@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Work+Sans:wght@400;500;600&family=Fira+Code:wght@400;600&display=swap');

:root {
  /* Brand Palette - 配方专家 */
  --primary: #166534;           /* 主色深绿 */
  --primary-dark: #14532D;
  --primary-muted: #E6F0E8;
  --secondary: #115E38;
  --accent: #B45309;            /* 品质金 */
  --accent-soft: #F9E8D7;
  --warning: #C2410C;

  /* 产品色系 */
  --coating-blue: #1E40AF;
  --coating-gray: #6B7280;
  --coating-white: #F9FAFB;

  --surface: #FFFFFF;
  --surface-muted: #F4F6F4;
  --muted-surface: var(--surface-muted);
  --background: #FAFAFA;
  --text-strong: #111827;
  --text: #1F2937;
  --text-soft: #6B7280;
  --border: #E5E7EB;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 8px 25px rgba(0, 0, 0, 0.08);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --max-width: 1220px;
  --space-xs: 0.5rem;
  --space-sm: 0.85rem;
  --space-md: 1.25rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --transition: 200ms ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Work Sans', 'Segoe UI', system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--background);
  line-height: 1.7;
  padding-top: 88px;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--secondary);
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-sm);
  font-family: 'DM Sans', 'Work Sans', sans-serif;
  color: var(--text-strong);
  line-height: 1.25;
}

p {
  margin: 0 0 var(--space-sm);
}

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

.container {
  width: 92%;
  max-width: var(--max-width);
  margin: 0 auto;
}

.section {
  padding: var(--space-xl) 0;
}

.section.tight {
  padding: var(--space-lg) 0;
}

.surface {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  padding: var(--space-lg);
}

.surface-muted {
  background: var(--muted-surface);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
}

.grid {
  display: grid;
  gap: var(--space-lg);
}

@media (min-width: 768px) {
  .grid.two-col {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid.three-col {
    grid-template-columns: repeat(3, 1fr);
  }
  .grid.four-col {
    grid-template-columns: repeat(4, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid.hero-grid {
    grid-template-columns: 1.2fr 1fr;
    align-items: center;
  }
}

.header {
  position: fixed;
  inset: 0 0 auto 0;
  height: 88px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(6px);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.06);
  z-index: 1000;
}

.nav-container {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 92%;
  max-width: var(--max-width);
  margin: 0 auto;
  gap: var(--space-md);
}

.logo {
  font-weight: 700;
  font-size: 1.4rem;
  letter-spacing: 0.02em;
  color: var(--primary);
  text-transform: uppercase;
}

.logo span {
  color: var(--accent);
}

.nav-menu {
  list-style: none;
  display: none;
  gap: var(--space-md);
  align-items: center;
  margin: 0;
  padding: 0;
}

.nav-item {
  position: relative;
}

.nav-item > a {
  font-weight: 600;
  color: var(--text-strong);
  padding: var(--space-sm) var(--space-xs);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-item > a:hover {
  color: var(--primary);
}

.nav-cta {
  padding: 0.55rem 0.95rem;
  background: var(--primary);
  color: #fff;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

.dropdown-menu-1,
.dropdown-menu-2 {
  position: absolute;
  left: 0;
  top: 100%;
  min-width: 240px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-xs) 0;
  list-style: none;
  margin: 0;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: var(--transition);
}

.nav-item:hover > .dropdown-menu-1,
.dropdown-item-1.has-submenu:hover > .dropdown-menu-2 {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item-1 a,
.dropdown-item-2 a {
  display: block;
  padding: 0.65rem 1rem;
  color: var(--text);
  font-weight: 500;
}

.dropdown-item-1 a:hover,
.dropdown-item-2 a:hover {
  background: var(--muted-surface);
  color: var(--primary);
}

.dropdown-menu-2 {
  left: 100%;
  top: 0;
}

.menu-toggle {
  display: inline-flex;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--primary);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
}

@media (min-width: 1024px) {
  .nav-menu {
    display: flex;
  }
  .menu-toggle {
    display: none;
  }
}

@media (max-width: 1023px) {
  .nav-menu {
    position: fixed;
    top: 88px;
    left: 0;
    right: 0;
    background: var(--surface);
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-md);
    gap: var(--space-sm);
    border-top: 1px solid var(--border);
    box-shadow: var(--shadow-md);
    max-height: calc(100vh - 88px);
    overflow-y: auto;
    z-index: 999;
  }

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

  .nav-item {
    width: 100%;
  }

  .nav-item > a {
    width: 100%;
    padding: 0.75rem 0.5rem;
    justify-content: space-between;
  }

