
    min-width: 140px;
  }

  .brand {
    min-width: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    scroll-behavior: auto !important;
    transition: none !important;
    animation: none !important;
  }

  button:active {
    transform: none;
  }
}

@media print {
  body {
    padding: 0;
    background: #ffffff;
    color: #000000;
  }

  .topbar {
    display: none;
  }

  article.instrument {
    box-shadow: none;
    border: none;
    border-radius: 0;
    padding: 24px;
  }

  .download-link,
  button,
  select {
    display: none !important;
  }
}