/* ============================================================
   52石墨烯 官网设计稿 v0.1
   品牌规范：深石墨 + 暖橙 / 思源黑体优先 / B2B 工业信任风
   状态：待审美与品牌质检机器人质检，未放行不对外使用
   ============================================================ */

:root {
  --orange: #F97316;
  --orange-deep: #EA580C;
  --graphite: #191C20;
  --ink: #1F2937;
  --muted: #6B7280;
  --paper: #FFFFFF;
  --mist: #F6F8FB;
  --line: #E5E7EB;
  --line-dark: rgba(255, 255, 255, 0.14);
  --text-on-dark: #E8EAED;
  --label-on-dark: #B7BCC2;
  --radius-card: 12px;
  --radius-btn: 8px;
  --shadow-card: 0 1px 2px rgba(25, 28, 32, 0.05), 0 10px 28px rgba(25, 28, 32, 0.08);
  --font-sans: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --container: 1200px;
  --nav-h: 68px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: 12px;
  z-index: 100;
  padding: 10px 16px;
  background: var(--orange);
  color: #fff;
  border-radius: var(--radius-btn);
  font-size: 0.9rem;
  transform: translateY(-300%);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: none;
}

:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

/* ---------------- 导航 ---------------- */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 60;
  background: rgba(25, 28, 32, 0.96);
  border-bottom: 1px solid var(--line-dark);
}

.nav {
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 5px;
  color: #fff;
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: 0.01em;
  line-height: 1;
  white-space: nowrap;
}

.brand .n {
  color: var(--orange);
}

.brand .cn {
  font-size: 1.05rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 30px;
}

.nav-links a {
  color: #D3D6DA;
  font-size: 0.95rem;
  transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.is-active {
  color: #fff;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  padding: 9px 18px;
  background: var(--orange);
  color: #fff;
  border-radius: var(--radius-btn);
  font-size: 0.92rem;
  font-weight: 700;
  transition: background 0.2s ease;
}

.nav-cta:hover {
  background: var(--orange-deep);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  padding: 0 9px;
  background: none;
  border: 1px solid var(--line-dark);
  border-radius: var(--radius-btn);
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: #fff;
  border-radius: 2px;
}

/* ---------------- 按钮 ---------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius-btn);
  font-size: 0.98rem;
  font-weight: 700;
  line-height: 1.2;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.15s ease;
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--orange);
  color: #fff;
}

.btn-primary:hover {
  background: var(--orange-deep);
}

.btn-ghost-light {
  border-color: rgba(255, 255, 255, 0.45);
  color: #fff;
}

.btn-ghost-light:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.06);
}

.btn-ghost-dark {
  border-color: var(--ink);
  color: var(--ink);
}

.btn-ghost-dark:hover {
  background: rgba(25, 28, 32, 0.05);
}

/* ---------------- 首屏 ---------------- */

.hero {
  background: var(--graphite);
  color: #fff;
  padding: calc(var(--nav-h) + clamp(52px, 9vw, 92px)) 0 clamp(60px, 8vw, 92px);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 56px;
  align-items: center;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 18px;
  color: var(--orange);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.24em;
}

.hero-title {
  margin: 0 0 22px;
  font-size: clamp(2.3rem, 5vw, 3.5rem);
  line-height: 1.14;
  font-weight: 800;
  letter-spacing: -0.015em;
}

.hero-sub {
  margin: 0 0 34px;
  color: var(--text-on-dark);
  font-size: clamp(1rem, 1.4vw, 1.12rem);
  max-width: 54ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.hero-media {
  position: relative;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--line-dark);
}

.hero-media img {
  width: 100%;
  height: 100%;
  min-height: 340px;
  object-fit: cover;
}

.hero-media figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 44px 18px 14px;
  background: linear-gradient(transparent, rgba(25, 28, 32, 0.78));
  color: #fff;
  font-size: 0.88rem;
}

.hero-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 44px;
  margin-top: 56px;
  padding-top: 28px;
  border-top: 1px solid var(--line-dark);
}

.hero-fact b {
  display: block;
  font-size: 1.8rem;
  font-weight: 800;
  line-height: 1.1;
  color: #fff;
}

.hero-fact b em {
  font-style: normal;
  color: var(--orange);
}

.hero-fact span {
  color: var(--label-on-dark);
  font-size: 0.9rem;
}

/* ---------------- 区块 ---------------- */

.section {
  padding: clamp(4rem, 8vw, 6.5rem) 0;
}

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

.section-head {
  max-width: 740px;
  margin-bottom: clamp(2.2rem, 4vw, 3.4rem);
}

.section-title {
  margin: 0 0 12px;
  font-size: clamp(1.6rem, 3vw, 2.25rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.25;
}

