/* ============================================================
   KESEMI 芯片智造 IDM 企业官网
   成都北亿纤通科技有限公司
   ============================================================ */

:root {
  --c-navy-900: #060f1f;
  --c-navy-800: #0a1b33;
  --c-navy-700: #0f2547;
  --c-navy-600: #16325e;
  --c-blue: #1e5eff;
  --c-cyan: #29e0c3;
  --c-cyan-soft: rgba(41, 224, 195, 0.12);
  --c-ink: #0e1b2c;
  --c-body: #4d5d71;
  --c-muted: #7b8a9c;
  --c-line: #e4ebf3;
  --c-bg: #ffffff;
  --c-bg-soft: #f4f8fc;
  --c-bg-deep: #f0f5fb;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow-sm: 0 4px 14px rgba(14, 27, 44, 0.06);
  --shadow-md: 0 14px 38px rgba(14, 27, 44, 0.10);
  --shadow-lg: 0 24px 64px rgba(10, 27, 51, 0.18);
  --header-h: 72px;
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC",
          "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 12px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  color: var(--c-ink);
  background: var(--c-bg);
  line-height: 1.7;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { font-family: inherit; cursor: pointer; }

.container {
  width: min(1180px, 100% - 48px);
  margin-inline: auto;
}

.section { padding: 96px 0; }

.section-head { max-width: 720px; margin: 0 auto 56px; text-align: center; }
.section-head .eyebrow { justify-content: center; }
.section-head h2 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: 0.5px;
  margin: 14px 0 12px;
  color: var(--c-ink);
}
.section-head .section-sub { color: var(--c-body); font-size: 16px; }
.section-head.light h2 { color: #fff; }
.section-head.light .section-sub { color: rgba(255, 255, 255, 0.72); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 2.5px;
  color: var(--c-blue);
  text-transform: uppercase;
}

.grad-text {
  background: linear-gradient(100deg, var(--c-cyan) 10%, var(--c-blue) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;
  white-space: nowrap;
}
.btn-primary {
  color: #fff;
  background: linear-gradient(100deg, var(--c-blue), #3a7bff);
  box-shadow: 0 10px 26px rgba(30, 94, 255, 0.32);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 16px 34px rgba(30, 94, 255, 0.42); }
.btn-ghost {
  color: #d9e8ff;
  border-color: rgba(217, 232, 255, 0.42);
  background: rgba(255, 255, 255, 0.04);
}
.btn-ghost:hover { background: rgba(255, 255, 255, 0.12); transform: translateY(-2px); }
.btn-sm { padding: 9px 18px; font-size: 14px; }
.btn-block { width: 100%; }

/* ---------- 顶栏 ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--header-h);
  z-index: 100;
  background: rgba(6, 15, 31, 0.72);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  transition: background 0.3s ease, box-shadow 0.3s ease;
}
.site-header.scrolled {
  background: rgba(6, 15, 31, 0.92);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.28);
}
.header-inner {
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 28px;
}

.brand { display: inline-flex; align-items: center; gap: 12px; }
.brand-mark { flex: none; }
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-text strong {
  color: #fff;
  font-size: 19px;
  letter-spacing: 2.5px;
  font-weight: 700;
}
.brand-text small {
  color: rgba(255, 255, 255, 0.62);
  font-size: 11px;
  letter-spacing: 0.6px;
  margin-top: 3px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}
.nav-link {
  position: relative;
  padding: 9px 13px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 14.5px;
  border-radius: 8px;
  transition: color 0.2s ease, background 0.2s ease;
}
.nav-link:hover { color: #fff; background: rgba(255, 255, 255, 0.08); }
.nav-link.active { color: var(--c-cyan); }
.nav-link.active::after {
  content: "";
  position: absolute;
  left: 14px; right: 14px; bottom: 4px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-blue));
}

