:root {
  --bg: #f3ede3;
  --ink: #1f2937;
  --muted: #5f6b73;
  --paper: #fff7ec;
  --line: #e2d2bc;
  --accent: #0f766e;
  --accent-dark: #0b5f57;
  --accent-warm: #d97706;
  --shadow: 0 24px 48px rgba(16, 24, 40, 0.12);
  --radius: 22px;
  --font-zh: "Noto Serif CJK SC", "Source Han Serif SC", "Songti SC", "STSong",
    "SimSun", serif;
  --font-ja: "Noto Serif JP", "Source Han Serif JP", "Yu Mincho",
    "Hiragino Mincho ProN", "MS Mincho", serif;
  --font-en: "Cormorant Garamond", "Playfair Display", "Times New Roman",
    "Georgia", serif;
  --font-base: var(--font-zh);
  --font-display: var(--font-zh);
  --weight-base: 400;
  --weight-display: 600;
}

* {
  box-sizing: border-box;
}

html[lang^="zh"] {
  --font-base: var(--font-zh);
  --font-display: var(--font-zh);
}

html[lang^="ja"] {
  --font-base: var(--font-ja);
  --font-display: var(--font-ja);
  --weight-base: 500;
  --weight-display: 600;
}

html[lang^="en"] {
  --font-base: var(--font-en);
  --font-display: var(--font-en);
}

body {
  margin: 0;
  background:
    radial-gradient(900px 600px at 10% -10%, rgba(244, 200, 127, 0.35), transparent),
    radial-gradient(800px 500px at 120% 10%, rgba(141, 208, 201, 0.35), transparent),
    linear-gradient(180deg, #fdf9f2 0%, #f2e8d9 100%);
  color: var(--ink);
  font-family: var(--font-base);
  font-weight: var(--weight-base);
  line-height: 1.5;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    repeating-linear-gradient(
      0deg,
      rgba(31, 41, 55, 0.06) 0,
      rgba(31, 41, 55, 0.06) 1px,
      transparent 1px,
      transparent 28px
    ),
    repeating-linear-gradient(
      90deg,
      rgba(31, 41, 55, 0.06) 0,
      rgba(31, 41, 55, 0.06) 1px,
      transparent 1px,
      transparent 28px
    );
  opacity: 0.2;
  pointer-events: none;
}

.page {
  position: relative;
  max-width: 1120px;
  margin: 28px auto 48px;
  padding: 0 20px 40px;
}

.page > * {
  position: relative;
  z-index: 1;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: 24px;
  align-items: end;
  margin-bottom: 24px;
}

.kicker {
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 12px;
  color: var(--muted);
  margin: 0 0 8px;
}

h1 {
  font-family: var(--font-display);
  font-size: 34px;
  font-weight: var(--weight-display);
  margin: 0 0 8px;
}

.lead {
  margin: 0;
  color: var(--muted);
  max-width: 46ch;
}

.hero-actions {
  display: grid;
  gap: 12px;
  justify-items: start;
}

.lang-switch {
  display: inline-flex;
  gap: 6px;
  padding: 6px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fffaf2;
  box-shadow: var(--shadow);
}

.chip {
  border: none;
  background: transparent;
  padding: 6px 14px;
  border-radius: 999px;
  cursor: pointer;
  color: var(--muted);
  font-weight: 600;
  transition: all 0.2s ease;
}

.chip.active {
  background: var(--accent);
  color: #f8fafc;
}

.mode-switch {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  width: 100%;
}

.mode {
  border: 1px solid var(--line);
  background: #fff7ec;
  padding: 10px 12px;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 600;
  color: var(--ink);
  transition: all 0.2s ease;
}

.mode.active {
  border-color: var(--accent);
  background: #e7f5f2;
  color: var(--accent-dark);
  box-shadow: 0 10px 20px rgba(15, 118, 110, 0.18);
}