.section-desc {
  margin: 0;
  color: var(--muted);
  max-width: 60ch;
}

.section-actions {
  margin-top: 36px;
}

/* ---------------- 解决方案编号行 ---------------- */

.solution-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 56px;
}

.solution-row {
  display: grid;
  grid-template-columns: 56px 1fr 28px;
  gap: 18px;
  align-items: center;
  padding: 26px 0;
  border-top: 1px solid var(--line);
}

.solution-row .no {
  font-size: 1rem;
  font-weight: 800;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.solution-row h3 {
  margin: 0 0 3px;
  font-size: 1.12rem;
  font-weight: 700;
  line-height: 1.3;
  transition: color 0.2s ease;
}

.solution-row p {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.solution-row .go {
  color: var(--muted);
  font-size: 1.15rem;
  transition: color 0.2s ease, transform 0.2s ease;
}

.solution-row:hover h3 {
  color: var(--orange);
}

.solution-row:hover .go {
  color: var(--orange);
  transform: translateX(3px);
}

.solution-row:last-child,
.solution-grid .solution-row:nth-last-child(2) {
  border-bottom: 1px solid var(--line);
}

/* ---------------- 服务流程 ---------------- */

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.step {
  padding-top: 22px;
  border-top: 2px solid var(--graphite);
}

.step .no {
  font-size: 0.92rem;
  font-weight: 800;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

.step h3 {
  margin: 12px 0 6px;
  font-size: 1.08rem;
  font-weight: 700;
}

.step p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--muted);
}

/* ---------------- 实景图库 ---------------- */

.gallery {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  grid-auto-rows: minmax(250px, auto);
  gap: 18px;
}

.g-item {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-card);
  background: var(--graphite);
}

.g-item.g-main {
  grid-row: span 2;
}

.g-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s ease;
}

.g-item:hover img {
  transform: scale(1.03);
}

.g-cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 40px 18px 14px;
  background: linear-gradient(transparent, rgba(25, 28, 32, 0.78));
  color: #fff;
  font-size: 0.88rem;
}

/* ---------------- 产品卡片 ---------------- */

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.product-card {
  display: flex;
  flex-direction: column;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.product-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
  border-color: #D4D9E0;
}

.product-media {
  aspect-ratio: 4 / 3;
}

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

.placeholder-media {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 24px;
  background: var(--mist);
  border-bottom: 1px dashed #C7D0DA;
  color: #94A3B8;
  font-size: 0.95rem;
}

.product-body {
  padding: 22px 22px 26px;
}

.product-body h3 {
  margin: 0 0 8px;
  font-size: 1.14rem;
  font-weight: 700;
}

.product-body p {
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 0.93rem;
}

.product-body .link {
  color: var(--orange);
  font-size: 0.92rem;
  font-weight: 700;
}

.product-body .link:hover {
  color: var(--orange-deep);
}

/* ---------------- 关于 ---------------- */

.about-band {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(32px, 6vw, 72px);
  align-items: center;
}

.about-band h2 {
  margin: 0 0 16px;
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  font-weight: 800;
  line-height: 1.3;
}

.about-band p {
  margin: 0 0 18px;
  color: var(--muted);
  max-width: 58ch;
}

.about-band .btn {
  margin-top: 8px;
}

.about-band figure {
  margin: 0;
  border-radius: var(--radius-card);
  overflow: hidden;
}

.about-band figure img {
  width: 100%;
  height: 100%;
  min-height: 300px;
  object-fit: cover;
}

.info-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 56px;
}

.info-item {
  padding: 24px 0;
  border-top: 1px solid var(--line);
}

.info-item h3 {
  margin: 0 0 6px;
  font-size: 1.05rem;
  font-weight: 700;
}

.info-item p {
  margin: 0;
  color: var(--muted);
  font-size: 0.93rem;
}

/* ---------------- 询盘 ---------------- */

.cta-band {
  background: var(--graphite);
  color: #fff;
  padding: clamp(3.5rem, 7vw, 5.5rem) 0;
}

.cta-inner {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
}

.cta-inner h2 {
  margin: 0 0 12px;
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 800;
  line-height: 1.25;
}

.cta-inner p {
  margin: 0;
  color: var(--text-on-dark);
  max-width: 50ch;
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: flex-end;
}

/* ---------------- 页脚 ---------------- */

.site-footer {
  background: var(--graphite);
  color: #C6CAD0;
  padding: 56px 0 30px;
  border-top: 1px solid var(--line-dark);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.8fr 1fr;
  gap: 44px;
  padding-bottom: 40px;
}

.footer-brand {
  font-size: 1.2rem;
  font-weight: 800;
  color: #fff;
}

.footer-brand .n {
  color: var(--orange);
}

.footer-col p {
  margin: 12px 0 0;
  font-size: 0.9rem;
  color: #A6ABB2;
}

.footer-col h4 {
  margin: 0 0 14px;
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
}

