/* Zenith — first-draft site styles
   Simple, modern, technological. No build step. */

:root {
  --bg: #f3f5f8;
  --bg-elevated: #ffffff;
  --ink: #0b1220;
  --ink-muted: #5c6b80;
  --line: #e1e6ee;
  --line-strong: #c9d2de;
  --navy: #0a1628;
  --navy-2: #102039;
  --navy-3: #173056;
  --accent: #0e9c8a;
  --accent-2: #14b8a6;
  --accent-bright: #2ee6d6;
  --accent-soft: #e6f7f4;
  --csa: #c8102e;
  --header-h: 4.25rem;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgba(11, 18, 32, 0.05), 0 10px 28px rgba(11, 18, 32, 0.06);
  --shadow-sm: 0 1px 2px rgba(11, 18, 32, 0.06);
  --font-display: "Space Grotesk", "Noto Sans SC", "Segoe UI", sans-serif;
  --font-body: "IBM Plex Sans", "Noto Sans SC", "Segoe UI", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --content: 1120px;
  --focus: 0 0 0 3px rgba(14, 156, 138, 0.35);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

html[lang="zh"] body {
  font-size: 16px;
}

html[lang="zh"] .lang-en,
html:not([lang="zh"]) .lang-zh {
  display: none !important;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--font-body);
  font-size: 16.5px;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

main {
  flex: 1 0 auto;
}

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

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

a:hover {
  color: #0b7d6e;
}

:focus-visible {
  outline: none;
  box-shadow: var(--focus);
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3.5rem;
  z-index: 100;
  background: var(--accent);
  color: #fff;
  padding: 0.5rem 0.85rem;
  border-radius: 6px;
  font-weight: 600;
}

.skip-link:focus {
  top: 0.75rem;
  color: #fff;
  box-shadow: var(--focus);
}

/* Header
   ---------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.header-inner,
.footer-inner,
.container {
  width: min(var(--content), calc(100% - 2.5rem));
  margin-inline: auto;
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--ink);
  flex-shrink: 0;
}

.brand:hover {
  color: var(--ink);
}

.brand img,
.brand-mark {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
}

.brand-text {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.05rem;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.14em;
}

.brand-sub {
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 8px;
  cursor: pointer;
  padding: 0;
  align-items: center;
  justify-content: center;
}

.nav-toggle-bars {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  position: relative;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--ink);
}

.nav-toggle-bars::before { top: -6px; }
.nav-toggle-bars::after { top: 6px; }

.nav {
  display: flex;
  align-items: center;
  gap: 0.25rem 1.35rem;
}

.nav a {
  color: var(--ink);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.3rem 0;
  border-bottom: 2px solid transparent;
}

.nav a:hover {
  color: var(--accent);
}

.nav a[aria-current="page"] {
  color: var(--navy);
  border-bottom-color: var(--accent-2);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.lang-toggle {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 999px;
  overflow: hidden;
  background: #fff;
}

.lang-toggle button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--ink-muted);
  font: 600 0.75rem/1 var(--font-body);
  letter-spacing: 0.06em;
  padding: 0.4rem 0.7rem;
  cursor: pointer;
}

.lang-toggle button[aria-pressed="true"] {
  background: var(--navy);
  color: #fff;
}

/* Hero
   ---------------------------------------------------------------------- */
.hero {
  background:
    linear-gradient(180deg, rgba(10, 22, 40, 0.2), transparent 40%),
    var(--navy);
  color: #eef3f8;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(26, 43, 72, 0.55) 1px, transparent 1px),
    linear-gradient(90deg, rgba(26, 43, 72, 0.55) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: radial-gradient(ellipse at 30% 40%, #000 20%, transparent 75%);
  pointer-events: none;
}

.hero-inner {
  width: min(var(--content), calc(100% - 2.5rem));
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: center;
  padding: 4.5rem 0 4.25rem;
  position: relative;
  z-index: 1;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--accent-bright);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 1rem;
}

.eyebrow::before {
  content: "";
  width: 1.25rem;
  height: 2px;
  background: var(--accent-bright);
}

.hero h1,
.page-hero h1 {
  font-family: var(--font-display);
  font-weight: 650;
  letter-spacing: -0.03em;
  line-height: 1.12;
  margin: 0 0 1rem;
}

