/* ==========================================================================
   成校长 · 于思成 — AI × 家庭教育 官网
   设计系统：白灰底 + 品牌蓝 + 薄荷绿（清爽 / 可信 / 有温度）
   比例：白灰 80% · 品牌蓝 15% · 薄荷绿 5%
   ========================================================================== */

/* ---------- 1. Design Tokens ---------- */
:root {
  /* 主背景与分区背景 */
  --bg: #ffffff;
  --bg-soft: #f5f5f6;

  /* 边框与分割线 */
  --line: #ebebee;
  --line-2: #e2e2e6;

  /* 文本 */
  --text: #25272d;
  --text-dim: #6d6f77;
  --text-mute: #74767d;

  /* 品牌蓝 */
  --brand: #6285f5;
  --brand-strong: #4d6fe0;
  --brand-soft: #eef2ff;

  /* 辅助薄荷绿 */
  --green: #268572;
  --green-soft: #eafaf5;

  /* 尺寸 */
  --radius: 14px;
  --radius-lg: 20px;
  --maxw: 1180px;
  --nav-h: 72px;

  /* 字体 */
  --font-sans: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei",
    "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "Cascadia Code", ui-monospace, Consolas,
    "SF Mono", monospace;
}

/* ---------- 2. Reset ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

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

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4,
p {
  margin: 0;
}

button,
input,
textarea,
select {
  font: inherit;
  color: inherit;
}

::selection {
  background: rgba(98, 133, 245, 0.18);
  color: var(--text);
}

/* 滚动条 */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
::-webkit-scrollbar-track {
  background: #fafafa;
}
::-webkit-scrollbar-thumb {
  background: #dcdce2;
  border-radius: 99px;
  border: 2px solid #fafafa;
}
::-webkit-scrollbar-thumb:hover {
  background: #c8c8d0;
}

/* ---------- 3. 布局工具类 ---------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 88px 0;
  position: relative;
}

.section--tight {
  padding: 56px 0;
}

/* 分区背景：功能介绍等用浅灰 */
.section--soft {
  background: var(--bg-soft);
}

.center {
  text-align: center;
}

/* 区块头部（标签 + 标题 + 说明）到内容区，统一留 44px。
   覆盖 HTML 里 44/52px 的内联间距，保证全站节奏一致。 */
.center + .grid,
.center + .steps,
.center + .shots {
  margin-top: 44px !important;
}

.grad-text {
  color: var(--brand-strong);
}

.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* 小标签 */
.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--brand-strong);
  padding: 5px 12px;
  border: 1px solid #dde4fd;
  border-radius: 99px;
  background: var(--brand-soft);
  margin-bottom: 18px;
}

.section-title {
  font-size: clamp(26px, 3.4vw, 38px);
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.section-lead {
  margin-top: 14px;
  max-width: 680px;
  color: var(--text-dim);
  font-size: 16.5px;
}

.center .section-lead {
  margin-inline: auto;
}

/* ---------- 4. 导航 ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-h);
  z-index: 100;
  display: flex;
  align-items: center;
  transition: background 0.25s ease, border-color 0.25s ease;
  border-bottom: 1px solid transparent;
}

.nav.is-scrolled {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom-color: var(--line);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

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

/* 应用图标：覆盖在备用文字之上；图标缺失时自动露出下面的「成」字 */
.brand__mark::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: url("../images/icon.png") center / cover no-repeat;
}

.brand__mark {
  position: relative;
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: var(--brand-strong);
  display: grid;
  place-items: center;
  font-weight: 700;
  color: #fff;
  font-size: 16px;
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand__name {
  font-weight: 600;
  font-size: 16px;
  letter-spacing: 0.02em;
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--text-mute);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav__links a {
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 14.5px;
  color: var(--text-dim);
  transition: color 0.2s, background 0.2s;
  position: relative;
}