.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-col li {
  margin-bottom: 8px;
}

.footer-col a {
  font-size: 0.9rem;
  color: #A6ABB2;
  transition: color 0.2s ease;
}

.footer-col a:hover {
  color: var(--orange);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--line-dark);
  display: flex;
  flex-wrap: wrap;
  gap: 10px 32px;
  justify-content: space-between;
  font-size: 0.85rem;
  color: #8D9299;
}

/* ---------------- 联系页 ---------------- */

.page-hero {
  background: var(--graphite);
  color: #fff;
  padding: calc(var(--nav-h) + 54px) 0 64px;
}

.page-hero h1 {
  margin: 0 0 10px;
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-hero p {
  margin: 0;
  color: var(--text-on-dark);
  max-width: 58ch;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(32px, 6vw, 72px);
  align-items: start;
}

.contact-info h2 {
  margin: 0 0 8px;
  font-size: 1.5rem;
  font-weight: 800;
}

.contact-info > p {
  margin: 0 0 30px;
  color: var(--muted);
}

.contact-row {
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

.contact-row:last-child {
  border-bottom: 1px solid var(--line);
}

.contact-row h3 {
  margin: 0 0 4px;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--muted);
}

.contact-row p,
.contact-row a {
  margin: 0;
  font-size: 1.08rem;
  font-weight: 600;
  color: var(--ink);
}

.contact-row a:hover {
  color: var(--orange);
}

.form-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: clamp(24px, 3vw, 36px);
}

.form-card h2 {
  margin: 0 0 6px;
  font-size: 1.35rem;
  font-weight: 800;
}

.form-card > p {
  margin: 0 0 24px;
  color: var(--muted);
  font-size: 0.95rem;
}

.field {
  margin-bottom: 18px;
}

.field label {
  display: block;
  margin-bottom: 6px;
  font-size: 0.9rem;
  font-weight: 700;
}

.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid #D4D9E0;
  border-radius: var(--radius-btn);
  font-family: inherit;
  font-size: 0.98rem;
  color: var(--ink);
  background: #fff;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.field textarea {
  resize: vertical;
  min-height: 110px;
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--orange);
  box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.18);
}

.form-note {
  margin: 16px 0 0;
  font-size: 0.88rem;
  color: var(--muted);
}

.form-alert {
  display: none;
  margin-top: 16px;
  padding: 12px 14px;
  border-radius: var(--radius-btn);
  background: var(--mist);
  border: 1px solid var(--line);
  color: var(--ink);
  font-size: 0.9rem;
}

.form-alert.show {
  display: block;
}

/* ---------------- 通用工具 ---------------- */

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.in-view {
  opacity: 1;
  transform: none;
}

/* ---------------- 响应式 ---------------- */

@media (max-width: 980px) {
  .nav-links {
    position: fixed;
    top: var(--nav-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    display: none;
    padding: 16px 24px 26px;
    background: var(--graphite);
    border-bottom: 1px solid var(--line-dark);
  }

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

  .nav-links a {
    padding: 12px 0;
    font-size: 1.02rem;
    width: 100%;
  }

  .nav-cta {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .hero-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-media img {
    min-height: 280px;
  }

  .solution-grid {
    grid-template-columns: 1fr;
    column-gap: 0;
  }

  .steps {
    grid-template-columns: 1fr 1fr;
  }

  .gallery {
    grid-template-columns: 1fr;
  }

  .gallery .g-main {
    grid-row: auto;
  }

  .product-grid {
    grid-template-columns: 1fr;
    max-width: 560px;
  }

  .about-band,
  .cta-inner,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .cta-actions {
    justify-content: flex-start;
  }

  .info-list {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 600px) {
  .steps {
    grid-template-columns: 1fr;
  }

  .hero-facts {
    gap: 28px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .btn {
    width: 100%;
  }

  .hero-actions .btn {
    width: auto;
    flex: 1 1 45%;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .g-item img,
  .product-card,
  .solution-row h3,
  .solution-row .go {
    transition: none;
  }
}

/* 产品参数表 */
.table-wrap { overflow-x: auto; margin: 16px 0 36px; }
.param-table { width: 100%; border-collapse: collapse; min-width: 640px; }
.param-table th, .param-table td { border: 1px solid #e5e7eb; padding: 8px 12px; font-size: 14px; text-align: left; vertical-align: top; }
.param-table th { background: #f6f8fb; font-weight: 700; white-space: nowrap; }
.series-title { font-size: 22px; font-weight: 800; margin: 8px 0 4px; }
.series-desc { color: #6b7280; margin-bottom: 4px; }