@font-face {
  font-family: "MiSans";
  src: url("../assets/MiSans-subset.woff2") format("woff2");
  font-weight: 100 900;
  font-display: swap;
}

:root {
  --leaf: #1e7a57;
  --leaf-ink: #14523c;
  --mint: #e8f5ef;
  --mint-deep: #d7ece2;
  --paper: #ffffff;
  --soft: #f5f7f6;
  --ink: #1c2420;
  --ink-soft: #3d4a44;
  --mute: #6b7a73;
  --line: rgba(28, 36, 32, 0.08);
  --shadow: 0 12px 40px rgba(20, 50, 40, 0.12);
  --shadow-soft: 0 4px 18px rgba(20, 50, 40, 0.08);
  /* 标题用系统宋体：自托管 PosterSerifSC 仅含少量汉字，会导致标题混字 */
  --serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", serif;
  --sans: "MiSans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --radius: 16px;
  --pill: 999px;
  --bar: 64px;
  --wrap: 1120px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--sans);
  font-weight: 400;
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  line-height: 1.6;
  font-synthesis: none;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }

:focus-visible {
  outline: 2px solid var(--leaf);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 100;
  padding: 8px 12px;
  background: #fff;
}
.skip:focus { left: 12px; top: 12px; }

.wrap {
  width: min(var(--wrap), calc(100% - 40px));
  margin: 0 auto;
}
.wrap.narrow { width: min(820px, calc(100% - 40px)); }

.wordmark {
  display: block;
  width: 92px;
  height: 22px;
  background: currentColor;
  -webkit-mask: url("../assets/tangan-brand-wordmark.svg") center / contain no-repeat;
  mask: url("../assets/tangan-brand-wordmark.svg") center / contain no-repeat;
}

.hero-wordmark {
  display: block;
  width: min(340px, 78vw);
  height: clamp(44px, 9vw, 72px);
  background: currentColor;
  color: var(--leaf);
  -webkit-mask: url("../assets/tangan-brand-wordmark.svg") left center / contain no-repeat;
  mask: url("../assets/tangan-brand-wordmark.svg") left center / contain no-repeat;
}

/* topbar */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 16px;
  height: var(--bar);
  padding: 0 clamp(16px, 4vw, 36px);
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid transparent;
  backdrop-filter: saturate(160%) blur(14px);
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}
.topbar.is-scrolled {
  border-bottom-color: var(--line);
  box-shadow: 0 1px 0 rgba(255,255,255,0.6);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--leaf);
}

.topnav {
  display: none;
  justify-content: center;
  gap: 28px;
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-soft);
}
.topnav a { opacity: 0.72; transition: opacity 0.2s ease, color 0.2s ease; }
.topnav a:hover,
.topnav a.is-active { opacity: 1; color: var(--leaf-ink); }

.menu {
  display: inline-flex;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 12px;
  background: var(--soft);
  cursor: pointer;
}
.menu i {
  display: block;
  width: 14px;
  height: 1.5px;
  background: var(--ink);
  box-shadow: 0 -5px 0 var(--ink), 0 5px 0 var(--ink);
}

@media (min-width: 900px) {
  .topnav { display: flex; }
  .menu { display: none; }
}
@media (max-width: 899px) {
  .topbar { grid-template-columns: 1fr auto auto; }
  .topbar .btn-sm { display: none; }
}

.drawer {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 39;
  padding: 88px 28px 40px;
  background: var(--paper);
}
.drawer.is-open { display: flex; flex-direction: column; gap: 8px; }
.drawer a:not(.btn) {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  font-family: var(--serif);
  font-size: 24px;
}

/* buttons — match app capsule CTA */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: var(--pill);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: transform 0.2s var(--ease), background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: #1a1f1c;
  color: #fff;
}
.btn-primary:hover { background: #000; color: #fff; }
.btn-ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--mute);
  cursor: default;
}
.btn-ghost:hover { transform: none; }
.btn-sm {
  min-height: 36px;
  padding: 0 14px;
  font-size: 13px;
  background: var(--leaf);
  color: #fff;
}
.btn-sm:hover { background: var(--leaf-ink); color: #fff; }
.btn-lg { min-height: 54px; padding: 0 28px; font-size: 16px; }

/* hero */
.hero {
  position: relative;
  overflow: hidden;
  padding: 28px 0 56px;
  background:
    radial-gradient(ellipse 70% 55% at 80% 20%, rgba(30, 122, 87, 0.12), transparent 60%),
    radial-gradient(ellipse 50% 40% at 10% 90%, rgba(232, 245, 239, 0.9), transparent 55%),
    var(--paper);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(28px, 5vw, 56px);
  align-items: center;
  min-height: calc(100svh - var(--bar) - 40px);
}

