:root {
  --ink: #151719;
  --iron: #262b2f;
  --graphite: #3c4146;
  --line: #d9dcdb;
  --paper: #f7f7f4;
  --white: #ffffff;
  --aluminum: #c6cbc8;
  --signal: #b94622;
  --signal-dark: #8f351c;
  --caution: #e1b84a;
  --green: #4e7762;
  --shadow: 0 18px 45px rgba(21, 23, 25, 0.12);
  --radius: 8px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Bahnschrift, Aptos, "Segoe UI", sans-serif;
  line-height: 1.5;
}

body.modal-open {
  overflow: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
  opacity: 0.28;
  background-image:
    linear-gradient(rgba(21, 23, 25, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(21, 23, 25, 0.04) 1px, transparent 1px);
  background-size: 42px 42px;
}

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

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

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  gap: 22px;
  align-items: center;
  padding: 14px clamp(18px, 4vw, 42px);
  color: var(--white);
  transition: background 180ms ease, box-shadow 180ms ease, color 180ms ease;
}

.site-header.is-scrolled {
  color: var(--ink);
  background: rgba(247, 247, 244, 0.94);
  box-shadow: 0 1px 0 var(--line);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  gap: 10px;
  align-items: center;
  min-width: 226px;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border: 2px solid currentColor;
  border-radius: 50%;
  font-family: Georgia, serif;
  font-weight: 700;
}

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

.brand small {
  color: currentColor;
  opacity: 0.72;
  font-size: 0.73rem;
}

.nav {
  justify-self: center;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 5px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 999px;
  background: rgba(21, 23, 25, 0.2);
}

.site-header.is-scrolled .nav {
  border-color: var(--line);
  background: var(--white);
}

.nav a {
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 0.86rem;
}

.nav a:hover {
  background: rgba(185, 70, 34, 0.14);
}

.header-cta,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 11px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-weight: 700;
  cursor: pointer;
}

.header-cta {
  color: var(--white);
  background: var(--signal);
}

.header-cta:hover,
.button.primary:hover {
  background: var(--signal-dark);
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid currentColor;
  border-radius: var(--radius);
  color: inherit;
  background: transparent;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 5px auto;
  background: currentColor;
}

.hero {
  position: relative;
  min-height: 82vh;
  display: grid;
  align-items: end;
  overflow: hidden;
  color: var(--white);
  background: var(--ink);
}

.hero-media,
.hero-overlay {
  position: absolute;
  inset: 0;
}

.hero-media {
  background-image: url("assets/products/新能源汽车发动机壳.jpg");
  background-position: center;
  background-size: cover;
  transform: scale(1.03);
  filter: saturate(0.88) contrast(1.05);
}

.hero-overlay {
  background:
    linear-gradient(90deg, rgba(21, 23, 25, 0.86), rgba(21, 23, 25, 0.46) 54%, rgba(21, 23, 25, 0.16)),
    linear-gradient(0deg, rgba(21, 23, 25, 0.86), transparent 42%);
}

.hero-content,
.hero-proof {
  position: relative;
  z-index: 1;
}

.hero-content {
  width: min(820px, calc(100% - 36px));
  margin: 0 auto;
  padding: 132px 0 150px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--signal);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: var(--caution);
}

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

h1,
h2 {
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 700;
  line-height: 1.03;
}

h1 {
  max-width: 780px;
  margin-bottom: 22px;
  font-size: clamp(3rem, 8vw, 6.8rem);
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(2rem, 4.2vw, 4.1rem);
}

h3 {
  font-size: 1.08rem;
}

.hero-copy {
  max-width: 680px;
  font-size: clamp(1rem, 2vw, 1.27rem);
  color: rgba(255, 255, 255, 0.88);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button.primary {
  color: var(--white);
  background: var(--signal);
}

.button.secondary {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.55);
  background: rgba(255, 255, 255, 0.08);
}

.button.secondary:hover {
  background: rgba(255, 255, 255, 0.16);
}

.hero-proof {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(21, 23, 25, 0.68);
  backdrop-filter: blur(10px);
}

