/* ==========================================================================
   FORTIS · 天津东铖金属科技有限公司
   工业 B2B 官网样式表
   ========================================================================== */

/* --- Reset ---------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, p, figure, blockquote, dl, dd, ul, ol { margin: 0; }
ul[class], ol[class] { list-style: none; padding: 0; }
/* hidden 属性必须能压过组件自身的 display */
[hidden] { display: none !important; }
img, svg { display: block; max-width: 100%; }
button, input, textarea, select { font: inherit; color: inherit; }
a { color: inherit; text-decoration: none; }

/* --- Tokens --------------------------------------------------------------- */
:root {
  --ink:        #14171a;
  --ink-soft:   #2b3136;
  --ink-mute:   #6d7883;
  --paper:      #f5f4f1;
  --paper-2:    #eceae5;
  --white:      #ffffff;
  --accent:     #c9501f;
  --accent-ink: #a8410f;
  --steel:      #8b97a3;
  --line:       #ddd9d2;
  --line-dark:  rgba(255,255,255,.14);

  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
          "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: "SF Mono", ui-monospace, "JetBrains Mono", Menlo, Consolas, monospace;

  --pad: clamp(20px, 5vw, 72px);
  --maxw: 1320px;
  --nav-h: 68px;
  --ease: cubic-bezier(.22,.61,.36,1);
}

/* --- Base ----------------------------------------------------------------- */
body {
  font-family: var(--font);
  background: var(--paper);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
::selection { background: var(--ink); color: var(--paper); }

.wrap { max-width: var(--maxw); margin-inline: auto; padding-inline: var(--pad); }
.eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  display: flex; align-items: center; gap: 10px;
}
.eyebrow::before {
  content: ""; width: 22px; height: 1px; background: var(--accent); flex: none;
}
h1, h2, h3, h4 { font-weight: 600; line-height: 1.14; letter-spacing: -.02em; }
.num { font-family: var(--mono); font-variant-numeric: tabular-nums; letter-spacing: -.01em; }

/* --- Nav ------------------------------------------------------------------ */
.nav {
  position: fixed; inset: 0 0 auto 0; height: var(--nav-h); z-index: 90;
  display: flex; align-items: center;
  background: rgba(245,244,241,.72);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s, background .3s;
}
.nav.is-stuck { border-bottom-color: var(--line); background: rgba(245,244,241,.94); }
.nav__inner {
  display: flex; align-items: center; gap: 32px;
  width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--pad);
}
.brand { display: flex; align-items: baseline; gap: 10px; flex: none; }
.brand__mark {
  font-weight: 700; font-size: 19px; letter-spacing: .22em; line-height: 1;
}
.brand__cn {
  font-size: 11px; color: var(--ink-mute); letter-spacing: .06em;
  border-left: 1px solid var(--line); padding-left: 10px;
}
.nav__links { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav__links a {
  position: relative; padding: 8px 13px; font-size: 14px; color: var(--ink-soft);
  border-radius: 2px; transition: color .2s; white-space: nowrap;
}
.nav__links a::after {
  content: ""; position: absolute; left: 13px; right: 13px; bottom: 3px; height: 1.5px;
  background: var(--accent); transform: scaleX(0); transform-origin: left;
  transition: transform .3s var(--ease);
}
.nav__links a:hover { color: var(--ink); }
.nav__links a:hover::after,
.nav__links a.is-active::after { transform: scaleX(1); }
.nav__links a.is-active { color: var(--ink); font-weight: 500; }

.lang {
  display: flex; align-items: center; border: 1px solid var(--line);
  border-radius: 999px; padding: 2px; background: var(--white); flex: none;
}
.lang button {
  border: 0; background: transparent; cursor: pointer;
  font-family: var(--mono); font-size: 11px; letter-spacing: .06em;
  padding: 4px 10px; border-radius: 999px; color: var(--ink-mute);
  transition: background .2s, color .2s;
}
.lang button.is-on { background: var(--ink); color: #fff; }