.header-cta { margin-left: 6px; }
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 10px;
  background: transparent;
  border: 0;
}
.nav-toggle span {
  width: 22px; height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--header-h) + 56px) 0 72px;
  background:
    radial-gradient(1200px 700px at 78% -10%, rgba(30, 94, 255, 0.24), transparent 60%),
    radial-gradient(900px 600px at 8% 110%, rgba(41, 224, 195, 0.14), transparent 55%),
    linear-gradient(180deg, var(--c-navy-900), var(--c-navy-800) 55%, #0b1e3a);
  color: #fff;
  overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.045) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(ellipse 90% 75% at 50% 40%, #000 30%, transparent 75%);
  mask-image: radial-gradient(ellipse 90% 75% at 50% 40%, #000 30%, transparent 75%);
}
.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.5;
}
.hero-glow-a { width: 420px; height: 420px; left: -120px; top: 12%; background: rgba(30, 94, 255, 0.42); }
.hero-glow-b { width: 380px; height: 380px; right: -100px; bottom: 4%; background: rgba(41, 224, 195, 0.30); }
.hero-wafer {
  position: absolute;
  right: -130px;
  top: 50%;
  width: 540px;
  transform: translateY(-50%);
  opacity: 0.55;
  animation: wafer-spin 90s linear infinite;
}
@keyframes wafer-spin {
  to { transform: translateY(-50%) rotate(360deg); }
}

.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items: center;
}
.hero-copy h1 {
  font-size: clamp(34px, 5vw, 56px);
  line-height: 1.22;
  font-weight: 800;
  letter-spacing: 0.5px;
  margin: 18px 0 20px;
}
.hero-sub {
  max-width: 560px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 17px;
  line-height: 1.9;
  margin-bottom: 30px;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 32px; }
.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
}
.hero-points li {
  position: relative;
  padding-left: 20px;
  color: rgba(255, 255, 255, 0.66);
  font-size: 14px;
}
.hero-points li::before {
  content: "";
  position: absolute;
  left: 0; top: 9px;
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--c-cyan);
  box-shadow: 0 0 10px var(--c-cyan);
}
.pulse-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--c-cyan);
  box-shadow: 0 0 0 0 rgba(41, 224, 195, 0.6);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(41, 224, 195, 0.55); }
  70% { box-shadow: 0 0 0 10px rgba(41, 224, 195, 0); }
  100% { box-shadow: 0 0 0 0 rgba(41, 224, 195, 0); }
}

.flow-card {
  position: relative;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 26px 26px 12px;
  box-shadow: var(--shadow-lg);
}
.flow-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}
.flow-head strong { font-size: 17px; letter-spacing: 0.5px; }
.flow-tag {
  font-size: 12px;
  font-weight: 600;
  color: var(--c-cyan);
  background: var(--c-cyan-soft);
  border: 1px solid rgba(41, 224, 195, 0.32);
  padding: 4px 10px;
  border-radius: 999px;
}
.flow-steps { display: grid; grid-template-columns: 1fr 1fr; gap: 4px 18px; }
.flow-step {
  display: flex;
  gap: 14px;
  padding: 14px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}
.step-no {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--c-cyan);
  padding-top: 3px;
}
.flow-step h3 { font-size: 15px; color: #fff; margin-bottom: 2px; }
.flow-step p { font-size: 12.5px; color: rgba(255, 255, 255, 0.58); line-height: 1.6; }

/* ---------- 徽标条 ---------- */
.strip {
  background: var(--c-bg);
  border-bottom: 1px solid var(--c-line);
}
.strip-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  padding: 30px 0;
}
.strip-item {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-left: 22px;
  border-left: 3px solid transparent;
  border-image: linear-gradient(180deg, var(--c-cyan), var(--c-blue)) 1;
}
.strip-item strong {
  font-size: 30px;
  font-weight: 800;
  background: linear-gradient(100deg, var(--c-blue), #3a7bff);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  letter-spacing: 0.5px;
}
.strip-item span { color: var(--c-body); font-size: 14px; }

