/* ============================================================
   易助手宣传官网 — 纯静态,无外部依赖
   设计系统:
   - 主色 #409eff,品牌渐变 linear-gradient(135deg, #667eea, #764ba2)
   - 间距节奏:区块 96px / 标题组 48px / 卡片内边距 28-34px
   - 圆角:卡片 16px,控件 10-12px,按钮 999px
   - 阴影:两档(静态 / 悬停),色相统一的蓝灰投影
   - 标题层级:eyebrow 13px 加粗主色 → h2 32px/800 → sub 16px 灰
   - 图标:全部内联 SVG,1.7px 线宽、圆角端点的线条风格
   ============================================================ */

:root {
  --primary: #409eff;
  --gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --text: #1f2733;
  --text-muted: #5c6b7f;
  --bg: #ffffff;
  --bg-alt: #f6f8fc;
  --border: #e6eaf2;
  --radius: 16px;
  --radius-sm: 12px;
  --shadow: 0 10px 30px rgba(64, 90, 160, 0.10);
  --shadow-hover: 0 16px 40px rgba(64, 90, 160, 0.16);
  --section-pad: 96px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

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

/* 等宽文本(代码、接口名) */
.mock-mono { font-family: "Cascadia Code", Consolas, Monaco, monospace; }

/* 线条 SVG 图标通用 */
.feature-icon svg,
.download-icon svg,
.ic {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.ic { width: 16px; height: 16px; }
.ic-muted { color: var(--primary); flex-shrink: 0; }

/* ---------- 导航(默认透明融入 Hero,滚动后雾化白底) ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}
.nav.scrolled {
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(14px) saturate(1.4);
  -webkit-backdrop-filter: blur(14px) saturate(1.4);
  border-bottom-color: rgba(229, 231, 235, 0.8);
  box-shadow: 0 6px 24px rgba(31, 41, 55, 0.06);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-logo {
  width: 36px; height: 36px; border-radius: 10px;
  box-shadow: 0 4px 14px rgba(15, 23, 42, 0.28);
  transition: transform 0.25s ease;
}
.brand:hover .brand-logo { transform: scale(1.06) rotate(-3deg); }
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-weight: 800; font-size: 17px; letter-spacing: 0.5px; color: #fff; transition: color 0.3s; }
.brand-sub { font-size: 11px; font-weight: 500; color: rgba(255, 255, 255, 0.66); letter-spacing: 1.6px; transition: color 0.3s; }
.nav.scrolled .brand-name { color: var(--text); }
.nav.scrolled .brand-sub { color: var(--text-muted); }
.nav-links { display: flex; align-items: center; gap: 30px; font-size: 15px; }
.nav-links a { position: relative; padding: 4px 0; color: rgba(255, 255, 255, 0.85); transition: color 0.3s; }
.nav.scrolled .nav-links a { color: var(--text-muted); }
.nav-links a:not(.nav-cta)::after {
  content: "";
  position: absolute;
  left: 0; right: 100%; bottom: -2px;
  height: 2px; border-radius: 2px;
  background: currentColor;
  transition: right 0.25s ease;
}
.nav-links a:not(.nav-cta):hover { color: #fff; }
.nav.scrolled .nav-links a:not(.nav-cta):hover { color: var(--primary); }
.nav-links a:not(.nav-cta):hover::after { right: 0; }
.nav-cta {
  padding: 8px 22px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.94);
  color: #5a3d9e !important;
  font-weight: 600;
  box-shadow: 0 6px 16px rgba(15, 23, 42, 0.22);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.3s ease;
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 10px 22px rgba(15, 23, 42, 0.3); }
.nav.scrolled .nav-cta {
  background: var(--gradient);
  color: #fff !important;
  box-shadow: 0 6px 16px rgba(102, 126, 234, 0.35);
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(135deg, #4f5ef7 0%, #6d5df3 38%, #8b4fd8 72%, #764ba2 100%);
  color: #fff;
  text-align: center;
  padding: 148px 0 96px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, #000 30%, transparent 75%);
  pointer-events: none;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, rgba(255,255,255,0.16), transparent 55%);
  pointer-events: none;
}
.hero-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  opacity: 0.5;
  pointer-events: none;
}
.hero-blob-a {
  width: 420px; height: 420px;
  background: #38bdf8;
  top: -160px; left: -120px;
}
.hero-blob-b {
  width: 380px; height: 380px;
  background: #f472b6;
  bottom: -180px; right: -100px;
  opacity: 0.35;
}
.hero-inner { position: relative; z-index: 1; }
.hero-badge {
  display: inline-block;
  padding: 6px 18px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.28);
  backdrop-filter: blur(6px);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 1px;
  margin-bottom: 26px;
}
.hero-title { font-size: 48px; font-weight: 800; line-height: 1.3; letter-spacing: 1px; }
.hero-sub { margin-top: 18px; font-size: 16px; opacity: 0.82; line-height: 1.9; }
.hero-actions { margin-top: 36px; display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-block;
  padding: 12px 32px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}
.btn-lg { padding: 14px 38px; }
.btn-primary { background: #fff; color: #5a3d9e; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(0,0,0,0.22); }
.btn-ghost { border: 1.5px solid rgba(255,255,255,0.7); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,0.14); }