.nav__burger {
  display: none; border: 0; background: none; cursor: pointer;
  width: 40px; height: 40px; padding: 10px; margin-left: 4px;
}
.nav__burger span {
  display: block; height: 1.5px; background: var(--ink); margin: 5px 0;
  transition: transform .3s, opacity .2s;
}
.nav.is-open .nav__burger span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav.is-open .nav__burger span:nth-child(2) { opacity: 0; }
.nav.is-open .nav__burger span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* --- Hero ----------------------------------------------------------------- */
.hero {
  position: relative; padding-top: calc(var(--nav-h) + clamp(64px, 11vh, 132px));
  padding-bottom: clamp(48px, 8vh, 96px); overflow: hidden;
}
.hero__grid {
  display: grid; grid-template-columns: minmax(0,1.15fr) minmax(0,.85fr);
  gap: clamp(32px, 5vw, 80px); align-items: end;
}
.hero h1 {
  font-size: clamp(34px, 5.6vw, 74px);
  line-height: 1.04; letter-spacing: -.035em; font-weight: 600;
  margin-top: 22px;
}
.hero h1 em { font-style: normal; color: var(--accent); }
.hero__lede {
  margin-top: 26px; font-size: clamp(15px, 1.15vw, 17.5px);
  color: var(--ink-soft); max-width: 46ch; line-height: 1.72;
}
.hero__aside { padding-bottom: 6px; }
.hero__aside p {
  font-size: 13.5px; color: var(--ink-mute); line-height: 1.8;
  border-left: 1px solid var(--line); padding-left: 16px;
}

/* 数据条 */
.stats {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--line); margin-top: clamp(48px, 7vh, 84px);
}
.stats div {
  padding: 22px 0 0; border-right: 1px solid var(--line);
}
.stats div:first-child { padding-left: 0; }
.stats div:last-child { border-right: 0; }
.stats div:not(:first-child) { padding-left: clamp(14px, 2vw, 28px); }
.stats b {
  display: block; font-family: var(--mono); font-weight: 500;
  font-size: clamp(24px, 3vw, 38px); letter-spacing: -.03em; line-height: 1;
}
.stats b small { font-size: .54em; margin-left: 3px; color: var(--ink-soft); letter-spacing: 0; font-weight: 400; }
.stats span {
  display: block; margin-top: 9px; font-size: 11.5px;
  color: var(--ink-mute); letter-spacing: .04em;
}

/* 锚点定位时给固定导航让位 */
section[id] { scroll-margin-top: calc(var(--nav-h) + 20px); }

/* --- Section shell -------------------------------------------------------- */
.section { padding-block: clamp(56px, 9vh, 116px); }
.section--tight { padding-block: clamp(40px, 6vh, 72px); }
.section--dark { background: var(--ink); color: var(--paper); }
.section--dark .eyebrow { color: rgba(255,255,255,.55); }
.section--dark .section__lede { color: rgba(255,255,255,.66); }
.section--paper2 { background: var(--paper-2); }

.section__head {
  display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1fr);
  gap: clamp(24px, 4vw, 64px); align-items: end;
  margin-bottom: clamp(32px, 5vh, 56px);
}
.section__head h2 {
  font-size: clamp(26px, 3.4vw, 44px); letter-spacing: -.03em; margin-top: 18px;
}
.section__lede { font-size: 15px; color: var(--ink-mute); line-height: 1.75; max-width: 44ch; }

/* --- Cards: capability ---------------------------------------------------- */
.caps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); }
.cap {
  background: var(--paper); padding: clamp(22px, 2.4vw, 34px);
  display: flex; flex-direction: column;
  transition: background .35s var(--ease);
}
.cap:hover { background: var(--white); }
.cap__no { font-family: var(--mono); font-size: 11px; color: var(--accent); letter-spacing: .1em; }
.cap h3 { font-size: 19px; margin-top: 18px; letter-spacing: -.01em; }
.cap p { font-size: 13.5px; color: var(--ink-mute); line-height: 1.72; margin-top: 10px; }
.cap ul { list-style: none; margin: 18px 0 0; padding: 16px 0 0; border-top: 1px solid var(--line); display: flex; flex-wrap: wrap; gap: 6px; }
.cap li {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .04em;
  border: 1px solid var(--line); padding: 3px 8px; color: var(--ink-soft); border-radius: 2px;
}
.cap__icon { margin-top: 20px; opacity: .55; }
.cap:hover .cap__icon { opacity: 1; }

