/* =========================================================
   南京腾翎航天航空新材料有限公司 · 官网样式
   设计基调：深蓝航天 + 金属纤维质感，专业克制，去 AI 味
   雕琢原则：等宽数字 / 同心圆角 / 错开淡入 / 标题平衡 / 多层柔影替边框
   ========================================================= */

:root {
  --c-navy:   #0E2A47;
  --c-navy-2: #163A63;
  --c-blue:   #2E6CB8;
  --c-steel:  #4A90D9;
  --c-silver: #C7CED6;
  --c-gold:   #B8985A;
  --c-bg:     #F4F7FA;
  --c-bg-soft:#ECF1F6;
  --c-white:  #FFFFFF;
  --c-ink:    #1C2A39;
  --c-muted:  #5B6B7B;

  /* 半径系统：同心圆角 = 外层半径 = 内层半径 + 内边距 */
  --r-card: 16px;
  --r-lg:   22px;     /* 大卡：内边距 18 → 内层 4，严格同心 */
  --r-sm:   10px;
  --r-pill: 999px;

  /* 多层柔和阴影（低透明中性色，换背景也自然融合，替代边框） */
  --shadow-soft:
     0 1px 2px  rgba(16,32,52,.04),
     0 3px 8px  rgba(16,32,52,.05),
     0 12px 26px rgba(16,32,52,.06);
  --shadow-soft-hover:
     0 2px 4px  rgba(16,32,52,.05),
     0 9px 18px  rgba(16,32,52,.08),
     0 22px 44px rgba(16,32,52,.09);
  /* 深色区块内的卡片阴影（偏暗，不抢光） */
  --shadow-dark:
     0 1px 2px  rgba(0,0,0,.18),
     0 6px 16px rgba(0,0,0,.22);

  --maxw: 1180px;
  --header-h: 68px;
  --ff: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: var(--header-h); }

body {
  margin: 0;
  font-family: var(--ff);
  color: var(--c-ink);
  background: var(--c-bg);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: var(--c-blue); text-decoration: none; }
a:hover { color: var(--c-steel); }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.section { padding: 84px 0; }
.section--tight { padding: 64px 0; }
.section--soft { background: var(--c-bg-soft); }
.section--dark {
  background: linear-gradient(160deg, var(--c-navy) 0%, var(--c-navy-2) 100%);
  color: #E7EEF6;
}

/* 标题平衡换行：避免末行只剩单个词 */
h1, h2, h3, h4, .section-title, .hero h1, .product-card h3, .app-card h3, .about-copy h2, .contact-info h2 {
  text-wrap: balance;
}
p { text-wrap: pretty; }

.eyebrow {
  display: inline-block;
  font-size: 13px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--c-blue);
  font-weight: 700;
  margin-bottom: 12px;
}
.section--dark .eyebrow { color: var(--c-steel); }

.section-title {
  font-size: 30px;
  font-weight: 800;
  margin: 0 0 14px;
  letter-spacing: .01em;
}
.section-sub {
  font-size: 16px;
  color: var(--c-muted);
  max-width: 720px;
  margin: 0 auto 44px;
}
.section--dark .section-sub { color: #B9C7D6; }

.center { text-align: center; }

/* 区块标题渐变下划线（参考站样式） */
.center .section-title { position: relative; }
.center .section-title::after {
  content: ""; display: block; width: 56px; height: 3px; margin: 16px auto 0;
  background: linear-gradient(90deg, var(--c-blue), var(--c-silver)); border-radius: 3px;
}