/* Hero 内的启动器示意窗口 */
.hero-mock {
  margin: 56px auto 0;
  max-width: 640px;
  text-align: left;
  box-shadow: 0 30px 80px rgba(20, 16, 60, 0.45);
}

/* ---------- 区块通用 ---------- */
.section { padding: var(--section-pad) 0; scroll-margin-top: 64px; }
.section-alt { background: var(--bg-alt); }
.section-eyebrow {
  text-align: center;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 3px;
  color: var(--primary);
  margin-bottom: 12px;
}
.section-title { font-size: 32px; font-weight: 800; text-align: center; line-height: 1.4; }
.section-sub { text-align: center; color: var(--text-muted); margin-top: 12px; font-size: 16px; max-width: 640px; margin-left: auto; margin-right: auto; }

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

/* ---------- 工作流步骤条 ---------- */
.steps {
  list-style: none;
  margin-top: 56px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 22px;
  counter-reset: step;
}
.step {
  position: relative;
  padding: 28px 24px 26px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.step:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
/* 阶段标签：创造 / 打磨 / 分享 */
.step-phase {
  position: absolute;
  top: 0;
  left: 24px;
  transform: translateY(-50%);
  padding: 3px 10px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(102,126,234,0.10), rgba(118,75,162,0.10));
  border: 1px solid rgba(102,126,234,0.25);
  color: #667eea;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 2px;
}
.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--gradient);
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  box-shadow: 0 6px 14px rgba(102, 126, 234, 0.35);
  margin-bottom: 14px;
}
.step h3 { font-size: 17px; margin-bottom: 6px; }
.step p { font-size: 14px; color: var(--text-muted); }

/* 工作流下的工作室示意窗口 */
.studio-mock {
  margin-top: 48px;
  max-width: 860px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------- 界面示意窗口(纯 CSS 绘制) ---------- */
.mock-window {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-hover);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
.mock-titlebar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 11px 16px;
  background: #f1f3f9;
  border-bottom: 1px solid var(--border);
}
.mock-dot { width: 11px; height: 11px; border-radius: 50%; flex-shrink: 0; }
.mock-dot:nth-child(1) { background: #ff5f57; }
.mock-dot:nth-child(2) { background: #febc2e; }
.mock-dot:nth-child(3) { background: #28c840; }
.mock-title { margin-left: 10px; font-size: 12.5px; color: var(--text-muted); }
.mock-titlebar-right { margin-left: auto; color: #9aa5b5; display: inline-flex; }
.mock-body { padding: 20px; flex: 1; }

.mock-search {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 11px 16px;
  border-radius: 10px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 13.5px;
}
.mock-apps {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 14px;
}

/* Hero 内平台切换标签 */
.mock-platform-bar {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px dashed var(--border);
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.platform-tag {
  display: inline-flex;
  align-items: center;
  padding: 5px 14px;
  border-radius: 999px;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-muted);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  cursor: default;
}
.platform-tag.is-active {
  color: #fff;
  background: var(--gradient);
  border-color: transparent;
}
.mock-platform-note {
  margin-left: auto;
  font-size: 12px;
  color: var(--text-muted);
}
.mock-app {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-muted);
}
.mock-app-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 600;
  color: #fff;
  box-shadow: 0 6px 14px rgba(64, 90, 160, 0.18);
}
.mock-app-icon.mock-mono { font-size: 17px; font-weight: 700; }

/* AI 工作室示意 */
.mock-studio { display: flex; flex-direction: column; gap: 16px; }
.mock-chat { display: flex; flex-direction: column; gap: 10px; }
.mock-bubble {
  max-width: 85%;
  padding: 9px 14px;
  border-radius: 12px;
  font-size: 13px;
  line-height: 1.6;
}
.mock-bubble-user { align-self: flex-end; background: var(--primary); color: #fff; border-bottom-right-radius: 4px; }
.mock-bubble-ai { align-self: flex-start; background: var(--bg-alt); border: 1px solid var(--border); border-bottom-left-radius: 4px; }

