:root {
  color-scheme: light;
  --blue: #075fe4;
  --blue-dark: #073f9d;
  --cyan: #15a3ff;
  --ink: #0b1424;
  --muted: #5f6f86;
  --line: #dce5f2;
  --soft: #f3f7fc;
  --white: #ffffff;
  --shadow: 0 20px 60px rgba(13, 48, 90, 0.12);
  --page-max: 1500px;
  --gutter: #eef3f9;
  --gutter-fade: 88px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(ellipse 90% 55% at 50% -8%, rgba(21, 163, 255, 0.04), transparent 62%),
    var(--white);
  font-family:
    "Inter", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.6;
}

body::before,
body::after {
  position: fixed;
  top: 0;
  bottom: 0;
  z-index: -1;
  width: max(
    0px,
    calc((100vw - var(--page-max)) / 2 + var(--gutter-fade))
  );
  content: "";
  pointer-events: none;
}

body::before {
  left: 0;
  background: linear-gradient(
    90deg,
    var(--gutter) 0%,
    #f4f7fb 28%,
    rgba(243, 247, 252, 0.72) 58%,
    rgba(255, 255, 255, 0.28) 82%,
    transparent 100%
  );
}

body::after {
  right: 0;
  background: linear-gradient(
    270deg,
    var(--gutter) 0%,
    #f4f7fb 28%,
    rgba(243, 247, 252, 0.72) 58%,
    rgba(255, 255, 255, 0.28) 82%,
    transparent 100%
  );
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 76px;
  padding: 14px clamp(20px, 5vw, 72px);
  max-width: 1500px;
  margin: 0 auto;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid rgba(220, 229, 242, 0.86);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 250px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  color: var(--white);
  background: linear-gradient(135deg, var(--blue), #0fb3ff);
  border-radius: 8px;
  font-weight: 800;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 20px;
  letter-spacing: 0;
}

.brand small {
  margin-top: 1px;
  color: var(--muted);
  font-size: 11px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2vw, 30px);
  font-size: 15px;
  font-weight: 600;
}

.site-nav a {
  position: relative;
  padding: 8px 0;
}

.site-nav a::after {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 2px;
  background: var(--blue);
  content: "";
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 160ms ease;
}

.site-nav a:hover::after {
  transform: scaleX(1);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 9px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
}

.nav-toggle span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(420px, 1.18fr);
  align-items: stretch;
  min-height: calc(100vh - 76px);
  max-width: 1500px;
  margin: 0 auto;
  overflow: hidden;
  background:
    radial-gradient(circle at 20% 22%, rgba(21, 163, 255, 0.14), transparent 30%),
    linear-gradient(115deg, #ffffff 0%, #f8fbff 47%, #eef5ff 100%);
}

.hero-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(54px, 8vw, 100px) clamp(22px, 6vw, 76px);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--blue);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 760px;
  margin-bottom: 14px;
  font-size: clamp(36px, 4.4vw, 60px);
  line-height: 1.08;
  letter-spacing: 0;
  overflow-wrap: anywhere;
}

h1 span {
  display: block;
}

.hero-lead {
  margin-bottom: 18px;
  color: var(--blue);
  font-size: clamp(24px, 2.3vw, 34px);
  font-weight: 800;
}

.hero-text {
  max-width: 640px;
  color: #3c4d64;
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin: 24px 0 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 24px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 800;
  cursor: pointer;
  transition:
    transform 160ms ease,
    box-shadow 160ms ease,
    background 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button.primary {
  color: var(--white);
  background: var(--blue);
  box-shadow: 0 12px 26px rgba(7, 95, 228, 0.22);
}

.button.secondary {
  color: var(--blue-dark);
  background: var(--white);
  border-color: #a9c4ef;
}

.address-line {
  max-width: 520px;
  color: var(--muted);
  font-size: 15px;
  overflow-wrap: anywhere;
}

.hero-media {
  position: relative;
  min-height: 460px;
}

.hero-media::before {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0.9), rgba(255, 255, 255, 0.08) 32%);
  content: "";
  pointer-events: none;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  padding: 0 clamp(20px, 5vw, 72px);
  max-width: 1500px;
  margin: 0 auto;
  background: var(--line);
}

.metric-strip div {
  padding: 30px 24px;
  background: var(--white);
}

.metric-strip strong,
.metric-strip span {
  display: block;
}

.metric-strip strong {
  color: var(--blue);
  font-size: clamp(26px, 3vw, 42px);
  line-height: 1;
}

.metric-strip span {
  margin-top: 8px;
  color: var(--muted);
}

.section {
  padding: clamp(66px, 8vw, 110px) clamp(20px, 5vw, 72px);
  max-width: 1500px;
  margin: 0 auto;
}

.split-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(30px, 6vw, 90px);
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(30px, 3.6vw, 48px);
  line-height: 1.15;
  letter-spacing: 0;
}

.section-copy,
.head-note,
.contact-section p,
.quality-panel p {
  color: var(--muted);
  font-size: 17px;
}

.soft-section {
  background: var(--soft);
}

.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 34px;
}

.product-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.product-tabs button {
  min-height: 38px;
  padding: 0 14px;
  color: #36506f;
  border: 1px solid #cbd9ec;
  border-radius: 8px;
  background: var(--white);
  cursor: pointer;
}

