:root {
  --bg-deep: #070814;
  --bg-mid: #16102c;
  --text: #f7f3ea;
  --text-dim: rgba(247, 243, 234, 0.7);
  --panel: rgba(16, 14, 32, 0.78);
  --line: rgba(255, 228, 168, 0.22);
  --gold: #f3d38a;
  --radius: 24px;
  --accent-a: #ff8a3d;
  --accent-b: #ffd166;
  --glow: rgba(255, 154, 67, 0.42);
  --display: "ZCOOL QingKe HuangYou", "Noto Sans SC", sans-serif;
}

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

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Noto Sans SC", sans-serif;
  color: var(--text);
  background: var(--bg-deep);
  overflow-x: hidden;
}

body[data-stage="primary"] {
  --accent-a: #ff8a3d;
  --accent-b: #ffd166;
  --glow: rgba(255, 154, 67, 0.42);
}

body[data-stage="junior"] {
  --accent-a: #2dd4bf;
  --accent-b: #7dd3fc;
  --glow: rgba(45, 212, 191, 0.36);
}

body[data-stage="senior"] {
  --accent-a: #8b5cf6;
  --accent-b: #f5c16c;
  --glow: rgba(139, 92, 246, 0.4);
}

.backdrop {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(1200px 640px at 50% -10%, rgba(88, 46, 160, 0.42), transparent 58%),
    linear-gradient(180deg, #1a1340 0%, var(--bg-deep) 72%);
}

.aurora {
  position: absolute;
  inset: -10% -8% auto;
  height: 58%;
  background:
    radial-gradient(circle at 18% 40%, color-mix(in srgb, var(--accent-a) 38%, transparent), transparent 36%),
    radial-gradient(circle at 82% 20%, rgba(245, 193, 108, 0.18), transparent 32%),
    radial-gradient(circle at 58% 70%, rgba(125, 211, 252, 0.12), transparent 34%);
  filter: blur(8px);
  animation: auroraShift 14s ease-in-out infinite;
}

.stars {
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(1px 1px at 8% 18%, rgba(255, 255, 255, 0.85), transparent),
    radial-gradient(1.4px 1.4px at 22% 42%, rgba(255, 236, 180, 0.7), transparent),
    radial-gradient(1px 1px at 36% 12%, rgba(255, 255, 255, 0.6), transparent),
    radial-gradient(1.2px 1.2px at 54% 28%, rgba(255, 255, 255, 0.75), transparent),
    radial-gradient(1px 1px at 71% 16%, rgba(255, 236, 180, 0.65), transparent),
    radial-gradient(1.5px 1.5px at 88% 34%, rgba(255, 255, 255, 0.7), transparent),
    radial-gradient(1px 1px at 14% 72%, rgba(255, 255, 255, 0.5), transparent),
    radial-gradient(1.2px 1.2px at 63% 78%, rgba(255, 236, 180, 0.55), transparent),
    radial-gradient(1px 1px at 81% 64%, rgba(255, 255, 255, 0.6), transparent);
  opacity: 0.85;
}

.vignette {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, transparent 55%, rgba(5, 6, 14, 0.55)),
    radial-gradient(circle at 50% 40%, transparent 42%, rgba(5, 6, 14, 0.55) 100%);
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(46px);
  pointer-events: none;
}

.orb-a {
  width: 280px;
  height: 280px;
  top: 8%;
  left: -80px;
  background: var(--accent-a);
  opacity: 0.28;
}

.orb-b {
  width: 340px;
  height: 340px;
  right: -90px;
  bottom: 4%;
  background: var(--accent-b);
  opacity: 0.16;
}

.orb-c {
  width: 180px;
  height: 180px;
  left: 42%;
  top: 18%;
  background: #7c5cff;
  opacity: 0.14;
}

.symbols {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  color: rgba(255, 236, 188, 0.18);
  font-family: var(--display);
  font-size: 30px;
}

.symbols span {
  position: absolute;
  animation: float 12s ease-in-out infinite;
}

.symbols span:nth-child(1) { top: 16%; left: 7%; }
.symbols span:nth-child(2) { top: 24%; right: 11%; animation-delay: -2s; }
.symbols span:nth-child(3) { top: 62%; left: 5%; animation-delay: -5s; }
.symbols span:nth-child(4) { bottom: 14%; right: 9%; animation-delay: -7s; }
.symbols span:nth-child(5) { top: 42%; right: 5%; animation-delay: -3s; }
.symbols span:nth-child(6) { bottom: 26%; left: 13%; animation-delay: -8s; }