.hero-proof div {
  min-height: 100px;
  padding: 22px clamp(16px, 3vw, 36px);
  border-right: 1px solid rgba(255, 255, 255, 0.16);
}

.hero-proof strong,
.hero-proof span {
  display: block;
}

.hero-proof strong {
  font-size: 1.1rem;
  color: var(--white);
}

.hero-proof span {
  margin-top: 5px;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.9rem;
}

.section,
.intro-band,
.profile-download {
  padding: clamp(64px, 8vw, 110px) 0;
}

.section-inner {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
}

.intro-band {
  background: var(--iron);
  color: var(--white);
}

.intro-grid,
.section-heading,
.quality-grid,
.about-grid,
.rfq-grid,
.footer-grid {
  display: grid;
  grid-template-columns: minmax(260px, 0.86fr) minmax(0, 1.14fr);
  gap: clamp(28px, 5vw, 72px);
  align-items: start;
}

.intro-grid p,
.section-heading p,
.about-copy p,
.rfq-grid p,
.quality-grid p {
  color: rgba(21, 23, 25, 0.72);
  font-size: 1rem;
}

.intro-grid p,
.intro-grid h2 {
  color: var(--white);
}

.intro-grid > p {
  margin: 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 1.08rem;
}

.profile-download {
  padding-top: 34px;
  padding-bottom: 34px;
  background: var(--white);
  border-bottom: 1px solid var(--line);
}

.profile-download-grid {
  display: grid;
  grid-template-columns: minmax(260px, 0.68fr) minmax(0, 1.32fr);
  gap: clamp(22px, 4vw, 56px);
  align-items: center;
}

.profile-download h2 {
  margin-bottom: 0;
  font-size: clamp(1.55rem, 2.4vw, 2.5rem);
}

.download-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 20px;
  align-items: center;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  box-shadow: 0 1px 0 rgba(21, 23, 25, 0.04);
}

.download-card h3 {
  margin-bottom: 8px;
}

.download-card p {
  max-width: 690px;
  margin-bottom: 0;
  color: rgba(21, 23, 25, 0.68);
}

.section-heading {
  margin-bottom: 30px;
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 22px;
}

.product-summary {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: -8px 0 22px;
}

.product-summary div {
  min-height: 88px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.product-summary strong,
.product-summary span {
  display: block;
}

.product-summary strong {
  color: var(--signal-dark);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 2rem;
  line-height: 1;
}

.product-summary span {
  margin-top: 7px;
  color: rgba(21, 23, 25, 0.64);
  font-weight: 800;
}

.filter-button {
  min-height: 38px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--graphite);
  background: var(--white);
  cursor: pointer;
}

.filter-button.is-active {
  color: var(--white);
  border-color: var(--ink);
  background: var(--ink);
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.product-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 1px 0 rgba(21, 23, 25, 0.04);
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.product-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}

.product-media {
  position: relative;
  display: block;
  width: 100%;
  padding: 0;
  border: 0;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(21, 23, 25, 0.03), rgba(21, 23, 25, 0.26)),
    var(--product-image) center / cover no-repeat,
    var(--aluminum);
  cursor: pointer;
}

.product-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 0 62%, rgba(21, 23, 25, 0.34));
  opacity: 0;
  transition: opacity 180ms ease;
}

.product-card:hover .product-media::after,
.product-media:focus-visible::after {
  opacity: 1;
}

.product-zoom-control {
  position: absolute;
  z-index: 1;
  top: 10px;
  right: 10px;
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.76);
  border-radius: var(--radius);
  color: var(--white);
  background: rgba(21, 23, 25, 0.78);
  box-shadow: 0 8px 22px rgba(21, 23, 25, 0.18);
  backdrop-filter: blur(10px);
}

.product-zoom-control::before,
.product-zoom-control::after {
  content: "";
  position: absolute;
  border-color: currentColor;
}

