/* ===========================================================
   Weidunzhi — official site
   Dark, quiet, editorial. Inspired by minimal app-studio sites.
   =========================================================== */

:root {
  --page: #15181a;
  --page-deep: #101314;
  --surface: #1b1f21;
  --surface-2: #202526;
  --text: #edece7;
  --muted: #a2aaa6;
  --muted-2: #7e8682;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.16);
  --accent: #e3a087;
  --accent-soft: rgba(227, 160, 135, 0.14);
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --radius-lg: 28px;
  --radius-md: 18px;
  --container: 1180px;
  --header-h: 74px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  color-scheme: dark;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--page);
  color: var(--text);
  font-size: 15px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

ul,
ol,
dl,
dd,
h1,
h2,
h3,
h4,
p {
  margin: 0;
  padding: 0;
}

ul,
ol {
  list-style: none;
}

::selection {
  background: var(--accent);
  color: #1a1a1a;
}

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 32px;
}

.skip-link {
  position: fixed;
  left: 20px;
  top: -60px;
  z-index: 200;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--accent);
  color: #1a1a1a;
  font-size: 13px;
  transition: top 0.25s var(--ease);
}

.skip-link:focus-visible {
  top: 16px;
}

/* ---------- header ---------- */

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: var(--header-h);
  border-bottom: 1px solid transparent;
  transition: background 0.4s var(--ease), border-color 0.4s var(--ease);
}

.site-header.is-scrolled {
  background: rgba(21, 24, 26, 0.82);
  -webkit-backdrop-filter: blur(20px) saturate(140%);
  backdrop-filter: blur(20px) saturate(140%);
  border-bottom-color: var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  height: 100%;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand-mark {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  object-fit: cover;
  filter: saturate(0.9);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.35);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-text strong {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.brand-text small {
  margin-top: 4px;
  font-size: 9px;
  letter-spacing: 0.26em;
  color: var(--muted-2);
}

.nav {
  position: absolute;
  top: 50%;
  left: 50%;
  display: flex;
  align-items: center;
  gap: 34px;
  transform: translate(-50%, -50%);
}

.nav a {
  position: relative;
  font-size: 13.5px;
  color: var(--muted);
  letter-spacing: 0.02em;
  transition: color 0.25s var(--ease);
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 100%;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s var(--ease);
}

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

.nav a:hover::after {
  transform: scaleX(1);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-shrink: 0;
}

/* language switch */

.lang {
  position: relative;
}

.lang-trigger {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 12px;
  color: var(--muted);
  list-style: none;
  cursor: pointer;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease),
    background 0.25s var(--ease);
}

.lang-trigger::-webkit-details-marker {
  display: none;
}

.lang-trigger:hover {
  color: var(--text);
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.03);
}

.lang-trigger .ico {
  width: 15px;
  height: 15px;
}

.lang-trigger .chevron {
  width: 12px;
  height: 12px;
  transition: transform 0.3s var(--ease);
}

.lang[open] .chevron {
  transform: rotate(180deg);
}

.lang-menu {
  position: absolute;
  top: calc(100% + 12px);
  right: 0;
  width: 224px;
  padding: 7px;
  border: 1px solid var(--line);
  border-radius: 15px;
  background: #202426;
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.55);
  z-index: 30;
  animation: menuIn 0.3s var(--ease);
}

@keyframes menuIn {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
}

.lang-menu button {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  padding: 10px 12px;
  border-radius: 9px;
  font-size: 13px;
  text-align: left;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.lang-menu button small {
  font-size: 10px;
  color: var(--muted-2);
}

.lang-menu button:hover {
  background: rgba(255, 255, 255, 0.05);
}

.lang-menu button[aria-checked="true"] {
  color: var(--accent);
  background: var(--accent-soft);
}

.lang-menu button[aria-checked="true"] small {
  color: rgba(227, 160, 135, 0.7);
}

/* buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 13px 26px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 13.5px;
  font-weight: 500;
  letter-spacing: 0.01em;
  white-space: nowrap;
  cursor: pointer;
  transition: transform 0.35s var(--ease), background 0.3s var(--ease),
    border-color 0.3s var(--ease), color 0.3s var(--ease),
    box-shadow 0.35s var(--ease);
}

.btn .ico {
  width: 16px;
  height: 16px;
}

.btn-primary {
  background: var(--accent);
  color: #201814;
  box-shadow: 0 10px 30px rgba(227, 160, 135, 0.16);
}