@keyframes auroraShift {
  0%, 100% { transform: translateY(0) scale(1); opacity: 0.9; }
  50% { transform: translateY(12px) scale(1.04); opacity: 1; }
}

@keyframes float {
  0%, 100% { transform: translateY(0) rotate(0deg); opacity: 0.4; }
  50% { transform: translateY(-16px) rotate(8deg); opacity: 0.9; }
}

.shell {
  width: min(1140px, calc(100% - 32px));
  margin: 0 auto;
  padding: 26px 0 72px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 34px;
  padding: 12px 14px 12px 12px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0.03));
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.22);
  backdrop-filter: blur(18px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  text-decoration: none;
  color: inherit;
}

.logo {
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background:
    radial-gradient(circle at 30% 25%, #fff3c4, transparent 38%),
    linear-gradient(160deg, var(--accent-b), var(--accent-a));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.55),
    0 10px 24px var(--glow);
  color: #2a1608;
  font-family: var(--display);
  font-size: 28px;
}

.brand h1 {
  margin: 0;
  font-family: var(--display);
  font-size: 30px;
  letter-spacing: 0.08em;
}

.brand p {
  margin: 2px 0 0;
  color: var(--text-dim);
  font-size: 13px;
}

.badge {
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 214, 130, 0.08);
  color: var(--gold);
  font-size: 13px;
  text-decoration: none;
}

.hero {
  margin: 8px 0 8px;
  text-align: center;
}

.hero-chip {
  display: inline-flex;
  margin-bottom: 14px;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid rgba(255, 214, 130, 0.28);
  background: rgba(255, 214, 130, 0.1);
  color: var(--gold);
  font-size: 12px;
  letter-spacing: 0.12em;
}

.hero h2 {
  margin: 0 0 10px;
  font-family: var(--display);
  font-size: clamp(36px, 6vw, 64px);
  letter-spacing: 0.08em;
  background: linear-gradient(180deg, #fff8e4 10%, #f3d38a 52%, #e8b15a 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 10px 24px rgba(243, 211, 138, 0.2));
}

.hero p {
  margin: 0 auto;
  max-width: 28em;
  color: var(--text-dim);
  font-size: 16px;
}

.stage-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin: 32px 0 42px;
}

.stage-card,
.grade-card,
.placeholder {
  position: relative;
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.05), transparent 28%),
    var(--panel);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.08),
    0 18px 40px rgba(0, 0, 0, 0.28);
}

.stage-card {
  overflow: hidden;
  padding: 0;
  border-radius: var(--radius);
  color: var(--text);
  text-align: left;
  cursor: pointer;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.stage-card[data-stage="primary"] { --card-a: #ff8a3d; --card-b: #ffd166; }
.stage-card[data-stage="junior"] { --card-a: #2dd4bf; --card-b: #7dd3fc; }
.stage-card[data-stage="senior"] { --card-a: #8b5cf6; --card-b: #f5c16c; }

.stage-card:hover,
.stage-card.is-active {
  transform: translateY(-8px);
  border-color: color-mix(in srgb, var(--card-a) 72%, white);
  box-shadow:
    0 0 0 1px color-mix(in srgb, var(--card-a) 45%, transparent),
    0 22px 40px color-mix(in srgb, var(--card-a) 28%, transparent);
}

.stage-art {
  height: 112px;
  overflow: hidden;
}

.stage-art svg {
  display: block;
  width: 100%;
  height: 100%;
}

.stage-body {
  padding: 18px 20px 20px;
}

.stage-icon {
  width: 42px;
  height: 42px;
  margin: -36px 0 12px;
  border-radius: 13px;
  display: grid;
  place-items: center;
  background: linear-gradient(160deg, var(--card-b), var(--card-a));
  box-shadow: 0 8px 18px color-mix(in srgb, var(--card-a) 40%, transparent);
  color: #1a120c;
  font-size: 22px;
  position: relative;
}

.stage-card h3 {
  margin: 0 0 6px;
  font-family: var(--display);
  font-size: 30px;
  letter-spacing: 0.08em;
}