/* --- Product table / catalog --------------------------------------------- */
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 28px; }
.filters button {
  border: 1px solid var(--line); background: transparent; cursor: pointer;
  padding: 7px 15px; border-radius: 999px; font-size: 13px; color: var(--ink-soft);
  transition: all .22s;
}
.filters button:hover { border-color: var(--ink-mute); }
.filters button.is-on { background: var(--ink); border-color: var(--ink); color: #fff; }

.catalog { border-top: 1px solid var(--line); }
.row {
  display: grid;
  grid-template-columns: 88px minmax(0,1.5fr) minmax(0,1.6fr) 150px;
  gap: clamp(14px, 2.4vw, 40px);
  padding: 22px 8px; border-bottom: 1px solid var(--line);
  align-items: start; transition: background .25s;
}
.row:hover { background: rgba(255,255,255,.66); }
.row__code { font-family: var(--mono); font-size: 12px; color: var(--accent); letter-spacing: .04em; padding-top: 3px; }
.row__name { font-size: 16.5px; font-weight: 550; letter-spacing: -.01em; }
.row__name small { display: block; font-weight: 400; font-size: 12px; color: var(--ink-mute); font-family: var(--mono); margin-top: 4px; letter-spacing: .03em; }
.row__desc { font-size: 13.5px; color: var(--ink-mute); line-height: 1.7; }
.row__spec { font-family: var(--mono); font-size: 11.5px; color: var(--ink-soft); line-height: 1.6; }
.row__spec em { display: block; color: var(--ink-mute); font-style: normal; font-size: 10.5px; letter-spacing: .04em; }

/* --- Projects ------------------------------------------------------------- */
.proj-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: clamp(16px, 2.4vw, 28px); }
.proj {
  position: relative; background: var(--white); border: 1px solid var(--line);
  overflow: hidden; display: flex; flex-direction: column;
  transition: transform .4s var(--ease), box-shadow .4s var(--ease);
}
.proj:hover { transform: translateY(-3px); box-shadow: 0 18px 40px -24px rgba(20,23,26,.28); }
.proj__art {
  background-color: #14171a;
  background-image:
    linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 24px 24px;
  background-position: center center;
  aspect-ratio: 16/9; max-height: 290px; position: relative; overflow: hidden;
}
.proj__art svg { width: 100%; height: 100%; }
.proj__tag {
  position: absolute; top: 14px; left: 14px; z-index: 2;
  font-family: var(--mono); font-size: 10px; letter-spacing: .1em;
  background: rgba(255,255,255,.14); color: #fff; padding: 4px 9px;
  backdrop-filter: blur(6px); border-radius: 2px;
}
.proj__body { padding: clamp(18px, 2vw, 26px); }
.proj h3 { font-size: 18px; letter-spacing: -.01em; }
.proj__meta { display: flex; gap: 18px; margin-top: 12px; flex-wrap: wrap; }
.proj__meta span { font-family: var(--mono); font-size: 11px; color: var(--ink-mute); letter-spacing: .03em; }
.proj p { font-size: 13.5px; color: var(--ink-mute); line-height: 1.7; margin-top: 12px; }

/* --- 统计条（区块内嵌，去掉首屏的大上间距） -------------------------------- */
.stats--flat { margin-top: 0; }

/* --- 分柜明细表（深色区） -------------------------------------------------- */
.tbl-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.spec { width: 100%; border-collapse: collapse; font-family: var(--mono); font-size: 11.5px; }
.spec caption {
  text-align: left; font-size: 10.5px; letter-spacing: .1em; text-transform: uppercase;
  color: rgba(255,255,255,.42); padding-bottom: 14px;
}
.spec th {
  text-align: right; font-weight: 400; font-size: 10px; letter-spacing: .08em;
  text-transform: uppercase; color: rgba(255,255,255,.42);
  padding: 0 0 9px; border-bottom: 1px solid var(--line-dark); white-space: nowrap;
}
.spec td {
  text-align: right; padding: 11px 0; color: rgba(255,255,255,.84);
  border-bottom: 1px solid var(--line-dark); white-space: nowrap;
}
.spec th:first-child, .spec td:first-child { text-align: left; }
.spec th:not(:first-child), .spec td:not(:first-child) { padding-left: 20px; }
.spec tr:last-child td {
  border-bottom: 0; border-top: 1px solid rgba(255,255,255,.26);
  color: #fff; font-weight: 600; padding-top: 13px;
}

