:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #5a5a68;
  --line: #e2e4e8;
  --card: #f7f8fa;
  --card-hover: #f0f2f6;
  --accent: #0072b2;
  --accent-hover: #005a8c;
  --accent2: #d55e00;
  --accent3: #009e73;
  --code: #f0f2f5;
  --maxw: 1040px;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.12);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1117;
    --fg: #e6edf3;
    --muted: #8b949e;
    --line: #2d333b;
    --card: #161b22;
    --card-hover: #1c2129;
    --accent: #58a6ff;
    --accent-hover: #79b8ff;
    --accent2: #ff9e64;
    --accent3: #3fb950;
    --code: #1f242c;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.35);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.55);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 4.5rem;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

header.site {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--bg) 90%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

nav {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  gap: 1.1rem;
  flex-wrap: wrap;
  align-items: center;
  padding: 0.75rem 1.25rem;
}

nav .brand {
  font-weight: 700;
  letter-spacing: 0.02em;
  margin-right: auto;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 1.05rem;
}

nav a {
  color: var(--fg);
  font-size: 0.92rem;
  font-weight: 500;
}

main {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2rem 1.25rem 5rem;
}

.hero {
  padding: 2rem 0 2.5rem;
  border-bottom: 1px solid var(--line);
  margin-bottom: 2.2rem;
}

.hero h1 {
  font-size: 2.35rem;
  line-height: 1.22;
  margin: 0.2rem 0 0.8rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.hero p.lede {
  font-size: 1.18rem;
  color: var(--muted);
  line-height: 1.6;
  margin: 0.4rem 0 1.2rem;
}

.hero-img-box {
  margin: 1.5rem 0 2rem;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  background: #000;
}

.hero-img-box img {
  width: 100%;
  height: auto;
  display: block;
}

.badges {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin: 0.8rem 0;
}

.badge {
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--card);
  color: var(--muted);
}

.badge.highlight {
  background: color-mix(in srgb, var(--accent) 15%, transparent);
  border-color: var(--accent);
  color: var(--accent);
}

.badge.green {
  background: color-mix(in srgb, var(--accent3) 15%, transparent);
  border-color: var(--accent3);
  color: var(--accent3);
}

.download-banner {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.3rem 1.5rem;
  margin: 1.6rem 0 2.2rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.2rem;
  box-shadow: var(--shadow);
}

.download-banner h3 {
  margin: 0 0 0.25rem;
  font-size: 1.15rem;
}

.download-banner p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--muted);
}

.btnrow {
  display: flex;
  gap: 0.65rem;
  flex-wrap: wrap;
  align-items: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.55rem 1.05rem;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--fg);
  font-size: 0.92rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn:hover {
  background: var(--card-hover);
  text-decoration: none;
  transform: translateY(-1px);
}

.btn.primary {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

.btn.primary:hover {
  background: var(--accent-hover);
  color: #ffffff;
}

.btn.secondary {
  background: var(--accent3);
  color: #ffffff;
  border-color: var(--accent3);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1.1rem;
  margin: 1.6rem 0 2.4rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1.2rem 1.3rem;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.card:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}

.card h3 {
  margin: 0.1rem 0 0.4rem;
  font-size: 1.08rem;
  font-weight: 700;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.93rem;
  line-height: 1.5;
}

.k {
  color: var(--accent2);
  font-weight: 800;
}

.section-header {
  margin-top: 3.2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.section-header h2 {
  font-size: 1.75rem;
  margin: 0 0 0.4rem;
  letter-spacing: -0.01em;
}

.section-header p.sub {
  color: var(--muted);
  font-size: 1.02rem;
  margin: 0 0 1.5rem;
}

.content h3 {
  font-size: 1.35rem;
  margin: 2.2rem 0 0.8rem;
}

.content h4 {
  font-size: 1.12rem;
  margin: 1.6rem 0 0.6rem;
}

.content p {
  margin: 0.8rem 0;
  line-height: 1.7;
}

.figure-block {
  margin: 2rem 0 2.6rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: var(--shadow);
}

