/* 上海助趣科技有限公司官网样式：移动端优先，仅使用系统字体 */
:root {
  --brand: #2563eb;
  --brand-dark: #1d4ed8;
  --brand-soft: #eff6ff;
  --accent: #0d9488;
  --ink: #0f172a;
  --text: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #ffffff;
  --bg-soft: #f6f8fb;
  --radius: 14px;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 120px; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans CJK SC", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
}
img { max-width: 100%; height: auto; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { color: var(--ink); line-height: 1.35; margin: 0 0 .6em; }
h1 { font-size: 1.85rem; }
h2 { font-size: 1.4rem; }
h3 { font-size: 1.1rem; }
p { margin: 0 0 1em; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }

.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 8px; z-index: 20; background: #fff; padding: 6px 12px; border-radius: 8px; }

/* 待填写占位：上线前必须全部替换 */
mark.todo { background: #fef08a; color: #b91c1c; font-weight: 600; padding: 0 .25em; border-radius: 4px; }

/* 页头 */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255, 255, 255, .94);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas: "brand lang" "nav nav";
  align-items: center;
  column-gap: 12px;
  padding-top: 10px;
}
.brand { grid-area: brand; display: flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 600; line-height: 1.25; }
.brand:hover { text-decoration: none; }
.brand img { flex: none; }
.lang-switch {
  grid-area: lang;
  font-size: .875rem; line-height: 1.6;
  border: 1px solid var(--line); border-radius: 999px;
  padding: 3px 12px; color: var(--ink); white-space: nowrap;
}
.lang-switch:hover { border-color: var(--brand); color: var(--brand); text-decoration: none; }
.site-nav {
  grid-area: nav;
  display: flex; gap: 2px;
  overflow-x: auto; scrollbar-width: none;
  margin: 4px -8px 0;
}
.site-nav::-webkit-scrollbar { display: none; }
.site-nav a { flex: none; padding: 8px; color: var(--text); font-size: .95rem; border-bottom: 2px solid transparent; }
.site-nav a:hover { color: var(--brand); text-decoration: none; }
.site-nav a[aria-current="page"] { color: var(--brand); border-bottom-color: var(--brand); font-weight: 600; }

@media (min-width: 900px) {
  html { scroll-padding-top: 80px; }
  .header-inner { grid-template-columns: auto 1fr auto; grid-template-areas: "brand nav lang"; padding: 0 16px; height: 64px; }
  .site-nav { margin: 0; justify-content: flex-end; gap: 6px; height: 100%; align-items: stretch; }
  .site-nav a { display: flex; align-items: center; padding: 0 10px; }
}

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 44px; padding: 0 22px; border-radius: 10px;
  background: var(--brand); color: #fff; font-weight: 600; border: 1px solid var(--brand);
}
.btn:hover { background: var(--brand-dark); text-decoration: none; }
.btn-ghost { background: #fff; color: var(--brand); border-color: #bfdbfe; }
.btn-ghost:hover { background: var(--brand-soft); }

/* 首页主视觉 */
.hero { background: linear-gradient(135deg, #eff6ff 0%, #ecfeff 60%, #f0fdf4 100%); padding: 40px 0 48px; }
.hero-inner { display: grid; gap: 28px; align-items: center; }
.eyebrow { font-size: .8rem; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); font-weight: 700; margin-bottom: .6em; }
.hero h1 { font-size: 2rem; }
.lead { font-size: 1.075rem; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.hero-art img { display: block; width: 100%; max-width: 360px; margin: 0 auto; }
@media (min-width: 900px) {
  .hero { padding: 72px 0 80px; }
  .hero-inner { grid-template-columns: 1.15fr .85fr; gap: 48px; }
  .hero h1 { font-size: 2.6rem; }
}

