/* ==========================================================================
   贸联通官网 · 版式基座
   中性纸面 + 墨色字 + 单一强调色；产品截图（实机）承担全部彩色
   ========================================================================== */

:root {
  --paper: #f4f4f2;
  --paper-2: #eaeae6;
  --ink: #121316;
  --ink-2: #26282d;
  --muted: #5d6067;
  --muted-2: #666a71;
  --hair: rgba(18, 19, 22, 0.14);
  --hair-2: rgba(18, 19, 22, 0.08);
  --accent: #4e33e0;
  --accent-ink: #3a25b8;
  --panel: #0f1013;
  --panel-2: #17181d;
  --panel-text: #f2f2ee;
  --panel-muted: rgba(242, 242, 238, 0.62);
  --panel-hair: rgba(242, 242, 238, 0.16);
  --maxw: 1240px;
  --gutter: clamp(20px, 4.4vw, 48px);
  --radius: 6px;
  --font-sans: "PingFang SC", "HarmonyOS Sans SC", "Source Han Sans SC",
    "Noto Sans CJK SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", "Roboto Mono", Menlo,
    Consolas, monospace;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.72;
  font-feature-settings: "kern" 1;
  overflow-x: hidden;
}

img,
svg {
  max-width: 100%;
}

a {
  color: inherit;
}

::selection {
  background: rgba(78, 51, 224, 0.18);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: -100px;
  z-index: 200;
  padding: 0.6em 1em;
  background: var(--ink);
  color: var(--paper);
  font-size: 0.86rem;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 12px;
}

/* --------------------------------------------------------------------------
   Shell
   -------------------------------------------------------------------------- */

.shell {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.section {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(64px, 8vw, 116px) var(--gutter);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(20px, 4vw, 64px);
  align-items: end;
  padding-top: 24px;
  border-top: 1px solid var(--hair);
  margin-bottom: clamp(28px, 4vw, 52px);
}

.section-head .lede {
  margin: 0;
  max-width: 44ch;
  justify-self: end;
  color: var(--muted);
  font-size: 0.96rem;
  line-height: 1.8;
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 22px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  background: var(--accent);
}

h1,
h2,
h3 {
  font-weight: 600;
  letter-spacing: -0.02em;
}

h2 {
  margin: 0;
  font-size: clamp(1.9rem, 3.5vw, 2.9rem);
  line-height: 1.14;
  letter-spacing: -0.025em;
}

[id] {
  scroll-margin-top: 84px;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--paper);
  border-bottom: 1px solid var(--hair-2);
  transition: border-color 0.25s ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--hair);
}

.header-inner {
  display: flex;
  align-items: center;
  width: 100%;
  max-width: var(--maxw);
  min-height: 68px;
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand img {
  width: 26px;
  height: 26px;
  border-radius: 7px;
}

.brand .wordmark {
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: 0.14em;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2vw, 28px);
  margin-left: auto;
}

.site-nav a {
  font-size: 0.86rem;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.site-nav a:hover {
  color: var(--ink);
}

.header-cta {
  margin-left: clamp(16px, 2.4vw, 32px);
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55em;
  height: 48px;
  padding: 0 1.4em;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 0.93rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.22s ease, border-color 0.22s ease,
    color 0.22s ease;
}

.btn svg {
  flex: none;
}

.btn .arrow {
  transition: transform 0.22s ease;
}

.btn:hover .arrow {
  transform: translateX(3px);
}

.btn-primary {
  background: var(--ink);
  color: var(--paper);
}

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

.btn-line {
  border-color: var(--hair);
  color: var(--ink);
  background: transparent;
}

.btn-line:hover {
  border-color: var(--ink);
}

.btn-sm {
  height: 38px;
  padding: 0 1.05em;
  font-size: 0.86rem;
}

.btn-light {
  background: var(--paper);
  color: var(--ink);
}

.btn-light:hover {
  background: var(--accent);
  color: #fff;
}

.btn-outline-light {
  border-color: var(--panel-hair);
  color: var(--panel-text);
}

