/* ============================================================
   园枢 · 应用介绍官网 —— 统一设计系统 v2
   设计语言：墨蓝 × 鎏金 × 宣纸暖白（Academic Art Nouveau）
   零外部依赖：无 CDN、无远程字体、无远程图片、无第三方库
   ============================================================ */

:root {
  /* 色彩体系 */
  --ink: #121B2E;          /* 墨色主文 */
  --navy: #0B1322;         /* 深墨蓝底 */
  --navy-2: #14223E;
  --blue: #2C4E8C;         /* 群青点缀 */
  --blue-deep: #1F3A68;
  --gold: #B08A3E;         /* 鎏金主色 */
  --gold-bright: #D8B96A;
  --gold-pale: #EBD9A8;
  --gold-soft: #F4ECD8;    /* 金纱浅底 */
  --paper: #F7F4EC;        /* 宣纸暖白 */
  --paper-deep: #EFEAE0;
  --card: #FFFFFF;
  --text: #252D3D;
  --muted: #6D7585;
  --line: #E4DDCC;         /* 暖发丝线 */

  --serif: "Songti SC", "STSong", "Noto Serif CJK SC", "SimSun", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;

  --radius: 18px;
  --shadow: 0 10px 32px rgba(18, 27, 46, 0.07);
  --shadow-hover: 0 20px 48px rgba(18, 27, 46, 0.13);
  --shadow-gold: 0 12px 34px rgba(176, 138, 62, 0.32);

  color-scheme: light;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  color: var(--text);
  background: var(--paper);
  line-height: 1.8;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { display: block; max-width: 100%; }
a { color: var(--blue); text-decoration: none; transition: color 0.25s ease; }
a:hover { color: var(--gold); }

::selection { background: var(--gold-pale); color: var(--ink); }

.container { max-width: 1120px; margin: 0 auto; padding: 0 28px; }

/* 锚点页签在吸顶导航下的偏移 */
[id] { scroll-margin-top: 86px; }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 244, 236, 0.9);
  backdrop-filter: blur(16px) saturate(1.4);
  -webkit-backdrop-filter: blur(16px) saturate(1.4);
  border-bottom: 1px solid var(--line);
  box-shadow: 0 8px 28px rgba(18, 27, 46, 0.05);
}

.site-header::before {
  content: "";
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--navy) 0%, var(--gold) 26%, var(--gold-bright) 50%, var(--gold) 74%, var(--navy) 100%);
}

.nav { display: flex; align-items: center; justify-content: space-between; height: 66px; }

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  box-shadow: 0 4px 14px rgba(18, 27, 46, 0.3);
  transition: transform 0.35s ease;
}

.brand:hover img { transform: rotate(-6deg) scale(1.05); }

.brand span {
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.32em;
  margin-right: -0.32em;
}

.nav-links { display: flex; align-items: center; gap: 26px; }

.nav-links a {
  color: var(--text);
  font-size: 14.5px;
  letter-spacing: 0.04em;
  padding: 6px 2px;
  position: relative;
  white-space: nowrap;
}

.nav-links a:hover { color: var(--gold); text-decoration: none; }

.nav-links a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  transform: translateX(-50%);
  transition: width 0.28s ease;
}

.nav-links a:hover::after { width: 100%; }

/* ---------- 首屏 Hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(900px 420px at 82% -8%, rgba(216, 185, 106, 0.16), transparent 62%),
    radial-gradient(720px 460px at -8% 108%, rgba(44, 78, 140, 0.5), transparent 60%),
    linear-gradient(158deg, var(--navy) 0%, var(--navy-2) 52%, #1B2F57 100%);
  color: #fff;
  padding: 108px 0 116px;
}

.hero::after { /* 内嵌画框线 */
  content: "";
  position: absolute;
  inset: 26px;
  border: 1px solid rgba(216, 185, 106, 0.22);
  border-radius: 4px;
  pointer-events: none;
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: 72px;
  position: relative;
  z-index: 1;
}