/* ---------- 一站式服务 ---------- */
.services { background: var(--c-bg); }
.service-rail {
  display: flex;
  align-items: stretch;
  justify-content: center;
  flex-wrap: wrap;
  gap: 18px;
}
.service-node {
  flex: 1 1 210px;
  max-width: 250px;
  padding: 34px 26px 30px;
  border-radius: var(--radius);
  background: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  text-align: center;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.service-node:hover {
  transform: translateY(-6px);
  border-color: rgba(30, 94, 255, 0.45);
  box-shadow: var(--shadow-md);
}
.node-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 58px; height: 58px;
  border-radius: 16px;
  font-size: 24px;
  color: #fff;
  background: linear-gradient(135deg, var(--c-blue), #3a7bff);
  box-shadow: 0 10px 22px rgba(30, 94, 255, 0.30);
  margin-bottom: 18px;
}
.service-node h3 { font-size: 18px; margin-bottom: 8px; }
.service-node p { font-size: 13.5px; color: var(--c-body); line-height: 1.7; }
.rail-arrow {
  align-self: center;
  color: var(--c-blue);
  font-size: 22px;
  font-weight: 700;
  opacity: 0.55;
  flex: none;
}

/* ---------- 四大业务 ---------- */
.business { background: var(--c-bg-soft); }
.biz-card {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0;
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: 20px;
  overflow: hidden;
  margin-bottom: 26px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s ease, transform 0.3s ease;
}
.biz-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.biz-visual {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 44px 24px;
  color: #fff;
  background:
    radial-gradient(120% 100% at 20% 0%, rgba(41, 224, 195, 0.25), transparent 55%),
    linear-gradient(150deg, var(--c-navy-700), var(--c-navy-900));
  position: relative;
  overflow: hidden;
}
.biz-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
  background-size: 30px 30px;
  -webkit-mask-image: radial-gradient(ellipse 90% 90% at 50% 50%, #000 20%, transparent 80%);
  mask-image: radial-gradient(ellipse 90% 90% at 50% 50%, #000 20%, transparent 80%);
  pointer-events: none;
}
.biz-icon {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px; height: 64px;
  border-radius: 18px;
  font-size: 28px;
  color: var(--c-cyan);
  background: rgba(41, 224, 195, 0.10);
  border: 1px solid rgba(41, 224, 195, 0.35);
  margin-bottom: 8px;
}
.biz-visual h3 { position: relative; font-size: 24px; letter-spacing: 1px; }
.biz-visual p { position: relative; font-size: 12px; letter-spacing: 2px; text-transform: uppercase; color: rgba(255, 255, 255, 0.55); }
.biz-body { padding: 38px 42px; }
.biz-body h4 { font-size: 21px; margin-bottom: 12px; color: var(--c-ink); }
.biz-body > p { color: var(--c-body); font-size: 15px; margin-bottom: 18px; max-width: 640px; }
.biz-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px 24px;
}
.biz-list li {
  position: relative;
  padding-left: 22px;
  font-size: 14px;
  color: var(--c-body);
  line-height: 1.7;
}
.biz-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 10px;
  width: 8px; height: 8px;
  border-radius: 2px;
  background: linear-gradient(135deg, var(--c-cyan), var(--c-blue));
}

/* ---------- IDM 模式 ---------- */
.idm {
  background:
    radial-gradient(1100px 600px at 90% 0%, rgba(30, 94, 255, 0.22), transparent 60%),
    radial-gradient(900px 600px at 0% 100%, rgba(41, 224, 195, 0.12), transparent 55%),
    linear-gradient(180deg, var(--c-navy-900), #0a1d3c);
  color: #fff;
}
.idm-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
}
.idm-card {
  position: relative;
  padding: 30px 24px 26px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
  transition: transform 0.25s ease, border-color 0.25s ease, background 0.25s ease;
  overflow: hidden;
}
.idm-card:hover { transform: translateY(-6px); border-color: rgba(41, 224, 195, 0.5); background: rgba(255, 255, 255, 0.08); }
.idm-no {
  position: absolute;
  top: 14px; right: 18px;
  font-family: var(--font-mono);
  font-size: 34px;
  font-weight: 800;
  color: rgba(255, 255, 255, 0.08);
}
.idm-card h3 { font-size: 19px; margin: 6px 0 10px; }
.idm-card p { font-size: 14px; color: rgba(255, 255, 255, 0.68); line-height: 1.8; }

