/* ============================================================
   Bang Qiao — Scandinavian Minimalist Design System
   Colors: #FAFAFA bg, #1E293B text, #D4A373 wood accent,
           #64748B slate, #E2E8F0 thin borders
   ============================================================ */

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #FAFAFA;
  --text: #1E293B;
  --wood: #D4A373;
  --wood-light: #E8CFB4;
  --slate: #64748B;
  --slate-light: #94A3B8;
  --border: #E2E8F0;
  --border-light: #F1F5F9;
  --white: #FFFFFF;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --gap: 1.5rem;
  --section-padding: 7rem 2rem;
  --max-width: 1200px;
}

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Typography --- */
h1, h2, h3, h4 {
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: 1.25rem; color: var(--wood); font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; font-size: 0.8rem; margin-bottom: 0.75rem; }
h4 { font-size: 1.125rem; margin-bottom: 0.5rem; }

p {
  color: var(--slate);
  max-width: 60ch;
  font-size: 1.05rem;
  line-height: 1.7;
}

a {
  color: var(--wood);
  text-decoration: none;
  transition: color 0.25s ease;
}

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

/* --- Layout Utilities --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

.section-label {
  font-family: var(--font);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--wood);
  margin-bottom: 1rem;
}

.section-title {
  margin-bottom: 1.5rem;
}

.thin-divider {
  width: 100%;
  height: 1px;
  background: var(--border);
  margin: 0;
}

/* --- Header / Navigation --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s ease;
}

.site-header.scrolled {
  background: rgba(250, 250, 250, 0.95);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 2rem;
}

.logo {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 1.25rem;
  color: var(--text);
  letter-spacing: -0.02em;
}

.logo-sub {
  font-weight: 400;
  font-size: 0.7rem;
  color: var(--slate);
  letter-spacing: 0.04em;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 2.5rem;
}

.nav-links a {
  color: var(--slate);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  padding-bottom: 0.25rem;
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s ease, color 0.25s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text);
  border-bottom-color: var(--wood);
}

.lang-switch {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--slate);
  cursor: pointer;
  background: none;
  border: 1px solid var(--border);
  padding: 0.3rem 0.75rem;
  border-radius: 4px;
  transition: border-color 0.25s ease, color 0.25s ease;
  font-family: var(--font);
}

.lang-switch:hover {
  border-color: var(--wood);
  color: var(--wood);
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-toggle span {
  display: block;
  width: 24px;
  height: 1.5px;
  background: var(--text);
  margin: 6px 0;
  transition: transform 0.3s ease;
}

/* --- Hero --- */
.hero {
  padding-top: 10rem;
  padding-bottom: 5rem;
  text-align: left;
  max-width: var(--max-width);
  margin: 0 auto;
  padding-left: 2rem;
  padding-right: 2rem;
}

.hero h1 {
  max-width: 14ch;
  margin-bottom: 1.5rem;
}

.hero p {
  font-size: 1.2rem;
  max-width: 48ch;
  margin-bottom: 2.5rem;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 2rem;
  background: transparent;
  border: 1px solid var(--text);
  color: var(--text);
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  letter-spacing: 0.02em;
}

.hero-cta:hover {
  background: var(--text);
  color: var(--bg);
}

.hero-cta svg {
  width: 16px;
  height: 16px;
  transition: transform 0.3s ease;
}

.hero-cta:hover svg {
  transform: translateX(4px);
}

/* --- Metrics --- */
.metrics {
  padding: var(--section-padding);
  max-width: var(--max-width);
  margin: 0 auto;
}

.metrics-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-top: 3rem;
}

.metric-item {
  text-align: left;
}

.metric-item:not(:last-child) {
  border-right: 1px solid var(--border);
  padding-right: 2rem;
}

.metric-number {
  font-size: 3.5rem;
  font-weight: 300;
  color: var(--text);
  line-height: 1;
  letter-spacing: -0.03em;
  margin-bottom: 0.5rem;
}

