:root {
  --primary-color: #4a90e2;
  --secondary-color: #5b9bd5;
  --text-color: #24364b;
  --text-light: #58708b;
  --bg-color: #ffffff;
  --bg-light: #f5f9ff;
  --border-color: #dce7f3;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.12);
  --transition: all 0.3s ease;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text-color);
  background: var(--bg-color);
  line-height: 1.6;
}

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

a {
  color: inherit;
  text-decoration: none;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.narrow {
  max-width: 900px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 0;
  padding-left: 2.5rem;
}

.home-link {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-color);
}

.home-link:hover,
.section-nav a:hover {
  color: var(--primary-color);
}

.section-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.section-nav a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-light);
  transition: var(--transition);
}

.hero {
  padding: 5.5rem 0 2.5rem;
  background: var(--bg-color);
}

.section-label {
  margin: 0 0 0.5rem;
  color: var(--primary-color);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  margin: 0;
  color: var(--text-color);
}

h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.2;
}

h2 {
  font-size: clamp(1.7rem, 3vw, 2.25rem);
  line-height: 1.25;
}

h3 {
  font-size: 1.15rem;
  line-height: 1.35;
}

.authors,
.affiliation {
  margin: 0.45rem 0 0;
  color: var(--text-light);
  font-size: 1rem;
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 1.25rem 0 1rem;
}

.action-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.72rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: 999px;
  background: var(--bg-light);
  color: var(--text-color);
  font-weight: 600;
  transition: var(--transition);
}

.action-pill:hover {
  border-color: var(--primary-color);
  color: var(--primary-color);
  transform: translateY(-1px);
}

.icon {
  width: 1rem;
  height: 1rem;
  display: inline-flex;
}

.icon svg {
  width: 100%;
  height: 100%;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.action-pill:last-child .icon svg {
  fill: currentColor;
  stroke: none;
}

.lead {
  max-width: 100%;
  margin: 0;
  color: var(--text-light);
  font-size: 1rem;
}

.hero-abstract {
  text-align: justify;
  text-justify: inter-word;
}

.hero-copy {
  max-width: 900px;
}

.hero-figure,
.figure-card,
.stat-card,
.step-card,
.code-card,
.application-card,
.insight-card {
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  box-shadow: var(--shadow);
}

.hero-figure {
  margin: 0;
  padding: 1rem;
  margin-top: 2.75rem;
}

.hero-figure-wide img {
  width: 100%;
}

.section {
  padding: 2.25rem 0;
}

.section.alt {
  background: var(--bg-light);
}

.section-heading {
  margin-bottom: 1.4rem;
}

.prose p {
  margin: 0 0 1rem;
  color: var(--text-light);
  font-size: 1rem;
}

.comparison-card {
  margin-top: 1.4rem;
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 1.25rem;
}

.comparison-card h3 {
  margin-bottom: 0.9rem;
}

.comparison-table-wrap {
  overflow-x: auto;
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 720px;
}

.comparison-table th,
.comparison-table td {
  padding: 0.9rem 0.95rem;
  border-bottom: 1px solid var(--border-color);
  text-align: left;
  vertical-align: top;
  font-size: 0.95rem;
}

.comparison-table th {
  color: var(--text-color);
  background: #e4eefb;
  font-weight: 700;
}

.comparison-table td {
  color: var(--text-light);
}

.comparison-table tbody tr:nth-child(odd) {
  background: #f3f8ff;
}

.comparison-table tbody tr:nth-child(odd) td {
  background: #f3f8ff !important;
}

.comparison-table tbody tr:nth-child(even) td {
  background: #ffffff;
}

.comparison-table tbody tr:last-child td {
  border-bottom: none;
}

.stats-grid,
.steps-grid,
.algorithm-grid,
.insight-grid,
.visual-grid,
.application-list {
  display: grid;
  gap: 1rem;
}

.application-list {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  align-items: stretch;
  gap: 0.8rem;
}

.stats-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 1.5rem;
}

.stat-card,
.step-card,
.code-card,
.application-card,
.insight-card {
  padding: 1.25rem;
  transition: var(--transition);
}

