:root {
  --bg: #edf3f5;
  --paper: rgba(255, 255, 255, 0.84);
  --paper-strong: rgba(255, 255, 255, 0.95);
  --ink: #18323b;
  --muted: #61757d;
  --line: rgba(24, 50, 59, 0.12);
  --teal: #1d7d81;
  --teal-deep: #145c60;
  --orange: #ff9955;
  --green: #30986d;
  --shadow: 0 24px 64px rgba(24, 52, 65, 0.14);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(255, 164, 102, 0.2), transparent 28%),
    radial-gradient(circle at top right, rgba(96, 190, 255, 0.16), transparent 26%),
    linear-gradient(180deg, #f9fcfd 0%, var(--bg) 100%);
}

button,
input {
  font: inherit;
}

.page {
  width: min(1440px, calc(100vw - 28px));
  margin: 22px auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px 22px;
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.76);
  backdrop-filter: blur(12px);
  box-shadow: 0 10px 30px rgba(24, 52, 65, 0.08);
  position: sticky;
  top: 12px;
  z-index: 20;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
  text-decoration: none;
  color: inherit;
}

.brand-mark {
  width: 22px;
  height: 22px;
  border-radius: 8px;
  background:
    radial-gradient(circle at 28% 30%, #ffcc7a 0 24%, transparent 25%),
    linear-gradient(135deg, var(--teal-deep) 0%, #1e707f 100%);
  box-shadow: inset 0 0 0 2px rgba(255, 255, 255, 0.42);
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.brand-text strong {
  font-size: 1rem;
  letter-spacing: 0.02em;
}

.brand-text em {
  font-size: 0.8rem;
  color: var(--muted);
  font-style: normal;
}

.top-nav {
  display: inline-flex;
  align-items: center;
  gap: 20px;
  color: var(--muted);
  font-size: 0.95rem;
}

.top-nav a {
  position: relative;
  color: inherit;
  text-decoration: none;
}

.top-nav a:hover {
  color: var(--ink);
}

.top-nav a:hover::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -8px;
  height: 2px;
  border-radius: 999px;
  background: var(--orange);
}

.site-return {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid rgba(20, 92, 96, 0.16);
  background: rgba(255, 255, 255, 0.86);
  color: var(--ink);
  text-decoration: none;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.site-return:hover {
  transform: translateY(-1px);
}

.hero,
.stage-panel,
.panel-card {
  border-radius: 30px;
  border: 1px solid rgba(255, 255, 255, 0.72);
  background: var(--paper);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

.hero {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: flex-start;
  padding: 30px 34px;
}

.hero__copy {
  max-width: 860px;
}

.hero__eyebrow {
  margin: 0 0 14px;
  color: var(--teal-deep);
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-size: clamp(30px, 3vw, 52px);
  line-height: 1.08;
}

.hero__desc {
  margin: 16px 0 0;
  color: var(--muted);
  line-height: 1.75;
  font-size: 16px;
}

.hero__formula {
  min-width: min(360px, 100%);
  padding: 18px 20px;
  border-radius: 24px;
  background: linear-gradient(150deg, rgba(20, 92, 96, 0.94), rgba(29, 125, 129, 0.84));
  color: #eefcff;
}

.hero__formula span {
  display: block;
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  opacity: 0.84;
}

.hero__formula strong {
  display: block;
  margin-top: 10px;
  font-size: clamp(28px, 2vw, 36px);
}

.hero__formula p {
  margin: 12px 0 0;
  line-height: 1.7;
  color: rgba(238, 252, 255, 0.92);
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(360px, 0.92fr);
  gap: 22px;
  margin-top: 22px;
  align-items: start;
}

.stage-panel {
  padding: 22px;
}

.panel-card {
  padding: 20px;
}

.sidebar {
  display: grid;
  gap: 18px;
}

.panel-head {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-start;
}

.panel-head--compact {
  margin-bottom: 14px;
}

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

.panel-head p {
  margin: 7px 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.button {
  padding: 10px 16px;
  border-radius: 999px;
  border: 0;
  background: linear-gradient(135deg, var(--teal), var(--teal-deep));
  color: white;
  cursor: pointer;
  box-shadow: 0 12px 28px rgba(20, 92, 96, 0.2);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button--ghost {
  background: rgba(255, 255, 255, 0.86);
  color: var(--teal-deep);
  border: 1px solid rgba(20, 92, 96, 0.16);
  box-shadow: none;
}

.scene-wrap {
  margin-top: 18px;
  padding: 14px;
  border-radius: 26px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(241, 247, 249, 0.9)),
    linear-gradient(135deg, rgba(255, 164, 102, 0.08), rgba(96, 190, 255, 0.12));
}

