:root {
  --bg: #f3efe6;
  --bg-deep: #e6dfd1;
  --paper: #fffdf8;
  --ink: #1c1915;
  --muted: #5f584e;
  --line: #ddd4c4;
  --accent: #0f6e62;
  --accent-soft: #e5f4f0;
  --coral: #c4552a;
  --danger: #8d2c2c;
  --shadow: 0 20px 50px rgba(48, 36, 16, 0.08);
  --serif: "Noto Serif", "Songti SC", "Noto Serif CJK SC", Georgia, serif;
  --sans: Inter, "WenQuanYi Micro Hei", "PingFang SC", "Noto Sans CJK SC",
    "Microsoft YaHei", "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", "Sarasa Mono SC", ui-monospace, "SFMono-Regular",
    Menlo, Consolas, monospace;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(900px 420px at 0% -10%, rgba(255, 250, 240, 0.9), transparent 60%),
    linear-gradient(180deg, #f7f3ea 0%, var(--bg) 40%, var(--bg-deep) 100%);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.55;
}

a {
  color: inherit;
}

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 5;
  padding: 0.5rem 0.8rem;
  background: var(--ink);
  color: var(--paper);
  border-radius: 8px;
}

.skip:focus {
  top: 0.75rem;
}

.wrap {
  width: min(1080px, calc(100% - 2rem));
  margin: 0 auto;
}

.site-header,
.site-footer {
  width: min(1080px, calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  display: block;
  padding: 1.1rem 0 0.35rem;
}

.header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.mark {
  width: 1.7rem;
  height: 1.7rem;
  border-radius: 7px;
  background: var(--ink);
  box-shadow: inset 0 0 0 2px #ef7d4a;
  position: relative;
}

.mark::after {
  content: "";
  position: absolute;
  width: 0.38rem;
  height: 0.38rem;
  border-radius: 50%;
  background: #f4efe6;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}

.lang {
  display: flex;
  gap: 0.35rem;
  padding: 0.2rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 253, 248, 0.7);
}

.lang a {
  text-decoration: none;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  color: var(--muted);
  font-size: 0.92rem;
}

.lang a[aria-current="page"] {
  background: var(--ink);
  color: #f7f3ea;
}

main {
  padding-bottom: 3rem;
}

.hero {
  padding: 1rem 0 1.4rem;
}

.kicker {
  margin: 0 0 0.6rem;
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  font-family: var(--serif);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

h1 {
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 4.4rem);
}

.lede {
  max-width: 40rem;
  margin: 0.9rem 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.tool {
  display: grid;
  grid-template-columns: minmax(240px, 0.85fr) 1.3fr;
  gap: 0;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.controls,
.results {
  padding: 1.35rem;
}

.controls {
  background:
    linear-gradient(180deg, rgba(15, 110, 98, 0.08), transparent 90px),
    var(--paper);
  border-right: 1px solid var(--line);
}

.field label,
.results-bar h2 {
  display: block;
  margin: 0;
}

.field label {
  font-weight: 700;
  margin-bottom: 0.55rem;
}

.stepper {
  display: grid;
  grid-template-columns: 2.7rem 1fr 2.7rem;
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
  background: #fff;
}

.stepper button,
.stepper input {
  border: 0;
  background: transparent;
  color: var(--ink);
  font: inherit;
}

.stepper button {
  cursor: pointer;
  font-size: 1.3rem;
}

.stepper button:hover,
.stepper button:focus-visible {
  background: var(--accent-soft);
}

.stepper input {
  width: 100%;
  min-height: 3.1rem;
  text-align: center;
  font-family: var(--mono);
  font-size: 1.25rem;
  border-left: 1px solid var(--line);
  border-right: 1px solid var(--line);
  -moz-appearance: textfield;
  appearance: textfield;
}

.stepper input::-webkit-outer-spin-button,
.stepper input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.stepper input:focus {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}

.hint,
.privacy,
.faq p,
.steps p,
.site-footer p {
  color: var(--muted);
}

.hint,
.error,
.privacy {
  margin: 0.7rem 0 0;
  font-size: 0.92rem;
}

.error {
  color: var(--danger);
  font-weight: 600;
}

.btn {
  appearance: none;
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 0.75rem 1.1rem;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.btn-primary {
  width: 100%;
  margin-top: 1rem;
  background: var(--ink);
  color: #f6f1e6;
}

.btn-primary:hover {
  background: #312c26;
}

.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--ink);
}

.btn-ghost:hover {
  border-color: var(--ink);
}

.btn-small {
  padding: 0.4rem 0.75rem;
  font-size: 0.85rem;
  white-space: nowrap;
}

.btn:focus-visible,
.lang a:focus-visible,
.brand:focus-visible,
.faq summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.results {
  display: flex;
  flex-direction: column;
  min-height: 100%;
  background: #fbf7f0;
}

.results-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.9rem;
}

.results-bar h2 {
  font-size: 1.25rem;
}

.results-bar h2 span {
  display: inline-grid;
  place-items: center;
  min-width: 1.6rem;
  margin-left: 0.3rem;
  padding: 0.05rem 0.4rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-family: var(--sans);
  font-size: 0.85rem;
  font-weight: 700;
}

.empty {
  margin: 0;
  padding: 1.4rem 1rem;
  border: 1px dashed var(--line);
  border-radius: 14px;
  text-align: center;
  color: var(--muted);
}