.stage-card p {
  margin: 0 0 14px;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.6;
}

.stage-meta {
  display: inline-flex;
  padding: 5px 10px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(0, 0, 0, 0.22);
  color: color-mix(in srgb, var(--card-b) 80%, white);
  font-size: 12px;
}

.frame-corner {
  position: absolute;
  width: 16px;
  height: 16px;
  z-index: 2;
  pointer-events: none;
  border: 2px solid var(--gold);
  opacity: 0.72;
}

.frame-corner.tl { top: 10px; left: 10px; border-right: 0; border-bottom: 0; }
.frame-corner.tr { top: 10px; right: 10px; border-left: 0; border-bottom: 0; }
.frame-corner.bl { bottom: 10px; left: 10px; border-right: 0; border-top: 0; }
.frame-corner.br { bottom: 10px; right: 10px; border-left: 0; border-top: 0; }

.grade-section {
  padding: 8px 2px 0;
}

.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 18px;
}

.section-kicker {
  display: block;
  margin-bottom: 4px;
  color: var(--gold);
  font-size: 12px;
  letter-spacing: 0.16em;
}

.section-head h2 {
  margin: 0;
  font-family: var(--display);
  font-size: 30px;
  letter-spacing: 0.08em;
}

.section-head p {
  margin: 0;
  color: var(--text-dim);
  font-size: 14px;
}

.grade-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.grade-card {
  display: flex;
  flex-direction: column;
  min-height: 214px;
  padding: 24px 22px 20px;
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.grade-card::before {
  content: "";
  position: absolute;
  inset: auto -20% 42% -20%;
  height: 90px;
  background: radial-gradient(circle, var(--glow), transparent 68%);
  opacity: 0.55;
  pointer-events: none;
}

.grade-card:hover {
  transform: translateY(-8px);
  border-color: color-mix(in srgb, var(--accent-a) 70%, white);
  box-shadow: 0 20px 36px var(--glow);
}

.grade-index {
  position: relative;
  width: 46px;
  height: 46px;
  margin-bottom: 18px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: linear-gradient(160deg, var(--accent-b), var(--accent-a));
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.5),
    0 8px 16px var(--glow);
  color: #24140a;
  font-weight: 700;
}

.grade-card h3 {
  position: relative;
  margin: 0 0 8px;
  font-family: var(--display);
  font-size: 28px;
  letter-spacing: 0.08em;
}

.grade-card p {
  position: relative;
  margin: 0 0 auto;
  color: var(--text-dim);
  font-size: 14px;
}

.enter,
.primary-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 16px;
  border-radius: 13px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.28), transparent 42%),
    linear-gradient(135deg, var(--accent-b), var(--accent-a));
  box-shadow:
    inset 0 -3px 0 rgba(0, 0, 0, 0.18),
    0 8px 16px var(--glow);
  color: #24140a;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.enter {
  margin-top: 18px;
  align-self: stretch;
}

.grade-grid.is-switching {
  animation: fadeSwap 0.28s ease;
}

@keyframes fadeSwap {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.catalog {
  margin-top: 8px;
}

.catalog-trail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 12px;
  margin: -8px 0 26px;
  color: var(--text-dim);
  font-size: 13px;
  line-height: 1.8;
}

.catalog-trail a { color: var(--text-dim); text-decoration: none; }
.catalog-trail a:hover { color: var(--gold); text-decoration: underline; }
.catalog-trail [aria-current="page"] { color: var(--gold); }
.catalog-trail a:focus-visible, .grade-card:focus-visible { outline: 3px solid var(--gold); outline-offset: 5px; }
.book-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.book-card { min-height: 280px; }
.category-order { margin: 0 22px 10px; color: var(--gold); font-size: 12px; letter-spacing: 0.1em; }

.edition {
  position: relative;
  display: inline-flex;
  align-self: flex-start;
  margin-bottom: 10px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid rgba(255, 214, 130, 0.28);
  background: rgba(255, 214, 130, 0.1);
  color: var(--gold);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.project-card .grade-index {
  margin-bottom: 12px;
}

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

.unit-empty {
  grid-column: 1 / -1;
  padding: 48px 24px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  text-align: center;
}