.nav__links a:hover {
  color: var(--text);
  background: var(--bg-soft);
}

.nav__links a.is-active {
  color: var(--brand-strong);
}

/* 导航 CTA 是按钮形态，命中当前页时不要出现下划线 */
.nav__cta.is-active::after {
  display: none;
}

.nav__links a.is-active::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 3px;
  height: 2px;
  border-radius: 2px;
  background: var(--brand-strong);
}

.nav__cta {
  margin-left: 12px;
}

.nav__toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 9px;
  cursor: pointer;
  position: relative;
}

.nav__toggle span {
  position: absolute;
  left: 10px;
  right: 10px;
  height: 1.5px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.2s;
}

.nav__toggle span:nth-child(1) {
  top: 13px;
}
.nav__toggle span:nth-child(2) {
  top: 19px;
}
.nav__toggle span:nth-child(3) {
  top: 25px;
}

.nav.is-open .nav__toggle span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}
.nav.is-open .nav__toggle span:nth-child(2) {
  opacity: 0;
}
.nav.is-open .nav__toggle span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 10px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
  white-space: nowrap;
}

/* 主按钮用深蓝，保证白字可读 */
.btn--primary {
  background: var(--brand-strong);
  color: #fff;
}

.btn--primary:hover {
  background: #3d5bc4;
}

.btn--ghost {
  background: #fff;
  border-color: var(--line-2);
  color: var(--text);
}

.btn--ghost:hover {
  background: var(--bg-soft);
  border-color: #d2d2da;
}

.btn--soft {
  background: var(--brand-soft);
  color: var(--brand-strong);
}

.btn--soft:hover {
  background: #e2e9ff;
}

.btn--sm {
  padding: 9px 16px;
  font-size: 14px;
}

.btn--lg {
  padding: 14px 26px;
  font-size: 16px;
}

.btn--block {
  width: 100%;
}

.btn__arrow {
  transition: transform 0.2s ease;
}

.btn:hover .btn__arrow {
  transform: translateX(2px);
}

/* ---------- 6. Hero（首屏：白 → 淡蓝 轻渐变） ---------- */
.hero {
  padding-top: calc(var(--nav-h) + 80px);
  padding-bottom: 88px;
  position: relative;
  /* 顶部淡蓝晕开，比三段渐变干净；底部自然回到白 */
  background: radial-gradient(
    120% 88% at 50% 0%,
    #eef2ff 0%,
    rgba(255, 255, 255, 0) 72%
  );
}

.hero__grid {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  gap: 52px;
  align-items: center;
}

/* 首屏只有单栏内容时（右侧不再有卡片），整体居中排版 */
.hero--center {
  text-align: center;
}

.hero--center .hero__desc {
  margin-inline: auto;
}

.hero--center .hero__actions,
.hero--center .hero__meta {
  justify-content: center;
}

.hero__title {
  font-size: clamp(32px, 5vw, 56px);
  line-height: 1.16;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.hero__title .line {
  display: block;
}

.hero__desc {
  margin-top: 20px;
  color: var(--text-dim);
  font-size: 17px;
  max-width: 560px;
}

.hero__actions {
  margin-top: 32px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero__meta {
  margin-top: 32px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  font-size: 13px;
  padding: 6px 12px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--text-dim);
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}

a.chip:hover {
  border-color: #dde4fd;
  color: var(--brand-strong);
  background: var(--brand-soft);
}

.chip--accent {
  border-color: #dde4fd;
  background: var(--brand-soft);
  color: var(--brand-strong);
}

/* Hero 右侧卡片 */
.hero__card {
  padding: 30px;
  border-radius: var(--radius-lg);
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: 0 12px 32px -20px rgba(37, 39, 45, 0.18);
}

.avatar {
  width: 76px;
  height: 76px;
  border-radius: 18px;
  background: var(--brand-strong);
  display: grid;
  place-items: center;
  font-size: 30px;
  font-weight: 700;
  color: #fff;
}