.btn-primary:hover {
  transform: translateY(-2px);
  background: #efb198;
  box-shadow: 0 16px 40px rgba(227, 160, 135, 0.24);
}

.btn-line {
  border-color: var(--line-strong);
  color: var(--text);
}

.btn-line:hover {
  border-color: rgba(255, 255, 255, 0.32);
  background: rgba(255, 255, 255, 0.04);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 9px 18px;
  font-size: 12.5px;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 50%;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 16px;
  height: 1.5px;
  background: var(--text);
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease);
}

.site-header.menu-open .nav-toggle span:first-child {
  transform: translateY(3.25px) rotate(45deg);
}

.site-header.menu-open .nav-toggle span:last-child {
  transform: translateY(-3.25px) rotate(-45deg);
}

/* ---------- shared type ---------- */

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 11.5px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
}

.eyebrow-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px rgba(227, 160, 135, 0.13);
}

h1,
h2,
h3 {
  font-weight: 560;
  letter-spacing: -0.04em;
}

h2 {
  font-size: clamp(30px, 3.5vw, 46px);
  line-height: 1.18;
}

h2 em,
h1 em {
  font-style: normal;
  color: var(--accent);
}

.ico {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.section {
  position: relative;
  padding: 118px 0;
}

.section-head {
  max-width: 640px;
  margin-bottom: 62px;
}

.section-head h2 {
  margin-top: 22px;
}

.section-desc {
  margin-top: 20px;
  max-width: 480px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.95;
}

.section-head.split {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 60px;
  max-width: none;
}

.section-head.split .section-desc {
  margin-top: 0;
  max-width: 330px;
  padding-bottom: 7px;
}

/* ---------- hero ---------- */

.hero {
  position: relative;
  padding: calc(var(--header-h) + 84px) 0 84px;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  inset: -180px 0 auto;
  height: 720px;
  background:
    radial-gradient(46% 52% at 66% 28%, rgba(227, 160, 135, 0.13), transparent 68%),
    radial-gradient(38% 48% at 22% 12%, rgba(126, 156, 176, 0.12), transparent 70%);
  pointer-events: none;
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.04fr 0.96fr;
  align-items: center;
  gap: 56px;
}

.hero-copy h1 {
  margin-top: 26px;
  font-size: clamp(44px, 5.1vw, 72px);
  line-height: 1.14;
}

.hero-desc {
  max-width: 470px;
  margin-top: 28px;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 2;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 36px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  margin-top: 44px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  max-width: 520px;
}

.hero-tags li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--muted-2);
}

.hero-tags li::before {
  content: "";
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.7;
}

/* hero visual / phones */

.hero-visual {
  position: relative;
  height: 560px;
  isolation: isolate;
}

.hero-halo {
  position: absolute;
  inset: 12% 4% 8%;
  border-radius: 50%;
  background: radial-gradient(circle at 55% 45%, rgba(227, 160, 135, 0.16), transparent 62%);
  filter: blur(30px);
}

.phone {
  position: absolute;
  border-radius: 42px;
  background: linear-gradient(160deg, #2b3032, #141718 42%, #24292b);
  padding: 8px;
  box-shadow: 0 40px 80px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(255, 255, 255, 0.07),
    inset 0 1px 0 rgba(255, 255, 255, 0.16);
}

.phone-a {
  width: 258px;
  height: 536px;
  left: 6%;
  top: 8px;
  transform: rotate(-7deg);
  z-index: 2;
  animation: floatA 9s ease-in-out infinite;
}

.phone-b {
  width: 214px;
  height: 452px;
  right: 2%;
  bottom: 4px;
  transform: rotate(6deg);
  z-index: 3;
  animation: floatB 11s ease-in-out infinite;
}

@keyframes floatA {
  0%,
  100% {
    transform: rotate(-7deg) translateY(0);
  }
  50% {
    transform: rotate(-5.5deg) translateY(-14px);
  }
}

@keyframes floatB {
  0%,
  100% {
    transform: rotate(6deg) translateY(0);
  }
  50% {
    transform: rotate(4.5deg) translateY(12px);
  }
}

.phone-screen {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 35px;
  overflow: hidden;
  background-size: cover;
  background-position: center;
  isolation: isolate;
}

.feed-shade {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to bottom,
    rgba(9, 12, 12, 0.5) 0%,
    rgba(9, 12, 12, 0.02) 28%,
    rgba(9, 12, 12, 0.12) 62%,
    rgba(9, 12, 12, 0.78) 100%
  );
}