/* diff 预览卡片 */
.mock-diff {
  align-self: flex-start;
  width: 100%;
  max-width: 460px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  font-size: 12.5px;
}
.mock-diff-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 14px;
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 12px;
}
.mock-diff-stat i { font-style: normal; font-weight: 700; }
.mock-diff-stat .add { color: #16a34a; }
.mock-diff-stat .del { color: #dc2626; }
.mock-diff .mock-code-line { padding: 2px 14px; line-height: 1.9; font-size: 12px; }
.tok-add { color: #15803d; background: rgba(22, 163, 74, 0.08); display: block; }
.tok-del { color: #b91c1c; background: rgba(220, 38, 38, 0.07); display: block; }
.mock-diff-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding: 10px 14px;
  border-top: 1px solid var(--border);
}
.mock-btn {
  padding: 4px 14px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
}
.mock-btn-primary { background: var(--gradient); color: #fff; }
.mock-btn-ghost { border: 1px solid var(--border); color: var(--text-muted); }

/* 代码编辑器示意 */
.mock-editor {
  background: #1e2430;
  border-radius: 10px;
  padding: 16px;
  font-size: 12.5px;
  color: #d5dbe7;
  line-height: 2;
  overflow-x: auto;
}
.tok-kw { color: #c792ea; }
.tok-var { color: #82aaff; }
.tok-fn { color: #ffcb6b; }
.tok-num { color: #f78c6c; }
.mock-caret-line { display: flex; align-items: center; gap: 8px; }
.mock-caret { width: 7px; height: 15px; background: var(--primary); animation: blink 1.1s steps(1) infinite; flex-shrink: 0; }
.mock-hint { color: #6b7688; font-size: 12px; font-family: "PingFang SC", "Microsoft YaHei", sans-serif; }
@keyframes blink { 50% { opacity: 0; } }

/* ---------- 特性网格 ---------- */
.feature-grid {
  margin-top: 52px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.feature-card { padding: 32px 28px; }
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.feature-icon {
  width: 48px; height: 48px;
  border-radius: 13px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(64, 158, 255, 0.10);
  color: var(--primary);
  margin-bottom: 16px;
}
.feature-icon svg { width: 24px; height: 24px; }
.feature-card:nth-child(2) .feature-icon { background: rgba(118, 75, 162, 0.10); color: #764ba2; }
.feature-card:nth-child(4) .feature-icon { background: rgba(118, 75, 162, 0.10); color: #764ba2; }
.feature-card h3 { font-size: 18px; margin-bottom: 8px; }
.feature-card p { font-size: 14.5px; color: var(--text-muted); }
.feature-card code { font-size: 12.5px; background: var(--bg-alt); border: 1px solid var(--border); border-radius: 6px; padding: 1px 6px; }

/* ---------- 移动端展示 ---------- */
.mobile-showcase {
  margin-top: 56px;
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 56px;
  align-items: center;
}

/* 手机框架(纯 CSS) */
.phone-frame {
  width: 260px;
  height: 520px;
  margin: 0 auto;
  background: #1f2330;
  border-radius: 38px;
  padding: 12px;
  box-shadow: 0 24px 60px rgba(20, 16, 60, 0.28), inset 0 0 0 2px rgba(255,255,255,0.12);
  position: relative;
}
.phone-notch {
  position: absolute;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  width: 92px;
  height: 22px;
  background: #1f2330;
  border-radius: 0 0 14px 14px;
  z-index: 2;
}
.phone-screen {
  width: 100%;
  height: 100%;
  background: #fff;
  border-radius: 28px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  padding: 34px 16px 20px;
}
.phone-header {
  text-align: center;
  margin-bottom: 16px;
}
.phone-title {
  display: block;
  font-size: 16px;
  font-weight: 700;
}
.phone-sub {
  font-size: 11px;
  color: var(--text-muted);
}
.phone-search {
  display: flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--bg-alt);
  color: var(--text-muted);
  font-size: 12px;
  margin-bottom: 16px;
}
.phone-apps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px 8px;
}
.phone-app {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  font-size: 10px;
  color: var(--text-muted);
  text-align: center;
}
.phone-app-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  box-shadow: 0 4px 10px rgba(64, 90, 160, 0.18);
}
.phone-app-icon.mock-mono { font-size: 13px; font-weight: 700; }
.phone-permission-toast {
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 10px;
  background: #fff;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  font-size: 11px;
  color: var(--text);
}
.phone-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