/* 区块 */
.section { padding: 48px 0; }
.section-soft { background: var(--bg-soft); }
.section-title { text-align: center; margin-bottom: 28px; }
.cards { display: grid; gap: 16px; }
@media (min-width: 720px) { .cards { grid-template-columns: repeat(3, 1fr); } .section { padding: 64px 0; } }
.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.card > :last-child { margin-bottom: 0; }
.icon {
  width: 44px; height: 44px; border-radius: 12px;
  display: grid; place-items: center;
  background: var(--brand-soft); color: var(--brand);
  margin-bottom: 14px;
}
.icon svg { width: 24px; height: 24px; }
.split { display: flex; flex-direction: column; gap: 16px; align-items: flex-start; }
.split > div > :last-child { margin-bottom: 0; }
@media (min-width: 720px) { .split { flex-direction: row; align-items: center; justify-content: space-between; gap: 40px; } }
.cta { text-align: center; }
.cta > :last-child { margin-bottom: 0; }

/* 内页 */
.page-head { background: linear-gradient(135deg, #eff6ff, #ecfeff); padding: 36px 0 28px; border-bottom: 1px solid var(--line); }
.page-head h1 { margin-bottom: .25em; }
.page-head p { margin: 0; color: var(--muted); }
.prose { max-width: 780px; }
.prose h2 { margin-top: 2em; font-size: 1.3rem; }
.prose h2:first-child, .prose .notice + h2 { margin-top: 0; }
.prose h3 { margin-top: 1.5em; }
.prose ul, .prose ol { padding-left: 1.3em; margin: 0 0 1em; }
.prose li { margin-bottom: .4em; }
.toc { background: var(--bg-soft); border-radius: var(--radius); padding: 16px 20px 16px 40px !important; }
.info { display: grid; grid-template-columns: max-content 1fr; gap: 8px 20px; margin: 0; }
.info dt { color: var(--muted); }
.info dd { margin: 0; color: var(--ink); overflow-wrap: anywhere; }
.notice { border-radius: 10px; padding: 14px 16px; margin-bottom: 28px; font-size: .95rem; }
.notice-draft { background: #fffbeb; border: 1px solid #fcd34d; color: #92400e; }
.note { color: var(--muted); margin-top: 24px; }

/* 产品 */
.product { display: grid; gap: 20px; }
@media (min-width: 720px) { .product { grid-template-columns: 112px 1fr; gap: 28px; } }
.app-icon {
  width: 96px; height: 96px; border-radius: 22px;
  border: 2px dashed #93c5fd; background: var(--bg-soft);
  display: grid; place-items: center; color: var(--muted); font-size: .85rem;
}
.app-icon-img { display: block; width: 96px; height: 96px; border-radius: 22px; box-shadow: 0 6px 18px rgba(15, 23, 42, .16); }
.tag { display: inline-block; font-size: .8rem; line-height: 1.8; background: #ecfeff; color: var(--accent); border-radius: 999px; padding: 0 10px; font-weight: 600; }
.links { display: flex; flex-wrap: wrap; gap: 8px 20px; }

/* 联系 */
.contact-grid { display: grid; gap: 16px; }
@media (min-width: 720px) { .contact-grid { grid-template-columns: repeat(2, 1fr); } }
.contact-grid h3 { margin-bottom: .3em; }
.contact-grid p { overflow-wrap: anywhere; }

/* 常见问题 */
.support-box { background: var(--brand-soft); border: 1px solid #bfdbfe; border-radius: var(--radius); padding: 20px 24px; margin-bottom: 36px; }
.support-box > :last-child { margin-bottom: 0; }
details { border: 1px solid var(--line); border-radius: 12px; padding: 0 16px; margin-bottom: 10px; background: #fff; }
summary { cursor: pointer; padding: 14px 28px 14px 0; font-weight: 600; color: var(--ink); list-style: none; position: relative; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; position: absolute; right: 0; top: 11px; font-size: 1.25rem; color: var(--muted); }
details[open] summary::after { content: "−"; }
details p { margin: 0 0 14px; }

/* 404 */
.notfound { text-align: center; padding: 72px 0 88px; }
.notfound .code { font-size: 4.5rem; font-weight: 800; line-height: 1; color: #bfdbfe; margin-bottom: 16px; }

/* 页脚 */
.site-footer { background: #0f172a; color: #94a3b8; padding: 32px 0 36px; font-size: .875rem; line-height: 1.9; }
.site-footer a { color: #cbd5e1; }
.site-footer p { margin: 0; }
.footer-links { display: flex; flex-wrap: wrap; gap: 4px 20px; margin-bottom: 14px; }
.beian { display: flex; flex-wrap: wrap; gap: 4px 20px; }