.feed-tabs {
  position: absolute;
  top: 44px;
  left: 0;
  right: 0;
  display: flex;
  justify-content: center;
  gap: 16px;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.tab-muted {
  color: rgba(255, 255, 255, 0.55);
}

.tab-active {
  position: relative;
  color: #fff;
}

.tab-active::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -7px;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: #fff;
  transform: translateX(-50%);
}

.feed-rail {
  position: absolute;
  right: 12px;
  bottom: 92px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 17px;
  color: #fff;
}

.rail-avatar {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1.5px solid rgba(255, 255, 255, 0.85);
  background: linear-gradient(150deg, #e3a087, #6d7f8c);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.rail-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.rail-item svg {
  width: 23px;
  height: 23px;
  fill: rgba(255, 255, 255, 0.94);
  stroke: none;
  filter: drop-shadow(0 2px 6px rgba(0, 0, 0, 0.4));
}

.rail-item b {
  font-size: 9px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.9);
}

.feed-caption {
  position: absolute;
  left: 14px;
  right: 62px;
  bottom: 18px;
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.feed-user {
  font-size: 10.5px;
  font-weight: 600;
  color: #fff;
}

.feed-line {
  display: block;
  height: 5px;
  border-radius: 3px;
  background: rgba(255, 255, 255, 0.38);
}

.feed-line.w-1 {
  width: 82%;
}

.feed-line.w-2 {
  width: 58%;
}

.feed-progress {
  display: block;
  height: 2px;
  margin-top: 5px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.22);
  overflow: hidden;
}

.feed-progress i {
  display: block;
  width: 42%;
  height: 100%;
  background: rgba(255, 255, 255, 0.92);
}

.phone-notch {
  position: absolute;
  top: 15px;
  left: 50%;
  width: 66px;
  height: 17px;
  border-radius: 999px;
  background: #0b0d0d;
  transform: translateX(-50%);
}

.hero-chip {
  position: absolute;
  top: 22px;
  right: 0;
  z-index: 4;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 10px 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(30, 34, 35, 0.86);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  font-size: 11.5px;
  color: var(--muted);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.4);
}

.chip-pulse {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #7fc98d;
  box-shadow: 0 0 0 0 rgba(127, 201, 141, 0.6);
  animation: pulse 2.4s infinite;
}

@keyframes pulse {
  70% {
    box-shadow: 0 0 0 7px rgba(127, 201, 141, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(127, 201, 141, 0);
  }
}

/* ---------- own app ---------- */

.section-app {
  border-block: 1px solid var(--line);
  background:
    radial-gradient(58% 78% at 76% 18%, rgba(227, 160, 135, 0.1), transparent 62%),
    linear-gradient(180deg, #171b1c, #14181a 60%, #171b1c);
}

.app-grid {
  display: grid;
  grid-template-columns: 1.06fr 0.94fr;
  align-items: center;
  gap: 64px;
}

.app-copy h2 {
  margin-top: 22px;
}

.app-desc {
  max-width: 470px;
  margin-top: 22px;
  color: var(--muted);
  font-size: 13.5px;
  line-height: 2;
}

.app-features {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px 34px;
  margin-top: 40px;
  max-width: 500px;
}

.app-features > div {
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.app-feature-index {
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: var(--accent);
  opacity: 0.85;
}

.app-features h3 {
  margin-top: 10px;
  font-size: 15px;
  letter-spacing: -0.01em;
}

.app-features p {
  margin-top: 8px;
  color: var(--muted);
  font-size: 12.5px;
  line-height: 1.85;
}

.app-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 40px;
}

.store-btn {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  padding: 9px 20px 9px 16px;
  border: 1px solid var(--line-strong);
  border-radius: 13px;
  color: var(--text);
  transition: transform 0.35s var(--ease), background 0.3s var(--ease),
    border-color 0.3s var(--ease);
}

.store-btn:hover {
  transform: translateY(-2px);
  border-color: rgba(255, 255, 255, 0.32);
  background: rgba(255, 255, 255, 0.05);
}

.store-ico {
  width: 22px;
  height: 22px;
  flex: none;
}

.store-text {
  display: flex;
  flex-direction: column;
  gap: 1px;
  line-height: 1.15;
  text-align: left;
}

.store-text small {
  font-size: 10px;
  letter-spacing: 0.04em;
  color: var(--muted-2);
}