/* 等宽数字：数值变动不左右晃动 */
.stat__num, .stat__num small, .spec-list .v, .mini-stat__num,
.product-card h3, .hero__stats .stat__num {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 26px; border-radius: var(--r-pill);
  font-size: 15px; font-weight: 700;
  border: none; cursor: pointer; transition: all .2s ease; white-space: nowrap;
}
.btn--primary { background: var(--c-blue); color: #fff; box-shadow: var(--shadow-soft); }
.btn--primary:hover { background: var(--c-steel); color: #fff; box-shadow: var(--shadow-soft-hover); }
.btn--ghost { background: transparent; color: #fff; box-shadow: inset 0 0 0 1.5px rgba(255,255,255,.45); }
.btn--ghost:hover { background: rgba(255,255,255,.10); color: #fff; }
.btn--outline { background: transparent; color: var(--c-blue); box-shadow: inset 0 0 0 1.5px var(--c-blue); }
.btn--outline:hover { background: var(--c-blue); color: #fff; }

/* ---------- 顶部导航 ---------- */
.header {
  position: sticky; top: 0; z-index: 50; height: var(--header-h);
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(160%) blur(10px);
  box-shadow: 0 1px 0 rgba(16,32,52,.06), 0 6px 18px rgba(16,32,52,.04);
}
.header__inner { height: 100%; display: flex; align-items: center; justify-content: space-between; }
.logo { display: flex; align-items: center; gap: 12px; }
.logo__mark {
  width: 38px; height: 38px; border-radius: 9px;
  background: linear-gradient(135deg, var(--c-navy), var(--c-blue));
  display: grid; place-items: center; color: #fff; font-weight: 800; font-size: 17px;
  box-shadow: var(--shadow-soft);
}
.logo__text { line-height: 1.2; }
.logo__name { font-weight: 800; font-size: 16px; color: var(--c-navy); }
.logo__sub { font-size: 11px; color: var(--c-muted); letter-spacing: .04em; }

.nav { display: flex; align-items: center; gap: 6px; }
.nav a {
  padding: 9px 14px; border-radius: 8px; color: var(--c-ink);
  font-size: 15px; font-weight: 600; transition: background .15s ease, color .15s ease;
}
.nav a:hover { background: var(--c-bg-soft); color: var(--c-blue); }
.nav a.active { color: var(--c-blue); }

.nav-toggle { display: none; background: none; border: none; width: 42px; height: 42px; cursor: pointer; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--c-navy); margin: 5px auto; border-radius: 2px; }

/* ---------- Hero（实景照片 + 深蓝遮罩，文字始终可读） ---------- */
.hero {
  position: relative;
  background: var(--c-navy);
  color: #EAF1F8; overflow: hidden;
}
.hero__track { position: absolute; inset: 0; z-index: 0; }
.hero__slide {
  position: absolute; inset: 0; opacity: 0; visibility: hidden;
  background-size: cover; background-position: center 40%;
  transform: scale(1.04);
  transition: opacity .9s ease, visibility .9s ease;
}
.hero__slide.is-active {
  opacity: 1; visibility: visible; transform: scale(1.12);
  transition: opacity .9s ease, visibility .9s ease, transform 7s linear;
}
.hero__overlay {
  position: absolute; inset: 0; z-index: 1;
  background: linear-gradient(102deg, rgba(9,22,38,.92) 0%, rgba(9,22,38,.78) 44%, rgba(9,22,38,.46) 100%);
}
.hero__inner {
  position: relative; z-index: 2; padding: 96px 0 104px;
  display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center;
}
.hero__badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(255,255,255,.07);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.16);
  color: #CFE0F2; padding: 7px 14px; border-radius: var(--r-pill);
  font-size: 13px; font-weight: 600; margin-bottom: 20px;
}
.hero__badge b { color: #fff; }
.hero h1 { font-size: 42px; line-height: 1.2; margin: 0 0 18px; font-weight: 800; letter-spacing: .01em; }
.hero h1 .hl { color: var(--c-steel); }
.hero__lead { font-size: 17px; color: #C6D4E3; max-width: 520px; margin: 0 0 30px; }
.hero__cta { display: flex; gap: 14px; flex-wrap: wrap; }