.unit-tip {
  font-size: 13px;
  color: var(--muted);
  background: #fffaf2;
  border: 1px dashed var(--line);
  padding: 10px 12px;
  border-radius: 12px;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 24px;
}

.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  animation: fadeUp 0.6s ease both;
}

.card-head {
  margin-bottom: 18px;
}

.card-head h2 {
  margin: 0 0 6px;
  font-size: 22px;
}

.card-sub {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.label {
  font-weight: 600;
}

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

.input-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 6px 10px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: #ffffff;
  transition: border 0.2s ease, box-shadow 0.2s ease;
}

.input-wrap:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.15);
}

input[type="number"] {
  width: 100%;
  border: none;
  outline: none;
  font-size: 16px;
  background: transparent;
  color: var(--ink);
  padding: 6px 0;
  font-family: inherit;
}

.unit {
  font-size: 12px;
  font-weight: 600;
  padding: 4px 8px;
  border-radius: 999px;
  background: #f1e6d5;
  color: #7a5a35;
  white-space: nowrap;
}

.actions {
  margin-top: 18px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

button.primary {
  background: linear-gradient(135deg, var(--accent) 0%, #14877d 100%);
  border: none;
  color: #f8fafc;
  padding: 10px 18px;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 600;
  box-shadow: 0 12px 24px rgba(15, 118, 110, 0.22);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

button.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 30px rgba(15, 118, 110, 0.25);
}

button.ghost {
  background: transparent;
  border: 1px solid var(--line);
  color: var(--ink);
  padding: 10px 18px;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.2s ease;
}

button.ghost:hover {
  border-color: var(--accent);
  color: var(--accent-dark);
}

.panel {
  display: none;
}

.panel.active {
  display: block;
}

.panel.result.active {
  display: grid;
  gap: 16px;
}

.panel[hidden] {
  display: none !important;
}

.results {
  position: relative;
  overflow: hidden;
}

.empty {
  padding: 24px;
  border: 1px dashed var(--line);
  border-radius: 18px;
  background: #fffaf2;
  text-align: center;
  color: var(--muted);
}

.empty-title {
  font-size: 18px;
  margin: 0 0 6px;
  color: var(--ink);
  font-weight: 600;
}

.empty-body {
  margin: 0;
  font-size: 14px;
}


.result-hero {
  padding: 18px;
  border-radius: 18px;
  background: linear-gradient(135deg, #0f766e 0%, #0b5f57 100%);
  color: #f8fafc;
  box-shadow: 0 18px 30px rgba(15, 118, 110, 0.3);
}

.result-eyebrow {
  margin: 0 0 6px;
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  opacity: 0.8;
}

.result-value {
  margin: 0;
  font-family: var(--font-display);
  font-size: 34px;
  font-weight: var(--weight-display);
}

.result-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.result-card {
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: #ffffff;
  display: grid;
  gap: 6px;
}

.result-label {
  font-size: 13px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

.result-number {
  font-size: 18px;
  font-weight: 600;
  color: var(--ink);
}

.result-value.is-alert {
  color: #fde68a;
}

.result-number.is-alert {
  color: #b45309;
}

.note {
  margin: 0;
  font-size: 12px;
  color: var(--muted);
}

.footer {
  margin-top: 24px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
}

.footer p {
  margin: 0;
}

.footer-link {
  margin-top: 6px;
}

.footer-link a {
  color: var(--accent-dark);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.footer-link a:hover {
  border-bottom-color: var(--accent-dark);
}

.footer-link a:focus-visible {
  outline: 2px solid rgba(15, 118, 110, 0.35);
  outline-offset: 2px;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 960px) {
  .hero {
    grid-template-columns: 1fr;
  }

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

  .mode-switch {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .page {
    margin: 18px auto 36px;
  }

  h1 {
    font-size: 28px;
  }

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

  .result-list {
    grid-template-columns: 1fr;
  }

  .card {
    padding: 18px;
  }
}

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