.store-text strong {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.app-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 640px;
  padding: 8px 0;
}

.app-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 470px;
  height: 470px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(227, 160, 135, 0.2), transparent 66%);
  filter: blur(26px);
  transform: translate(-50%, -50%);
}

.app-devices {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 468px;
  height: 600px;
}

.app-frame {
  position: absolute;
  padding: 9px;
  border-radius: 42px;
  background: linear-gradient(160deg, #2b3032, #141718 42%, #252a2c);
  box-shadow: 0 50px 90px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.07),
    inset 0 1px 0 rgba(255, 255, 255, 0.16);
  transition: transform 0.8s var(--ease);
}

.app-frame-a {
  top: 0;
  left: 0;
  z-index: 3;
  width: 246px;
  transform: rotate(-4deg);
}

.app-frame-b {
  right: 0;
  bottom: 0;
  z-index: 2;
  width: 204px;
  transform: rotate(4.5deg);
}

.app-frame-a:hover {
  transform: rotate(-1deg) translateY(-8px);
}

.app-frame-b:hover {
  transform: rotate(1.5deg) translateY(-8px);
}

.app-frame img {
  width: 100%;
  height: auto;
  border-radius: 34px;
}

.app-badge {
  position: absolute;
  z-index: 4;
  right: 0;
  top: 6px;
  display: flex;
  align-items: center;
  gap: 11px;
  max-width: 198px;
  padding: 12px 17px 12px 12px;
  border: 1px solid var(--line-strong);
  border-radius: 15px;
  background: rgba(22, 26, 27, 0.82);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  box-shadow: 0 20px 44px rgba(0, 0, 0, 0.42);
}

.app-badge-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: var(--accent);
  color: #241a15;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.app-badge-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  line-height: 1.3;
}

.app-badge-text strong {
  font-size: 12.5px;
  font-weight: 600;
}

.app-badge-text small {
  font-size: 10.5px;
  color: var(--muted-2);
}

/* ---------- services ---------- */

.service-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line);
}

.service-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 32px 28px 30px;
  border-bottom: 1px solid var(--line);
  border-right: 1px solid var(--line);
  transition: background 0.45s var(--ease), transform 0.45s var(--ease);
}

.service-card:nth-child(3n) {
  border-right: 0;
}

.service-card:hover {
  background: rgba(255, 255, 255, 0.028);
  transform: translateY(-3px);
}

.card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 18px;
}

.card-index {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--accent);
  opacity: 0.8;
}

.card-tag {
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--muted-2);
}

.service-card h3 {
  margin-top: 46px;
  font-size: 21px;
  letter-spacing: -0.02em;
  line-height: 1.4;
}

.service-card p {
  margin-top: 14px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.95;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 28px;
  font-size: 12px;
  color: var(--muted-2);
  transition: color 0.3s var(--ease), gap 0.3s var(--ease);
}

.card-link .ico {
  width: 14px;
  height: 14px;
}

.service-card:hover .card-link {
  color: var(--accent);
  gap: 9px;
}

/* ---------- process ---------- */

.section-dark {
  background: linear-gradient(180deg, var(--page-deep), #141819 55%, var(--page-deep));
  border-block: 1px solid var(--line);
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 34px;
}

.steps li {
  position: relative;
  padding-top: 26px;
  border-top: 1px solid var(--line-strong);
}

.steps li::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 34px;
  height: 1px;
  background: var(--accent);
}

.step-num {
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--accent);
}

.steps h3 {
  margin-top: 20px;
  font-size: 18px;
  letter-spacing: -0.01em;
}

.steps p {
  margin-top: 11px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.9;
}

/* ---------- about ---------- */

.about-grid {
  display: grid;
  grid-template-columns: 0.92fr 1.08fr;
  align-items: center;
  gap: 72px;
}

.about-media {
  position: relative;
}

.about-media img {
  width: 100%;
  aspect-ratio: 4 / 4.6;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 1px solid var(--line);
  filter: saturate(0.9) brightness(0.92);
}

.about-media::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  background: linear-gradient(200deg, transparent 45%, rgba(12, 15, 16, 0.55));
  pointer-events: none;
}

.about-tag {
  position: absolute;
  left: 22px;
  bottom: 22px;
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 18px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 14px;
  background: rgba(18, 22, 23, 0.7);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
}

.tag-kicker {
  font-size: 9px;
  letter-spacing: 0.26em;
  color: var(--accent);
}