.metric-label {
  font-size: 0.85rem;
  color: var(--slate);
  font-weight: 400;
  line-height: 1.5;
}

.metric-plus {
  color: var(--wood);
  font-weight: 300;
}

/* --- Services (Asymmetric L-shaped Grid) --- */
.services {
  padding: var(--section-padding);
  max-width: var(--max-width);
  margin: 0 auto;
}

.services-header {
  margin-bottom: 4rem;
}

.services-l-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
}

.service-main {
  grid-row: 1 / 3;
  padding-right: 3rem;
  border-right: 1px solid var(--border);
  padding-bottom: 3rem;
}

.service-main h4 {
  font-size: 1.75rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  line-height: 1.3;
}

.service-main p {
  font-size: 1rem;
  max-width: 40ch;
}

.service-secondary {
  padding: 1.5rem 0 1.5rem 3rem;
  border-bottom: 1px solid var(--border);
}

.service-secondary:last-child {
  border-bottom: none;
}

.service-secondary h4 {
  font-size: 1.2rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
}

.service-secondary p {
  font-size: 0.95rem;
  max-width: 40ch;
}

.service-num {
  font-family: var(--font);
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--slate-light);
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
  display: block;
}

/* --- Process --- */
.process {
  padding: var(--section-padding);
  max-width: var(--max-width);
  margin: 0 auto;
}

.process-header {
  margin-bottom: 4rem;
}

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

.process-step {
  position: relative;
  padding: 2.5rem 2rem 2.5rem 0;
}

.process-step:not(:last-child)::after {
  content: '';
  position: absolute;
  right: 0;
  top: 50%;
  width: 1px;
  height: 40px;
  background: var(--border);
  transform: translateY(-50%);
}

.process-step-num {
  font-size: 4rem;
  font-weight: 200;
  color: var(--wood-light);
  line-height: 1;
  letter-spacing: -0.04em;
  margin-bottom: 1rem;
}

.process-step h4 {
  font-size: 1.15rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 0.75rem;
}

.process-step p {
  font-size: 0.95rem;
}

/* Bracket connectors between steps (thin line brackets) */
.process-bracket {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin: 2rem 0;
}

.process-bracket span {
  width: 32px;
  height: 1px;
  background: var(--border);
}

/* --- About --- */
.about {
  padding: var(--section-padding);
  max-width: var(--max-width);
  margin: 0 auto;
}

.about-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6rem;
  align-items: start;
}

.about-left h2 {
  margin-bottom: 1.5rem;
}

.about-left p {
  margin-bottom: 1rem;
}

.about-right {
  padding-top: 3rem;
}

.about-stat {
  margin-bottom: 2.5rem;
}

.about-stat-number {
  font-size: 2.5rem;
  font-weight: 300;
  color: var(--wood);
  letter-spacing: -0.03em;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.about-stat-label {
  font-size: 0.85rem;
  color: var(--slate);
  line-height: 1.5;
}

/* --- CTA --- */
.cta {
  background: var(--wood-light);
  padding: 5rem 2rem;
  text-align: center;
}

.cta-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.cta h2 {
  color: var(--text);
  font-size: 1.75rem;
  font-weight: 500;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.cta p {
  color: var(--slate);
  margin: 0 auto 2rem;
}

.cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.9rem 2.5rem;
  background: var(--text);
  border: 1px solid var(--text);
  color: var(--bg);
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  letter-spacing: 0.02em;
}

.cta-btn:hover {
  background: transparent;
  color: var(--text);
}

.cta-btn svg {
  width: 16px;
  height: 16px;
}

/* --- Contact --- */
.contact {
  padding: var(--section-padding);
  max-width: var(--max-width);
  margin: 0 auto;
}

.contact-header {
  margin-bottom: 4rem;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6rem;
}

.contact-info-item {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border);
}

.contact-info-item:first-child {
  border-top: 1px solid var(--border);
}

.contact-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--wood);
  margin-bottom: 0.5rem;
}