.btn-outline-light:hover {
  border-color: var(--panel-text);
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 48px;
  color: var(--ink);
  font-size: 0.93rem;
  text-decoration: none;
  border-bottom: 1px solid var(--hair);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.link-arrow:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.link-arrow svg {
  transition: transform 0.22s ease;
}

.link-arrow:hover svg {
  transform: translateX(3px);
}

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

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
  gap: clamp(32px, 5vw, 88px);
  align-items: center;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(44px, 6vw, 88px) var(--gutter) clamp(56px, 7vw, 104px);
}

.hero-copy {
  position: relative;
  z-index: 1;
}

.hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 clamp(26px, 3vw, 40px);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
}

.hero-kicker::before {
  content: "";
  width: 7px;
  height: 7px;
  background: var(--accent);
}

.hero h1 {
  margin: 0;
  font-size: clamp(3rem, 7.6vw, 6.2rem);
  line-height: 0.98;
  letter-spacing: -0.035em;
  font-weight: 600;
}

.hero h1 .line {
  display: block;
}

.hero h1 .line-2 {
  padding-left: clamp(24px, 5vw, 64px);
}

.hero-sub {
  max-width: 40ch;
  margin: clamp(26px, 3vw, 38px) 0 0;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.82;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 24px;
  margin-top: clamp(28px, 3.4vw, 40px);
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 0;
  margin-top: clamp(30px, 3.6vw, 46px);
  padding-top: 18px;
  border-top: 1px solid var(--hair);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.hero-meta span + span::before {
  content: "/";
  margin: 0 12px;
  color: var(--hair);
}

/* 实机截图展台 */
.plate {
  position: relative;
  justify-self: end;
  width: min(100%, 430px);
  padding: clamp(18px, 2.2vw, 30px) clamp(16px, 2vw, 26px)
    clamp(14px, 1.8vw, 20px);
  border: 1px solid var(--hair);
  background: var(--paper-2);
}

.plate::before {
  content: "01 / 单聊";
  position: absolute;
  top: 14px;
  left: 18px;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.18em;
  color: var(--muted-2);
}

.plate-shot {
  display: block;
  width: min(286px, 82%);
  margin: clamp(28px, 3vw, 40px) auto 0;
}

.device {
  position: relative;
  padding: 8px;
  border-radius: 38px;
  background: var(--ink);
  box-shadow: 0 26px 60px -34px rgba(18, 19, 22, 0.55);
}

.device::after {
  content: "";
  position: absolute;
  inset: 8px;
  border-radius: 30px;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
  pointer-events: none;
}

.device img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 30px;
}

.plate-caption {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin: clamp(16px, 2vw, 22px) 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--hair);
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.plate-caption .mark {
  width: 7px;
  height: 7px;
  background: var(--accent);
}

/* --------------------------------------------------------------------------
   Feature index
   -------------------------------------------------------------------------- */

.index-list {
  border-bottom: 1px solid var(--hair);
}

.index-row {
  display: grid;
  grid-template-columns: 56px minmax(0, 0.9fr) minmax(0, 1.4fr) minmax(0, 0.6fr);
  gap: clamp(16px, 2.4vw, 40px);
  align-items: start;
  padding: clamp(22px, 2.6vw, 32px) 0;
  border-top: 1px solid var(--hair);
  transition: background-color 0.25s ease;
}

.index-row:hover {
  background: rgba(18, 19, 22, 0.025);
}

.index-num {
  padding-top: 0.35em;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--muted-2);
}

.index-title {
  margin: 0;
  font-size: clamp(1.1rem, 1.7vw, 1.4rem);
  font-weight: 600;
  letter-spacing: -0.015em;
}

.index-desc {
  margin: 0;
  max-width: 54ch;
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.8;
}

.index-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: flex-end;
}

.tag {
  padding: 0.24em 0.6em;
  border: 1px solid var(--hair);
  border-radius: 2px;
  font-size: 0.72rem;
  color: var(--muted);
  white-space: nowrap;
}

