/* 爪信官网 — 浅色商务风格首页布局 */

:root {
  --zz-blue: #1a5cff;
  --zz-blue-dark: #1246cc;
  --zz-blue-soft: #e8f0ff;
  --zz-text: #1a1d26;
  --zz-text2: #4a5568;
  --zz-muted: #718096;
  --zz-border: #e2e8f0;
  --zz-bg: #ffffff;
  --zz-bg-alt: #f5f7fb;
  --zz-warm: #e85d4c;
  --font-sans: "SimHei", "Heiti SC", "STHeiti", "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --radius: 10px;
  --header-h: 64px;
  --max: 1140px;
  --section-pad: 56px 0;
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--font-sans);
}

body.page-zz {
  margin: 0;
  min-width: 0;
  font-family: inherit;
  font-size: 16px;
  line-height: 1.65;
  color: var(--zz-text);
  background: var(--zz-bg);
  overflow-x: hidden;
}

/* 跳过导航：键盘用户可聚焦进入正文，利于无障碍与爬虫理解主内容区 */
.zz-skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

.zz-skip-link:focus {
  position: fixed;
  left: 16px;
  top: 16px;
  z-index: 10001;
  width: auto;
  height: auto;
  clip: auto;
  overflow: visible;
  white-space: normal;
  padding: 12px 18px;
  border-radius: 8px;
  background: var(--zz-blue);
  color: #fff;
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(26, 92, 255, 0.35);
}

.zz-skip-link:focus-visible {
  outline: 2px solid #fff;
  outline-offset: 2px;
}

body.page-zz.zz-nav-open {
  overflow: hidden;
  touch-action: none;
}

a {
  color: var(--zz-blue);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--zz-blue-dark);
}

.section-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 28px);
}

/* 顶栏 */
.zz-header {
  position: sticky;
  top: 0;
  z-index: 200;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid var(--zz-border);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.03);
  transition: box-shadow 0.2s;
}

.zz-header.zz-header--scrolled {
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
}

.zz-header-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 28px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 28px;
}

/* DOM 顺序：Logo → 按钮区 → 汉堡 → Nav，用 order 还原桌面「Logo | 导航 | 按钮」 */
.zz-logo {
  order: 1;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--zz-text);
  flex-shrink: 0;
}

.zz-logo:hover {
  color: var(--zz-text);
}

.zz-logo-img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  object-fit: cover;
  display: block;
  flex-shrink: 0;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.zz-logo-text {
  font-weight: 700;
  font-size: 1.15rem;
}

.zz-nav {
  order: 2;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 22px;
  flex: 1;
  justify-content: center;
}

.zz-nav a {
  color: var(--zz-text2);
  font-size: 0.9rem;
  font-weight: 500;
}

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

.zz-nav a.is-active {
  color: var(--zz-blue);
  font-weight: 600;
}

.zz-header--simple .zz-header-actions,
.zz-header--simple .zz-nav-toggle {
  display: none;
}

.zz-header--simple .zz-nav--simple {
  order: 3;
  flex: 1;
  justify-content: flex-end;
  margin-left: auto;
  gap: 14px 20px;
}

.page-legal .zz-legal-wrap {
  padding: 28px 0 56px;
  background: var(--zz-bg-alt);
  min-height: 50vh;
}

.zz-legal-page {
  background: var(--zz-bg);
  border-radius: var(--radius);
  border: 1px solid var(--zz-border);
  padding: 28px 24px 40px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.zz-legal-meta {
  margin: 0 0 20px;
  font-size: 0.82rem;
  color: var(--zz-muted);
  line-height: 1.55;
}

.zz-legal-links {
  margin: -8px 0 18px;
  font-size: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 10px;
}

.zz-legal-links a {
  color: var(--zz-blue);
  font-weight: 600;
  text-decoration: none;
}

.zz-legal-links a:hover {
  color: var(--zz-blue-dark);
  text-decoration: none;
}