.hero-text { flex: 1.3; }

.hero-tag {
  display: inline-block;
  font-size: 12.5px;
  letter-spacing: 0.42em;
  margin-right: -0.42em;
  color: var(--gold-pale);
  border: 1px solid rgba(216, 185, 106, 0.5);
  border-radius: 999px;
  padding: 6px 18px 6px 20px;
  margin-bottom: 30px;
}

.hero h1 {
  font-family: var(--serif);
  font-size: 86px;
  line-height: 1.1;
  font-weight: 700;
  letter-spacing: 0.3em;
  margin-right: -0.3em;
  margin-bottom: 22px;
  background: linear-gradient(115deg, #FBF2D3 0%, #E9CD8D 30%, #CAA554 50%, #F7E9BE 68%, #BC9350 88%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-slogan {
  font-family: var(--serif);
  font-size: 21px;
  letter-spacing: 0.3em;
  margin-right: -0.3em;
  color: rgba(255, 255, 255, 0.92);
  margin-bottom: 26px;
}

.hero-desc {
  font-size: 15.5px;
  color: rgba(255, 255, 255, 0.72);
  max-width: 580px;
  margin-bottom: 38px;
  border-left: 2px solid rgba(216, 185, 106, 0.6);
  padding-left: 20px;
}

.hero-actions { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 14px 38px;
  border-radius: 999px;
  font-size: 15.5px;
  font-weight: 600;
  letter-spacing: 0.12em;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease, color 0.25s ease;
}

.btn:hover { transform: translateY(-2px); text-decoration: none; }

.btn-gold {
  background: linear-gradient(135deg, #D9BC66, var(--gold));
  color: var(--ink);
  box-shadow: var(--shadow-gold);
}

.btn-gold:hover { box-shadow: 0 18px 44px rgba(216, 185, 106, 0.5); }

.btn-ghost {
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.5);
}

.btn-ghost:hover { background: rgba(255, 255, 255, 0.1); border-color: rgba(216, 185, 106, 0.8); color: var(--gold-pale); }

.hero-note {
  margin-top: 24px;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: rgba(255, 255, 255, 0.55);
}

.hero-icon { flex: 0.7; display: flex; flex-direction: column; align-items: center; gap: 20px; }

.hero-icon img {
  width: 224px;
  height: 224px;
  border-radius: 48px;
  box-shadow: 0 30px 70px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(216, 185, 106, 0.35), 0 0 64px rgba(216, 185, 106, 0.12);
  animation: floaty 6s ease-in-out infinite;
}

@keyframes floaty {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.hero-icon .status {
  font-size: 12.5px;
  letter-spacing: 0.18em;
  color: var(--gold-pale);
  background: rgba(216, 185, 106, 0.12);
  border: 1px solid rgba(216, 185, 106, 0.45);
  padding: 7px 20px;
  border-radius: 999px;
}

/* ---------- 通用板块 ---------- */
.section { padding: 96px 0; }

.section-alt {
  background: var(--card);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.section-head { text-align: center; max-width: 780px; margin: 0 auto 56px; }

.section-head .kicker {
  display: inline-block;
  font-size: 12.5px;
  letter-spacing: 0.5em;
  margin-right: -0.5em;
  color: var(--gold);
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.section-head h2 {
  font-family: var(--serif);
  font-size: 38px;
  color: var(--ink);
  letter-spacing: 0.16em;
  margin-right: -0.16em;
  line-height: 1.4;
  margin-bottom: 18px;
}

.section-head h2::after {
  content: "◆";
  display: block;
  font-size: 11px;
  color: var(--gold);
  margin-top: 16px;
  letter-spacing: 0;
}

.section-head p { color: var(--muted); font-size: 15.5px; }

/* ---------- 应用介绍 ---------- */
.intro-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }

.intro-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px 36px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.intro-card::before {
  content: "";
  position: absolute;
  left: 0; top: 0;
  width: 3px; height: 0;
  background: linear-gradient(180deg, var(--gold-bright), var(--gold));
  transition: height 0.35s ease;
}

.intro-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: var(--gold-pale); }
.intro-card:hover::before { height: 100%; }

.intro-card h3 {
  font-family: var(--serif);
  font-size: 19.5px;
  color: var(--ink);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  letter-spacing: 0.06em;
}