/* ---------- 应用领域 ---------- */
.applications { background: var(--c-bg); }
.app-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.app-card {
  padding: 26px 22px;
  border-radius: var(--radius);
  background: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  text-align: center;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.app-card:hover {
  transform: translateY(-5px);
  border-color: rgba(30, 94, 255, 0.4);
  box-shadow: var(--shadow-md);
}
.app-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px; height: 48px;
  border-radius: 14px;
  font-size: 20px;
  color: var(--c-blue);
  background: rgba(30, 94, 255, 0.10);
  margin-bottom: 14px;
}
.app-card h3 { font-size: 16px; margin-bottom: 6px; }
.app-card p { font-size: 13px; color: var(--c-muted); }

/* ---------- 质量体系 ---------- */
.quality { background: var(--c-bg-soft); }
.quality-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.quality-card {
  padding: 30px 26px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--c-line);
  box-shadow: var(--shadow-sm);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.quality-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-md); }
.quality-card h3 {
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--c-blue);
  margin-bottom: 10px;
  letter-spacing: 0.5px;
}
.quality-card p { font-size: 14px; color: var(--c-body); }

/* ---------- 关于我们 ---------- */
.about { background: var(--c-bg); }
.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 44px;
  align-items: start;
}
.about-text p { color: var(--c-body); font-size: 15.5px; margin-bottom: 16px; line-height: 2; }
.about-text strong { color: var(--c-ink); }
.about-list { margin-top: 22px; }
.about-list li {
  display: flex;
  gap: 10px;
  align-items: baseline;
  color: var(--c-body);
  font-size: 14.5px;
  padding: 8px 0;
}
.about-list li span { color: var(--c-cyan); font-weight: 800; }
.about-card {
  border-radius: 18px;
  overflow: hidden;
  border: 1px solid var(--c-line);
  box-shadow: var(--shadow-md);
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(41, 224, 195, 0.10), transparent 55%),
    #fff;
}
.about-card-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 20px 24px;
  border-bottom: 1px solid var(--c-line);
}
.about-card-item:last-child { border-bottom: 0; }
.about-key { font-size: 13px; color: var(--c-muted); flex: none; }
.about-card-item strong { font-size: 15px; color: var(--c-ink); text-align: right; }

/* ---------- 联系我们 ---------- */
.contact {
  background:
    radial-gradient(1000px 520px at 8% 0%, rgba(30, 94, 255, 0.22), transparent 60%),
    radial-gradient(800px 520px at 96% 100%, rgba(41, 224, 195, 0.12), transparent 55%),
    linear-gradient(180deg, var(--c-navy-900), #0a1d3c);
  color: #fff;
}
.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 44px;
  align-items: start;
}
.contact-item {
  display: flex;
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.10);
}
.contact-item:last-child { border-bottom: 0; }
.contact-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px; height: 46px;
  flex: none;
  border-radius: 12px;
  font-size: 18px;
  color: var(--c-cyan);
  background: rgba(41, 224, 195, 0.10);
  border: 1px solid rgba(41, 224, 195, 0.28);
}
.contact-item h3 { font-size: 15px; margin-bottom: 4px; }
.contact-item p { font-size: 14px; color: rgba(255, 255, 255, 0.66); }
.contact-item a { color: var(--c-cyan); }