.hero__card h3 {
  margin-top: 18px;
  font-size: 22px;
  font-weight: 700;
}

.hero__card .role {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-mute);
  letter-spacing: 0.06em;
  margin-top: 6px;
}

.hero__card .note {
  margin-top: 14px;
  color: var(--text-dim);
  font-size: 14.5px;
}

.skill-list {
  margin-top: 22px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.skill__head {
  display: flex;
  justify-content: space-between;
  font-size: 13.5px;
  color: var(--text-dim);
  margin-bottom: 6px;
}

.skill__bar {
  height: 5px;
  border-radius: 99px;
  background: #f0f0f3;
  overflow: hidden;
}

.skill__fill {
  height: 100%;
  width: 0;
  border-radius: 99px;
  background: var(--brand);
  transition: width 1.2s cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- 7. 数据统计条 ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.stat {
  background: #fff;
  padding: 28px 20px;
  text-align: center;
}

/* 重点数字用品牌蓝 */
.stat__num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.2vw, 34px);
  font-weight: 700;
  color: var(--brand-strong);
  line-height: 1.2;
}

.stat__label {
  margin-top: 6px;
  font-size: 13.5px;
  color: var(--text-mute);
}

/* ---------- 8. 通用卡片 ---------- */
.card {
  position: relative;
  padding: 24px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--line);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  border-color: #dcdce4;
  box-shadow: 0 10px 28px -18px rgba(37, 39, 45, 0.22);
}

.card__num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-mute);
  letter-spacing: 0.12em;
}

/* 图标底色用淡蓝，图形用品牌蓝 */
.card__icon {
  width: 42px;
  height: 42px;
  border-radius: 11px;
  display: grid;
  place-items: center;
  font-size: 20px;
  background: var(--brand-soft);
  border: 1px solid #dfe6fe;
  margin-bottom: 14px;
}

/* 成长 / 陪伴类图标用薄荷绿 */
.card__icon--green {
  background: var(--green-soft);
  border-color: #d3f0e5;
}

.card h3 {
  font-size: 17.5px;
  font-weight: 600;
  line-height: 1.45;
}

.card p {
  margin-top: 8px;
  color: var(--text-dim);
  font-size: 14.6px;
}

/* 网格 */
.grid {
  display: grid;
  gap: 20px;
}

.grid--2 {
  grid-template-columns: repeat(2, 1fr);
}
.grid--3 {
  grid-template-columns: repeat(3, 1fr);
}
.grid--4 {
  grid-template-columns: repeat(4, 1fr);
}

/* ---------- 9. 身份 / 头衔 ---------- */
.identity {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 54px;
  align-items: start;
}

.title-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.title-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 13px 16px;
  border-radius: 10px;
  background: #fff;
  border: 1px solid var(--line);
  transition: border-color 0.2s, background 0.2s;
}

.title-item:hover {
  border-color: #dfe6fe;
  background: var(--brand-soft);
}

.title-item .dot {
  flex: none;
  width: 6px;
  height: 6px;
  margin-top: 10px;
  border-radius: 50%;
  background: var(--brand);
}

.title-item span {
  font-size: 15px;
  color: var(--text-dim);
}

/* ---------- 10. 课程卡 ---------- */
.course {
  display: flex;
  flex-direction: column;
  min-height: 100%;
}

/* 功能标签用淡蓝底 + 品牌蓝字 */
.course__tag {
  display: inline-block;
  align-self: flex-start;
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 6px;
  margin-bottom: 14px;
  color: var(--brand-strong);
  background: var(--brand-soft);
  border: 1px solid #dfe6fe;
}

/* 变体：分别落在蓝 / 绿两端，避免引入规范外色相 */
.course__tag--warm {
  color: var(--brand-strong);
  background: #eef2ff;
  border-color: #dfe6fe;
}

.course__tag--violet {
  color: #4b5bbf;
  background: #f1f3fd;
  border-color: #dfe2f8;
}