.hero-copy h1 { margin: 0; line-height: 0; }

.hero-pill {
  display: inline-flex;
  margin: 18px 0 0;
  padding: 6px 12px;
  border-radius: var(--pill);
  background: var(--mint);
  color: var(--leaf-ink);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.hero-title {
  margin: 14px 0 0;
  font-family: var(--serif);
  font-size: clamp(28px, 4.2vw, 42px);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.25;
  color: var(--ink);
}

.hero-lead {
  margin: 16px 0 0;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-soft);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.hero-note {
  margin: 18px 0 0;
  font-size: 12px;
  color: var(--mute);
  letter-spacing: 0.04em;
}

.hero-shot {
  margin: 0;
  justify-self: center;
  width: min(320px, 78vw);
  border-radius: 28px;
  overflow: hidden;
  box-shadow: var(--shadow);
  background: var(--mint);
}
.hero-shot img {
  width: 100%;
  height: auto;
  display: block;
}

.shot {
  margin: 0;
  flex: 0 0 auto;
  width: min(220px, 58vw);
  border-radius: 22px;
  overflow: hidden;
  background: #fff;
  box-shadow: var(--shadow-soft);
}
.shot img {
  width: 100%;
  height: auto;
  display: block;
}
.shot-lg {
  width: min(300px, 78vw);
  box-shadow: var(--shadow);
}

.shot-rail {
  display: flex;
  gap: 16px;
  margin-top: 32px;
  padding: 8px 4px 20px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}
.shot-rail .shot { scroll-snap-align: start; }
.shot-rail::-webkit-scrollbar { height: 6px; }
.shot-rail::-webkit-scrollbar-thumb {
  background: rgba(30, 122, 87, 0.28);
  border-radius: 999px;
}

.feature-pair {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: clamp(28px, 5vw, 56px);
  align-items: center;
  margin-top: 48px;
}
.feature-pair:first-child { margin-top: 28px; }
.feature-pair-rev { direction: rtl; }
.feature-pair-rev > * { direction: ltr; }

.stack-card {
  padding: 22px 22px 18px;
  border-radius: var(--radius);
  background: var(--soft);
  border: 1px solid var(--line);
}
.stack-card h3 {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink);
}
.stack-card p { margin: 0 0 12px; font-family: var(--sans); }
.stack-card p:last-child { margin-bottom: 0; }
.stack-card strong { font-family: var(--sans); font-weight: 650; }
.stack-card.ok { background: var(--mint); border-color: rgba(30, 122, 87, 0.14); }
.stack-card.no { background: #fff; }

.block-label {
  margin: 28px 0 12px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--leaf-ink);
}

.chain {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: chain;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: #fff;
}
.chain li {
  counter-increment: chain;
  padding: 14px 12px;
  border-right: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-soft);
}
.chain li:last-child { border-right: 0; }
.chain li::before {
  content: "0" counter(chain);
  display: block;
  margin-bottom: 8px;
  font-family: var(--serif);
  font-size: 13px;
  color: var(--leaf);
}

.strategy-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.strategy-grid li {
  padding: 18px 18px 16px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--line);
}
.strategy-grid strong {
  display: block;
  font-family: var(--serif);
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--ink);
}
.strategy-grid span {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.compare-point {
  margin: 18px 0 0 !important;
  font-family: var(--serif);
  font-size: 16px !important;
  letter-spacing: 0.03em;
  color: var(--leaf-ink) !important;
  line-height: 1.7 !important;
}

.timeline {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 28px;
}
.timeline > div {
  padding: 22px 22px 18px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid rgba(30, 122, 87, 0.12);
}
.timeline h3 {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink);
}
.timeline li { font-family: var(--sans); }
.timeline ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.timeline li {
  position: relative;
  padding: 8px 0 8px 14px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  color: var(--ink-soft);
}
.timeline li:first-child { border-top: 0; }
.timeline li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--leaf);
}

.audience-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 24px;
}
.bullet {
  margin: 0;
  padding: 0;
  list-style: none;
}
.bullet li {
  padding: 10px 0;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.65;
  color: var(--ink-soft);
}
.bullet li:first-child { border-top: 0; }
.aside-note {
  margin: 12px 0 0 !important;
  font-size: 12px !important;
  color: var(--mute) !important;
}

/* sections */
.band {
  padding: clamp(56px, 9vw, 96px) 0;
  background: var(--paper);
}
.band-mint { background: var(--mint); }
.band-soft { background: var(--soft); }
.band-cta {
  padding: clamp(40px, 6vw, 64px) 0;
  background: linear-gradient(180deg, var(--mint) 0%, var(--mint-deep) 100%);
}