/* --- Split / about -------------------------------------------------------- */
.split { display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1fr); gap: clamp(28px, 5vw, 76px); align-items: start; }
.prose p { font-size: 15px; line-height: 1.85; color: var(--ink-soft); margin-bottom: 18px; max-width: 56ch; }
.prose p:last-child { margin-bottom: 0; }
.prose strong { font-weight: 600; color: var(--ink); }

.factlist { border-top: 1px solid var(--line); }
.factlist div {
  display: grid; grid-template-columns: 120px 1fr; gap: 16px;
  padding: 15px 0; border-bottom: 1px solid var(--line); font-size: 13.5px;
}
.factlist dt, .factlist div > span:first-child {
  font-family: var(--mono); font-size: 11px; letter-spacing: .08em;
  color: var(--ink-mute); text-transform: uppercase; padding-top: 2px;
}
.section--dark .factlist { border-color: var(--line-dark); }
.section--dark .factlist div { border-color: var(--line-dark); color: rgba(255,255,255,.9); }
.section--dark .factlist div > span:first-child { color: rgba(255,255,255,.45); }

/* --- Process / timeline --------------------------------------------------- */
.steps { display: grid; grid-template-columns: repeat(5, 1fr); gap: 1px; background: var(--line-dark); border-block: 1px solid var(--line-dark); }
.steps--3 { grid-template-columns: repeat(3, 1fr); }
.steps--2 { grid-template-columns: repeat(2, 1fr); }
.step { padding: 26px 20px 30px; position: relative; background: var(--ink); }
.step__no { font-family: var(--mono); font-size: 11px; color: var(--accent); letter-spacing: .1em; }
.step h4 { font-size: 15px; margin-top: 14px; color: var(--paper); }
.step p { font-size: 12.5px; color: rgba(255,255,255,.55); line-height: 1.65; margin-top: 8px; }

/* --- CTA ------------------------------------------------------------------ */
.cta {
  display: grid; grid-template-columns: minmax(0,1.2fr) minmax(0,.8fr);
  gap: clamp(24px,4vw,64px); align-items: center;
  padding-block: clamp(48px, 7vh, 88px);
  border-top: 1px solid var(--line);
}
.cta h2 { font-size: clamp(24px, 3vw, 38px); letter-spacing: -.03em; }
.cta p { font-size: 14px; color: var(--ink-mute); margin-top: 14px; max-width: 44ch; line-height: 1.75; }
.cta__actions { display: flex; gap: 12px; flex-wrap: wrap; justify-content: flex-end; }

.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 13px 24px; font-size: 14px; font-weight: 500;
  border: 1px solid var(--ink); border-radius: 2px; cursor: pointer;
  transition: all .28s var(--ease); white-space: nowrap;
}
.btn--solid { background: var(--ink); color: var(--paper); }
.btn--solid:hover { background: var(--accent); border-color: var(--accent); }
.btn--ghost { background: transparent; color: var(--ink); }
.btn--ghost:hover { background: var(--ink); color: var(--paper); }
.btn svg { transition: transform .3s var(--ease); }
.btn:hover svg { transform: translateX(3px); }

/* --- Footer --------------------------------------------------------------- */
.footer { background: var(--ink); color: rgba(255,255,255,.62); padding-block: clamp(44px, 6vh, 72px) 28px; font-size: 13px; }
.footer__top {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: clamp(24px, 4vw, 56px); padding-bottom: 40px;
  border-bottom: 1px solid var(--line-dark);
}
.footer h4 { color: #fff; font-size: 11px; font-family: var(--mono); letter-spacing: .14em; text-transform: uppercase; margin-bottom: 16px; font-weight: 500; }
.footer ul { display: grid; gap: 9px; list-style: none; margin: 0; padding: 0; }
.footer a:hover { color: #fff; }
.footer__brand .brand__mark { color: #fff; font-size: 20px; }
.footer__brand p { margin-top: 14px; line-height: 1.75; max-width: 32ch; }
.footer__bottom {
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  padding-top: 22px; font-family: var(--mono); font-size: 10.5px; letter-spacing: .05em;
  color: rgba(255,255,255,.38);
}