.intro-card h3 .num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 1px solid var(--gold);
  border-radius: 9px;
  background: var(--gold-soft);
  color: var(--gold);
  font-family: var(--serif);
  font-size: 15px;
  flex-shrink: 0;
}

.intro-card p { color: var(--muted); font-size: 15px; }

/* ---------- 功能特性 ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }

.feature-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px 30px 30px;
  box-shadow: var(--shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
  position: relative;
}

.feature-card::after {
  content: "";
  position: absolute;
  right: 18px; top: 18px;
  width: 44px; height: 44px;
  border-top: 1px solid var(--gold-pale);
  border-right: 1px solid var(--gold-pale);
  border-radius: 0 14px 0 0;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-hover); border-color: var(--gold-pale); }
.feature-card:hover::after { opacity: 1; }

.feature-ico {
  width: 54px;
  height: 54px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--serif);
  font-size: 17px;
  font-weight: 700;
  color: var(--gold);
  background: var(--gold-soft);
  border: 1px solid var(--gold-pale);
  margin-bottom: 20px;
  letter-spacing: 0.06em;
}

.feature-card h3 { font-family: var(--serif); font-size: 19px; color: var(--ink); margin-bottom: 12px; letter-spacing: 0.05em; }
.feature-card p { font-size: 14.5px; color: var(--muted); }

/* ---------- 应用截图（轮播） ---------- */
.carousel { position: relative; max-width: 980px; margin: 0 auto; }

.cvr-stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 22px;
  overflow: hidden;
  height: 760px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-hover);
  background:
    radial-gradient(720px 300px at 50% 0%, rgba(216, 185, 106, 0.14), transparent 70%),
    radial-gradient(600px 300px at 12% 100%, rgba(44, 78, 140, 0.35), transparent 62%),
    linear-gradient(165deg, var(--navy) 0%, #101C38 60%, var(--navy-2) 100%);
}

.cvr-stage::after { /* 舞台衬线 */
  content: "";
  position: absolute;
  inset: 14px;
  border: 1px solid rgba(216, 185, 106, 0.28);
  border-radius: 14px;
  pointer-events: none;
  z-index: 3;
}

.cvr-phone {
  position: relative;
  height: calc(100% - 88px);
  aspect-ratio: 1284 / 2778;
  border-radius: 40px;
  overflow: hidden;
  background: #fff;
  border: 7px solid #0A1220;
  outline: 1px solid rgba(216, 185, 106, 0.5);
  box-shadow:
    0 40px 90px rgba(0, 0, 0, 0.55),
    0 0 0 7px rgba(216, 185, 106, 0.08),
    0 0 90px rgba(216, 185, 106, 0.12);
}

.cvr-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  opacity: 0;
  transform: scale(1.03);
  transition: opacity 0.65s ease, transform 0.9s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.cvr-img.active { opacity: 1; transform: scale(1); z-index: 2; }

.cvr-meta {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 20px;
}

.cvr-chip {
  display: inline-block;
  font-family: var(--serif);
  font-size: 15px;
  letter-spacing: 0.28em;
  margin-right: -0.28em;
  color: var(--ink);
  background: linear-gradient(135deg, #E9D392, var(--gold));
  border: 1px solid rgba(255, 245, 214, 0.9);
  padding: 9px 28px 9px 32px;
  border-radius: 999px;
  box-shadow: 0 8px 22px rgba(176, 138, 62, 0.28);
}

.cvr-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 5;
  width: 54px;
  height: 54px;
  border-radius: 50%;
  border: 1.5px solid rgba(216, 185, 106, 0.65);
  background: rgba(11, 19, 34, 0.55);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: var(--gold-pale);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3), 0 0 0 4px rgba(216, 185, 106, 0.08);
  transition: background 0.25s ease, color 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
}

.cvr-arrow:hover {
  background: linear-gradient(135deg, #D9BC66, var(--gold));
  color: var(--ink);
  box-shadow: var(--shadow-gold);
  transform: translateY(-50%) scale(1.07);
}

