/* ── Reset & base ────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #F2F2F0;
  --surface:   #F7F7F5;
  --border:    #C0C0BE;
  --border-lt: #E0E0DE;
  --text:      #232320;
  --muted:     #888886;
  --chrome:    #232320;
  --chrome-sub:#383836;
  --chrome-txt:#DEDEDC;
  --accent:    #CC8800;
  --accent-dk: #AA6600;
  --code-bg:   #ECECEA;
  --radius:    6px;
  --mono: "DM Mono", "Menlo", "Consolas", monospace;
  --sans: "Inter", system-ui, sans-serif;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-dk); text-decoration: none; }
a:hover { color: var(--text); text-decoration: underline; }

code {
  font-family: var(--mono);
  font-size: 0.87em;
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--text);
}

/* ── Layout ─────────────────────────────────────────────────────────────── */
.section-inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 32px;
}

/* ── Nav ────────────────────────────────────────────────────────────────── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--chrome);
  border-bottom: 1px solid var(--chrome-sub);
}
.nav-inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 32px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-links { display: flex; gap: 20px; }
.nav-link {
  font-size: 13px;
  font-weight: 400;
  color: var(--chrome-txt);
  text-decoration: none;
}
.nav-link:hover { color: #fff; text-decoration: none; }
.wordmark {
  font-weight: 500;
  font-size: 14px;
  color: var(--chrome-txt);
  letter-spacing: 0.01em;
}
.wordmark:hover { text-decoration: none; color: #fff; }

/* ── Hero ───────────────────────────────────────────────────────────────── */
.hero {
  padding: 72px 0 56px;
}
.hero-inner {
  position: relative;
  z-index: 1;
}
h1 {
  font-size: clamp(2rem, 4.5vw, 2.8rem);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.025em;
  margin-bottom: 16px;
  color: var(--text);
}
.hero-sub {
  font-size: 15px;
  color: var(--muted);
  font-weight: 400;
  line-height: 1.6;
}
.hero-screenshot {
  width: 100%;
  margin-top: 36px;
  border-radius: var(--radius);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.12);
}

/* ── Section headings ─────────────────────────────────────────────────── */
.install h2, .features h2 {
  font-size: 1.2rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--text);
  margin-bottom: 24px;
}

/* ── Features section ──────────────────────────────────────────────────── */
.features {
  padding: 56px 0;
  border-top: 1px solid var(--border-lt);
}
.feature {
  margin-bottom: 20px;
}
.feature:last-of-type { margin-bottom: 24px; }
.feature h3 {
  font-size: 14px;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 6px;
}
.feature p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.7;
}
.feature kbd {
  font-family: var(--mono);
  font-size: 11px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  color: var(--text);
  white-space: nowrap;
}
.manual-link {
  margin-top: 20px;
  font-size: 13px;
  font-weight: 500;
}

/* ── Download section ───────────────────────────────────────────────────── */
.install {
  padding: 56px 0;
  border-top: 1px solid var(--border-lt);
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 32px;
}
.download-card {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 18px 16px;
  background: var(--surface);
  border: 1px solid var(--border-lt);
  border-radius: var(--radius);
  text-decoration: none !important;
  transition: border-color 0.15s;
}
.download-card:hover { border-color: var(--text); }
.dl-platform { font-size: 14px; font-weight: 500; color: var(--text); }
.dl-detail   { font-size: 11px; color: var(--muted); line-height: 1.4; }
.dl-cta      { margin-top: 8px; font-size: 12px; font-weight: 500; color: var(--accent-dk); }

/* ── CSS-only tabs ──────────────────────────────────────────────────────── */
#tab-mac, #tab-win, #tab-linux { display: none; }

.tab-labels {
  display: flex;
  gap: 0;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border-lt);
}
.tab-label {
  font-size: 13px;
  font-weight: 500;
  padding: 6px 14px;
  cursor: pointer;
  color: var(--muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color 0.15s;
}
.tab-label:hover { color: var(--text); }

#tab-mac:checked ~ .tab-labels label[for="tab-mac"],
#tab-win:checked ~ .tab-labels label[for="tab-win"],
#tab-linux:checked ~ .tab-labels label[for="tab-linux"] {
  color: var(--text);
  border-bottom-color: var(--accent);
}

.tab-content { display: none; }
#tab-mac:checked ~ #content-mac,
#tab-win:checked ~ #content-win,
#tab-linux:checked ~ #content-linux { display: block; }

/* ── Step list ──────────────────────────────────────────────────────────── */
.run-steps {
  list-style: decimal;
  padding-left: 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.run-steps li {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}
.run-steps pre { margin-top: 8px; }

pre {
  background: var(--code-bg);
  border: 1px solid var(--border-lt);
  border-radius: var(--radius);
  padding: 12px 14px;
  overflow-x: auto;
}
pre code {
  background: none;
  padding: 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--text);
}

/* ── Footnote ──────────────────────────────────────────────────────────── */
.footnote {
  padding: 40px 0;
}
.footnote-image {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.12);
}
.footnote-caption {
  font-size: 12px;
  color: var(--muted);
  margin-top: 10px;
}

/* ── Manual page ───────────────────────────────────────────────────────── */
.manual { padding: 48px 0 64px; }
.manual-title {
  font-size: 1.4rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 40px;
}
.manual-section {
  margin-bottom: 40px;
}
.manual-section h2 {
  font-size: 1.1rem;
  font-weight: 500;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-lt);
}
.manual-section h3 {
  font-size: 12px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin: 20px 0 10px;
}
.manual-section p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.75;
  margin-bottom: 10px;
}
.manual-section p:last-child { margin-bottom: 0; }
.manual-list {
  list-style: none;
  padding: 0;
}
.manual-list li {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.75;
  padding-left: 16px;
  position: relative;
}
.manual-list li::before {
  content: "–";
  position: absolute;
  left: 0;
  color: var(--border);
}
.mode-tag {
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 100px;
  padding: 1px 7px;
  margin-left: 6px;
  vertical-align: middle;
}
.nav-link--active { color: var(--chrome-txt); }

/* ── Shortcut grid (shared: manual + legacy) ───────────────────────────── */
.shortcut-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 6px 24px;
}
.shortcut {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.8;
}
.shortcut kbd {
  font-family: var(--mono);
  font-size: 11px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 6px;
  color: var(--text);
  white-space: nowrap;
}

/* ── Footer ─────────────────────────────────────────────────────────────── */
footer {
  background: var(--chrome);
  border-top: 1px solid var(--chrome-sub);
  padding: 20px 0;
}
.footer-inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.footer-wordmark { font-size: 12px; color: var(--chrome-txt); font-weight: 500; }
.footer-wordmark:hover { color: var(--chrome-txt); }
.footer-links {
  display: flex;
  gap: 16px;
}
.footer-link {
  font-size: 12px;
  color: var(--chrome-txt);
  text-decoration: none;
}
.footer-link:hover { color: #fff; text-decoration: none; }

/* ── Responsive ─────────────────────────────────────────────────────────── */
@media (max-width: 520px) {
  .hero { padding: 48px 0 40px; }
  h1 { font-size: 1.8rem; }
  .download-grid { grid-template-columns: 1fr; }
  .shortcut-grid { grid-template-columns: 1fr; }
}