/* 页脚右下角：标语 + 后台入口 */
.footer__end { display: inline-flex; align-items: center; gap: 16px; flex-wrap: wrap; }

.admin-link {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 10px 5px 9px; border-radius: 2px; text-decoration: none;
  border: 1px solid rgba(255,255,255,.15);
  color: rgba(255,255,255,.44); letter-spacing: .1em;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}
.admin-link svg { width: 10px; height: 10px; flex: 0 0 auto; opacity: .75; }
.admin-link:hover {
  color: #fff; border-color: rgba(201,80,31,.85);
  background: rgba(201,80,31,.14);
}
.admin-link:hover svg { opacity: 1; }


/* --- Inner page hero ------------------------------------------------------ */
.pagehead {
  padding-top: calc(var(--nav-h) + clamp(48px, 8vh, 88px));
  padding-bottom: clamp(32px, 5vh, 56px);
  border-bottom: 1px solid var(--line);
}
.pagehead h1 { font-size: clamp(30px, 4.4vw, 58px); letter-spacing: -.035em; margin-top: 20px; }
.pagehead p { font-size: 15px; color: var(--ink-mute); margin-top: 18px; max-width: 60ch; line-height: 1.75; }
.crumb { font-family: var(--mono); font-size: 11px; color: var(--ink-mute); letter-spacing: .08em; margin-top: 26px; }
.crumb a:hover { color: var(--accent); }

/* --- Contact form --------------------------------------------------------- */
.form { display: grid; gap: 18px; }
.form__row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { display: grid; gap: 7px; }
.field label {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .1em;
  text-transform: uppercase; color: var(--ink-mute);
}
.field input, .field textarea, .field select {
  border: 1px solid var(--line); background: var(--white);
  padding: 12px 14px; font-size: 14px; border-radius: 2px;
  transition: border-color .2s, box-shadow .2s; width: 100%;
}
/* 下拉框：去掉系统箭头，换细线三角，和整体线条风格一致 */
.field select {
  appearance: none; -webkit-appearance: none;
  padding-right: 40px; cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8' fill='none' stroke='%236d7883' stroke-width='1.2'%3E%3Cpath d='M1 1.5 6 6.5 11 1.5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
}
.field textarea { resize: vertical; min-height: 120px; }
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(201,80,31,.1);
}
.form__note { font-size: 11.5px; color: var(--ink-mute); line-height: 1.7; }
.form__ok {
  display: none; padding: 14px 16px; background: #eef5ef; border: 1px solid #c6ddc9;
  color: #2f5d38; font-size: 13.5px; border-radius: 2px;
}
.form__ok.is-on { display: block; }

.contact-grid { display: grid; grid-template-columns: minmax(0,1.1fr) minmax(0,.9fr); gap: clamp(32px, 5vw, 72px); }
.contact-card { background: var(--paper-2); padding: clamp(22px, 2.6vw, 32px); }
.contact-card h3 { font-size: 15px; margin-bottom: 16px; }
.contact-card dl { display: grid; gap: 15px; }
.contact-card dt { font-family: var(--mono); font-size: 10px; letter-spacing: .1em; color: var(--ink-mute); text-transform: uppercase; }
.contact-card dd { font-size: 14px; margin-top: 3px; color: var(--ink-soft); }
.contact-card dd a:hover { color: var(--accent); }

/* --- Internal gate -------------------------------------------------------- */
.gate {
  min-height: 72vh; display: grid; place-items: center;
  padding: calc(var(--nav-h) + 40px) var(--pad) 60px;
}
.gate__box {
  width: min(420px, 100%); background: var(--white); border: 1px solid var(--line);
  padding: clamp(26px, 4vw, 40px);
}
.gate__box h1 { font-size: 22px; margin-top: 6px; }
.gate__box p { font-size: 13.5px; color: var(--ink-mute); margin-top: 10px; line-height: 1.7; }
.gate__box form { margin-top: 24px; display: grid; gap: 14px; }
.gate__err { color: var(--accent); font-size: 12.5px; min-height: 18px; }