/* Hero 轮播导航（圆点 + 箭头） */
.hero__nav { position: absolute; left: 0; right: 0; bottom: 30px; z-index: 3; }
.hero__nav-inner { display: flex; align-items: center; gap: 20px; }
.hero__dots { display: flex; gap: 10px; }
.hero__dot {
  width: 34px; height: 4px; padding: 0; border: 0; border-radius: 999px;
  background: rgba(255,255,255,.36); cursor: pointer;
  transition: background .3s ease, width .3s ease;
}
.hero__dot.is-active { width: 56px; background: var(--c-steel); }
.hero__arrows { display: flex; gap: 10px; margin-left: auto; }
.hero__arrow {
  width: 46px; height: 46px; border-radius: 50%;
  border: 1px solid rgba(255,255,255,.4); background: transparent;
  color: #fff; font-size: 22px; line-height: 1; cursor: pointer;
  display: grid; place-items: center;
  transition: background .25s ease, border-color .25s ease;
}
.hero__arrow:hover { background: var(--c-blue); border-color: var(--c-blue); }

/* 同心圆角统计块：外层 22 / 内边距 18 / 内层 4 */
.hero__stats {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px;
  background: rgba(255,255,255,.06);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.14), var(--shadow-dark);
  border-radius: var(--r-lg); padding: 18px;
  overflow: hidden;
}
.stat { text-align: center; padding: 8px 4px; border-radius: 4px; }
.stat__num { font-size: 28px; font-weight: 800; color: #fff; line-height: 1.1; }
.stat__num small { font-size: 15px; font-weight: 700; }
.stat__label { font-size: 13px; color: #AFC2D6; margin-top: 6px; }

/* ---------- 特性网格 ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px; }
.feature-card {
  background: var(--c-white); border-radius: var(--r-card);
  padding: 26px 20px; text-align: center;
  box-shadow: var(--shadow-soft); transition: transform .2s ease, box-shadow .2s ease;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-soft-hover); }
.feature-card__no { font-size: 13px; font-weight: 800; color: var(--c-silver); letter-spacing: .1em; }
.feature-card__icon {
  width: 52px; height: 52px; margin: 10px auto 14px; border-radius: 14px;
  background: linear-gradient(135deg, #EAF1F9, #D8E6F5);
  display: grid; place-items: center;
}
.feature-card__icon svg { width: 26px; height: 26px; stroke: var(--c-blue); }
.feature-card h3 { font-size: 17px; margin: 0 0 8px; color: var(--c-navy); }
.feature-card p { font-size: 13.5px; color: var(--c-muted); margin: 0; }

/* ---------- 产品型号（卡顶部实物图） ---------- */
.product-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.product-card {
  background: var(--c-white); border-radius: var(--r-card);
  box-shadow: var(--shadow-soft); overflow: hidden;
  display: flex; flex-direction: column; transition: transform .2s ease, box-shadow .2s ease;
}
.product-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-soft-hover); }
.product-card__media { aspect-ratio: 16 / 10; overflow: hidden; background: #E4EDF6; }
.product-card__media img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform .4s ease; }
.product-card:hover .product-card__media img { transform: scale(1.04); }
.product-card__body { padding: 26px 26px 28px; display: flex; flex-direction: column; flex: 1; }
.product-card__tag {
  align-self: flex-start; font-size: 12px; font-weight: 700; letter-spacing: .05em;
  color: var(--c-blue); background: #EAF1F9; padding: 4px 12px; border-radius: var(--r-pill); margin-bottom: 14px;
}
.product-card h3 { font-size: 21px; margin: 0 0 6px; color: var(--c-navy); }
.product-card__desc { font-size: 14px; color: var(--c-muted); margin: 0 0 18px; min-height: 42px; }
.spec-list { list-style: none; padding: 0; margin: 0 0 8px; }
.spec-list li {
  display: flex; justify-content: space-between; align-items: baseline;
  padding: 11px 2px; box-shadow: 0 1px 0 rgba(16,32,52,.06); font-size: 14.5px;
}
.spec-list li:last-child { box-shadow: none; }
.spec-list .k { color: var(--c-muted); }
.spec-list .v { font-weight: 700; color: var(--c-ink); }