.also {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 14px;
  margin: clamp(24px, 3vw, 36px) 0 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.also .label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.also .item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.also .item + .item::before {
  content: "";
  width: 3px;
  height: 3px;
  background: var(--hair);
  margin-right: 6px;
}

/* --------------------------------------------------------------------------
   Dark band + gallery
   -------------------------------------------------------------------------- */

.dark {
  background: var(--panel);
  color: var(--panel-text);
}

.dark .section {
  padding-block: clamp(64px, 8vw, 110px);
}

.dark .section-head {
  border-top-color: var(--panel-hair);
}

.dark .section-head .lede {
  color: var(--panel-muted);
}

.dark .eyebrow {
  color: var(--panel-muted);
}

.dark .eyebrow::before {
  background: var(--accent);
}

.dark h2 {
  color: var(--panel-text);
}

.gallery {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 40px);
  align-items: start;
}

.gallery .shot:nth-child(2) {
  margin-top: clamp(24px, 4vw, 56px);
}

.gallery .shot:nth-child(3) {
  margin-top: clamp(12px, 2vw, 28px);
}

.shot {
  margin: 0;
}

.shot .device {
  background: #1b1c21;
  box-shadow: none;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.shot figcaption {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 14px;
  padding-top: 10px;
  border-top: 1px solid var(--panel-hair);
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--panel-muted);
}

/* --------------------------------------------------------------------------
   Privacy split
   -------------------------------------------------------------------------- */

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
  gap: clamp(28px, 5vw, 88px);
  align-items: start;
}

.split-intro {
  position: sticky;
  top: 108px;
}

.split-intro p {
  max-width: 34ch;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 0.96rem;
  line-height: 1.8;
}

.split-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  margin-top: 28px;
}

.text-link {
  font-size: 0.88rem;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid var(--hair);
  padding-bottom: 2px;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.text-link:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.rule-list {
  border-bottom: 1px solid var(--hair);
}

.rule-item {
  display: grid;
  grid-template-columns: minmax(0, 0.6fr) minmax(0, 1fr);
  gap: 8px clamp(16px, 3vw, 40px);
  padding: clamp(20px, 2.4vw, 28px) 0;
  border-top: 1px solid var(--hair);
}

.rule-item h3 {
  margin: 0;
  font-size: 1rem;
  font-weight: 600;
}

.rule-item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.8;
}

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

.dl-frame {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(0, 0.55fr);
  gap: clamp(28px, 4vw, 64px);
  align-items: center;
  padding: clamp(26px, 4vw, 56px);
  border: 1px solid var(--ink);
}

.dl-frame h2 {
  margin: 0;
  font-size: clamp(2rem, 4.2vw, 3.4rem);
  line-height: 1.06;
  letter-spacing: -0.03em;
}

.dl-frame .dl-sub {
  max-width: 42ch;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 0.96rem;
  line-height: 1.8;
}

.dl-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: clamp(24px, 3vw, 34px);
}

.dl-note {
  margin: 18px 0 0;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.qr-block {
  justify-self: end;
  width: min(212px, 100%);
  padding: 16px;
  border: 1px solid var(--hair);
  background: #fff;
}

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

.qr-block p {
  margin: 12px 0 0;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted-2);
  text-align: center;
}

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

.site-footer {
  background: var(--panel);
  color: var(--panel-text);
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) repeat(3, minmax(0, auto));
  gap: clamp(28px, 5vw, 72px);
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(52px, 6vw, 76px) var(--gutter) clamp(36px, 4vw, 48px);
}

.footer-brand .brand {
  color: var(--panel-text);
}

.footer-brand p {
  max-width: 30ch;
  margin: 18px 0 0;
  color: var(--panel-muted);
  font-size: 0.86rem;
  line-height: 1.8;
}

.footer-col h4 {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 400;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--panel-muted);
}

.footer-col a {
  display: block;
  padding: 5px 0;
  color: var(--panel-text);
  font-size: 0.86rem;
  text-decoration: none;
  opacity: 0.82;
  transition: opacity 0.2s ease;
}

.footer-col a:hover {
  opacity: 1;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 18px var(--gutter) 32px;
  border-top: 1px solid var(--panel-hair);
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--panel-muted);
}