  .dropdown-menu-1,
  .dropdown-menu-2 {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border: none;
    background: transparent;
    padding-left: 0.75rem;
  }

  .dropdown-item-1 a,
  .dropdown-item-2 a {
    padding: 0.5rem 0.25rem;
  }
}

.mobile-menu {
  position: fixed;
  inset: 88px 0 auto 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  padding: var(--space-md);
  display: none;
  flex-direction: column;
  gap: var(--space-sm);
  z-index: 999;
}

.mobile-menu.open {
  display: flex;
}

.mobile-menu a {
  font-weight: 600;
  color: var(--text-strong);
}

.hero {
  position: relative;
  padding: calc(var(--space-xl) + 32px) 0 var(--space-xl);
  background-size: cover;
  background-position: center;
  color: #fff;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(20, 83, 45, 0.9), rgba(17, 94, 56, 0.82));
}

.hero .container {
  position: relative;
  z-index: 2;
}

.hero-eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.85rem;
  color: var(--accent);
  margin-bottom: var(--space-xs);
  font-weight: 700;
}

.hero h1 {
  color: #fff;
  font-size: clamp(2rem, 4vw, 3.2rem);
}

.hero .lede {
  max-width: 720px;
  color: #f3f4f6;
  margin: var(--space-sm) 0 var(--space-md);
  font-size: 1.05rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  background: var(--primary);
  color: #fff;
  border: 1px solid var(--primary);
  transition: var(--transition);
  text-transform: none;
}

.btn:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
}

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

.btn.ghost {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--muted-surface);
  color: var(--text-strong);
  font-weight: 600;
  font-size: 0.9rem;
}

.pill.accent {
  background: var(--accent-soft);
  color: var(--accent);
}

.pill.warning {
  background: #FEF2E2;
  color: var(--warning);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  padding: var(--space-md);
  transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.card img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-sm);
}

@media (max-width: 768px) {
  .card img {
    height: 200px;
  }
}

.stat-grid {
  display: grid;
  gap: var(--space-md);
}

@media (min-width: 768px) {
  .stat-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.stat {
  padding: var(--space-md);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.stat .value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
}

.stat .label {
  margin-top: var(--space-xs);
  color: var(--text-soft);
  font-weight: 600;
}

.media-block {
  display: grid;
  gap: var(--space-md);
}

@media (min-width: 1024px) {
  .media-block {
    grid-template-columns: 1.1fr 1fr;
    align-items: center;
  }
}

.list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: var(--space-xs);
}

.list li {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  color: var(--text);
}

.list li::before {
  content: "•";
  color: var(--primary);
  font-weight: 700;
  margin-top: 0.1rem;
}

.table {
  width: 100%;
  border-collapse: collapse;
  margin-top: var(--space-md);
}

.table th,
.table td {
  padding: 0.75rem 0.85rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

.table thead th {
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  border-bottom: none;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  font-weight: 600;
  background: var(--muted-surface);
  color: var(--text-strong);
}

.tag.protective { background: rgba(22, 101, 52, 0.12); color: #0f3b25; }
.tag.water { background: rgba(30, 64, 175, 0.12); color: #142968; }
.tag.adhesive { background: rgba(180, 83, 9, 0.14); color: #7a2f06; }
.tag.sealant { background: rgba(107, 114, 128, 0.16); color: #1f2937; }

.eyebrow {
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: var(--space-xs);
}

.lede {
  font-size: 1.05rem;
  color: var(--text-soft);
  max-width: 760px;
}

.cta-banner {
  background: linear-gradient(120deg, var(--primary), var(--secondary));
  color: #fff;
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  display: grid;
  gap: var(--space-md);
  align-items: center;
  box-shadow: var(--shadow-md);
}

@media (min-width: 768px) {
  .cta-banner {
    grid-template-columns: 3fr auto;
  }
}

.badge-grid {
  display: grid;
  gap: var(--space-xs);
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}

.badge {
  padding: 0.65rem 0.85rem;
  background: var(--muted-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-weight: 600;
  color: var(--text-strong);
}

.case-card {
  display: grid;
  gap: var(--space-sm);
}

.case-metric {
  font-weight: 700;
  color: var(--primary);
}

.filter-bar {
  display: grid;
  gap: var(--space-sm);
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.input,
select,
textarea {
  width: 100%;
  padding: 0.65rem 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: #fff;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text);
}

textarea {
  min-height: 140px;
  resize: vertical;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.7rem;
  background: var(--muted-surface);
  border-radius: 999px;
  font-weight: 600;
}

.resource-grid {
  display: grid;
  gap: var(--space-md);
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.resource {
  display: grid;
  gap: var(--space-xs);
}

