/* MiraBrief — minimal static site (no frameworks, no external requests) */

:root {
  --paper: #f7f4ee;
  --paper-2: #efe9dd;
  --ink: #1b1a17;
  --ink-soft: #4d4941;
  --muted: #827c70;
  --line: #e5decf;
  --accent: #b23a2b;
  --accent-ink: #8f2e22;
  --accent-soft: #f4e3df;
  --card: #fffdf8;
  --ok: #2f7d4f;
  --warn: #9a6b1f;

  --font-serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Noto Serif SC", "Songti SC", "SimSun", serif;
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;

  --container: 1080px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Language switching: English default; add .lang-zh on <html> to show Chinese. */
html:not(.lang-zh) [data-lang="zh"] { display: none !important; }
html.lang-zh [data-lang="en"] { display: none !important; }

a { color: inherit; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(247, 244, 238, 0.86);
  backdrop-filter: saturate(1.2) blur(10px);
  border-bottom: 1px solid var(--line);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.28rem;
  letter-spacing: -0.01em;
}

.brand img { width: 26px; height: 26px; border-radius: 6px; }

.nav-links { display: flex; align-items: center; gap: 4px; }

.nav-links a {
  text-decoration: none;
  color: var(--ink-soft);
  font-size: 0.92rem;
  font-weight: 500;
  padding: 7px 11px;
  border-radius: 8px;
}

.nav-links a:hover { color: var(--ink); background: var(--paper-2); }

.lang-toggle {
  display: inline-flex;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--card);
  gap: 2px;
}

.lang-toggle button {
  border: 0;
  background: transparent;
  font: inherit;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--muted);
  padding: 4px 11px;
  border-radius: 999px;
  cursor: pointer;
}

.lang-toggle button.is-active { background: var(--ink); color: var(--paper); }

/* ---------- Hero ---------- */

.hero {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 48px;
  align-items: center;
  padding: 64px 0 56px;
}

.eyebrow {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 14px;
}

.hero h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.2rem, 5.2vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
}

.hero h1 .mark { color: var(--accent); }

.hero .lede {
  font-size: 1.12rem;
  color: var(--ink-soft);
  max-width: 30rem;
  margin: 0 0 26px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 26px;
}

.hero-meta span {
  font-size: 0.82rem;
  color: var(--ink-soft);
  background: var(--card);
  border: 1px solid var(--line);
  padding: 4px 10px;
  border-radius: 999px;
}

.cta-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.98rem;
  border-radius: 12px;
  padding: 13px 22px;
  border: 1px solid transparent;
  cursor: pointer;
}

.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-ink); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--muted); }

.btn .icon { font-size: 1.05rem; line-height: 1; }

/* Phone mockup */
.phone {
  position: relative;
  margin: 0 auto;
  max-width: 300px;
  border-radius: 30px;
  background: #141318;
  padding: 11px;
  box-shadow: 0 30px 60px -24px rgba(27, 26, 23, 0.45);
}

.phone-screen { border-radius: 20px; overflow: hidden; background: #fff; line-height: 0; }
.phone-screen img { display: block; width: 100%; height: auto; }

.hero-visual { display: flex; justify-content: center; }

/* ---------- Sections ---------- */

.section { padding: 56px 0; }

.section-head { max-width: 42rem; margin: 0 auto 36px; text-align: center; }

.section-head h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3.4vw, 2.2rem);
  letter-spacing: -0.015em;
  margin: 0 0 12px;
}

.section-head p { color: var(--ink-soft); margin: 0; }

.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 26px 24px;
}

.feature .num {
  font-family: var(--font-serif);
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature h3 { font-size: 1.06rem; margin: 0 0 8px; font-weight: 650; }

.feature p { color: var(--ink-soft); font-size: 0.94rem; margin: 0; }

/* Bilingual showcase */
.showcase {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: start;
}

.showcase figure { margin: 0; text-align: center; }

.showcase figcaption {
  font-size: 0.84rem;
  color: var(--muted);
  margin-top: 12px;
}

.showcase .phone { max-width: 250px; }

/* ---------- Download ---------- */

.download-card {
  max-width: 640px;
  margin: 0 auto;
  background: var(--card);
  border: 1px solid var(--line);
  border-top: 4px solid var(--accent);
  border-radius: 18px;
  padding: 36px 32px;
  text-align: center;
}

.download-card h2 { font-family: var(--font-serif); font-size: 1.7rem; margin: 0 0 8px; }

.download-card .sub { color: var(--ink-soft); margin: 0 0 22px; }

.dl-meta {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 0 0 24px;
  text-align: left;
}

.dl-meta div {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 14px;
}

.dl-meta .k { display: block; font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 3px; }
.dl-meta .v { font-weight: 650; font-size: 0.95rem; }

.sha {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--ink-soft);
  word-break: break-all;
  text-align: left;
  background: var(--paper);
  border: 1px dashed var(--line);
  border-radius: 10px;
  padding: 12px 14px;
  margin: 20px 0 8px;
}

.sha .k { color: var(--muted); }

.install-note {
  font-size: 0.86rem;
  color: var(--ink-soft);
  text-align: left;
  background: var(--accent-soft);
  border-radius: 10px;
  padding: 12px 14px;
  margin: 18px 0 0;
}

/* ---------- Privacy teaser ---------- */

.privacy-teaser {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: center;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 28px 30px;
}

.privacy-teaser h3 { margin: 0 0 6px; font-size: 1.1rem; }
.privacy-teaser p { margin: 0; color: var(--ink-soft); max-width: 40rem; }

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--line);
  padding: 32px 0 44px;
  margin-top: 24px;
  color: var(--muted);
  font-size: 0.88rem;
}

.footer-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 28px;
  justify-content: space-between;
  align-items: center;
}

.footer-row a { color: var(--ink-soft); text-decoration: none; }
.footer-row a:hover { color: var(--ink); }

/* ---------- Privacy page ---------- */

.prose { max-width: 46rem; }

.prose h1 {
  font-family: var(--font-serif);
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  letter-spacing: -0.02em;
  margin: 0 0 6px;
}

.prose .updated { color: var(--muted); font-size: 0.88rem; margin: 0 0 32px; }

.prose h2 {
  font-size: 1.15rem;
  margin: 28px 0 10px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--line);
}

.prose p, .prose li { color: var(--ink-soft); }

.prose ul { padding-left: 20px; }

.prose .notice {
  background: var(--accent-soft);
  border-radius: 10px;
  padding: 14px 16px;
  font-size: 0.92rem;
  color: var(--ink-soft);
  margin: 20px 0;
}

.page-hero { padding: 48px 0 24px; }

.backlink { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); text-decoration: none; font-size: 0.9rem; margin-bottom: 20px; }
.backlink:hover { color: var(--ink); }

/* ---------- Responsive ---------- */

@media (max-width: 820px) {
  .hero { grid-template-columns: 1fr; gap: 32px; padding: 40px 0 40px; }
  .hero-visual { order: -1; }
  .features { grid-template-columns: 1fr; }
  .showcase { grid-template-columns: 1fr 1fr; }
  .dl-meta { grid-template-columns: 1fr; }
  .privacy-teaser { grid-template-columns: 1fr; }
  .nav-links a { display: none; }   /* collapse nav links on small screens */
  .nav-links a.nav-dl { display: inline-block; }  /* keep Download reachable */
}

@media (max-width: 480px) {
  .container { padding: 0 18px; }
  .showcase { grid-template-columns: 1fr; }
  .showcase .phone { max-width: 240px; }
  .cta-row { flex-direction: column; align-items: stretch; }
  .btn { justify-content: center; }
}