.band h2 {
  margin: 0 0 18px;
  font-family: var(--serif);
  font-size: clamp(26px, 3.6vw, 36px);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.3;
  color: var(--ink);
}

.band h3 {
  margin: 16px 0 8px;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink);
}

.lead {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink);
}
.lead.center { text-align: center; max-width: 36em; margin-left: auto; margin-right: auto; }

.band p {
  margin: 0 0 12px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-soft);
}

.fine {
  margin-top: 20px !important;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 12px !important;
  color: var(--mute) !important;
  line-height: 1.7 !important;
}
.fine.center {
  text-align: center;
  border-top: 0;
  padding-top: 8px;
}
.fine a {
  color: var(--leaf-ink);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.two {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: clamp(24px, 4vw, 48px);
  margin-top: 28px;
  align-items: start;
}

.check {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}
.check li {
  padding: 16px 18px;
  border-radius: var(--radius);
  background: var(--soft);
  border: 1px solid var(--line);
}
.check strong {
  display: block;
  margin-bottom: 6px;
  font-size: 15px;
  color: var(--leaf-ink);
}
.check span {
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.split-media {
  display: grid;
  grid-template-columns: 0.85fr 1.15fr;
  gap: clamp(28px, 5vw, 56px);
  align-items: center;
}

.steps {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  counter-reset: s;
  display: grid;
  gap: 12px;
}
.steps li {
  counter-increment: s;
  display: grid;
  grid-template-columns: 2rem 1fr;
  gap: 12px;
  padding: 14px 16px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(30, 122, 87, 0.12);
}
.steps li::before {
  content: counter(s);
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--leaf);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
}
.steps strong {
  display: block;
  font-size: 15px;
  color: var(--ink);
}
.steps span {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink-soft);
}

.compare {
  margin-top: 28px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: #fff;
}
.compare-row {
  display: grid;
  grid-template-columns: 5.5rem 1fr 1.15fr;
  gap: 12px;
  padding: 14px 18px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.5;
}
.compare-row:first-child { border-top: 0; }
.compare-head {
  background: var(--soft);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mute);
}
.compare-row > :first-child {
  font-weight: 600;
  color: var(--ink);
}
.compare-row > :nth-child(2) { color: var(--mute); }
.compare-row > :nth-child(3) {
  color: var(--leaf-ink);
  font-weight: 600;
}

.cta-box {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 28px 32px;
  border-radius: 24px;
  background: #fff;
  box-shadow: var(--shadow-soft);
}
.cta-box h2 { margin: 0 0 8px; }
.cta-box p { margin: 0; color: var(--ink-soft); }

.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 28px;
  align-items: start;
}

.note-card {
  padding: 22px 22px 18px;
  border-radius: var(--radius);
  background: var(--soft);
  border: 1px solid var(--line);
}
.note-card h3 {
  margin-top: 0;
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink);
}
.note-card li { font-family: var(--sans); }
.note-card ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
.note-card li {
  position: relative;
  padding: 10px 0 10px 14px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  color: var(--ink-soft);
}
.note-card li:first-child { border-top: 0; }
.note-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.15em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--leaf);
}

.site-foot {
  padding: 28px 0 36px;
  border-top: 1px solid var(--line);
  color: var(--mute);
  font-size: 12px;
  line-height: 1.7;
}
.foot-inner { display: grid; gap: 8px; }
.foot-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--leaf);
  margin-bottom: 4px;
}
.foot-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  margin: 0;
}
.foot-links a:hover { color: var(--leaf-ink); }

@media (max-width: 960px) {
  .hero-grid,
  .two,
  .feature-pair,
  .feature-pair-rev,
  .about-grid,
  .timeline,
  .audience-grid,
  .strategy-grid {
    grid-template-columns: 1fr;
    direction: ltr;
  }
  .hero-grid { min-height: 0; }
  .hero-shot { order: -1; width: min(280px, 72vw); }
  .feature-pair .shot-lg { justify-self: center; }
  .cta-box { flex-direction: column; align-items: flex-start; }
  .chain { grid-template-columns: 1fr; }
  .chain li {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .chain li:last-child { border-bottom: 0; }
}

@media (max-width: 640px) {
  .compare-head { display: none; }
  .compare-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }
  .compare-row > :nth-child(2)::before { content: "旧 · "; }
  .compare-row > :nth-child(3)::before { content: "棠安 · "; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn:hover { transform: none; }
}