:root {
  color-scheme: light;
  --bg: #ffffff;
  --panel: #f4f7f6;
  --panel-strong: #e7efec;
  --text: #16211d;
  --muted: #53635e;
  --line: #cbd9d4;
  --accent: #087f5b;
  --accent-strong: #056247;
  --accent-light: #e6f5ef;
  --alert: #b42318;
  --code-bg: #101814;
  --code-text: #ecf7f1;
  --link: #0b6bcb;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.09);
  --shadow-card-hover: 0 8px 24px rgba(8, 127, 91, 0.12);
  --radius: 10px;
  --radius-sm: 8px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 4rem;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  line-height: 1.6;
  letter-spacing: 0;
}

a {
  color: var(--link);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  transition: color 0.2s ease;
}

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

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

code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.95em;
}

/* ─── Scroll Animations ─── */

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1),
              transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.08s; }
.reveal-delay-2 { transition-delay: 0.16s; }
.reveal-delay-3 { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ─── Site Header ─── */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem clamp(1rem, 4vw, 3rem);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: box-shadow 0.3s ease;
}

.site-header.scrolled {
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.06);
}

.brand {
  color: var(--text);
  font-weight: 800;
  letter-spacing: 0;
  text-decoration: none;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.brand svg {
  width: 22px;
  height: 22px;
  fill: var(--accent);
}

nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.3rem;
  font-size: 0.95rem;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  padding: 0.35rem 0.65rem;
  border-radius: 6px;
  position: relative;
  transition: color 0.2s ease, background 0.2s ease;
}

nav a:hover {
  color: var(--text);
  background: var(--accent-light);
}

nav a.active {
  color: var(--accent-strong);
  font-weight: 600;
  background: var(--accent-light);
}

/* Hamburger menu button */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.4rem;
  color: var(--text);
  border-radius: 6px;
  transition: background 0.2s ease;
}

.menu-toggle:hover {
  background: var(--panel);
}

.menu-toggle svg {
  width: 24px;
  height: 24px;
  display: block;
}

/* ─── Hero / Intro ─── */

.intro {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(18rem, 0.95fr);
  gap: clamp(1.5rem, 5vw, 4rem);
  align-items: center;
  max-width: 1180px;
  margin: 0 auto;
  padding: clamp(2.5rem, 7vw, 5.5rem) clamp(1rem, 4vw, 3rem) 3rem;
  position: relative;
}

.intro::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: 120%;
  height: 100%;
  background: radial-gradient(ellipse at 30% 20%, rgba(8, 127, 91, 0.06) 0%, transparent 60%),
              radial-gradient(ellipse at 80% 80%, rgba(11, 107, 203, 0.04) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

.intro-copy h1 {
  margin: 0;
  max-width: 11ch;
  font-size: 4.6rem;
  line-height: 0.98;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--text) 0%, #2a4a3e 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.eyebrow {
  margin: 0 0 0.75rem;
  color: var(--accent-strong);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.lede {
  max-width: 43rem;
  color: var(--muted);
  font-size: 1.15rem;
  line-height: 1.7;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.4rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.7rem;
  border-radius: var(--radius-sm);
  padding: 0.62rem 1.3rem;
  border: 1px solid var(--accent);
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.22, 1, 0.36, 1);
}

.button.primary {
  background: var(--accent);
  color: white;
  box-shadow: 0 2px 8px rgba(8, 127, 91, 0.25);
}

.button.primary:hover {
  background: var(--accent-strong);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(8, 127, 91, 0.35);
  color: white;
}

.button.secondary {
  color: var(--accent-strong);
  background: white;
}

.button.secondary:hover {
  background: var(--accent-light);
  transform: translateY(-1px);
  color: var(--accent-strong);
}

/* ─── Quick Panel (terminal-style code block) ─── */

.quick-panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.quick-panel h2 {
  margin: 0;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--muted);
  padding: 0.7rem 1rem 0;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.quick-panel pre {
  margin: 0;
  border-radius: 0;
  background: var(--code-bg);
  color: var(--code-text);
  padding: 1rem;
}

/* ─── Code Blocks ─── */

pre {
  margin: 0;
  overflow-x: auto;
  border-radius: var(--radius-sm);
  background: var(--code-bg);
  color: var(--code-text);
  padding: 1rem;
  position: relative;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

pre code {
  color: inherit;
}

.code-block-wrapper {
  position: relative;
}

.copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: rgba(255, 255, 255, 0.6);
  border-radius: 6px;
  padding: 0.3rem 0.55rem;
  font-size: 0.75rem;
  font-family: inherit;
  cursor: pointer;
  opacity: 0;
  transition: all 0.2s ease;
  line-height: 1;
}