/* ---------- 关于预览 ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.split__media {
  border-radius: var(--r-lg); overflow: hidden; box-shadow: var(--shadow-soft);
  aspect-ratio: 4 / 3; background: #E4EDF6; position: relative;
}
.split__media img { width: 100%; height: 100%; object-fit: cover; display: block; }
.about-copy h2 { font-size: 28px; color: var(--c-navy); margin: 0 0 16px; }
.about-copy p { color: var(--c-muted); margin: 0 0 16px; }
.about-copy .lead { color: var(--c-ink); font-size: 17px; }

.mini-stats { display: flex; gap: 30px; margin: 24px 0 26px; flex-wrap: wrap; }
.mini-stat__num { font-size: 30px; font-weight: 800; color: var(--c-blue); line-height: 1; }
.mini-stat__label { font-size: 13px; color: var(--c-muted); margin-top: 6px; }

/* ---------- 应用领域卡片（一排四个，自适应手机平板） ---------- */
.app-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; }
.app-card {
  background: var(--c-white); border-radius: var(--r-lg);
  padding: 28px; box-shadow: var(--shadow-soft); overflow: hidden;
  transition: transform .2s ease, box-shadow .2s ease;
}
.app-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-soft-hover); }
.app-card__media {
  margin: -28px -28px 22px; aspect-ratio: 16 / 9; overflow: hidden; background: #E4EDF6;
}
.app-card__media img { width: 100%; height: 100%; object-fit: cover; display: block; }
.app-card__no { font-size: 13px; font-weight: 800; letter-spacing: .12em; color: var(--c-steel); }
.app-card h3 { font-size: 20px; margin: 8px 0 16px; color: var(--c-navy); }
.app-card__row { margin-bottom: 12px; }
.app-card__row .lab {
  display: inline-block; font-size: 12px; font-weight: 700; padding: 2px 10px; border-radius: 6px; margin-bottom: 6px;
}
.lab--pain { background: #FBEAEA; color: #B4453B; }
.lab--sol  { background: #E7F3EA; color: #2F7A45; }
.app-card__row p { margin: 0; font-size: 14.5px; color: var(--c-muted); }

/* ---------- 图册（同心圆角 + overflow 继承） ---------- */
.gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.gallery__item {
  position: relative; border-radius: var(--r-sm); overflow: hidden;
  aspect-ratio: 4 / 3; background: #E4EDF6;
  box-shadow: var(--shadow-soft); cursor: zoom-in;
}
.gallery__item img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform .4s ease; }
.gallery__item:hover img { transform: scale(1.04); }
.gallery__item .cap {
  position: absolute; left: 0; right: 0; bottom: 0; padding: 10px 12px;
  font-size: 13px; font-weight: 700; color: #fff;
  background: linear-gradient(transparent, rgba(8,18,32,.62));
}

/* ---------- 选型建议 ---------- */
.tips { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.tip { background: var(--c-white); border-radius: var(--r-card); padding: 22px 20px; box-shadow: var(--shadow-soft); }
.tip h4 { margin: 0 0 8px; font-size: 16px; color: var(--c-navy); }
.tip p { margin: 0; font-size: 13.5px; color: var(--c-muted); }