.figure-img-wrap {
  padding: 1.2rem;
  background: #ffffff;
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  position: relative;
}

.figure-img-wrap img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  transition: transform 0.2s ease;
}

.figure-img-wrap:hover img {
  transform: scale(1.01);
}

.figure-img-wrap::after {
  content: "🔍 Click to expand";
  position: absolute;
  bottom: 12px;
  right: 16px;
  background: rgba(0, 0, 0, 0.75);
  color: #fff;
  font-size: 0.76rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
  opacity: 0;
  transition: opacity 0.2s ease;
  pointer-events: none;
}

.figure-img-wrap:hover::after {
  opacity: 1;
}

.figure-caption {
  padding: 1.2rem 1.4rem;
  font-size: 0.93rem;
  line-height: 1.6;
}

.figure-caption h4 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--fg);
}

.figure-caption p {
  margin: 0.4rem 0 0;
  color: var(--muted);
}

.figure-caption .key-takeaway {
  margin-top: 0.6rem;
  padding: 0.6rem 0.9rem;
  background: color-mix(in srgb, var(--accent) 8%, var(--card));
  border-left: 3px solid var(--accent);
  border-radius: 4px;
  font-size: 0.9rem;
  color: var(--fg);
}

.figure-grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.figure-grid-2 .figure-block {
  margin: 0;
}

.data-table-wrap {
  margin: 1.4rem 0 2rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  background: var(--card);
}

.data-table-wrap .table-header {
  padding: 0.9rem 1.2rem;
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.data-table-wrap .table-header h4 {
  margin: 0;
  font-size: 1rem;
}

table.data-table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.88rem;
  margin: 0;
  display: table;
}

table.data-table th,
table.data-table td {
  border-bottom: 1px solid var(--line);
  padding: 0.6rem 0.9rem;
  text-align: left;
}

table.data-table th {
  background: var(--card-hover);
  font-weight: 600;
  color: var(--fg);
}

table.data-table tr:hover td {
  background: color-mix(in srgb, var(--accent) 5%, transparent);
}

.content code {
  background: var(--code);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.88em;
  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
}

.content pre {
  background: var(--code);
  padding: 1.1rem;
  border-radius: 10px;
  overflow-x: auto;
  border: 1px solid var(--line);
}

.content pre code {
  background: none;
  padding: 0;
}

.note {
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent2);
  border-radius: 8px;
  padding: 0.85rem 1.2rem;
  font-size: 0.94rem;
  color: var(--fg);
  margin: 1.4rem 0;
}

.note.info {
  border-left-color: var(--accent);
}

.note.success {
  border-left-color: var(--accent3);
}

/* Lightbox Modal */
.modal {
  display: none;
  position: fixed;
  z-index: 1000;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(8px);
  justify-content: center;
  align-items: center;
  padding: 2rem;
}

.modal.active {
  display: flex;
}

.modal-content {
  max-width: 92vw;
  max-height: 90vh;
  position: relative;
  background: #ffffff;
  padding: 1rem;
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.modal-content img {
  max-width: 100%;
  max-height: 78vh;
  object-fit: contain;
  border-radius: 6px;
}

.modal-close {
  position: absolute;
  top: -14px;
  right: -14px;
  width: 34px;
  height: 34px;
  background: #ffffff;
  color: #1a1a1a;
  border: 2px solid var(--line);
  border-radius: 50%;
  font-size: 1.2rem;
  font-weight: bold;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow);
}

.modal-caption {
  margin-top: 0.6rem;
  font-size: 0.9rem;
  color: #1a1a1a;
  text-align: center;
  max-width: 900px;
}

footer.site {
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.88rem;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 1.85rem;
  }
  .figure-grid-2 {
    grid-template-columns: 1fr;
  }
  .download-banner {
    flex-direction: column;
    align-items: flex-start;
  }
}