/* 移动端能力清单 */
.mobile-features {
  display: flex;
  flex-direction: column;
  gap: 22px;
}
.mobile-feature-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.mobile-feature-icon {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(64, 158, 255, 0.10);
  color: var(--primary);
}
.mobile-feature-icon svg {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.mobile-feature-item h3 { font-size: 16px; margin-bottom: 4px; }
.mobile-feature-item p { font-size: 14px; color: var(--text-muted); line-height: 1.7; }
.mobile-feature-item code {
  font-size: 12px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1px 5px;
}

.mobile-note {
  margin-top: 42px;
  padding: 18px 22px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-muted);
  text-align: center;
}
.mobile-note a { color: var(--primary); font-weight: 600; }
.mobile-note a:hover { text-decoration: underline; }

/* ---------- 下载 ---------- */
.version-badge {
  display: inline-block;
  vertical-align: middle;
  margin-left: 12px;
  padding: 4px 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  background: rgba(64, 158, 255, 0.10);
  border: 1px solid rgba(64, 158, 255, 0.35);
  border-radius: 999px;
}
.version-badge[hidden] { display: none; }
.download-group {
  margin-top: 48px;
}
.download-group-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}
.download-group-header h3 {
  font-size: 18px;
  font-weight: 700;
}
.download-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}
.download-grid-mobile {
  grid-template-columns: repeat(2, 1fr);
  max-width: 560px;
}
.download-card {
  display: block;
  padding: 36px 26px;
  text-align: center;
}
.download-card:not(.is-disabled):hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(64, 158, 255, 0.5);
}
.download-icon {
  width: 56px; height: 56px;
  margin: 0 auto 14px;
  border-radius: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(64, 158, 255, 0.10);
  color: var(--primary);
}
.download-icon svg { width: 28px; height: 28px; }
.download-card.is-disabled .download-icon { background: #eef1f6; color: #9aa5b5; }
.download-card h3 { font-size: 19px; }
.download-desc { margin-top: 6px; font-size: 13.5px; color: var(--text-muted); }
.download-meta {
  display: inline-block;
  margin-top: 18px;
  padding: 8px 22px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  background: var(--gradient);
  color: #fff;
}
.download-card.is-disabled { cursor: not-allowed; opacity: 0.7; }
.download-card.is-disabled .download-meta { background: #c4cbd8; }
.download-note {
  margin-top: 28px;
  text-align: center;
  font-size: 13.5px;
  color: var(--text-muted);
}

/* ---------- 页脚 ---------- */
.footer {
  border-top: 1px solid var(--border);
  background: var(--bg);
  padding: 44px 0;
  text-align: center;
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 17px;
}
.footer-note { margin-top: 10px; font-size: 13.5px; color: var(--text-muted); }

/* ---------- 滚动淡入 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { transition: none; opacity: 1; transform: none; }
  html { scroll-behavior: auto; }
}

/* ---------- 响应式 ---------- */
.only-mobile { display: none; }

@media (max-width: 1080px) {
  .mobile-showcase { grid-template-columns: 1fr; gap: 36px; }
  .download-grid { grid-template-columns: repeat(2, 1fr); }
  .download-grid-mobile { max-width: none; }
}

@media (max-width: 860px) {
  :root { --section-pad: 68px; }
  .hero { padding: 120px 0 72px; }
  .hero-title { font-size: 32px; }
  .hero-sub { font-size: 14.5px; line-height: 1.9; }
  .only-mobile { display: block; }
  .only-pc { display: none; }
  .section-title { font-size: 26px; }
  .steps { grid-template-columns: 1fr; gap: 24px; margin-top: 66px; }
  .feature-grid { grid-template-columns: 1fr; }
  .mock-apps { grid-template-columns: repeat(5, 1fr); }
  .mock-platform-note { display: none; }
}

@media (max-width: 640px) {
  .download-grid { grid-template-columns: 1fr; }
  .mobile-build-steps ol { gap: 10px; }
}

@media (max-width: 480px) {
  .nav-links { gap: 12px; font-size: 13px; }
  .nav-cta { padding: 6px 12px; }
  .brand-sub { display: none; }
  .hero-badge { font-size: 12px; margin-bottom: 20px; }
  .hero-title { font-size: 28px; }
  .btn-lg { padding: 12px 28px; font-size: 15px; }
  .mock-apps { grid-template-columns: repeat(3, 1fr); }
  .phone-frame { transform: scale(0.92); }
}