/* ---------- 联系 / 页脚 ---------- */
.contact-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start; }
.contact-info h2 { font-size: 26px; color: var(--c-navy); margin: 0 0 18px; }
.contact-list { list-style: none; padding: 0; margin: 0; }
.contact-list li {
  display: flex; gap: 12px; align-items: flex-start; padding: 12px 0;
  box-shadow: 0 1px 0 rgba(16,32,52,.07); font-size: 15px; color: var(--c-muted);
}
.contact-list li:last-child { box-shadow: none; }
.contact-list li b { color: var(--c-ink); display: block; font-size: 13px; margin-bottom: 2px; }
.contact-list .ic { color: var(--c-blue); flex: 0 0 auto; margin-top: 2px; display: grid; place-items: center; }
.contact-list .ic svg { width: 20px; height: 20px; stroke: var(--c-blue); fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.map-card {
  border-radius: var(--r-lg); overflow: hidden; box-shadow: var(--shadow-soft); min-height: 280px;
  background:
    linear-gradient(135deg, rgba(46,108,184,.10), rgba(14,42,71,.06)),
    repeating-linear-gradient(0deg, #E9EEF4 0 1px, transparent 1px 28px),
    repeating-linear-gradient(90deg, #E9EEF4 0 1px, transparent 1px 28px),
    #F4F7FA;
  display: grid; place-items: center; text-align: center; padding: 24px;
}
.map-card .pin { font-size: 13px; color: var(--c-muted); }
.map-card .pin b { color: var(--c-navy); display: block; font-size: 15px; margin-bottom: 4px; }

.footer { background: var(--c-navy); color: #C6D4E3; padding: 46px 0 26px; font-size: 14px; }
.footer__top {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 32px;
  padding-bottom: 28px; box-shadow: 0 1px 0 rgba(255,255,255,.10);
}
.footer h4 { color: #fff; font-size: 15px; margin: 0 0 14px; }
.footer a { color: #C6D4E3; }
.footer a:hover { color: #fff; }
.footer ul { list-style: none; padding: 0; margin: 0; }
.footer li { padding: 5px 0; }
.footer__brand p { margin: 12px 0 0; max-width: 360px; color: #9FB2C6; font-size: 13.5px; }
.footer__bottom { padding-top: 18px; font-size: 12.5px; color: #8FA3B8; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; }

/* ---------- 灯箱（同心圆角：外层 overflow:hidden 自动继承内层） ---------- */
.lightbox { position: fixed; inset: 0; z-index: 100; background: rgba(8,18,32,.82); display: none; align-items: center; justify-content: center; padding: 30px; }
.lightbox.open { display: flex; }
.lightbox__box {
  background: #fff; border-radius: var(--r-lg); overflow: hidden; max-width: 760px; width: 100%;
  padding: 22px; text-align: center; box-shadow: 0 24px 60px rgba(0,0,0,.4);
}
.lightbox__box .ph {
  width: 100%; aspect-ratio: 16/9; object-fit: contain; border-radius: 12px;
  background: #E4EDF6; display: block; margin-bottom: 14px;
}
.lightbox__close { position: absolute; top: 22px; right: 26px; background: none; border: none; color: #fff; font-size: 30px; cursor: pointer; }

/* ---------- 返回顶部 ---------- */
.totop {
  position: fixed; right: 22px; bottom: 22px; z-index: 40;
  width: 46px; height: 46px; border-radius: 50%;
  background: var(--c-blue); color: #fff; border: none; cursor: pointer;
  box-shadow: var(--shadow-soft); display: grid; place-items: center;
  opacity: 0; pointer-events: none; transition: opacity .25s ease;
}
.totop.show { opacity: 1; pointer-events: auto; }

/* ---------- 错开淡入（不整块入场） ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ===== 产品中心页 ===== */
.page-banner { position: relative; background: var(--c-navy); color: #EAF1F8; overflow: hidden; }
.page-banner__photo { position: absolute; inset: 0; background: url(assets/img/product-spools-trio.jpg) center 40% / cover no-repeat; }
.page-banner__overlay { position: absolute; inset: 0; background: linear-gradient(102deg, rgba(9,22,38,.92), rgba(9,22,38,.55)); }
.page-banner .container { position: relative; z-index: 2; padding: 88px 24px 72px; }

.adv-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.adv-card { background: var(--c-white); border-radius: var(--r-card); padding: 30px 26px; box-shadow: var(--shadow-soft); transition: transform .2s ease, box-shadow .2s ease; }
.adv-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-soft-hover); }
.adv-card__no { font-size: 13px; font-weight: 800; letter-spacing: .1em; color: var(--c-silver); }
.adv-card h3 { font-size: 19px; margin: 10px 0 10px; color: var(--c-navy); }
.adv-card p { font-size: 14px; color: var(--c-muted); margin: 0; }