.footer-bottom .icp {
  color: var(--panel-muted);
  text-decoration: none;
}

.to-top {
  color: var(--panel-muted);
  text-decoration: none;
}

.to-top:hover {
  color: var(--panel-text);
}

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

.page-hero {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(48px, 6vw, 84px) var(--gutter) clamp(28px, 4vw, 44px);
}

.page-hero h1 {
  margin: 0;
  font-size: clamp(2.4rem, 5.6vw, 4rem);
  line-height: 1.04;
  letter-spacing: -0.03em;
}

.page-hero .lede {
  max-width: 46ch;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.8;
}

.page-hero .hero-meta {
  max-width: 560px;
  margin-top: 28px;
}

.wechat-tip {
  display: none;
  gap: 12px;
  align-items: flex-start;
  max-width: var(--maxw);
  margin: 0 auto 18px;
  padding: 14px 0 14px 18px;
  border-left: 2px solid var(--accent);
  color: var(--ink);
  font-size: 0.9rem;
  line-height: 1.7;
}

.wechat-tip.is-visible {
  display: flex;
}

.wechat-tip b {
  font-weight: 600;
}

.channels {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--hair);
}

.channel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: clamp(24px, 3vw, 40px) 0;
}

.channel + .channel {
  padding-left: clamp(24px, 3vw, 44px);
  border-left: 1px solid var(--hair);
}

.channel .label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.channel h2 {
  margin: 0;
  font-size: clamp(1.7rem, 3vw, 2.4rem);
  letter-spacing: -0.025em;
}

.channel .desc {
  margin: 0;
  max-width: 38ch;
  color: var(--muted);
  font-size: 0.93rem;
  line-height: 1.8;
}

.channel-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-top: auto;
  padding-top: 6px;
}

.channel-note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.channels-hint {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.channels-hint a {
  color: var(--accent-ink);
  text-decoration: none;
  border-bottom: 1px solid rgba(78, 51, 224, 0.3);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 4vw, 56px);
  counter-reset: step;
  border-bottom: 1px solid var(--hair);
}

.step {
  padding: clamp(18px, 2.4vw, 26px) 0;
  border-top: 1px solid var(--hair);
  counter-increment: step;
}

.step::before {
  content: "0" counter(step);
  display: block;
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--muted-2);
}

.step h3 {
  margin: 0 0 8px;
  font-size: 1rem;
  font-weight: 600;
}

.step p {
  margin: 0;
  color: var(--muted);
  font-size: 0.91rem;
  line-height: 1.8;
}

.scan {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: clamp(24px, 4vw, 64px);
  align-items: center;
  padding-top: 24px;
  border-top: 1px solid var(--hair);
}

.scan h2 {
  margin: 0 0 10px;
  font-size: clamp(1.4rem, 2.4vw, 1.9rem);
}

.scan p {
  max-width: 44ch;
  margin: 0;
  color: var(--muted);
  font-size: 0.93rem;
  line-height: 1.8;
}

.scan .url {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--muted-2);
}

.faq {
  border-bottom: 1px solid var(--hair);
}

.faq details {
  border-top: 1px solid var(--hair);
}

.faq summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 0;
  cursor: pointer;
  list-style: none;
  font-size: 0.97rem;
  font-weight: 500;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "";
  flex: none;
  width: 8px;
  height: 8px;
  margin-right: 2px;
  border-right: 1.5px solid var(--muted);
  border-bottom: 1.5px solid var(--muted);
  transform: rotate(45deg);
  transition: transform 0.22s ease;
}

.faq details[open] summary::after {
  transform: rotate(-135deg);
}

.faq details p {
  max-width: 66ch;
  margin: 0 0 22px;
  color: var(--muted);
  font-size: 0.93rem;
  line-height: 1.85;
}

.faq details p a {
  color: var(--accent-ink);
  text-decoration: none;
  border-bottom: 1px solid rgba(78, 51, 224, 0.3);
}