.code-block-wrapper:hover .copy-btn {
  opacity: 1;
}

.copy-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  color: rgba(255, 255, 255, 0.9);
}

.copy-btn.copied {
  color: #4ade80;
  border-color: rgba(74, 222, 128, 0.3);
}

/* ─── Band Sections ─── */

.band {
  background: var(--panel);
  border-block: 1px solid var(--line);
  padding: clamp(2.25rem, 5vw, 4rem) clamp(1rem, 4vw, 3rem);
}

/* ─── Summary / Features ─── */

.summary {
  display: grid;
  grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.3fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}

.summary,
.content-section,
.two-column {
  max-width: 1180px;
  margin: 0 auto;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.feature-grid li,
.command-item,
.example-row {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: white;
  transition: all 0.3s cubic-bezier(0.22, 1, 0.36, 1);
}

.feature-grid li {
  padding: 1rem;
  box-shadow: var(--shadow-sm);
}

.feature-grid li:hover,
.command-item:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-2px);
}

/* ─── Content Sections ─── */

.content-section {
  padding: clamp(2.5rem, 6vw, 5rem) clamp(1rem, 4vw, 3rem);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 1.5rem;
}

h2 {
  margin: 0 0 0.75rem;
  font-size: 2.7rem;
  line-height: 1.08;
  letter-spacing: -0.01em;
}

h3 {
  margin: 0;
  font-size: 1.35rem;
}

/* ─── Flow Figure ─── */

.flow-figure {
  margin: 0;
}

.flow-figure img {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: white;
  box-shadow: var(--shadow-md);
  transition: box-shadow 0.3s ease;
}

.flow-figure img:hover {
  box-shadow: var(--shadow-lg);
}

figcaption {
  color: var(--muted);
  font-size: 0.92rem;
  margin-top: 0.65rem;
}

/* ─── Command List ─── */

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

.command-item {
  padding: 1.25rem;
  box-shadow: var(--shadow-sm);
}

.command-item h3 {
  color: var(--accent-strong);
}

.command-item p {
  color: var(--muted);
}

.command-item pre {
  margin: 0.9rem 0;
}

.command-item ul,
.plain-list {
  margin: 1rem 0 0;
  padding-left: 1.2rem;
}

.command-item li,
.plain-list li {
  margin: 0.45rem 0;
}

/* ─── Two Column Layout ─── */

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  align-items: start;
}

/* ─── Example Row ─── */

.example-row {
  display: grid;
  grid-template-columns: minmax(16rem, 0.8fr) minmax(0, 1.2fr);
  gap: 1rem;
  align-items: center;
  padding: 1rem;
  box-shadow: var(--shadow-sm);
}

/* ─── History ─── */

.history-text {
  max-width: 820px;
  border-left: 4px solid var(--accent);
  padding-left: 1.25rem;
}

/* ─── Footer ─── */

.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.8rem clamp(1rem, 4vw, 3rem);
  color: var(--muted);
  background: var(--panel-strong);
}

.site-footer .footer-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.site-footer p {
  margin: 0;
}

.site-footer .credit {
  font-size: 0.92rem;
}

.site-footer a {
  color: var(--accent-strong);
  text-decoration: none;
  font-weight: 500;
}

.site-footer a:hover {
  text-decoration: underline;
}

/* ─── Scroll-to-Top Button ─── */

.scroll-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--accent);
  color: white;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 14px rgba(8, 127, 91, 0.35);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: all 0.3s cubic-bezier(0.22, 1, 0.36, 1);
  z-index: 90;
}

.scroll-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.scroll-top:hover {
  background: var(--accent-strong);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(8, 127, 91, 0.45);
}

.scroll-top svg {
  width: 20px;
  height: 20px;
}

/* ─── Responsive ─── */

@media (max-width: 820px) {
  .menu-toggle {
    display: flex;
  }

  .site-header {
    flex-wrap: wrap;
  }

  .site-header nav {
    display: none;
    flex-basis: 100%;
    flex-direction: column;
    gap: 0.15rem;
    padding-bottom: 0.5rem;
  }

  .site-header nav.open {
    display: flex;
  }

  nav a {
    padding: 0.5rem 0.65rem;
    border-radius: 6px;
  }

  .intro,
  .summary,
  .two-column,
  .example-row {
    grid-template-columns: 1fr;
  }

  .intro-copy h1 {
    max-width: 100%;
    font-size: 2.7rem;
    line-height: 1.04;
  }

  .intro::before {
    display: none;
  }

  h2 {
    font-size: 2rem;
  }

  .feature-grid,
  .command-list {
    grid-template-columns: 1fr;
  }

  .site-footer .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}