.course__tag--lime {
  color: var(--green);
  background: var(--green-soft);
  border-color: #d3f0e5;
}

.course h3 {
  font-size: 18px;
}

.course__sub {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-mute);
  margin-top: 6px;
  letter-spacing: 0.04em;
}

.course p {
  margin-top: 12px;
  font-size: 14.6px;
  color: var(--text-dim);
  flex: 1;
}

.course ul {
  margin-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.course li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  color: var(--text-dim);
}

.course li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 11px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #c9cee8;
}

/* ---------- 11. 流程 / 步骤 ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.step {
  padding: 24px 20px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--line);
  transition: border-color 0.2s;
}

.step:hover {
  border-color: #dcdce4;
}

.step__n {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--brand-strong);
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}

.step h3 {
  font-size: 17px;
  font-weight: 600;
}

.step p {
  margin-top: 10px;
  font-size: 14.4px;
  color: var(--text-dim);
}

/* ---------- 12. 时间线 ---------- */
.timeline {
  position: relative;
  padding-left: 30px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: var(--line-2);
}

.tl-item {
  position: relative;
  padding-bottom: 32px;
}

.tl-item:last-child {
  padding-bottom: 0;
}

.tl-item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 10px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: #fff;
  border: 2px solid var(--brand);
}

.tl-item__year {
  font-family: var(--font-mono);
  font-size: 13.5px;
  color: var(--brand-strong);
  letter-spacing: 0.06em;
}

.tl-item h3 {
  margin-top: 6px;
  font-size: 17.5px;
  font-weight: 600;
}

.tl-item p {
  margin-top: 8px;
  color: var(--text-dim);
  font-size: 14.8px;
}

/* ---------- 13. 引用块（家庭陪伴 / 成长 → 淡绿） ---------- */
.quote {
  padding: 44px 40px;
  border-radius: var(--radius-lg);
  background: var(--green-soft);
  border: 1px solid #d3f0e5;
  text-align: center;
}

.quote__text {
  font-size: clamp(20px, 2.7vw, 29px);
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: -0.01em;
}

.quote__by {
  margin-top: 16px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--green);
  letter-spacing: 0.08em;
}

/* ---------- 14. 标签云 ---------- */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  font-size: 13.5px;
  padding: 6px 12px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--text-dim);
  transition: border-color 0.2s, background 0.2s, color 0.2s;
}

.tag:hover {
  color: var(--brand-strong);
  border-color: #dde4fd;
  background: var(--brand-soft);
}

/* ---------- 17. 折叠问答 ---------- */
.faq {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  overflow: hidden;
  transition: border-color 0.2s;
}

.faq + .faq {
  margin-top: 10px;
}

.faq.is-open {
  border-color: #dde4fd;
}

.faq__q {
  width: 100%;
  text-align: left;
  background: none;
  border: 0;
  padding: 18px 20px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.faq__q::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--brand-strong);
  font-size: 20px;
  line-height: 1;
  transition: transform 0.25s ease;
  flex: none;
}

.faq.is-open .faq__q::after {
  transform: rotate(45deg);
}

.faq__a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.faq__a p {
  padding: 0 20px 18px;
  color: var(--text-dim);
  font-size: 14.8px;
}

/* ---------- 18. CTA 区块 ---------- */
.cta {
  padding: 56px 44px;
  border-radius: var(--radius-lg);
  background: var(--brand-soft);
  border: 1px solid #dfe6fe;
  text-align: center;
}

.cta h2 {
  font-size: clamp(22px, 3.2vw, 34px);
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.cta p {
  margin-top: 14px;
  color: var(--text-dim);
  max-width: 620px;
  margin-inline: auto;
}

.cta .hero__actions {
  justify-content: center;
}

/* ---------- 19. 页脚 ---------- */
.footer {
  border-top: 1px solid var(--line);
  margin-top: 40px;
  padding: 52px 0 32px;
  background: var(--bg-soft);
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: 32px;
}