.hero h1 {
  font-size: clamp(2.05rem, 4.2vw, 3.35rem);
  color: #fff;
  max-width: 18ch;
}

html[lang="zh"] .hero h1 {
  max-width: 16ch;
  letter-spacing: 0.02em;
}

.hero .lede {
  margin: 0 0 1.75rem;
  color: #b7c3d4;
  font-size: 1.08rem;
  max-width: 40rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.hero-graphic {
  justify-self: end;
  width: min(100%, 460px);
  filter: drop-shadow(0 20px 40px rgba(0, 0, 0, 0.28));
}

.trust-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  border-radius: 999px;
  padding: 0.3rem 0.7rem;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  border: 1px solid transparent;
}

.badge-csa {
  background: rgba(200, 16, 46, 0.12);
  border-color: rgba(200, 16, 46, 0.35);
  color: #ffd5db;
}

.badge-csa::before {
  content: "CSA";
  display: inline-block;
  background: var(--csa);
  color: #fff;
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  padding: 0.08rem 0.32rem;
  border-radius: 3px;
}

.badge-muted {
  background: rgba(255, 255, 255, 0.04);
  border-color: #243a5c;
  color: #c5d0de;
}

/* Buttons
   ---------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.75rem 1.15rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  line-height: 1.2;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease, transform 0.15s ease;
}

.btn:hover {
  text-decoration: none;
}

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

.btn-primary:hover {
  background: #0b8576;
  color: #fff;
}

.btn-ghost {
  background: transparent;
  color: #fff;
  border-color: #3a5478;
}

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

.btn-secondary {
  background: #fff;
  color: var(--navy);
  border-color: var(--line-strong);
}

.btn-secondary:hover {
  color: var(--navy);
  border-color: var(--accent);
}

/* Sections
   ---------------------------------------------------------------------- */
.section {
  padding: 4.25rem 0;
}

.section-header {
  max-width: 40rem;
  margin-bottom: 2.25rem;
}

.section-header h2,
.page-hero h1,
.category-block h2,
.contact-card h2 {
  font-family: var(--font-display);
  letter-spacing: -0.03em;
  line-height: 1.18;
}

.section-header h2,
.category-block h2 {
  font-size: clamp(1.55rem, 2.4vw, 2rem);
  margin: 0 0 0.6rem;
  color: var(--navy);
}

.section-kicker {
  margin: 0 0 0.4rem;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.muted,
.section-header p,
.page-hero p {
  color: var(--ink-muted);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.why-card,
.preview-card,
.product-card,
.contact-card,
.info-card {
  padding: 1.4rem 1.45rem 1.5rem;
}

.why-card h3,
.preview-card h3,
.product-card h3,
.info-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  margin: 0.7rem 0 0.45rem;
}

.why-card p,
.preview-card p,
.product-card p,
.info-card p {
  margin: 0;
  color: var(--ink-muted);
}

.icon-pill {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--accent-soft);
  color: var(--accent);
  display: grid;
  place-items: center;
}

.icon-pill svg {
  width: 22px;
  height: 22px;
}

.placeholder {
  font-family: var(--font-mono);
  font-size: 0.92em;
  color: #8a5a12;
  background: #fff6e5;
  padding: 0.05em 0.32em;
  border-radius: 4px;
  border: 1px dashed #e4c48a;
  white-space: nowrap;
}

/* Category preview
   ---------------------------------------------------------------------- */
.section-alt {
  background: #fff;
  border-block: 1px solid var(--line);
}

.preview-card {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
  min-height: 100%;
}

.preview-card:hover {
  border-color: var(--accent-2);
  box-shadow: var(--shadow);
  color: inherit;
  transform: translateY(-2px);
}

.preview-card .code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--accent);
  font-weight: 500;
}

.preview-card .more {
  margin-top: auto;
  padding-top: 1rem;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent);
}

/* CTA band
   ---------------------------------------------------------------------- */
.cta-band {
  background: var(--navy-2);
  color: #e8eef7;
}

.cta-band .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
  padding: 2.75rem 0;
}

.cta-band h2 {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 2.2vw, 1.85rem);
  letter-spacing: -0.03em;
  margin: 0 0 0.4rem;
  color: #fff;
}

.cta-band p {
  margin: 0;
  color: #9aabc2;
}

/* Page hero (inner pages)
   ---------------------------------------------------------------------- */
.page-hero {
  background: var(--navy);
  color: #fff;
  padding: 3rem 0 2.6rem;
  border-bottom: 3px solid var(--accent);
}

.page-hero h1 {
  font-size: clamp(1.8rem, 3vw, 2.55rem);
  margin: 0 0 0.6rem;
}

.page-hero p {
  margin: 0;
  color: #b7c3d4;
  max-width: 42rem;
  font-size: 1.05rem;
}

/* Products
   ---------------------------------------------------------------------- */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0 0 2rem;
}