.unit-empty h3 { margin: 0 0 12px; font-size: 22px; }
.unit-empty p { margin: 0; color: var(--text-dim); font-size: 14px; line-height: 1.8; }

.category-card {
  padding: 0 0 20px;
}

.category-art {
  height: 120px;
  margin-bottom: 18px;
  overflow: hidden;
}

.category-art svg {
  display: block;
  width: 100%;
  height: 100%;
}

.category-card h3,
.category-card p,
.category-card .enter {
  margin-left: 22px;
  margin-right: 22px;
}

.placeholder {
  width: min(640px, 100%);
  margin: 56px auto 0;
  padding: 48px 32px 40px;
  border-radius: 30px;
  text-align: center;
  overflow: hidden;
}

.mark-wrap {
  position: relative;
  width: 96px;
  height: 96px;
  margin: 0 auto 18px;
}

.mark-ring {
  position: absolute;
  inset: 0;
  border: 1px solid rgba(243, 211, 138, 0.45);
  border-radius: 50%;
  animation: pulse 2.6s ease-in-out infinite;
}

.mark {
  position: absolute;
  inset: 14px;
  border-radius: 22px;
  display: grid;
  place-items: center;
  background: linear-gradient(160deg, var(--accent-b), var(--accent-a));
  box-shadow: 0 10px 24px var(--glow);
  color: #24140a;
  font-size: 34px;
}

.placeholder .crumb {
  margin: 0 0 10px;
  color: var(--gold);
  letter-spacing: 0.14em;
  font-size: 13px;
}

.placeholder h2 {
  margin: 0 0 10px;
  font-family: var(--display);
  font-size: 52px;
  letter-spacing: 0.1em;
}

.placeholder p {
  margin: 0 0 26px;
  color: var(--text-dim);
}

.primary-link {
  min-width: 148px;
  text-decoration: none;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.7; }
  50% { transform: scale(1.08); opacity: 1; }
}

@media (max-width: 860px) {
  .stage-grid,
  .grade-grid,
  .category-grid {
    grid-template-columns: 1fr 1fr;
  }

  .topbar {
    align-items: center;
  }
}

@media (max-width: 560px) {
  .stage-grid,
  .grade-grid,
  .category-grid {
    grid-template-columns: 1fr;
  }

  .section-head {
    flex-direction: column;
    align-items: flex-start;
  }

  .section-head h2 {
    font-size: 24px;
    white-space: nowrap;
  }

  .brand h1,
  .placeholder h2 {
    font-size: 28px;
  }

  .placeholder {
    padding: 32px 20px;
  }
}

.area-lesson {
  margin-top: 8px;
}

.lesson-picker {
  display: flex;
  gap: 8px;
  margin: 8px 0 16px;
}

.lesson-picker button {
  min-height: 40px;
  padding: 0 16px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--text-dim);
  font: inherit;
  cursor: pointer;
}

.lesson-picker button[aria-selected="true"] {
  border-color: transparent;
  background: linear-gradient(135deg, var(--accent-b), var(--accent-a));
  color: #24140a;
  font-weight: 700;
}

.area-head .crumb,
.area-kicker {
  margin: 0;
  color: var(--gold);
  letter-spacing: 0.14em;
  font-size: 13px;
}

.area-kicker {
  margin-top: 8px;
}

.area-head h2 {
  margin: 8px 0 8px;
  font-family: var(--display);
  font-size: 42px;
  letter-spacing: 0.08em;
}

.area-head p:last-child {
  margin: 0;
  max-width: 40em;
  color: var(--text-dim);
}

.area-board {
  display: grid;
  grid-template-columns: 168px minmax(0, 1fr) 250px;
  gap: 16px;
  margin-top: 22px;
  align-items: start;
}

.area-steps {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.area-steps button,
.area-btn,
.area-seg button {
  font: inherit;
  color: inherit;
  cursor: pointer;
}

.area-steps button {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  min-height: 42px;
  padding: 6px 10px;
  border: 1px solid transparent;
  border-radius: 14px;
  background: transparent;
  color: var(--text-dim);
  text-align: left;
}

.area-steps button span {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, 0.08);
  font-size: 12px;
  flex: none;
}

.area-steps button.is-current {
  border-color: rgba(255, 214, 130, 0.45);
  background: rgba(255, 214, 130, 0.1);
  color: var(--text);
}