.zz-legal-links-sep {
  color: var(--zz-muted);
  user-select: none;
}

.zz-legal-pre {
  margin: 0;
  font-family: inherit;
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--zz-text);
  white-space: pre-wrap;
  word-break: break-word;
  overflow-wrap: anywhere;
}

.zz-legal-meta a,
.zz-legal-pre a {
  color: var(--zz-blue);
  font-weight: 600;
  text-decoration: none;
}

.zz-legal-meta a:hover,
.zz-legal-pre a:hover {
  color: var(--zz-blue-dark);
  text-decoration: none;
}

.zz-footer--legal {
  margin-top: 0;
}

.zz-footer-legal-inner {
  padding: 24px 0;
  text-align: center;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.zz-footer-legal-back {
  margin: 0;
  font-size: 0.88rem;
  color: #a0aec0;
}

.zz-footer-legal-back a {
  color: #cbd5e0;
  text-decoration: none;
}

.zz-footer-legal-back a:hover {
  color: #fff;
  text-decoration: underline;
}

.zz-header-actions {
  order: 3;
  display: flex;
  gap: 10px;
  flex-shrink: 0;
  align-items: center;
}

/* 汉堡按钮 — 仅小屏显示 */
.zz-nav-toggle {
  order: 4;
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  margin: 0;
  border: none;
  background: transparent;
  cursor: pointer;
  border-radius: 8px;
  flex-shrink: 0;
  -webkit-tap-highlight-color: transparent;
}

.zz-nav-toggle:focus-visible {
  outline: 2px solid var(--zz-blue);
  outline-offset: 2px;
}

.zz-nav-toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  margin: 0 auto;
  background: var(--zz-text);
  border-radius: 1px;
  transition: transform 0.2s, opacity 0.2s;
}

body.zz-nav-open .zz-nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

body.zz-nav-open .zz-nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

body.zz-nav-open .zz-nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.zz-nav-backdrop {
  display: none;
}

.zz-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 9px 18px;
  border-radius: var(--radius);
  font-size: 0.88rem;
  font-weight: 600;
  font-family: inherit;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.zz-btn--primary {
  background: var(--zz-blue);
  color: #fff;
  border-color: var(--zz-blue);
}

.zz-btn--primary:hover {
  background: var(--zz-blue-dark);
  border-color: var(--zz-blue-dark);
  color: #fff;
}

.zz-btn--ghost {
  background: var(--zz-bg-alt);
  color: var(--zz-text2);
  border-color: var(--zz-border);
}

.zz-btn--ghost:hover {
  border-color: var(--zz-blue);
  color: var(--zz-blue);
}

.zz-btn--outline {
  background: #fff;
  color: var(--zz-blue);
  border-color: var(--zz-blue);
}

.zz-btn--outline:hover {
  background: var(--zz-blue-soft);
}

.zz-btn--lg {
  padding: 12px 28px;
  font-size: 0.95rem;
}

/* 首屏 */
.zz-hero {
  padding: 48px 0 56px;
  background: linear-gradient(180deg, var(--zz-blue-soft) 0%, #fff 55%);
  border-bottom: 1px solid var(--zz-border);
}

.zz-hero-inner {
  text-align: center;
}

.zz-hero-kicker {
  margin: 0 0 12px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--zz-warm);
  letter-spacing: 0.08em;
}

.zz-hero-title {
  margin: 0 0 20px;
  font-size: clamp(1.75rem, 3.2vw, 2.35rem);
  font-weight: 700;
  line-height: 1.35;
  color: var(--zz-text);
}

.zz-hero-sub {
  margin: 0 auto 28px;
  max-width: 920px;
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.75;
  color: var(--zz-text2);
}

.zz-hero-sub strong {
  color: var(--zz-text);
  font-weight: 600;
}

.zz-hero-tags {
  list-style: none;
  margin: 0 auto 28px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  max-width: 800px;
}

.zz-hero-tags li {
  padding: 8px 16px;
  background: #fff;
  border: 1px solid var(--zz-border);
  border-radius: 999px;
  font-size: 0.85rem;
  color: var(--zz-text2);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.zz-hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
}