.resource-image {
  width: 100%;
  height: 260px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

@media (max-width: 768px) {
  .resource-image {
    height: 220px;
  }
}

.ribbon {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  padding: var(--space-sm) 0;
}

.ribbon .container {
  display: grid;
  gap: var(--space-sm);
}

@media (min-width: 1024px) {
  .ribbon .container {
    grid-template-columns: 1.4fr 1fr;
    align-items: center;
  }
}

.swatch-row {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(170px, 1fr);
  gap: var(--space-sm);
  overflow-x: auto;
  padding-bottom: 0.25rem;
}

.swatch-card {
  background: var(--surface-muted);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-sm);
  box-shadow: var(--shadow-sm);
  display: grid;
  gap: 0.35rem;
  min-width: 170px;
}

.swatch-bar {
  height: 54px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(0, 0, 0, 0.04);
}

.swatch-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 700;
  color: var(--text-strong);
}

.swatch-note {
  color: var(--text-soft);
  font-size: 0.9rem;
}

.swatch-protective { background: var(--primary-muted); }
.swatch-water { background: #E6EBFA; }
.swatch-adhesive { background: #FBE8D9; }
.swatch-sealant { background: #ECEEF1; }
.swatch-allied { background: #F7F7F5; }

.tds-quick {
  background: #0f1a12;
  color: #e5e7eb;
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  display: grid;
  gap: var(--space-sm);
  box-shadow: var(--shadow-md);
}

@media (min-width: 768px) {
  .tds-quick {
    grid-template-columns: 2fr 1.2fr;
    align-items: center;
  }
}

.tds-quick h3 {
  margin: 0;
  color: #fff;
}

.tds-actions {
  display: grid;
  gap: var(--space-xs);
}

.tds-actions .input {
  background: #111827;
  color: #fff;
  border-color: rgba(229, 231, 235, 0.3);
}

.selector {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.selector-header {
  padding: var(--space-sm) var(--space-md);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
}

.selector-tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  padding: var(--space-sm) var(--space-md) 0;
}

.selector-tab {
  padding: 0.55rem 0.9rem;
  border-radius: 999px;
  background: var(--surface-muted);
  border: 1px solid var(--border);
  color: var(--text-strong);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.selector-tab.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  box-shadow: var(--shadow-sm);
}

.selector-panel {
  display: none;
  padding: var(--space-md);
  border-top: 1px solid var(--border);
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

.selector-panel.active {
  display: grid;
}

@media (min-width: 900px) {
  .selector-panel {
    grid-template-columns: 1.1fr 1fr;
    align-items: center;
  }
}

.selector-panel img {
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.swatch-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-md);
}

.swatch-tile {
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  background: var(--surface);
  display: grid;
  grid-template-rows: 120px 1fr;
}

.swatch-tile .tile-color {
  border-bottom: 1px solid var(--border);
}

.swatch-tile .tile-body {
  padding: var(--space-md);
  display: grid;
  gap: 0.35rem;
}

.tile-body h3 {
  margin: 0;
}

.tile-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-soft);
  font-weight: 600;
}

.stat-compact {
  display: grid;
  gap: 0.25rem;
}

.stat-compact .value {
  font-weight: 700;
  color: var(--primary);
}

.stat-compact .label {
  color: var(--text-soft);
}

.footer {
  background: #0f1a12;
  color: #d1d5db;
  padding: var(--space-xl) 0 var(--space-lg);
  margin-top: var(--space-xl);
}

.footer h4 {
  color: var(--accent);
  margin-bottom: var(--space-sm);
}

.footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.5rem;
}

.footer a {
  color: #d1d5db;
}

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

.footer-bottom {
  margin-top: var(--space-lg);
  padding-top: var(--space-sm);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  text-align: center;
  color: #94a3b8;
}

.table-note {
  margin-top: var(--space-xs);
  color: var(--text-soft);
  font-size: 0.95rem;
}

.timeline {
  border-left: 2px solid var(--border);
  padding-left: var(--space-md);
  display: grid;
  gap: var(--space-md);
}

.timeline-item h4 {
  margin-bottom: 0.35rem;
}

.sds-callout {
  border-left: 4px solid var(--warning);
  padding: var(--space-sm) var(--space-md);
  background: #fdf3e6;
  border-radius: var(--radius-sm);
}

.table-striped tbody tr:nth-child(even) {
  background: var(--muted-surface);
}

.text-right {
  text-align: right;
}

.text-center {
  text-align: center;
}

.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

.align-center {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

@media (max-width: 600px) {
  .hero {
    padding: var(--space-lg) 0;
  }
  .section {
    padding: var(--space-lg) 0;
  }
}