.product-tabs button.active {
  color: var(--white);
  background: var(--blue);
  border-color: var(--blue);
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.product-card {
  display: flex;
  flex-direction: column;
  min-height: 100%;
  overflow: hidden;
  background: var(--white);
  border: 1px solid #e4ebf5;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.product-card[hidden] {
  display: none;
}

.product-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  background: #f7f9fd;
}

.product-card div {
  padding: 24px;
}

.product-card h3 {
  margin-bottom: 8px;
  font-size: 24px;
}

.product-card p {
  color: var(--muted);
}

.fast-band {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: 28px;
  align-items: center;
  padding: 64px clamp(20px, 5vw, 72px);
  max-width: 1500px;
  margin: 0 auto;
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(6, 60, 123, 0.94), rgba(5, 122, 204, 0.84)),
    url("assets/hero-production.png") center / cover;
}

.fast-band .eyebrow {
  color: #bce9ff;
}

.fast-band h2 {
  margin: 0;
}

.fast-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.fast-list span {
  display: grid;
  min-height: 86px;
  place-items: center;
  padding: 16px;
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.26);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
  font-weight: 800;
}

.process {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 14px;
}

.process div {
  position: relative;
  min-height: 180px;
  padding: 22px 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: linear-gradient(180deg, #ffffff, #f6faff);
}

.process strong {
  display: block;
  margin-bottom: 28px;
  color: var(--blue);
  font-size: 28px;
}

.process span,
.process small {
  display: block;
}

.process span {
  font-weight: 800;
}

.process small {
  margin-top: 8px;
  color: var(--muted);
  font-size: 13px;
}

.quality-section {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: 28px;
  background: #f8fbff;
}

.quality-panel {
  padding: 34px;
  color: var(--white);
  border-radius: 8px;
  background:
    linear-gradient(145deg, rgba(6, 46, 103, 0.94), rgba(0, 125, 210, 0.78)),
    url("assets/battery-products.png") center / cover;
}

.quality-panel .eyebrow,
.quality-panel p {
  color: #dff4ff;
}

.quality-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.quality-grid div {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
}

.quality-grid strong,
.quality-grid span {
  display: block;
}

.quality-grid strong {
  margin-bottom: 8px;
  font-size: 20px;
}

.quality-grid span {
  color: var(--muted);
}

.contact-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 0.75fr);
  gap: clamp(28px, 5vw, 70px);
}

address {
  margin-top: 24px;
  color: #364b65;
  font-style: normal;
  font-weight: 700;
}

.inquiry-form {
  display: grid;
  gap: 16px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.inquiry-form label {
  display: grid;
  gap: 8px;
  color: #24364d;
  font-weight: 700;
}

.inquiry-form input,
.inquiry-form select,
.inquiry-form textarea {
  width: 100%;
  padding: 12px 13px;
  color: var(--ink);
  border: 1px solid #cbd9ec;
  border-radius: 8px;
  font: inherit;
}

.form-note {
  min-height: 22px;
  margin: 0;
  color: var(--blue-dark);
  font-size: 14px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 28px clamp(20px, 5vw, 72px);
  max-width: 1500px;
  margin: 0 auto;
  color: #6d7d92;
  border-top: 1px solid var(--line);
  background: #f9fbfe;
}

@media (max-width: 1050px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .hero-copy {
    padding-bottom: 30px;
  }

  .hero-media {
    min-height: 360px;
  }

  .metric-strip,
  .product-grid,
  .process {
    grid-template-columns: repeat(2, 1fr);
  }

  .fast-band,
  .quality-section,
  .contact-section,
  .split-section {
    grid-template-columns: 1fr;
  }

  .fast-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 760px) {
  .site-header {
    min-height: 66px;
  }

  .brand {
    min-width: 0;
  }

  .brand strong {
    font-size: 17px;
  }

  .brand small {
    display: none;
  }

  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: 66px;
    right: 14px;
    left: 14px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--white);
    box-shadow: var(--shadow);
  }

  .site-nav.open {
    display: flex;
  }

  .site-nav a {
    padding: 12px;
  }

  .hero {
    min-height: auto;
  }

  .hero-copy {
    padding-top: 46px;
  }

  h1 {
    font-size: 35px;
    line-height: 1.14;
    word-break: break-all;
  }

  .hero-lead {
    font-size: 24px;
  }

  .hero-text {
    font-size: 16px;
    overflow-wrap: anywhere;
  }

  .address-line {
    font-size: 13px;
    word-break: break-all;
  }

  .hero-media {
    min-height: 260px;
  }

  .section-head {
    align-items: start;
    flex-direction: column;
  }

  .metric-strip,
  .product-grid,
  .process,
  .quality-grid,
  .fast-list {
    grid-template-columns: 1fr;
  }

  .metric-strip {
    padding: 0;
  }

  .metric-strip div {
    padding: 24px 18px;
  }

  .section {
    padding-top: 58px;
    padding-bottom: 58px;
  }

  .site-footer {
    flex-direction: column;
  }
}