.table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.spec-table { width: 100%; min-width: 620px; border-collapse: separate; border-spacing: 0; background: var(--c-white); border-radius: var(--r-lg); overflow: hidden; box-shadow: var(--shadow-soft); font-size: 15px; }
.spec-table th, .spec-table td { padding: 16px 18px; text-align: center; }
.spec-table thead th { background: var(--c-navy); color: #fff; font-weight: 700; }
.spec-table thead th:first-child { text-align: left; }
.spec-table tbody td:first-child { text-align: left; color: var(--c-muted); font-weight: 600; }
.spec-table tbody td { color: var(--c-ink); font-variant-numeric: tabular-nums; font-feature-settings: "tnum" 1; }
.spec-table tbody tr:nth-child(even) td { background: var(--c-bg-soft); }

.cta-dark { background: linear-gradient(160deg, var(--c-navy) 0%, var(--c-navy-2) 100%); color: #EAF1F8; }
.cta-dark h2 { color: #fff; font-size: 26px; margin: 0 0 10px; }
.cta-dark p { color: #C6D4E3; margin: 0 0 22px; max-width: 620px; }
.cta-dark .cta-btns { display: flex; gap: 14px; flex-wrap: wrap; }

/* ===== 内页大图 banner + 通用卡片配图 ===== */
.page-banner .eyebrow { color: #9FC2E8; }
  .page-banner--app  .page-banner__photo { background-image: url(assets/img/app-wire-datacable.jpg); }
  .page-banner--about .page-banner__photo { background-image: url(assets/img/prod-fiber-full.jpg); }

/* 卡片顶部实拍缩略（让纯文字栏目也带图） */
.card-media {
  aspect-ratio: 16 / 9; overflow: hidden; border-radius: var(--r-sm);
  background: #E4EDF6; margin-bottom: 16px;
}
.card-media img { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform .4s ease; }
.adv-card:hover .card-media img,
.tip:hover .card-media img,
.app-card:hover .card-media img { transform: scale(1.04); }

/* 预约参观：占位地图改为实拍图 */
.map-card--photo {
  background: #E4EDF6; padding: 0; min-height: 320px;
}
.map-card--photo img {
  width: 100%; height: 100%; min-height: 320px; object-fit: cover; display: block;
  border-radius: var(--r-lg);
}

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .hero__inner { grid-template-columns: 1fr; gap: 36px; }
  .adv-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .product-grid { grid-template-columns: 1fr; }
  .split, .contact-wrap { grid-template-columns: 1fr; }
  .app-grid { grid-template-columns: repeat(2, 1fr); }
  .tips { grid-template-columns: repeat(2, 1fr); }
  .gallery { grid-template-columns: repeat(2, 1fr); }
  .footer__top { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 680px) {
  .section { padding: 60px 0; }
  .hero__arrows { display: none; }
  .hero__nav { bottom: 22px; }
  .hero__nav-inner { gap: 14px; }
  .nav { display: none; position: absolute; top: var(--header-h); left: 0; right: 0; flex-direction: column; background: #fff; box-shadow: 0 10px 24px rgba(16,32,52,.08); padding: 10px 16px; gap: 2px; }
  .nav.open { display: flex; }
  .nav a { padding: 12px 10px; }
  .nav-toggle { display: block; }
  .hero h1 { font-size: 32px; }
  .feature-grid { grid-template-columns: 1fr; }
  .app-grid { grid-template-columns: 1fr; }
  .tips { grid-template-columns: 1fr; }
  .gallery { grid-template-columns: 1fr; }
  .footer__top { grid-template-columns: 1fr; }
  .section-title { font-size: 25px; }
  .spec-table { font-size: 13px; }
  .spec-table th, .spec-table td { padding: 12px 10px; }
}