:root {
  --bg: #f7fafc;
  --panel: #ffffff;
  --ink: #172033;
  --muted: #5b667a;
  --line: #dce5ef;
  --green: #2e7d4f;
  --green-dark: #1f5f3b;
  --green-soft: #e6f3ec;
  --blue-soft: #e7f0f8;
  --shadow: 0 24px 70px rgba(30, 55, 90, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at top left, rgba(104, 162, 127, 0.18), transparent 36rem),
    linear-gradient(180deg, #f3f8fb 0%, var(--bg) 36rem);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}

a {
  color: inherit;
}

img {
  display: block;
  max-width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(18px);
  background: rgba(247, 250, 252, 0.78);
  border-bottom: 1px solid rgba(220, 229, 239, 0.75);
}

.nav {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  color: var(--muted);
  font-size: 0.94rem;
}

.nav-links a {
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--green-dark);
}

.hero {
  width: min(1040px, calc(100% - 32px));
  margin: 0 auto;
  padding: 58px 0 38px;
  text-align: center;
}

.hero h1 {
  max-width: 920px;
  margin: 0 auto;
  font-size: clamp(1.8rem, 3.5vw, 3.25rem);
  line-height: 1.06;
  letter-spacing: -0.045em;
}

.subtitle {
  max-width: 760px;
  margin: 28px auto 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2.2vw, 1.32rem);
}

.authors {
  max-width: 980px;
  margin: 22px auto 0;
  color: #313c4f;
  font-size: 1.05rem;
  line-height: 1.85;
}

.authors span {
  display: block;
  color: var(--muted);
}

.authors .note {
  font-size: 0.95rem;
  line-height: 1.5;
}

.actions {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

.button {
  min-width: 142px;
  border: 1px solid var(--green);
  border-radius: 999px;
  padding: 11px 18px;
  background: #fff;
  color: var(--green-dark);
  text-decoration: none;
  font-weight: 800;
  box-shadow: none;
  transition:
    background 160ms ease,
    color 160ms ease,
    transform 160ms ease,
    box-shadow 160ms ease;
}

.button:hover {
  background: var(--green);
  color: #fff;
  box-shadow: 0 12px 30px rgba(46, 125, 79, 0.2);
  transform: translateY(-1px);
}

.section-narrow,
.section-wide {
  width: min(1040px, calc(100% - 32px));
  margin: 0 auto;
}

.section-wide {
  width: min(1160px, calc(100% - 32px));
}

.plain-figure {
  margin: 0;
  display: flex;
  justify-content: center;
}

.plain-figure img {
  width: 100%;
  max-width: 1040px;
  height: auto;
}

.method-grid article,
.result-list article {
  border: 1px solid var(--line);
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 12px 36px rgba(30, 55, 90, 0.07);
}

.content-section {
  padding: 42px 0;
}

.section-title {
  margin: 0 auto 24px;
  text-align: center;
  font-size: clamp(1.8rem, 3.2vw, 2.75rem);
  line-height: 1.05;
  letter-spacing: -0.045em;
}

.section-intro {
  max-width: 920px;
  margin: -6px auto 24px;
  text-align: center;
  color: var(--muted);
  font-size: 1.05rem;
}

.motivation-text {
  max-width: 1040px;
  margin-left: auto;
  margin-right: auto;
  color: #303b4f;
  font-size: 1.08rem;
}

.video-intro {
  margin-top: 34px;
}

.content-section > p {
  color: #303b4f;
  font-size: 1.08rem;
}

.keyword-highlight {
  color: var(--green-dark);
  font-weight: 800;
  padding: 0 0.04em;
}

.method-grid,
.result-list {
  display: grid;
  gap: 14px;
}

.method-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-bottom: 34px;
}

.method-grid article,
.result-list article {
  padding: 22px;
}

.step-heading {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-left: 12px;
  white-space: nowrap;
}

.legend-dot {
  width: 0.75em;
  height: 0.75em;
  border-radius: 50%;
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.88);
}

.legend-dot.selected {
  background: #17b7d8;
}

.legend-dot.human {
  background: #50c878;
}

.legend-dot.vocabulary {
  background: #d83bd2;
}

.visual-caption {
  max-width: 1040px;
  margin: 0 auto 16px;
  color: #303b4f;
  font-size: 1.02rem;
  text-align: center;
}

.method-grid span {
  flex: 0 0 auto;
  display: inline-grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 50%;
  background: var(--green-soft);
  color: var(--green-dark);
  font-weight: 900;
}

.method-grid h3,
.result-list h3 {
  margin: 0;
  line-height: 1.18;
}

.method-grid p,
.result-list p {
  margin: 0;
  color: var(--muted);
}

.result-list {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.video-grid article {
  margin: 0;
}

.video-grid video {
  width: 100%;
  display: block;
  border-radius: 14px;
  background: #101826;
}

.video-grid p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 0.95rem;
  text-align: center;
}

pre {
  overflow-x: auto;
  margin: 0;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #101826;
  color: #d9f5df;
  font-size: 0.92rem;
  line-height: 1.55;
}

@media (max-width: 900px) {
  .result-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .video-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 640px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
    padding: 16px 0;
  }

  .nav-links {
    width: 100%;
    justify-content: space-between;
    gap: 10px;
    font-size: 0.86rem;
  }

  .hero {
    padding-top: 44px;
  }

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

  .content-section {
    padding: 36px 0;
  }
}