.product-zoom-control::before {
  width: 13px;
  height: 13px;
  border: 2px solid currentColor;
  border-radius: 50%;
  transform: translate(-2px, -2px);
}

.product-zoom-control::after {
  width: 9px;
  height: 2px;
  background: currentColor;
  transform: translate(7px, 7px) rotate(45deg);
}

.product-media:hover .product-zoom-control,
.product-media:focus-visible .product-zoom-control {
  background: var(--signal);
}

.product-media:focus-visible {
  outline: 3px solid rgba(185, 70, 34, 0.34);
  outline-offset: 3px;
}

.product-body {
  padding: 16px;
}

.tag {
  display: inline-flex;
  margin-bottom: 10px;
  padding: 4px 8px;
  border-radius: 999px;
  color: var(--signal-dark);
  background: rgba(185, 70, 34, 0.12);
  font-size: 0.76rem;
  font-weight: 800;
}

.product-body h3 {
  min-height: 52px;
  margin-bottom: 8px;
  line-height: 1.25;
}

.product-body p {
  min-height: 48px;
  margin-bottom: 0;
  color: rgba(21, 23, 25, 0.68);
  font-size: 0.92rem;
}

.product-modal {
  position: fixed;
  z-index: 80;
  inset: 0;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 22px;
}

.product-modal.is-open {
  display: flex;
}

.product-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(21, 23, 25, 0.72);
  backdrop-filter: blur(8px);
}

.product-modal-panel {
  position: relative;
  z-index: 1;
  width: min(1040px, 100%);
  max-height: min(760px, calc(100vh - 44px));
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 28px 80px rgba(0, 0, 0, 0.34);
}

.product-modal-close {
  position: absolute;
  z-index: 2;
  top: 14px;
  right: 14px;
  min-height: 36px;
  padding: 8px 11px;
  border: 1px solid rgba(21, 23, 25, 0.16);
  border-radius: var(--radius);
  color: var(--ink);
  background: rgba(255, 255, 255, 0.9);
  font: inherit;
  font-size: 0.78rem;
  font-weight: 900;
  text-transform: uppercase;
  cursor: pointer;
}

.product-modal-close:hover,
.product-modal-close:focus-visible {
  color: var(--white);
  background: var(--signal);
}

.product-modal-image {
  width: 100%;
  min-height: min(720px, calc(100vh - 44px));
  background:
    linear-gradient(180deg, rgba(21, 23, 25, 0), rgba(21, 23, 25, 0.16)),
    var(--product-image) center / contain no-repeat,
    #e4e5e2;
}

.capabilities {
  background: #ecece8;
}

.capability-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.75fr) minmax(0, 1.25fr);
  gap: 22px;
}

.capability-panel,
.rfq-form {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.capability-panel {
  padding: 26px;
}

.feature-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.feature-list li {
  position: relative;
  padding-left: 18px;
  color: rgba(21, 23, 25, 0.74);
}

.feature-list li::before {
  content: "";
  position: absolute;
  top: 0.68em;
  left: 0;
  width: 7px;
  height: 7px;
  background: var(--signal);
}

.process-rail {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  min-height: 260px;
  border: 1px solid rgba(21, 23, 25, 0.16);
  border-radius: var(--radius);
  background: repeating-linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.7),
    rgba(255, 255, 255, 0.7) 10px,
    rgba(198, 203, 200, 0.28) 10px,
    rgba(198, 203, 200, 0.28) 20px
  );
}

.process-rail span {
  display: flex;
  align-items: end;
  justify-content: center;
  padding: 18px 10px;
  border-right: 1px solid rgba(21, 23, 25, 0.14);
  font-weight: 800;
  text-align: center;
}

.process-rail span:nth-child(odd) {
  background: rgba(255, 255, 255, 0.46);
}

.quality {
  color: var(--white);
  background: var(--ink);
}

.quality h2,
.quality p {
  color: var(--white);
}

.quality-grid > div > p {
  color: rgba(255, 255, 255, 0.74);
}

.text-link {
  display: inline-flex;
  margin-top: 8px;
  color: var(--caution);
  font-weight: 800;
}

