body.case-light *,
body.case-light *::before,
body.case-light *::after {
  box-sizing: border-box;
}

body.case-light {
  --bg: #f6f7f8;
  --panel: #ffffff;
  --panel-soft: #f1f6f7;
  --text: #20252b;
  --muted: #66717d;
  --accent: #17636d;
  --accent-dark: #124f57;
  --line: #d9dfe5;
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}

.case-wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px 20px 56px;
}

.case-nav {
  margin-bottom: 28px;
  font-size: 13px;
}

.case-nav a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 700;
}

.case-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(340px, 0.92fr);
  gap: 24px;
  align-items: center;
  padding: 24px 0 32px;
}

.eyebrow {
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.case-hero h1 {
  margin: 0;
  max-width: 760px;
  font-size: clamp(2.35rem, 4.8vw, 3.85rem);
  line-height: 1.04;
  letter-spacing: 0;
}

.lead {
  max-width: 680px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 16px;
}

.case-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid var(--accent);
  border-radius: 8px;
  background: var(--accent);
  color: #ffffff;
  font-size: 13px;
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
  font-family: inherit;
  max-width: 100%;
}

.btn.secondary {
  background: transparent;
  color: var(--accent);
}

.visual-card,
.panel,
.metric {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel);
  box-shadow: 0 12px 28px rgba(31, 41, 55, 0.06);
}

.visual-card {
  overflow: hidden;
}

.visual-stage {
  position: relative;
  min-height: 320px;
  background: linear-gradient(135deg, #eef4f5, #ffffff 58%, #e9f1f3);
  overflow: hidden;
}

.visual-card figcaption {
  padding: 12px 14px;
  color: var(--muted);
  font-size: 12px;
  border-top: 1px solid var(--line);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-top: 22px;
}

.metric {
  padding: 15px;
  min-height: 92px;
}

.metric strong {
  display: block;
  color: var(--accent);
  font-size: 22px;
  line-height: 1.1;
}

.metric span {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}

.section {
  margin-top: 34px;
}

.section h2 {
  margin: 0 0 14px;
  font-size: 22px;
  letter-spacing: 0;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.panel {
  padding: 18px;
}

.panel h3 {
  margin: 0 0 8px;
  font-size: 16px;
  letter-spacing: 0;
}

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

.steps {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
}

.step {
  min-height: 140px;
  padding: 15px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #ffffff;
}

.step::before {
  content: attr(data-step);
  display: inline-grid;
  place-items: center;
  width: 34px;
  height: 34px;
  margin-bottom: 12px;
  border-radius: 50%;
  background: var(--panel-soft);
  color: var(--accent);
  font-size: 12px;
  font-weight: 900;
  border: 1px solid #c8d8dd;
}

.step h3 {
  margin: 0 0 6px;
  font-size: 14px;
}

.step p {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

.tags span {
  display: inline-flex;
  align-items: center;
  min-height: 31px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #f8fafb;
  color: #34444d;
  font-size: 12px;
}

.cta-band {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-top: 36px;
  padding: 20px;
  border: 1px solid #c8d8dd;
  border-radius: 12px;
  background: #edf6f7;
}

.cta-band h2 {
  margin: 0 0 6px;
  font-size: 20px;
}

.cta-band p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.toast {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: 8px;
  background: #172026;
  color: #fff;
  font-size: 13px;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.2s, transform 0.2s;
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

.entry-visual .sheet,
.entry-visual .system,
.billing-visual .source,
.billing-visual .ledger {
  position: absolute;
  border: 1px solid rgba(23, 99, 109, 0.2);
  background: rgba(255, 255, 255, 0.86);
  box-shadow: 0 14px 28px rgba(31, 41, 55, 0.08);
}

.entry-visual .sheet {
  left: 8%;
  top: 15%;
  width: 32%;
  height: 58%;
  border-radius: 8px;
}

.entry-visual .system {
  right: 8%;
  top: 18%;
  width: 34%;
  height: 52%;
  border-radius: 10px;
}

.entry-visual .arrow,
.billing-visual .arrow {
  position: absolute;
  left: 43%;
  top: 43%;
  width: 14%;
  height: 3px;
  background: var(--accent);
}

.entry-visual .arrow::after,
.billing-visual .arrow::after {
  content: "";
  position: absolute;
  right: -2px;
  top: -5px;
  width: 12px;
  height: 12px;
  border-top: 3px solid var(--accent);
  border-right: 3px solid var(--accent);
  transform: rotate(45deg);
}

.entry-visual .line,
.billing-visual .line {
  position: absolute;
  left: 16%;
  right: 16%;
  height: 6px;
  border-radius: 999px;
  background: #b8c7cf;
}

.entry-visual .l1 { top: 26%; }
.entry-visual .l2 { top: 38%; width: 58%; }
.entry-visual .l3 { top: 50%; }
.entry-visual .l4 { top: 62%; width: 46%; }

.entry-visual .system .line { left: 14%; right: 14%; background: #8fb7c0; }
.entry-visual .system .l1 { top: 28%; }
.entry-visual .system .l2 { top: 42%; width: auto; }
.entry-visual .system .l3 { top: 56%; }

.entry-visual .badge {
  position: absolute;
  left: 50%;
  bottom: 16%;
  transform: translateX(-50%);
  padding: 8px 12px;
  border-radius: 999px;
  background: #17636d;
  color: #fff;
  font-size: 12px;
  font-weight: 800;
}

.billing-visual .source {
  left: 7%;
  top: 17%;
  width: 26%;
  height: 56%;
  border-radius: 22px;
}

.billing-visual .ledger {
  right: 7%;
  top: 14%;
  width: 42%;
  height: 62%;
  border-radius: 8px;
}

.billing-visual .source .line { left: 18%; right: 18%; background: #c5a962; }
.billing-visual .source .l1 { top: 28%; }
.billing-visual .source .l2 { top: 42%; }
.billing-visual .source .l3 { top: 56%; }

.billing-visual .ledger .row {
  position: absolute;
  left: 10%;
  right: 10%;
  height: 12%;
  border-bottom: 1px solid #d9dfe5;
}

.billing-visual .ledger .r1 { top: 16%; }
.billing-visual .ledger .r2 { top: 31%; }
.billing-visual .ledger .r3 { top: 46%; }
.billing-visual .ledger .r4 { top: 61%; }

.billing-visual .sum {
  position: absolute;
  right: 13%;
  bottom: 12%;
  padding: 8px 10px;
  border-radius: 8px;
  background: #17636d;
  color: #fff;
  font-size: 12px;
  font-weight: 800;
}

@media (max-width: 900px) {
  .case-hero,
  .grid-2 {
    grid-template-columns: 1fr;
  }

  .metrics,
  .grid-3,
  .steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 560px) {
  .case-wrap {
    padding: 20px 14px 42px;
  }

  .case-hero {
    gap: 18px;
  }

  .case-actions,
  .cta-band {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }

  .metrics,
  .grid-3,
  .grid-2,
  .steps {
    grid-template-columns: 1fr;
  }

  .visual-stage {
    min-height: 260px;
  }
}