.tag-text {
  font-size: 12px;
  color: var(--text);
}

.about-copy h2 {
  margin-top: 22px;
}

.about-body {
  margin-top: 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  color: var(--muted);
  font-size: 13.5px;
  line-height: 2;
}

.facts {
  margin-top: 38px;
  border-top: 1px solid var(--line);
}

.facts > div {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 20px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
}

.facts dt {
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--muted-2);
}

.facts dd {
  font-size: 13px;
  color: var(--text);
}

/* ---------- contact ---------- */

.contact-panel {
  position: relative;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 60px;
  padding: 64px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(60% 120% at 8% 0%, rgba(227, 160, 135, 0.1), transparent 60%),
    linear-gradient(150deg, #1d2224, #171b1c 62%);
  overflow: hidden;
}

.contact-copy h2 {
  margin-top: 22px;
}

.contact-desc {
  max-width: 380px;
  margin-top: 20px;
  color: var(--muted);
  font-size: 13.5px;
  line-height: 1.95;
}

.contact-copy .btn {
  margin-top: 34px;
}

.contact-list {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0;
}

.contact-list li {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 17px 0;
  border-bottom: 1px solid var(--line);
}

.contact-list li:first-child {
  border-top: 1px solid var(--line);
}

.contact-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted-2);
}

.contact-label .ico {
  width: 14px;
  height: 14px;
  color: var(--accent);
  opacity: 0.85;
}

.contact-value {
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text);
}

.contact-value.link {
  transition: color 0.25s var(--ease);
}

.contact-value.link:hover {
  color: var(--accent);
}

/* ---------- footer ---------- */

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--page-deep);
  padding-top: 62px;
}

.footer-main {
  display: grid;
  grid-template-columns: 1.5fr 0.7fr 0.8fr;
  gap: 48px;
  padding-bottom: 54px;
}

.footer-brand p {
  max-width: 300px;
  margin-top: 20px;
  color: var(--muted-2);
  font-size: 12.5px;
  line-height: 1.9;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 11px;
}

.footer-col h4 {
  margin-bottom: 8px;
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.footer-col a,
.footer-col span {
  font-size: 12.5px;
  color: var(--muted);
  transition: color 0.25s var(--ease);
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
  padding: 22px 32px;
  border-top: 1px solid var(--line);
  font-size: 11px;
  color: var(--muted-2);
}

.footer-bottom a {
  transition: color 0.25s var(--ease);
}

.footer-bottom a:hover {
  color: var(--muted);
}

/* ---------- reveal ---------- */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.9s var(--ease), transform 0.9s var(--ease);
}

.reveal.is-visible {
  opacity: 1;
  transform: none;
}

.service-grid .reveal:nth-child(2),
.steps .reveal:nth-child(2) {
  transition-delay: 0.08s;
}

.service-grid .reveal:nth-child(3),
.steps .reveal:nth-child(3) {
  transition-delay: 0.16s;
}

.service-grid .reveal:nth-child(4),
.steps .reveal:nth-child(4) {
  transition-delay: 0.1s;
}

.service-grid .reveal:nth-child(5) {
  transition-delay: 0.18s;
}

.service-grid .reveal:nth-child(6) {
  transition-delay: 0.26s;
}

/* ---------- language-specific typography ---------- */

html[lang="zh-Hans"] h1,
html[lang="zh-Hant"] h1 {
  letter-spacing: -0.02em;
  line-height: 1.22;
}

html[lang="zh-Hans"] h2,
html[lang="zh-Hant"] h2 {
  letter-spacing: -0.015em;
  line-height: 1.3;
}

html[lang="zh-Hans"] .hero-desc,
html[lang="zh-Hant"] .hero-desc {
  line-height: 2.05;
}

html[lang="en"] .hero-copy h1 {
  letter-spacing: -0.045em;
  line-height: 1.08;
}

html[lang="en"] .brand-text strong {
  letter-spacing: 0.01em;
}

html[lang="en"] .brand-text small {
  display: none;
}

html[lang="en"] .eyebrow {
  letter-spacing: 0.18em;
}

/* ---------- language transition ---------- */

html.lang-switching body {
  animation: langFade 0.5s var(--ease);
}

@keyframes langFade {
  from {
    opacity: 0.5;
  }
  to {
    opacity: 1;
  }
}