.results ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.result-row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 0.7rem;
  align-items: center;
  padding: 0.55rem 0.65rem;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
}

.result-index {
  min-width: 1.4rem;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.78rem;
  text-align: right;
}

.result-row code {
  font-family: var(--mono);
  font-size: 0.92rem;
  word-break: break-all;
}

.steps,
.about,
.faq {
  margin-top: 2.4rem;
}

.section-title {
  margin: 0 0 0.9rem;
  font-size: clamp(1.6rem, 3vw, 2.1rem);
}

.step-grid,
.about-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.8rem;
}

.step-grid article,
.faq details,
.about-grid article {
  background: rgba(255, 253, 248, 0.78);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 1rem 1rem 0.9rem;
}

.step-num {
  margin: 0;
  color: var(--coral);
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 700;
}

.step-grid h3,
.faq summary,
.about-grid h3 {
  margin: 0.35rem 0 0.35rem;
  font-size: 1.15rem;
}

.step-grid p,
.faq p,
.about-grid p {
  margin: 0;
}

.faq {
  display: grid;
  gap: 0.6rem;
}

.faq details {
  padding: 0.35rem 1rem 0.2rem;
}

.faq summary {
  cursor: pointer;
  padding: 0.7rem 0;
}

.faq details p {
  padding-bottom: 0.85rem;
}

.site-footer {
  padding: 0.5rem 0 2rem;
  border-top: 1px solid transparent;
}

.site-footer p {
  margin: 0;
  font-size: 0.92rem;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 800px) {
  .tool,
  .step-grid,
  .about-grid {
    grid-template-columns: 1fr;
  }

  .controls {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .result-row {
    grid-template-columns: auto minmax(0, 1fr);
  }

  .result-row .btn {
    grid-column: 1 / -1;
    justify-self: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

.tool-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  padding: 0.85rem 0 0.15rem;
}

.tool-nav a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.86rem;
  padding: 0.28rem 0.65rem;
  border-radius: 999px;
  border: 1px solid transparent;
}

.tool-nav a[aria-current="page"] {
  color: var(--ink);
  font-weight: 700;
  background: var(--paper);
  border-color: var(--line);
}

.versions {
  border: 0;
  margin: 0 0 1rem;
  padding: 0;
}

.versions legend {
  font-weight: 700;
  padding: 0;
  margin-bottom: 0.45rem;
}

.version-options {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.version-options label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  font-weight: 600;
}

textarea,
.mono-input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-family: var(--mono);
  font-size: 0.92rem;
}

textarea {
  min-height: 9rem;
  padding: 0.75rem;
  resize: vertical;
}

.bulk-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-top: 0.85rem;
}

.prose h2 {
  margin: 1.7rem 0 0.55rem;
  font-size: clamp(1.45rem, 3vw, 1.9rem);
}

.prose p,
.prose li {
  margin-top: 0;
}

.prose ul {
  margin: 0.4rem 0 0;
  padding-left: 1.15rem;
}

.prose li + li {
  margin-top: 0.35rem;
}

pre {
  margin: 0.8rem 0 0;
  padding: 0.95rem 1rem;
  overflow: auto;
  background: #1c1915;
  color: #f6f1e6;
  border-radius: 14px;
  font-family: var(--mono);
  font-size: 0.84rem;
  line-height: 1.5;
}

.table-scroll {
  overflow-x: auto;
  margin-top: 0.8rem;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--paper);
}

.compare,
.checks {
  width: 100%;
  border-collapse: collapse;
}

.compare th,
.compare td,
.checks th,
.checks td {
  text-align: left;
  vertical-align: top;
  padding: 0.7rem 0.8rem;
  border-bottom: 1px solid var(--line);
}

.compare th,
.checks th {
  background: #f6f1e6;
  font-size: 0.88rem;
}

.checks td:nth-child(2),
.decode-card code,
.decode-card dd {
  font-family: var(--mono);
  font-size: 0.86rem;
  word-break: break-all;
}

.decode-card {
  padding: 0.75rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--paper);
}

.decode-card + .decode-card {
  margin-top: 0.5rem;
}

.decode-card dl {
  display: grid;
  grid-template-columns: minmax(7.5rem, 10rem) minmax(0, 1fr);
  gap: 0.28rem 0.7rem;
  margin: 0.55rem 0 0;
}

.decode-card dt {
  color: var(--muted);
}

.decode-card dd {
  margin: 0;
}

.ok {
  color: var(--accent);
  font-weight: 700;
}

.bad {
  color: var(--danger);
  font-weight: 700;
}

.related {
  margin-top: 2.2rem;
}

.related ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.9rem;
  margin: 0.4rem 0 0;
  padding: 0;
  list-style: none;
}

.related a {
  color: var(--accent);
}

.mono-input {
  min-height: 3.1rem;
  padding: 0.65rem 0.75rem;
}

.swatch {
  min-height: 8.5rem;
  border-radius: 16px;
  border: 1px solid rgba(28, 25, 21, 0.18);
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.color-stats {
  display: grid;
  gap: 0.45rem;
  margin: 0.9rem 0 0;
}

.color-stats div {
  display: grid;
  grid-template-columns: 7rem minmax(0, 1fr);
  gap: 0.6rem;
  align-items: baseline;
}

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

.color-stats dd {
  margin: 0;
  font-family: var(--mono);
  word-break: break-all;
}

[hidden] {
  display: none !important;
}

.output {
  display: flex;
  flex-direction: column;
}