#scene {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 22px;
  background:
    radial-gradient(circle at top, rgba(255, 255, 255, 0.96), rgba(235, 242, 246, 0.92)),
    linear-gradient(180deg, rgba(248, 251, 252, 0.96), rgba(229, 237, 241, 0.96));
}

.timeline-card {
  margin-top: 18px;
  padding: 18px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid var(--line);
}

.timeline-head {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  align-items: baseline;
}

.timeline-head label {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
}

.timeline-tip {
  font-size: 13px;
  color: var(--muted);
  white-space: nowrap;
}

#progress {
  width: 100%;
  margin-top: 14px;
  accent-color: var(--teal);
}

.timeline-markers {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin-top: 12px;
  font-size: 12px;
  color: var(--muted);
}

.timeline-markers span {
  text-align: center;
}

.chart-section {
  margin-top: 18px;
  padding: 18px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid var(--line);
}

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

.chart-card {
  padding: 16px;
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.84);
  border: 1px solid var(--line);
}

.chart-card h3 {
  margin: 0;
  font-size: 18px;
}

.chart-card p {
  margin: 8px 0 0;
  color: var(--muted);
  line-height: 1.6;
  font-size: 14px;
}

.chart-card svg {
  display: block;
  width: 100%;
  height: auto;
  margin-top: 14px;
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(251, 253, 254, 0.98), rgba(241, 247, 249, 0.98));
}

.reading-grid {
  display: grid;
  gap: 12px;
}

.reading {
  padding: 16px 18px;
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.78);
}

.reading span {
  display: block;
  color: var(--muted);
  font-size: 14px;
}

.reading strong {
  display: block;
  margin-top: 8px;
  font-size: clamp(28px, 2vw, 34px);
  line-height: 1;
}

.reading--air {
  background: linear-gradient(135deg, rgba(255, 153, 85, 0.16), rgba(255, 255, 255, 0.96));
}

.reading--water {
  background: linear-gradient(135deg, rgba(96, 190, 255, 0.17), rgba(255, 255, 255, 0.96));
}

.reading--force {
  background: linear-gradient(135deg, rgba(48, 152, 109, 0.14), rgba(255, 255, 255, 0.96));
}

.formula-bar {
  margin-top: 14px;
  padding: 13px 15px;
  border-radius: 18px;
  background: rgba(24, 50, 59, 0.94);
  color: white;
  line-height: 1.7;
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.field {
  padding: 14px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--line);
}

.field span {
  display: block;
  color: var(--muted);
  font-size: 14px;
}

.field__row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
}

.field input {
  width: 100%;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid rgba(24, 50, 59, 0.14);
  background: var(--paper-strong);
  color: var(--ink);
}

.field em {
  font-style: normal;
  color: var(--muted);
}

.step-list {
  display: grid;
  gap: 12px;
}

.step {
  padding: 16px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.step strong {
  display: block;
  font-size: 16px;
}

.step p {
  margin: 8px 0 0;
  color: var(--muted);
  line-height: 1.65;
}

.step.is-active {
  transform: translateY(-2px);
  border-color: rgba(29, 125, 129, 0.34);
  background: linear-gradient(135deg, rgba(228, 248, 246, 0.96), rgba(255, 252, 247, 0.96));
}

.equation {
  padding: 18px;
  border-radius: 22px;
  background: linear-gradient(180deg, rgba(251, 253, 254, 0.96), rgba(241, 248, 250, 0.94));
  border: 1px solid var(--line);
}

.equation__main {
  font-size: clamp(28px, 2vw, 34px);
  font-weight: 700;
  color: var(--teal-deep);
}

.equation__detail {
  margin-top: 10px;
  line-height: 1.7;
  color: var(--muted);
}

.conclusion {
  margin: 14px 2px 0;
  color: var(--muted);
  line-height: 1.75;
}

@media (max-width: 1220px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .site-header {
    border-radius: 28px;
    flex-direction: column;
    align-items: flex-start;
  }

  .hero {
    flex-direction: column;
  }

  .hero__formula {
    width: 100%;
  }

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

@media (max-width: 760px) {
  .page {
    width: min(100vw - 16px, 100%);
    margin: 8px auto 16px;
  }

  .hero,
  .stage-panel,
  .panel-card {
    border-radius: 22px;
  }

  .site-header {
    padding: 18px;
  }

  .hero,
  .stage-panel,
  .panel-card {
    padding: 16px;
  }

  .panel-head,
  .timeline-head {
    flex-direction: column;
  }

  .actions {
    width: 100%;
  }

  .button {
    flex: 1 1 auto;
  }

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

  .top-nav {
    gap: 14px;
    flex-wrap: wrap;
    font-size: 0.88rem;
  }
}