.footer__title {
  font-size: 13px;
  font-family: var(--font-mono);
  letter-spacing: 0.08em;
  color: var(--text-mute);
  text-transform: uppercase;
  margin-bottom: 14px;
  font-weight: 500;
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.footer__links a {
  font-size: 14.5px;
  color: var(--text-dim);
  transition: color 0.2s;
}

.footer__links a:hover {
  color: var(--brand-strong);
}

.footer__about {
  color: var(--text-dim);
  font-size: 14.5px;
  margin-top: 14px;
  max-width: 320px;
}

.footer__bottom {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 13.2px;
  color: var(--text-mute);
}

/* ---------- 20. 滚动进场动画 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

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

/* ---------- 21. 顶部阅读进度条 ---------- */
.progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0;
  background: var(--brand-strong);
  z-index: 200;
  transition: width 0.1s linear;
}

/* ---------- 22. 下载页 ---------- */
/* 平台入口卡片 */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.platform-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 26px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--line);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.platform-card:hover {
  border-color: #dde4fd;
  box-shadow: 0 8px 24px -16px rgba(37, 39, 45, 0.2);
}

.platform-card__head {
  display: flex;
  align-items: center;
  gap: 12px;
}

.platform-card__icon {
  flex: none;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-size: 21px;
  background: var(--brand-soft);
  border: 1px solid #dfe6fe;
}

.platform-card__icon--green {
  background: var(--green-soft);
  border-color: #d3f0e5;
}

.platform-card h3 {
  font-size: 17px;
  font-weight: 600;
}

.platform-card__meta {
  font-size: 13px;
  color: var(--text-mute);
  margin-top: 2px;
}

.platform-card p {
  color: var(--text-dim);
  font-size: 14.5px;
  flex: 1;
}

/* 亮点列表 */
.highlight {
  display: flex;
  gap: 14px;
  padding: 20px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--line);
}

.highlight__icon {
  flex: none;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  font-size: 18px;
  background: var(--brand-soft);
  border: 1px solid #dfe6fe;
}

.highlight__icon--green {
  background: var(--green-soft);
  border-color: #d3f0e5;
}

.highlight h3 {
  font-size: 16px;
  font-weight: 600;
}

.highlight p {
  margin-top: 6px;
  color: var(--text-dim);
  font-size: 14.2px;
}

/* 版本信息条 */
.version-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 10px 24px;
  padding: 16px 20px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--line);
  font-size: 13.5px;
  color: var(--text-dim);
}

.version-bar strong {
  color: var(--text);
  font-weight: 600;
}

.version-bar span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* ---------- 23. 响应式 ---------- */
@media (max-width: 1024px) {
  .hero__grid,
  .identity {
    grid-template-columns: 1fr;
    gap: 44px;
  }
  .grid--4,
  .steps,
  .platform-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid--3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer__grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 760px) {
  .section {
    padding: 68px 0;
  }
  .nav__toggle {
    display: block;
  }
  .nav__links {
    position: fixed;
    top: var(--nav-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 16px 24px 24px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    box-shadow: 0 16px 32px -24px rgba(37, 39, 45, 0.24);
    transform: translateY(-10px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease, transform 0.2s ease;
  }
  .nav.is-open .nav__links {
    opacity: 1;
    transform: none;
    pointer-events: auto;
  }
  .nav__links a {
    padding: 12px 14px;
    font-size: 15.5px;
    border-radius: 8px;
  }
  .nav__links a.is-active::after {
    display: none;
  }
  .nav__links a.is-active {
    background: var(--brand-soft);
  }
  .nav__cta {
    margin: 8px 0 0;
  }
  .nav__cta .btn {
    width: 100%;
  }
  .brand__sub {
    display: none;
  }
  .grid--2,
  .grid--3,
  .grid--4,
  .steps,
  .platform-grid {
    grid-template-columns: 1fr;
  }
  .footer__grid {
    grid-template-columns: 1fr;
    gap: 26px;
  }
  .cta {
    padding: 40px 22px;
  }
  .quote {
    padding: 32px 22px;
  }
  .card,
  .hero__card {
    padding: 22px;
  }
  .hero {
    padding-top: calc(var(--nav-h) + 44px);
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}