.intro-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); }
.intro-card {
  background: var(--paper); padding: 24px; transition: background .3s;
  display: flex; flex-direction: column; gap: 8px;
}
.intro-card:hover { background: var(--white); }
.intro-card h3 { font-size: 15.5px; }
.intro-card p { font-size: 12.5px; color: var(--ink-mute); line-height: 1.65; }
.intro-card span.k { font-family: var(--mono); font-size: 10px; color: var(--accent); letter-spacing: .1em; }

/* --- 双语切换：中文为默认，英文整块替换 ---------------------------------- */
html[lang="en"] .zh { display: none !important; }
html[lang="en"] .en { display: revert; }
html:not([lang="en"]) .en { display: none !important; }

/* --- Reveal animation ----------------------------------------------------- */
.rv { opacity: 0; transform: translateY(18px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.rv.is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .rv { opacity: 1; transform: none; transition: none; }
  * { animation-duration: .01ms !important; }
}

/* --- Responsive ----------------------------------------------------------- */
@media (max-width: 1040px) {
  .hero__grid { grid-template-columns: 1fr; align-items: start; }
  .hero__aside { display: none; }
  .section__head { grid-template-columns: 1fr; gap: 16px; }
  .caps { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  /* 奇数个步骤在双列下会把最后一格空出来，让它跨满整行 */
  .steps > .step:last-child:nth-child(odd) { grid-column: 1 / -1; }
  .steps--3 { grid-template-columns: 1fr; }
  .proj-grid { grid-template-columns: 1fr; }
  .split, .contact-grid { grid-template-columns: 1fr; }
  .cta { grid-template-columns: 1fr; }
  .cta__actions { justify-content: flex-start; }
  .footer__top { grid-template-columns: 1fr 1fr; }
  .intro-grid { grid-template-columns: repeat(2, 1fr); }
}

/* --- 平板及以下：导航切汉堡 ------------------------------------------------ */
@media (max-width: 1000px) {
  .brand__cn { display: none; }
  .nav__links {
    position: fixed; inset: var(--nav-h) 0 auto 0;
    background: var(--paper); border-bottom: 1px solid var(--line);
    flex-direction: column; align-items: stretch; gap: 0; padding: 8px var(--pad) 20px;
    transform: translateY(-120%); transition: transform .38s var(--ease);
    box-shadow: 0 20px 30px -24px rgba(20,23,26,.3);
  }
  .nav.is-open .nav__links { transform: none; }
  .nav__links a { padding: 13px 2px; border-bottom: 1px solid var(--line); font-size: 15px; }
  .nav__links a::after { display: none; }
  .nav__burger { display: block; margin-left: 10px; }
  .lang { margin-left: auto; }
  .hero { padding-bottom: clamp(36px, 5vh, 64px); }
}

@media (max-width: 760px) {
  :root { --nav-h: 60px; }
  .stats { grid-template-columns: 1fr 1fr; }
  .stats div { padding: 18px 0 4px; }
  .stats div:nth-child(2) { border-right: 0; }
  .stats div:nth-child(3) { padding-left: 0; }
  .stats div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .stats div:nth-child(n+3) { padding-top: 18px; }
  .caps { grid-template-columns: 1fr; }
  .cap { min-height: 0; }
  .steps, .steps--2 { grid-template-columns: 1fr; }
  .row { grid-template-columns: 62px 1fr; gap: 12px; padding: 18px 4px; }
  .row__desc { grid-column: 2; }
  .row__spec { grid-column: 2; display: flex; gap: 14px; flex-wrap: wrap; }
  .row__spec em { display: inline; }
  .form__row { grid-template-columns: 1fr; }
  .footer__top { grid-template-columns: 1fr; gap: 28px; }
  .intro-grid { grid-template-columns: 1fr; }
  .pagehead { padding-top: calc(var(--nav-h) + 40px); }
}