.filter-btn {
  appearance: none;
  border: 1px solid var(--line-strong);
  background: #fff;
  color: var(--ink);
  font: 600 0.88rem/1 var(--font-body);
  padding: 0.5rem 0.85rem;
  border-radius: 999px;
  cursor: pointer;
}

.filter-btn:hover {
  border-color: var(--accent);
}

.filter-btn[aria-pressed="true"] {
  background: var(--navy);
  border-color: var(--navy);
  color: #fff;
}

.category-block {
  margin-bottom: 3rem;
}

.category-block header {
  margin-bottom: 1.15rem;
}

.category-block header p {
  margin: 0;
  color: var(--ink-muted);
  max-width: 46rem;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.15rem;
}

.product-card h3 {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.45rem 0.75rem;
}

.type-code {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--navy);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 0.1rem 0.45rem;
}

.product-card .type-name {
  font-weight: 650;
}

.spec-list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.4rem;
}

.spec-list li {
  display: grid;
  grid-template-columns: 8.5rem 1fr;
  gap: 0.75rem;
  font-size: 0.9rem;
  padding: 0.28rem 0;
  border-top: 1px solid var(--line);
}

.spec-list .label {
  color: var(--ink-muted);
}

.note {
  margin: 2rem 0 0;
  padding: 0.9rem 1rem;
  background: #fff;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-sm);
  color: var(--ink-muted);
  font-size: 0.92rem;
}

/* About / contact
   ---------------------------------------------------------------------- */
.prose {
  max-width: 42rem;
}

.prose p {
  margin: 0 0 1rem;
}

.prose p:last-child {
  margin-bottom: 0;
}

.split {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 1.5rem;
  align-items: start;
}

.contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.contact-list li {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 0.75rem;
  padding: 0.85rem 0;
  border-top: 1px solid var(--line);
  align-items: baseline;
}

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

.contact-list .label {
  color: var(--ink-muted);
  font-weight: 500;
}

.contact-list a {
  font-weight: 600;
  text-decoration: none;
}

.contact-list a:hover {
  text-decoration: underline;
}

.domain-link {
  color: var(--navy);
  font-weight: 600;
}

/* Footer
   ---------------------------------------------------------------------- */
.site-footer {
  background: var(--navy);
  color: #b7c3d4;
  padding: 2.5rem 0 1.75rem;
  margin-top: auto;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr;
  gap: 2rem;
}

.site-footer a {
  color: #d5deea;
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--accent-bright);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: #fff;
  text-decoration: none;
  margin-bottom: 0.85rem;
}

.footer-brand:hover { color: #fff; }

.footer-col h2 {
  font-family: var(--font-display);
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #8b9bb4;
  margin: 0 0 0.7rem;
  font-weight: 600;
}

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

.footer-col li + li {
  margin-top: 0.4rem;
}


.site-footer .brand-name {
  color: #fff;
}

.site-footer .brand-sub {
  color: #8b9bb4;
}

.copyright {
  width: min(var(--content), calc(100% - 2.5rem));
  margin: 2rem auto 0;
  padding-top: 1.25rem;
  border-top: 1px solid #1c3050;
  font-size: 0.85rem;
  color: #8b9bb4;
}

/* Utilities
   ---------------------------------------------------------------------- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.is-hidden {
  display: none !important;
}

/* Responsive
   ---------------------------------------------------------------------- */
@media (max-width: 900px) {
  .hero-inner,
  .grid-3,
  .split,
  .footer-inner,
  .cta-band .container {
    grid-template-columns: 1fr;
  }

  .hero-inner {
    padding: 3rem 0 2.5rem;
    gap: 2rem;
  }

  .hero h1 {
    max-width: none;
  }

  .hero-graphic {
    justify-self: center;
    width: min(100%, 400px);
  }

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

  .cta-band .container {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav {
    display: none;
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    align-items: stretch;
    padding: 0.75rem 1.25rem 1rem;
    gap: 0;
  }

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

  .nav a {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--line);
  }

  .nav a[aria-current="page"] {
    border-bottom-color: var(--line);
  }

  .spec-list li,
  .contact-list li {
    grid-template-columns: 1fr;
    gap: 0.15rem;
  }
}

@media (max-width: 600px) {
  .header-inner,
  .container,
  .footer-inner,
  .hero-inner,
  .copyright {
    width: min(var(--content), calc(100% - 1.5rem));
  }

  .section {
    padding: 3rem 0;
  }

  .brand-sub {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn,
  .preview-card {
    transition: none;
  }
}