.area-steps button.is-current span {
  background: linear-gradient(160deg, var(--accent-b), var(--accent-a));
  color: #24140a;
  font-weight: 700;
}

.area-stage,
.area-insight,
.area-formula {
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.05), transparent 30%),
    rgba(8, 8, 18, 0.72);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

.area-stage {
  border-radius: 24px;
  padding: 8px 8px 12px;
}

.area-stage svg {
  display: block;
  width: 100%;
  height: auto;
  touch-action: manipulation;
}

.area-stage .disk {
  fill: #ffb15e;
}

.area-stage .slice {
  stroke: rgba(255, 255, 255, 0.92);
  stroke-width: 1.6px;
  stroke-linejoin: round;
  vector-effect: non-scaling-stroke;
  cursor: pointer;
}

.area-stage .slice.is-hot,
.area-stage #refRed.is-hot,
.area-stage #refBlue.is-hot {
  stroke: #ffe08a;
  stroke-width: 3px;
}

.area-stage #refRed { fill: rgba(255, 90, 106, 0.72); }
.area-stage #refBlue { fill: rgba(60, 125, 255, 0.72); }

.area-stage .ring {
  fill: none;
  stroke: rgba(255, 246, 232, 0.9);
  stroke-width: 2px;
  vector-effect: non-scaling-stroke;
  pointer-events: none;
}

.area-stage .guide-hit {
  stroke: rgba(255, 224, 138, 0.01);
  stroke-width: 18px;
  pointer-events: stroke;
  vector-effect: non-scaling-stroke;
}

.area-stage .on-circle {
  stroke: #fff8ea;
}

.area-stage .rim-dot {
  fill: #fff8ea;
  stroke: #24140a;
  stroke-width: 1.5px;
}

.area-stage .guide-line,
.area-stage .dim-line,
.area-stage .dim-tick {
  stroke: #ffe08a;
  stroke-width: 2.5px;
  stroke-linecap: round;
  vector-effect: non-scaling-stroke;
  pointer-events: none;
  fill: none;
}

.area-stage .radius-line.hint-pulse {
  animation: radiusHint 1.5s ease-in-out infinite;
}

.area-stage .dim-line-group.is-on .dim-line,
.area-stage .guide-line.is-hot {
  stroke: #fff6d4;
  stroke-width: 4px;
}

.area-stage .center-dot {
  fill: #1b1428;
  stroke: #fff6e8;
  stroke-width: 2px;
  cursor: pointer;
}

.area-stage .center-dot.is-hot,
.area-stage #centerDot.is-hot .center-dot {
  stroke: #ffe08a;
}

.area-stage text {
  font-family: "Noto Sans SC", sans-serif;
  font-size: 18px;
  font-weight: 700;
  fill: #ffe08a;
}

.area-stage .center-label {
  fill: #fff8ea;
  font-size: 15px;
  cursor: pointer;
}

.area-stage .dim-label {
  cursor: pointer;
}

.area-stage .dim-label rect {
  fill: rgba(18, 14, 28, 0.88);
  stroke: rgba(255, 224, 138, 0.9);
  stroke-width: 1.4;
}

.area-stage .dim-label.is-on rect {
  fill: #ffe08a;
}

.area-stage .dim-label.is-on text {
  fill: #24140a;
}

.area-stage .shape-outline {
  fill: rgba(255, 224, 138, 0.001);
  stroke: rgba(255, 224, 138, 0.95);
  stroke-width: 2px;
  stroke-dasharray: 7 5;
  vector-effect: non-scaling-stroke;
  pointer-events: none;
}

.area-stage .shape-outline[data-hot] {
  pointer-events: all;
  cursor: pointer;
  fill: rgba(255, 224, 138, 0.08);
}

.area-stage .shape-outline.is-on {
  fill: rgba(255, 224, 138, 0.2);
}

.area-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  align-items: center;
  margin: 4px 12px 2px;
  color: var(--text-dim);
  font-size: 13px;
}

.swatch {
  width: 12px;
  height: 12px;
  border-radius: 4px;
  display: inline-block;
  margin-right: 4px;
}