.cvr-arrow:active { transform: translateY(-50%) scale(0.96); }

.cvr-arrow.prev { left: 26px; }
.cvr-arrow.next { right: 26px; }

.cvr-caption {
  text-align: center;
  margin-top: 12px;
  font-size: 15px;
  color: var(--muted);
  min-height: 27px;
  transition: opacity 0.3s ease;
}

.cvr-rail {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 18px;
  padding: 4px 6px;
  overflow-x: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--gold-pale) transparent;
}

.cvr-thumb {
  flex: 0 0 auto;
  width: 52px;
  height: 52px;
  padding: 0;
  border-radius: 12px;
  overflow: hidden;
  border: 3px solid transparent;
  background: none;
  cursor: pointer;
  opacity: 0.42;
  filter: saturate(0.7);
  transition: opacity 0.25s ease, border-color 0.25s ease, transform 0.25s ease, filter 0.25s ease, box-shadow 0.25s ease;
}

.cvr-thumb img { width: 100%; height: 100%; object-fit: cover; object-position: top; }

.cvr-thumb:hover { opacity: 0.85; transform: translateY(-2px); }

.cvr-thumb.active {
  opacity: 1;
  filter: none;
  border-color: var(--gold);
  transform: scale(1.07);
  box-shadow: 0 6px 18px rgba(176, 138, 62, 0.38);
}

/* ---------- 平台架构 ---------- */
.flow-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }

.flow-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.flow-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); border-color: var(--gold-pale); }

.flow-card img { width: 100%; height: auto; transition: transform 0.5s ease; }

.flow-card:hover img { transform: scale(1.015); }

.flow-cap { padding: 20px 24px 22px; border-top: 1px solid var(--line); }

.flow-cap .fig-no {
  display: inline-block;
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--gold);
  background: var(--gold-soft);
  border: 1px solid var(--gold-pale);
  border-radius: 999px;
  padding: 3px 13px;
  margin-bottom: 10px;
}

.flow-cap h3 { font-family: var(--serif); font-size: 17px; color: var(--ink); margin-bottom: 8px; letter-spacing: 0.04em; }
.flow-cap p { font-size: 13.5px; color: var(--muted); }

/* ---------- 系统与隐私 ---------- */
.sys-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 28px; }

.sys-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px 32px;
  box-shadow: var(--shadow);
}

.sys-card h3 {
  font-family: var(--serif);
  font-size: 18px;
  letter-spacing: 0.1em;
  color: var(--ink);
  margin-bottom: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
  position: relative;
}

.sys-card h3::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 44px;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), transparent);
}

.sys-card ul { list-style: none; }

.sys-card li {
  font-size: 14.5px;
  color: var(--muted);
  padding: 8px 0 8px 24px;
  position: relative;
}

.sys-card li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 16px;
  width: 7px;
  height: 7px;
  transform: rotate(45deg);
  background: var(--gold);
  opacity: 0.85;
}

/* ---------- 关于我们 ---------- */
.about-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 44px 48px;
  box-shadow: var(--shadow);
  position: relative;
}

.about-card::before {
  content: "";
  position: absolute;
  inset: 16px;
  border: 1px solid rgba(176, 138, 62, 0.2);
  border-radius: 12px;
  pointer-events: none;
}

.about-card h3 {
  font-family: var(--serif);
  font-size: 20px;
  letter-spacing: 0.12em;
  color: var(--ink);
  margin: 24px 0 12px;
}

.about-card h3:first-child { margin-top: 0; }
.about-card p { color: var(--muted); font-size: 15px; }

.about-table { margin-top: 10px; }

.about-table .row {
  display: flex;
  gap: 20px;
  padding: 12px 0;
  border-bottom: 1px dashed var(--line);
  font-size: 15px;
}

.about-table .row:last-child { border-bottom: none; }
.about-table .k { width: 116px; flex-shrink: 0; color: var(--ink); font-weight: 600; letter-spacing: 0.08em; }
.about-table .v { color: var(--muted); word-break: break-all; }

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--navy);
  color: rgba(255, 255, 255, 0.76);
  padding: 56px 0 42px;
  position: relative;
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--gold), var(--gold-bright), var(--gold), transparent);
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  align-items: flex-start;
  justify-content: space-between;
}