/* ---------- responsive ---------- */

@media (max-width: 1080px) {
  .nav {
    gap: 24px;
  }

  .contact-panel {
    padding: 52px;
    gap: 40px;
  }

  .about-grid {
    gap: 48px;
  }
}

@media (max-width: 960px) {
  .header-cta {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    padding: 18px 32px 30px;
    background: rgba(19, 22, 23, 0.98);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--line);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.3s var(--ease), transform 0.3s var(--ease),
      visibility 0.3s;
  }

  .site-header.menu-open .nav {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav a {
    width: 100%;
    padding: 13px 0;
    font-size: 15px;
    border-bottom: 1px solid var(--line);
  }

  .nav a::after {
    display: none;
  }

  .hero {
    padding-top: calc(var(--header-h) + 56px);
  }

  .hero-inner {
    grid-template-columns: 1fr;
    gap: 54px;
  }

  .hero-copy h1 {
    font-size: clamp(40px, 8vw, 64px);
  }

  .hero-visual {
    height: 500px;
    max-width: 560px;
    margin-inline: auto;
    width: 100%;
  }

  .phone-a {
    left: 2%;
  }

  .phone-b {
    right: 0;
  }

  .section {
    padding: 88px 0;
  }

  .section-head.split {
    flex-direction: column;
    align-items: flex-start;
    gap: 18px;
  }

  .section-head {
    margin-bottom: 46px;
  }

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

  .service-card:nth-child(3n) {
    border-right: 1px solid var(--line);
  }

  .service-card:nth-child(2n) {
    border-right: 0;
  }

  .steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 36px 28px;
  }

  .app-grid {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .app-visual {
    min-height: 0;
    flex-direction: column;
    justify-content: center;
    padding-top: 12px;
  }

  .app-devices {
    max-width: 420px;
    height: 536px;
    margin-inline: auto;
  }

  .app-frame-a {
    width: 222px;
  }

  .app-frame-b {
    width: 184px;
  }

  .app-badge {
    position: static;
    align-self: center;
    margin-top: 24px;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .about-media {
    max-width: 560px;
  }

  .about-media img {
    aspect-ratio: 4 / 3;
  }

  .contact-panel {
    grid-template-columns: 1fr;
    gap: 40px;
    padding: 44px 34px;
  }

  .footer-main {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }

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

@media (max-width: 640px) {
  .container {
    padding-inline: 22px;
  }

  .brand-text small {
    display: none;
  }

  .lang-trigger {
    padding: 8px 10px;
  }

  .lang-trigger span {
    font-size: 11px;
  }

  .lang-trigger .chevron {
    display: none;
  }

  .lang-menu {
    right: -46px;
  }

  .hero {
    padding-bottom: 66px;
  }

  .hero-visual {
    height: 430px;
  }

  .phone-a {
    width: 204px;
    height: 424px;
    left: 4px;
    top: 0;
  }

  .hero-chip {
    display: none;
  }

  .phone-b {
    width: 166px;
    height: 352px;
    right: 0;
  }

  .phone {
    border-radius: 34px;
    padding: 6px;
  }

  .phone-screen {
    border-radius: 29px;
  }

  .feed-tabs {
    top: 36px;
  }

  .feed-rail {
    bottom: 76px;
    right: 9px;
    gap: 13px;
  }

  .rail-item svg {
    width: 19px;
    height: 19px;
  }

  .hero-actions .btn {
    flex: 1 1 auto;
  }

  .hero-tags {
    margin-top: 34px;
    gap: 9px 14px;
  }

  .section {
    padding: 70px 0;
  }

  .section-head h2 {
    font-size: 30px;
  }

  .app-features {
    grid-template-columns: 1fr;
    gap: 22px;
    margin-top: 32px;
  }

  .app-devices {
    max-width: 360px;
    height: 462px;
  }

  .app-frame {
    padding: 8px;
    border-radius: 36px;
  }

  .app-frame-a {
    width: 194px;
  }

  .app-frame-b {
    width: 158px;
  }

  .app-frame img {
    border-radius: 29px;
  }

  .app-actions .btn {
    flex: 1 1 auto;
  }

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

  .service-card,
  .service-card:nth-child(3n) {
    border-right: 0;
    padding-inline: 4px;
  }

  .service-card h3 {
    margin-top: 30px;
  }

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

  .contact-panel {
    padding: 38px 24px;
    border-radius: 22px;
  }

  .contact-panel h2 {
    font-size: 28px;
  }

  .contact-copy .btn {
    width: 100%;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 20px 22px 28px;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}