.swatch.red { background: #ff5a6a; }
.swatch.blue { background: #3c7dff; }

.area-insight {
  border-radius: 24px;
  padding: 18px 16px 16px;
}

.area-step-no {
  margin: 0 0 6px;
  color: var(--gold);
  font-size: 12px;
  letter-spacing: 0.12em;
}

.area-insight h3 {
  margin: 0 0 8px;
  font-family: var(--display);
  font-size: 28px;
  letter-spacing: 0.06em;
}

.area-insight p {
  margin: 0;
  color: var(--text-dim);
  line-height: 1.65;
}

.hot-card {
  margin-top: 14px;
  padding: 12px 12px 14px;
  border-radius: 16px;
  background: rgba(255, 214, 130, 0.1);
  border: 1px solid rgba(255, 214, 130, 0.28);
}

.hot-card p:first-child {
  margin-bottom: 4px;
  color: var(--gold);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.hot-card h4 {
  margin: 0 0 6px;
  font-size: 18px;
}

.hot-value {
  margin-bottom: 6px;
  color: #ffe08a;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.hot-card #hotNote {
  color: var(--text);
}

.area-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-top: 14px;
}

.area-btn {
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: rgba(255, 255, 255, 0.04);
}

.area-btn:disabled {
  opacity: 0.4;
  cursor: default;
}

.area-btn-primary {
  border: none;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.28), transparent 42%),
    linear-gradient(135deg, var(--accent-b), var(--accent-a));
  box-shadow: inset 0 -3px 0 rgba(0, 0, 0, 0.18), 0 8px 16px var(--glow);
  color: #24140a;
  font-weight: 700;
}

.area-seg {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text-dim);
  font-size: 14px;
}

.area-seg button {
  min-height: 36px;
  padding: 0 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: transparent;
}

.area-seg button.is-current {
  border-color: transparent;
  background: linear-gradient(135deg, var(--accent-b), var(--accent-a));
  color: #24140a;
  font-weight: 700;
}

.area-radius {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-dim);
  font-size: 14px;
}

.area-radius strong {
  color: var(--text);
  min-width: 1.2em;
}

.area-radius input {
  accent-color: #ffb15e;
  width: 120px;
}

.area-formula {
  margin: 14px 0 0;
  padding: 14px 16px;
  border-radius: 18px;
  color: var(--text);
  line-height: 1.6;
}

.area-formula strong {
  color: #ffe08a;
  font-size: 18px;
}

@keyframes radiusHint {
  0%, 100% { stroke-width: 2.5px; }
  50% { stroke-width: 5px; }
}

@media (max-width: 980px) {
  .area-board {
    grid-template-columns: 1fr;
  }

  .area-steps {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .area-steps button {
    width: auto;
    white-space: nowrap;
  }
}

@media (max-width: 560px) {
  .area-head h2 {
    font-size: 32px;
  }

  .area-insight h3 {
    font-size: 24px;
  }
}

.shade-picks {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.shade-picks button {
  min-height: 36px;
  padding: 0 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--text-dim);
  font: inherit;
  cursor: pointer;
}

.shade-picks button[aria-selected="true"] {
  border-color: transparent;
  background: linear-gradient(135deg, var(--accent-b), var(--accent-a));
  color: #24140a;
  font-weight: 700;
}

.shade-lesson .area-stage svg {
  touch-action: none;
  cursor: grab;
  user-select: none;
}

.shade-lesson .area-stage svg:active {
  cursor: grabbing;
}

.shade-lesson .shade {
  fill: rgba(110, 182, 255, 0.92);
  stroke: #f4fbff;
  stroke-width: 2;
  stroke-linejoin: round;
}

.shade-lesson .board {
  fill: #171926;
  stroke: #f3ecdf;
  stroke-width: 2.5;
}

.shade-lesson .paper {
  fill: rgba(255, 255, 255, 0.03);
  stroke: #f3ecdf;
  stroke-width: 2.5;
}

.shade-lesson .ink {
  fill: none;
  stroke: #f3ecdf;
  stroke-width: 2.5;
  stroke-linejoin: round;
}

.shade-lesson .ghost {
  fill: none;
  stroke: rgba(243, 236, 223, 0.45);
  stroke-width: 2;
  stroke-dasharray: 6 6;
}

.shade-lesson .label {
  fill: #ffe08a;
  font-family: "Noto Sans SC", sans-serif;
  font-size: 16px;
  font-weight: 700;
}