/* 通用区块 */
.zz-section {
  padding: var(--section-pad);
}

.zz-section--alt {
  background: var(--zz-bg-alt);
}

.zz-section--contact {
  background: linear-gradient(180deg, var(--zz-bg-alt), #fff);
  border-top: 1px solid var(--zz-border);
}

.zz-block-head {
  text-align: center;
  margin-bottom: 36px;
}

.zz-h2 {
  margin: 0 0 12px;
  font-size: 1.65rem;
  font-weight: 700;
  color: var(--zz-text);
}

.zz-lead {
  margin: 0 auto;
  max-width: 800px;
  font-size: 0.98rem;
  color: var(--zz-text2);
  line-height: 1.7;
}

.zz-lead strong {
  color: var(--zz-text);
  font-weight: 600;
}

/* 产品简介三卡 */
.zz-intro-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.zz-intro-card {
  padding: 22px;
  background: var(--zz-bg);
  border: 1px solid var(--zz-border);
  border-radius: var(--radius);
  box-shadow: 0 2px 8px rgba(26, 92, 255, 0.06);
}

.zz-section--alt .zz-intro-card {
  background: #fff;
}

.zz-intro-card h3 {
  margin: 0 0 10px;
  font-size: 1.05rem;
  color: var(--zz-text);
}

.zz-intro-card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--zz-text2);
  line-height: 1.6;
}

/* 核心优势 */
.zz-adv-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.zz-adv-card {
  padding: 22px 18px;
  background: var(--zz-bg);
  border: 1px solid var(--zz-border);
  border-radius: var(--radius);
  text-align: center;
}

.zz-section--alt .zz-adv-card {
  background: #fff;
}

.zz-adv-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--zz-blue-soft);
  color: var(--zz-blue);
  font-weight: 700;
  font-size: 1.1rem;
}

.zz-adv-card h3 {
  margin: 0 0 8px;
  font-size: 0.98rem;
  color: var(--zz-text);
}

.zz-adv-card p {
  margin: 0;
  font-size: 0.82rem;
  color: var(--zz-muted);
  line-height: 1.55;
}

/* 功能特色 */
.zz-feat {
  margin-bottom: 22px;
  padding: 22px 24px;
  background: #fff;
  border: 1px solid var(--zz-border);
  border-radius: var(--radius);
  border-left: 4px solid var(--zz-blue);
}

.zz-section--alt .zz-feat {
  background: var(--zz-bg);
}

.zz-feat-head h3 {
  margin: 0 0 14px;
  font-size: 1.1rem;
  color: var(--zz-text);
}

.zz-feat-list {
  margin: 0;
  padding-left: 1.2em;
  color: var(--zz-text2);
  font-size: 0.92rem;
  line-height: 1.85;
}

.zz-feat-list li {
  margin-bottom: 4px;
}

/* 应用下载 */
.zz-dl-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.zz-dl-grid--platforms {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.zz-dl-foot {
  margin: 20px 0 0;
  text-align: center;
  font-size: 0.9rem;
}

.zz-dl-foot a {
  color: var(--zz-primary, #1a5cff);
  text-decoration: none;
}

.zz-dl-foot a:hover {
  text-decoration: underline;
}

.zz-dl-card {
  padding: 24px;
  background: var(--zz-bg);
  border: 1px solid var(--zz-border);
  border-radius: var(--radius);
  text-align: center;
}

.zz-dl-card--highlight {
  border-color: rgba(26, 92, 255, 0.35);
  box-shadow: 0 4px 20px rgba(26, 92, 255, 0.08);
}

.zz-dl-card h3 {
  margin: 0 0 10px;
  font-size: 1.1rem;
}

.zz-dl-desc {
  margin: 0 0 16px;
  font-size: 0.88rem;
  color: var(--zz-text2);
  line-height: 1.6;
  min-height: 3.2em;
}