.contact-form {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius);
  padding: 30px;
  backdrop-filter: blur(10px);
}
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.form-field { margin-bottom: 16px; }
.form-field label {
  display: block;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 7px;
}
.form-field input,
.form-field select,
.form-field textarea {
  width: 100%;
  padding: 11px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(255, 255, 255, 0.07);
  color: #fff;
  font-size: 14.5px;
  font-family: inherit;
  outline: none;
  transition: border-color 0.2s ease, background 0.2s ease;
}
.form-field input:focus,
.form-field select:focus,
.form-field textarea:focus {
  border-color: var(--c-cyan);
  background: rgba(255, 255, 255, 0.10);
}
.form-field select option { color: var(--c-ink); }
.form-field textarea { resize: vertical; min-height: 96px; }
.form-field input::placeholder,
.form-field textarea::placeholder { color: rgba(255, 255, 255, 0.35); }
.form-tip { margin-top: 12px; font-size: 13.5px; color: var(--c-cyan); min-height: 20px; }
.form-tip.error { color: #ff8f8f; }

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--c-navy-900);
  color: rgba(255, 255, 255, 0.66);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}
.footer-top {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.2fr;
  gap: 40px;
  padding: 54px 0 40px;
}
.footer-brand p {
  margin-top: 18px;
  font-size: 14px;
  line-height: 1.9;
  max-width: 340px;
}
.footer-col h4 {
  color: #fff;
  font-size: 15px;
  margin-bottom: 16px;
  letter-spacing: 1px;
}
.footer-col a, .footer-col p {
  display: block;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.62);
  margin-bottom: 10px;
  line-height: 1.7;
  transition: color 0.2s ease;
}
.footer-col a:hover { color: var(--c-cyan); }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}
.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  padding: 20px 0;
  font-size: 13px;
}
.footer-bottom a { color: rgba(255, 255, 255, 0.72); }
.footer-bottom a:hover { color: var(--c-cyan); }

/* ---------- 返回顶部 ---------- */
.back-top {
  position: fixed;
  right: 26px;
  bottom: 28px;
  width: 46px; height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--c-blue), #3a7bff);
  color: #fff;
  font-size: 18px;
  box-shadow: 0 10px 26px rgba(30, 94, 255, 0.36);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
  z-index: 90;
}
.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-top:hover { transform: translateY(-3px); }

/* ---------- 滚动显现 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero-card { max-width: 620px; }
  .hero-wafer { opacity: 0.3; }
  .idm-grid { grid-template-columns: repeat(2, 1fr); }
  .app-grid { grid-template-columns: repeat(2, 1fr); }
  .quality-grid { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-top { grid-template-columns: 1fr 1fr; }
  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 14px 24px 20px;
    background: rgba(6, 15, 31, 0.98);
    border-bottom: 1px solid rgba(255, 255, 255, 0.10);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.28s ease, opacity 0.28s ease, visibility 0.28s;
  }
  .main-nav.open { transform: translateY(0); opacity: 1; visibility: visible; }
  .nav-link { padding: 13px 10px; font-size: 15px; }
  .nav-toggle { display: flex; }
  .header-cta { display: none; }
  .header-inner { gap: 12px; }
}

@media (max-width: 720px) {
  .section { padding: 68px 0; }
  .strip-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .service-rail { gap: 14px; }
  .service-node { flex: 1 1 44%; max-width: none; }
  .rail-arrow { display: none; }
  .biz-card { grid-template-columns: 1fr; }
  .biz-visual { padding: 34px 20px; }
  .biz-body { padding: 28px 22px; }
  .biz-list { grid-template-columns: 1fr; }
  .idm-grid { grid-template-columns: 1fr; }
  .app-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .quality-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .contact-form { padding: 22px; }
  .footer-top { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom-inner { flex-direction: column; text-align: center; }
  .flow-steps { grid-template-columns: 1fr; }
  .hero { padding-top: calc(var(--header-h) + 44px); }
  .hero-actions .btn { width: 100%; }
  .back-top { right: 16px; bottom: 18px; }
}

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