.help {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px 32px;
  margin-top: clamp(32px, 4vw, 48px);
  padding: clamp(22px, 3vw, 30px);
  border: 1px solid var(--hair);
}

.help p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.8;
}

.help .mail {
  font-family: var(--font-mono);
  font-size: 0.86rem;
  color: var(--ink);
}

/* --------------------------------------------------------------------------
   Reveal (JS-gated so content is never hidden without JS)
   -------------------------------------------------------------------------- */

.js-anim [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.6s cubic-bezier(0.2, 0.7, 0.3, 1),
    transform 0.6s cubic-bezier(0.2, 0.7, 0.3, 1);
  transition-delay: var(--delay, 0ms);
}

.js-anim [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

.hero-line {
  display: block;
  animation: hero-in 0.9s cubic-bezier(0.2, 0.7, 0.3, 1) both;
}

.hero-line.line-2 {
  animation-delay: 0.08s;
}

@keyframes hero-in {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .js-anim [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .hero-line {
    animation: none;
  }

  .btn,
  .btn .arrow,
  .link-arrow,
  .link-arrow svg,
  .index-row {
    transition: none;
  }
}

@media print {
  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}

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

@media (max-width: 1024px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .plate {
    justify-self: start;
    width: min(100%, 420px);
  }

  .split {
    grid-template-columns: 1fr;
  }

  .split-intro {
    position: static;
  }

  .index-row {
    grid-template-columns: 44px minmax(0, 1fr) minmax(0, 1.6fr);
  }

  .index-tags {
    display: none;
  }

  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 860px) {
  .site-nav {
    display: none;
  }

  .header-cta {
    margin-left: auto;
  }

  .section-head {
    grid-template-columns: 1fr;
    align-items: start;
  }

  .section-head .lede {
    justify-self: start;
    max-width: 52ch;
  }

  .gallery {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .gallery .shot:nth-child(2),
  .gallery .shot:nth-child(3) {
    margin-top: 0;
  }
}

@media (max-width: 760px) {
  .hero h1 {
    font-size: clamp(2.6rem, 11.5vw, 3.6rem);
  }

  .hero h1 .line-2 {
    padding-left: 18px;
  }

  .index-row {
    grid-template-columns: 34px minmax(0, 1fr);
    gap: 4px 16px;
    padding: 22px 0;
  }

  .index-desc {
    grid-column: 2;
    max-width: 46ch;
  }

  .channels {
    grid-template-columns: 1fr;
  }

  .channel + .channel {
    padding-left: 0;
    border-left: 0;
    border-top: 1px solid var(--hair);
  }

  .steps {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .scan {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .scan .qr-block {
    justify-self: start;
  }

  .dl-frame {
    grid-template-columns: 1fr;
  }

  .qr-block {
    justify-self: start;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 24px 20px;
  }
}

@media (max-width: 520px) {
  .header-inner {
    min-height: 62px;
  }

  .hero {
    padding-top: 32px;
  }

  .hero-kicker {
    margin-bottom: 22px;
  }

  .hero h1 {
    font-size: clamp(2.3rem, 11vw, 3rem);
    letter-spacing: -0.03em;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .hero-actions .btn,
  .hero-actions .link-arrow {
    width: 100%;
    justify-content: center;
    border-bottom: 0;
  }

  .plate {
    padding: 16px 14px 14px;
  }

  .plate::before {
    top: 12px;
    left: 14px;
  }

  .plate-shot {
    width: min(240px, 80%);
  }

  .gallery {
    display: flex;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    gap: 16px;
    padding-bottom: 8px;
    -webkit-overflow-scrolling: touch;
  }

  .gallery .shot {
    flex: 0 0 72%;
    scroll-snap-align: start;
  }

  .rule-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .dl-actions,
  .channel-actions,
  .help {
    flex-direction: column;
    align-items: stretch;
  }

  .dl-actions .btn,
  .channel-actions .btn {
    width: 100%;
  }

  .qr-block {
    width: min(180px, 100%);
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 22px;
  }

  .footer-bottom {
    justify-content: flex-start;
    gap: 6px 16px;
  }
}