.zz-dl-placeholder {
  display: block;
  padding: 10px;
  font-size: 0.8rem;
  color: var(--zz-muted);
  background: var(--zz-bg-alt);
  border-radius: 6px;
}

/* 关于 */
.zz-about-box {
  max-width: 900px;
  margin: 0 auto;
  padding: 24px 28px;
  background: #fff;
  border: 1px solid var(--zz-border);
  border-radius: var(--radius);
  font-size: 0.95rem;
  color: var(--zz-text2);
  line-height: 1.75;
}

.zz-section--alt .zz-about-box {
  background: var(--zz-bg);
}

.zz-about-box strong {
  color: var(--zz-text);
}

.zz-compliance-box {
  margin-top: 28px;
  border-left: 4px solid var(--zz-primary, #1a5cff);
}

.zz-compliance-title {
  margin: 0 0 12px;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--zz-text);
}

.zz-compliance-box p + p {
  margin-top: 12px;
}

/* 手风琴 */
.zz-accordion .accordion-item {
  background: #fff;
  border-color: var(--zz-border);
}

.zz-section .accordion-trigger {
  font-family: inherit;
}

.accordion {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-width: 800px;
  margin: 0 auto;
}

.accordion-item {
  border-radius: var(--radius);
  border: 1px solid var(--zz-border);
  background: #fff;
  overflow: hidden;
}

.accordion-item:has(.accordion-trigger[aria-expanded="true"]) {
  border-color: rgba(26, 92, 255, 0.35);
}

.accordion-trigger {
  width: 100%;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 14px 18px;
  text-align: left;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--zz-text);
  background: transparent;
  border: none;
  cursor: pointer;
}

.accordion-trigger:hover {
  background: var(--zz-bg-alt);
}

.accordion-title {
  justify-self: start;
}

.accordion-icon {
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--zz-blue);
  border-bottom: 2px solid var(--zz-blue);
  transform: rotate(45deg);
  transition: transform 0.25s;
}

.accordion-trigger[aria-expanded="true"] .accordion-icon {
  transform: rotate(-135deg);
  margin-top: 4px;
}

.accordion-panel {
  padding: 0 18px 14px;
  color: var(--zz-text2);
  font-size: 0.9rem;
  line-height: 1.6;
}

.accordion-panel[hidden] {
  display: none;
}

.accordion-panel:not([hidden]) {
  display: block;
}

/* 联系 */
.contact-shell {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

.contact-form {
  min-width: 0;
  padding: 22px;
  border-radius: var(--radius);
  border: 1px solid var(--zz-border);
  background: #fff;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-bottom: 12px;
}

.form-field input,
.form-field textarea {
  font-family: inherit;
  font-size: 0.88rem;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--zz-border);
  background: #fff;
  color: var(--zz-text);
}

.form-field input:focus,
.form-field textarea:focus {
  outline: none;
  border-color: var(--zz-blue);
  box-shadow: 0 0 0 3px rgba(26, 92, 255, 0.12);
}

.form-label {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--zz-muted);
}

.form-submit {
  width: 100%;
  margin-top: 6px;
}

.form-hint {
  margin: 10px 0 0;
  min-height: 1.2em;
  font-size: 0.8rem;
  color: var(--zz-blue);
}

.contact-panel {
  min-width: 0;
}

.contact-panel-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.contact-tile {
  padding: 14px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--zz-border);
  background: #fff;
}

.contact-tile--brand {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.contact-tile-block .contact-label {
  margin-bottom: 4px;
}

.contact-tile--channels .contact-label {
  margin-bottom: 8px;
}

.contact-label {
  display: block;
  font-size: 0.72rem;
  color: var(--zz-muted);
  font-weight: 600;
}

.contact-value {
  margin: 0;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--zz-text);
}

.contact-value a {
  color: var(--zz-blue);
}

.contact-value a:hover {
  color: var(--zz-blue-dark);
}

.contact-channels {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.contact-channels li {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.contact-channels-key {
  font-size: 0.68rem;
  color: var(--zz-muted);
}