.stat-card:hover,
.step-card:hover,
.figure-card:hover,
.application-card:hover,
.insight-card:hover {
  box-shadow: var(--shadow-hover);
}

.stat-value {
  display: inline-block;
  margin-bottom: 0.45rem;
  color: var(--primary-color);
  font-size: 1.8rem;
  font-weight: 700;
}

.stat-label {
  margin: 0;
  color: var(--text-light);
  font-size: 0.95rem;
}

.steps-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.step-index {
  display: inline-block;
  margin-bottom: 0.7rem;
  color: var(--primary-color);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.step-card p,
.application-copy p,
.insight-card p {
  margin: 0.65rem 0 0;
  color: var(--text-light);
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.95fr);
  gap: 1rem;
  align-items: start;
  margin-top: 1.25rem;
}

.figure-card {
  margin: 0;
  overflow: hidden;
}

.figure-card img {
  width: 100%;
}

.figure-card figcaption {
  padding: 0.8rem 1rem 1rem;
  color: var(--text-light);
  font-size: 0.92rem;
}

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

.code-card h3 {
  margin-bottom: 0.8rem;
}

.algorithm-shell {
  border: 1px solid var(--border-color);
  border-radius: 12px;
  background: linear-gradient(180deg, #fbfcfe 0%, #f4f7fb 100%);
  padding: 1rem 1rem 0.95rem;
}

.citation-card pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: 'JetBrains Mono', 'SFMono-Regular', Consolas, monospace;
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--text-color);
}

.algorithm-meta {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 0.75rem;
  align-items: start;
}

.algorithm-meta + .algorithm-meta {
  margin-top: 0.95rem;
  padding-top: 0.95rem;
  border-top: 1px solid var(--border-color);
}

.algorithm-meta span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2rem;
  border-radius: 999px;
  background: #eaf2fd;
  color: var(--primary-color);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.algorithm-meta p {
  margin: 0.15rem 0 0;
  color: var(--text-color);
  font-size: 0.98rem;
}

.algorithm-steps {
  margin: 1rem 0 0;
  padding-left: 0;
  color: var(--text-color);
  list-style: none !important;
}

.algorithm-steps > li {
  margin-bottom: 0;
}

.algorithm-steps ol {
  margin: 0.75rem 0 0;
  padding-left: 1.15rem;
  list-style: none !important;
}

.algorithm-steps li::marker,
.algorithm-steps ol li::marker {
  content: "";
}

.algorithm-steps li {
  margin-bottom: 0.65rem;
}

.algorithm-steps li:last-child {
  margin-bottom: 0;
}

.algorithm-steps strong {
  color: var(--text-color);
}

.application-copy ul {
  margin: 0.9rem 0 0;
  padding-left: 1.15rem;
  color: var(--text-light);
}

.application-copy li + li {
  margin-top: 0.4rem;
}

.visual-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 1rem;
}

.wide {
  margin-top: 1rem;
}

.application-visual {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  align-items: stretch;
  min-width: 0;
}

.application-figure {
  margin: 0;
  border: 1px solid var(--border-color);
  border-radius: 12px;
  overflow: hidden;
  background: #f7fafe;
  aspect-ratio: 1 / 1;
}

.application-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.application-copy h3 {
  text-align: center;
  font-size: 1rem;
}

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

.closing {
  padding-bottom: 3.5rem;
}

@media (max-width: 980px) {
  .two-column,
  .steps-grid,
  .algorithm-grid,
  .stats-grid,
  .insight-grid,
  .visual-grid,
  .application-list,
  .application-visual {
    grid-template-columns: 1fr;
  }

  .section-nav {
    display: none;
  }
}

@media (max-width: 640px) {
  .container {
    padding: 0 1rem;
  }

  .hero {
    padding-top: 5rem;
  }

  .action-pill {
    width: 100%;
    justify-content: center;
  }

  .stat-card,
  .step-card,
  .code-card,
  .application-card,
  .insight-card {
    padding: 1rem;
  }
}