/* ==========================================================================
   24. 移动端适配
   说明：HTML 中部分元素带内联样式（.identity 的 gap:54px、.quote 的 padding、
   .hero__title 的 font-size 等），内联优先级高于样式表，因此这里必须用
   !important 才能让手机端的间距与字号真正生效。
   ========================================================================== */

/* 触摸设备：去掉点击高亮方块与双击缩放延迟 */
.btn,
.nav__links a,
.nav__toggle,
.faq__q,
.tag,
.chip,
.card,
.highlight,
.title-item {
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

@media (max-width: 760px) {
  /* 覆盖内联间距，避免手机上留白过大 */
  .identity {
    gap: 32px !important;
  }
  .grid {
    gap: 16px !important;
  }
  /* 手机上区块头部到内容的间距也一并收紧 */
  .center + .grid,
  .center + .steps,
  .center + .shots {
    margin-top: 32px !important;
  }
  .quote {
    padding: 30px 20px !important;
  }
  .hero__title {
    font-size: clamp(28px, 7.4vw, 40px) !important;
  }

  .hero__desc {
    font-size: 16px;
  }
  .hero__actions {
    gap: 10px;
  }
  /* 手机上主按钮占满一行，便于点按 */
  .hero__actions .btn {
    width: 100%;
  }
  .stat {
    padding: 20px 12px;
  }
  .stat__num {
    font-size: 24px;
  }
  .stat__label {
    font-size: 12.5px;
  }
  .faq__q {
    padding: 16px;
    font-size: 15.5px;
  }
  .faq__a p {
    padding: 0 16px 16px;
  }
  .cta {
    padding: 34px 20px;
  }
}

/* 小屏手机（iPhone SE / 紧凑安卓机） */
@media (max-width: 480px) {
  .wrap,
  .nav__inner {
    padding: 0 18px;
  }
  .section {
    padding: 56px 0;
  }
  .section--tight {
    padding: 40px 0;
  }
  .hero {
    padding-top: calc(var(--nav-h) + 30px);
    padding-bottom: 52px;
  }
  .hero__title {
    font-size: clamp(26px, 8vw, 32px) !important;
  }
  .section-title {
    font-size: clamp(21px, 5.8vw, 26px);
  }
  .card,
  .platform-card,
  .highlight,
  .step,
  .cta {
    padding: 18px !important;
  }
  .quote {
    padding: 24px 18px !important;
  }
  .card__icon,
  .highlight__icon,
  .platform-card__icon {
    width: 36px;
    height: 36px;
    font-size: 17px;
  }
  .version-bar {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  .eyebrow {
    font-size: 11px;
    letter-spacing: 0.1em;
    padding: 5px 10px;
  }
  .footer__grid {
    gap: 22px;
  }
  .footer__bottom {
    margin-top: 28px;
    font-size: 12.5px;
  }
}

/* ==========================================================================
   25. 界面截图展示
   桌面三列并排；手机上改为横向滑动（截图是竖屏比例，挤成三列会看不清）
   ========================================================================== */
.shots {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  /* 竖屏截图很高，限宽居中，避免整个区块被撑得过长 */
  max-width: 880px;
  margin-inline: auto;
}

.shot {
  margin: 0;
  border-radius: 18px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--bg-soft);
  box-shadow: 0 20px 44px -30px rgba(37, 39, 45, 0.5);
}

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

@media (max-width: 760px) {
  .shots {
    display: flex;
    gap: 14px;
    margin-top: 32px;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 10px;
  }
  .shot {
    flex: 0 0 68%;
    scroll-snap-align: center;
  }
}