.contact-channels a {
  font-size: 0.88rem;
  font-weight: 500;
  word-break: break-all;
}

.contact-tile--address {
  grid-column: 1 / -1;
}

.contact-value--multiline {
  line-height: 1.55;
  word-break: break-all;
  overflow-wrap: anywhere;
}

.contact-map-wrap {
  position: relative;
  margin-top: 12px;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid rgba(0, 0, 0, 0.08);
  background: #fff;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

.contact-map-leaflet {
  width: 100%;
  height: 220px;
  z-index: 0;
}

.contact-map-wrap .leaflet-container {
  font-family: inherit;
  background: #f1f5f9 !important;
}

.contact-map-overlay {
  display: none;
  position: absolute;
  inset: 0;
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background: rgba(255, 255, 255, 0.96);
  text-align: center;
  font-size: 0.78rem;
  line-height: 1.55;
  color: var(--zz-muted);
}

.contact-map-overlay.is-visible {
  display: flex;
}

.contact-map-overlay p {
  margin: 0;
  max-width: 280px;
}

.contact-map-actions {
  margin: 10px 0 0;
  font-size: 0.72rem;
  color: var(--zz-muted);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 4px;
}

.contact-map-actions a {
  color: var(--zz-blue);
  font-weight: 500;
  text-decoration: none;
}

.contact-map-actions a:hover {
  color: var(--zz-blue-dark);
  text-decoration: underline;
}

.contact-map-actions-sep {
  color: var(--zz-muted);
  user-select: none;
}

/* 页脚 */
.zz-footer {
  background: #2d3748;
  color: #e2e8f0;
  padding-top: 40px;
}

.zz-footer a {
  color: #cbd5e0;
}

.zz-footer a:hover {
  color: #fff;
}

.zz-footer-main {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.zz-footer-brand {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.zz-logo-img--footer {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  box-shadow: none;
}

.zz-footer-brand strong {
  display: block;
  margin-bottom: 6px;
  color: #fff;
  font-size: 1rem;
}

.zz-footer-brand p {
  margin: 0;
  font-size: 0.85rem;
  color: #a0aec0;
  line-height: 1.5;
}

.zz-footer-col-title {
  display: block;
  font-size: 0.75rem;
  color: #718096;
  margin-bottom: 12px;
  font-weight: 600;
}

.zz-footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.zz-footer-links a {
  font-size: 0.88rem;
}

.zz-footer-bar {
  position: relative;
  padding: 20px 0 28px;
}

.zz-footer-bar-inner {
  text-align: center;
}

.zz-footer-bar-inner p {
  margin: 6px 0;
  font-size: 0.8rem;
  color: #a0aec0;
}

.zz-footer-icp {
  font-size: 0.75rem !important;
  color: #718096 !important;
}

.zz-footer-icp a {
  color: inherit;
  text-decoration: none;
}

.zz-footer-icp a:hover {
  color: #a0aec0;
  text-decoration: underline;
}

.zz-footer-icp--legal {
  margin: 0 0 12px;
  text-align: center;
}

.to-top {
  position: fixed;
  right: 24px;
  bottom: 28px;
  z-index: 150;
  font-family: inherit;
  font-size: 0.75rem;
  padding: 10px 14px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(45, 55, 72, 0.95);
  color: #e2e8f0;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.to-top:hover {
  background: var(--zz-blue);
  border-color: var(--zz-blue);
  color: #fff;
}

/* 滚动显现 */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

/* —— 平板：优势四宫格两列 —— */
@media (max-width: 1024px) {
  .zz-adv-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* —— 手机与小屏：侧滑导航 + 单栏布局 —— */
@media (max-width: 900px) {
  :root {
    --header-h: 56px;
    --section-pad: 40px 0;
  }

  .zz-header {
    height: auto;
    min-height: var(--header-h);
  }

  .zz-header-inner {
    padding: 10px 16px;
    min-height: var(--header-h);
    flex-wrap: nowrap;
    gap: 10px;
  }