.quality-matrix {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.quality-matrix div,
.industry-grid article {
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.06);
}

.quality-matrix div {
  min-height: 118px;
  padding: 18px;
}

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

.quality-matrix span {
  margin-top: 8px;
  color: rgba(255, 255, 255, 0.68);
}

.industry-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.industry-grid article {
  min-height: 260px;
  padding: 22px;
  border-color: var(--line);
  background: var(--white);
}

.industry-grid p {
  color: rgba(21, 23, 25, 0.7);
}

.industry-grid span {
  display: block;
  margin-top: 18px;
  color: var(--signal-dark);
  font-size: 0.88rem;
  font-weight: 800;
}

.about {
  background: #dedfdb;
}

.about-copy {
  column-count: 2;
  column-gap: 28px;
}

.about-copy p {
  break-inside: avoid;
}

.rfq-section {
  background: var(--white);
}

.rfq-contact {
  display: grid;
  gap: 4px;
  margin-top: 28px;
  padding: 18px;
  border-left: 4px solid var(--signal);
  background: var(--paper);
}

.rfq-contact span {
  color: rgba(21, 23, 25, 0.58);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

.rfq-contact a {
  color: var(--signal-dark);
  font-weight: 900;
}

.rfq-form {
  padding: 24px;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

label {
  display: grid;
  gap: 7px;
  margin-bottom: 14px;
  color: rgba(21, 23, 25, 0.78);
  font-size: 0.86rem;
  font-weight: 800;
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
  color: var(--ink);
  background: var(--white);
  font: inherit;
}

textarea {
  resize: vertical;
}

input:focus,
select:focus,
textarea:focus {
  outline: 3px solid rgba(185, 70, 34, 0.2);
  border-color: var(--signal);
}

.full {
  width: 100%;
}

.form-status {
  min-height: 24px;
  margin: 12px 0 0;
  color: var(--green);
  font-weight: 800;
}

.form-status.is-error {
  color: var(--signal-dark);
}

.site-footer {
  padding: 34px 0;
  color: var(--white);
  background: var(--iron);
}

.site-footer p {
  margin: 7px 0 0;
  color: rgba(255, 255, 255, 0.7);
}

.site-footer a {
  justify-self: end;
  color: var(--caution);
  font-weight: 800;
}

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

  .menu-toggle {
    display: block;
    justify-self: end;
  }

  .nav {
    position: absolute;
    top: 70px;
    left: 18px;
    right: 18px;
    display: none;
    padding: 12px;
    border-radius: var(--radius);
    background: var(--white);
    color: var(--ink);
    box-shadow: var(--shadow);
  }

  .nav.is-open {
    display: grid;
  }

  .header-cta {
    display: none;
  }

  .product-grid,
  .industry-grid,
  .product-summary {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .process-rail {
    grid-template-columns: 1fr;
  }

  .process-rail span {
    min-height: 58px;
    align-items: center;
    border-right: 0;
    border-bottom: 1px solid rgba(21, 23, 25, 0.14);
  }
}

@media (max-width: 760px) {
  .brand {
    min-width: auto;
  }

  .brand small {
    display: none;
  }

  .hero {
    min-height: auto;
  }

  .hero-content {
    padding: 108px 0 76px;
  }

  .hero-proof,
  .intro-grid,
  .profile-download-grid,
  .download-card,
  .section-heading,
  .quality-grid,
  .about-grid,
  .rfq-grid,
  .capability-layout,
  .form-row,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero-proof div {
    min-height: 82px;
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  }

  .product-grid,
  .industry-grid,
  .quality-matrix,
  .product-summary {
    grid-template-columns: 1fr;
  }

  .about-copy {
    column-count: 1;
  }

  .site-footer a {
    justify-self: start;
  }

  .product-modal {
    padding: 14px;
  }

  .product-modal-image {
    min-height: min(520px, calc(100vh - 28px));
  }

  .product-zoom-control {
    top: 8px;
    right: 8px;
  }
}