.footer-col h4 {
  font-family: var(--serif);
  color: var(--gold-pale);
  font-size: 16px;
  letter-spacing: 0.28em;
  margin-bottom: 16px;
}

.footer-col p, .footer-col a { font-size: 14px; line-height: 2.05; color: rgba(255, 255, 255, 0.68); }
.footer-col a:hover { color: var(--gold-bright); text-decoration: none; }

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--serif);
  font-size: 22px;
  letter-spacing: 0.3em;
  color: #fff;
  margin-bottom: 14px;
}

.footer-brand img { width: 36px; height: 36px; border-radius: 10px; }

.footer-col .legal a { display: inline-block; margin-right: 18px; }

.copyright {
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid rgba(216, 185, 106, 0.18);
  font-size: 13.5px;
  line-height: 2.1;
  color: rgba(255, 255, 255, 0.56);
  text-align: center;
}

.copyright .domain { color: var(--gold-pale); }

/* ---------- 协议文档页 ---------- */
.doc-wrap {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 56px 62px;
  box-shadow: var(--shadow);
  margin: 56px 0 80px;
  position: relative;
}

.doc-wrap::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  border-radius: var(--radius) var(--radius) 0 0;
  background: linear-gradient(90deg, var(--navy), var(--gold), var(--gold-bright), var(--gold), var(--navy));
}

.doc-wrap h1 {
  font-family: var(--serif);
  font-size: 34px;
  color: var(--ink);
  text-align: center;
  letter-spacing: 0.24em;
  margin-right: -0.24em;
  margin-bottom: 14px;
}

.doc-meta {
  text-align: center;
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 42px;
  padding-bottom: 30px;
  border-bottom: 1px solid var(--line);
}

.doc-wrap h2 {
  font-family: var(--serif);
  font-size: 20px;
  letter-spacing: 0.1em;
  color: var(--ink);
  margin: 32px 0 14px;
  padding-left: 16px;
  border-left: 3px solid var(--gold);
}

.doc-wrap p { color: var(--text); font-size: 15px; margin-bottom: 12px; }
.doc-wrap li { font-size: 15px; margin-bottom: 8px; }
.doc-wrap ul, .doc-wrap ol { padding-left: 26px; margin-bottom: 12px; }

/* ---------- 无障碍：尊重系统减弱动态效果 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero-icon img { animation: none; }
  .cvr-img, .intro-card, .feature-card, .flow-card, .btn, .brand img { transition: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .hero-inner { flex-direction: column-reverse; text-align: center; gap: 48px; }
  .hero-desc { margin: 0 auto 38px; text-align: left; }
  .hero-actions { justify-content: center; }
  .hero h1 { font-size: 64px; }
  .hero-icon img { width: 180px; height: 180px; border-radius: 40px; }
  .intro-grid, .sys-grid, .flow-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .cvr-stage { height: 640px; }
  .doc-wrap { padding: 38px 26px; }
}

@media (max-width: 640px) {
  .nav { height: auto; padding: 12px 0; flex-direction: column; gap: 10px; }
  .nav-links { flex-wrap: wrap; gap: 12px 16px; justify-content: center; }
  .hero { padding: 64px 0 72px; }
  .hero h1 { font-size: 50px; letter-spacing: 0.24em; margin-right: -0.24em; }
  .hero-slogan { letter-spacing: 0.16em; margin-right: -0.16em; font-size: 18px; }
  .section { padding: 68px 0; }
  .feature-grid { grid-template-columns: 1fr; }
  .cvr-stage { height: 520px; }
  .cvr-phone { border-radius: 30px; border-width: 5px; height: calc(100% - 64px); }
  .cvr-arrow { width: 42px; height: 42px; }
  .cvr-arrow.prev { left: 14px; }
  .cvr-arrow.next { right: 14px; }
  .cvr-rail { justify-content: flex-start; }
  .about-card { padding: 30px 22px; }
  .about-table .k { width: 92px; }
  .section-head h2 { font-size: 30px; }
}