.contact-value {
  font-size: 1.05rem;
  color: var(--text);
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.9rem 0;
  border: none;
  border-bottom: 1px solid var(--border);
  background: transparent;
  font-family: var(--font);
  font-size: 0.95rem;
  color: var(--text);
  transition: border-color 0.25s ease;
  outline: none;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--slate-light);
}

.form-group input:focus,
.form-group textarea:focus {
  border-bottom-color: var(--wood);
}

.form-group textarea {
  min-height: 100px;
  resize: vertical;
}

.form-submit {
  align-self: flex-start;
  padding: 0.85rem 2.5rem;
  background: transparent;
  border: 1px solid var(--text);
  color: var(--text);
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  letter-spacing: 0.04em;
  transition: all 0.3s ease;
  text-transform: uppercase;
}

.form-submit:hover {
  background: var(--text);
  color: var(--bg);
}

/* --- Footer --- */
.site-footer {
  padding: 4rem 2rem 3rem;
  border-top: 1px solid var(--border);
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 4rem;
  flex-wrap: wrap;
}

.footer-brand p {
  max-width: 30ch;
  font-size: 0.85rem;
  margin-top: 0.75rem;
}

.footer-links {
  display: flex;
  gap: 4rem;
}

.footer-col h4 {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--wood);
  margin-bottom: 1rem;
}

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

.footer-col li {
  margin-bottom: 0.5rem;
}

.footer-col a {
  font-size: 0.9rem;
  color: var(--slate);
  font-weight: 400;
}

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

.footer-bottom {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-bottom p {
  font-size: 0.8rem;
}

/* --- Legal Pages --- */
.legal-page {
  padding-top: 8rem;
  padding-bottom: 5rem;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 2rem;
  padding-right: 2rem;
}

.legal-page h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.legal-page .last-updated {
  color: var(--slate);
  font-size: 0.85rem;
  margin-bottom: 3rem;
}

.legal-page h2 {
  font-size: 1.5rem;
  font-weight: 500;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.legal-page p,
.legal-page li {
  font-size: 1rem;
}

.legal-page ul {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.legal-page li {
  color: var(--slate);
  margin-bottom: 0.5rem;
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Responsive --- */
@media (max-width: 768px) {
  :root {
    --section-padding: 4rem 1.5rem;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--bg);
    flex-direction: column;
    padding: 1.5rem 2rem;
    gap: 1.25rem;
    border-bottom: 1px solid var(--border);
  }

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

  .mobile-toggle {
    display: block;
  }

  .hero {
    padding-top: 7rem;
    padding-bottom: 3rem;
  }

  .metrics-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }

  .metric-item:nth-child(2) {
    border-right: none;
  }

  .metric-item:not(:last-child) {
    border-right: none;
  }

  .metrics-grid {
    gap: 2rem;
  }

  .metrics-grid .metric-item:nth-child(1),
  .metrics-grid .metric-item:nth-child(2) {
    border-bottom: 1px solid var(--border);
    padding-bottom: 1.5rem;
  }

  .services-l-grid {
    grid-template-columns: 1fr;
  }

  .service-main {
    grid-row: auto;
    padding-right: 0;
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding-bottom: 2rem;
    margin-bottom: 1.5rem;
  }

  .service-secondary {
    padding-left: 0;
  }

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

  .process-step:not(:last-child)::after {
    display: none;
  }

  .process-step {
    border-bottom: 1px solid var(--border);
  }

  .about-inner {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .about-right {
    padding-top: 0;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .footer-inner {
    flex-direction: column;
    gap: 2rem;
  }

  .footer-links {
    flex-direction: column;
    gap: 2rem;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 480px) {
  .metrics-grid {
    grid-template-columns: 1fr;
  }

  .metrics-grid .metric-item {
    border-right: none !important;
    border-bottom: 1px solid var(--border);
    padding-bottom: 1rem;
    padding-right: 0;
  }

  .metrics-grid .metric-item:last-child {
    border-bottom: none;
  }
}