  .zz-logo-text {
    font-size: 1.05rem;
  }

  .zz-header-actions {
    order: 2;
    margin-left: auto;
  }

  .zz-nav-toggle {
    display: flex;
    order: 3;
  }

  .zz-nav {
    order: 10;
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    bottom: 0;
    max-height: calc(100vh - var(--header-h));
    max-height: calc(100dvh - var(--header-h));
    flex: none;
    flex-direction: column;
    justify-content: flex-start;
    align-items: stretch;
    gap: 0;
    padding: 8px 0 max(16px, env(safe-area-inset-bottom, 0px));
    margin: 0;
    background: #fff;
    border-top: 1px solid var(--zz-border);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12);
    overflow-x: hidden;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    transform: translateX(100%);
    visibility: hidden;
    transition: transform 0.28s ease, visibility 0.28s;
    z-index: 199;
  }

  body.zz-nav-open .zz-nav {
    transform: translateX(0);
    visibility: visible;
  }

  .zz-nav a {
    padding: 16px 20px;
    font-size: 1rem;
    border-bottom: 1px solid var(--zz-border);
  }

  .zz-nav a.is-active {
    background: var(--zz-blue-soft);
  }

  .zz-header-actions .zz-btn--nav-dl {
    display: none;
  }

  .zz-header-actions .zz-btn {
    padding: 8px 12px;
    font-size: 0.78rem;
    white-space: nowrap;
  }

  .zz-nav-backdrop {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 198;
    background: rgba(15, 23, 42, 0.45);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.25s ease, visibility 0.25s;
  }

  body.zz-nav-open .zz-nav-backdrop {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }

  .zz-h2 {
    font-size: 1.4rem;
  }

  .zz-block-head {
    margin-bottom: 28px;
  }

  .zz-lead {
    font-size: 0.92rem;
  }

  .zz-hero {
    padding: 28px 0 36px;
  }

  .zz-hero-kicker {
    font-size: 0.88rem;
  }

  .zz-hero-title {
    font-size: clamp(1.3rem, 6.5vw, 1.85rem);
    margin-bottom: 16px;
  }

  .zz-hero-sub {
    font-size: 0.9rem;
    margin-bottom: 20px;
    text-align: left;
  }

  .zz-hero-inner {
    text-align: left;
  }

  .zz-hero-tags {
    justify-content: flex-start;
    margin-bottom: 22px;
  }

  .zz-hero-tags li {
    font-size: 0.78rem;
    padding: 6px 12px;
  }

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

  .zz-hero-cta .zz-btn {
    width: 100%;
    justify-content: center;
  }

  .zz-intro-grid,
  .zz-dl-grid {
    grid-template-columns: 1fr;
  }

  .zz-adv-grid {
    grid-template-columns: 1fr;
  }

  .contact-shell {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .contact-panel-grid {
    grid-template-columns: 1fr;
  }

  .contact-tile--address {
    grid-column: 1;
  }

  .zz-footer-main {
    grid-template-columns: 1fr;
    gap: 28px;
    text-align: center;
  }

  .zz-footer-brand {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .zz-footer-links {
    align-items: center;
  }

  .zz-feat {
    padding: 16px 14px;
  }

  .zz-feat-list {
    font-size: 0.88rem;
    padding-left: 1.1em;
  }

  .accordion-trigger {
    padding: 16px 14px;
    font-size: 0.88rem;
    min-height: 48px;
  }

  .zz-dl-desc {
    min-height: 0;
  }

  .zz-about-box {
    padding: 18px 16px;
    font-size: 0.9rem;
  }

  .to-top {
    right: max(12px, env(safe-area-inset-right, 0px));
    bottom: max(14px, env(safe-area-inset-bottom, 0px));
    padding: 11px 13px;
  }
}

@media (min-width: 901px) {
  .zz-nav-backdrop {
    display: none !important;
  }
}

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

  .zz-nav,
  body.zz-nav-open .zz-nav-backdrop {
    transition: none;
  }
}