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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-weight: 400;
  font-size: 16px;
  line-height: 1.6;
  color: #2c2c2c;
  background-color: #fafafa;
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  opacity: 0.75;
}

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

button {
  font-family: inherit;
  border: none;
  background: none;
  cursor: pointer;
}

/* ===== Layout ===== */
.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

.container.narrow {
  max-width: 720px;
}

/* ===== Header ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 250, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid #ececec;
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.logo-mark {
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: #1a1a1a;
}

.logo-sub {
  font-size: 0.65rem;
  font-weight: 400;
  letter-spacing: 0.18em;
  color: #888;
  text-transform: uppercase;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav {
  display: flex;
  gap: 28px;
}

.nav a {
  font-size: 0.875rem;
  font-weight: 500;
  color: #555;
  letter-spacing: 0.02em;
  transition: color 0.2s ease;
}

.nav a:hover {
  color: #111;
  opacity: 1;
}

/* ===== Language Switcher ===== */
.lang-switcher {
  position: relative;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 500;
  color: #555;
  padding: 6px 10px;
  border-radius: 6px;
  transition: background 0.15s, color 0.15s;
}

.lang-btn:hover,
.lang-btn.active {
  background: #f0f0f0;
  color: #111;
}

.lang-btn svg {
  opacity: 0.6;
  transition: transform 0.2s;
}

.lang-btn.active svg {
  transform: rotate(180deg);
}

.lang-dropdown {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  min-width: 130px;
  background: #fff;
  border: 1px solid #e8e8e8;
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  padding: 6px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 0.15s, transform 0.15s, visibility 0.15s;
  z-index: 200;
}

.lang-dropdown.open {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-dropdown button {
  display: block;
  width: 100%;
  text-align: left;
  padding: 8px 12px;
  font-size: 0.85rem;
  color: #444;
  border-radius: 5px;
  transition: background 0.12s;
}

.lang-dropdown button:hover {
  background: #f5f5f5;
  color: #111;
}

/* ===== Hero ===== */
.hero {
  padding: 100px 0 80px;
  text-align: center;
  background: linear-gradient(180deg, #fafafa 0%, #f5f5f5 100%);
}

.hero-chinese {
  font-size: 1rem;
  color: #888;
  letter-spacing: 0.15em;
  margin-bottom: 12px;
  font-weight: 400;
}

.hero h1 {
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  font-weight: 600;
  letter-spacing: 0.08em;
  color: #1a1a1a;
  margin-bottom: 16px;
}

.hero-tagline {
  font-size: 1.05rem;
  font-weight: 400;
  color: #666;
  margin-bottom: 20px;
}

.hero-desc {
  max-width: 540px;
  margin: 0 auto;
  font-size: 0.95rem;
  color: #777;
  line-height: 1.7;
}

/* ===== Sections ===== */
.section {
  padding: 80px 0;
}

.section-alt {
  background-color: #f3f3f3;
}

.section h2 {
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #1a1a1a;
  margin-bottom: 32px;
  text-align: center;
}

.section p {
  color: #555;
  margin-bottom: 1.1em;
  font-size: 0.975rem;
}

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

/* ===== Cards ===== */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
  margin-top: 8px;
}

.card {
  background: #fff;
  border: 1px solid #e8e8e8;
  border-radius: 10px;
  padding: 32px 28px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  border-color: #d0d0d0;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
}

.card-icon {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: #999;
  margin-bottom: 16px;
  padding: 4px 10px;
  background: #f5f5f5;
  border-radius: 4px;
}

.card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: #1a1a1a;
  margin-bottom: 12px;
}

.card p {
  font-size: 0.9rem;
  color: #666;
  line-height: 1.65;
  margin: 0;
}

/* ===== Contact ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px 48px;
}

.contact-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.contact-item .label {
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #999;
}

.contact-item span,
.contact-item a {
  font-size: 0.95rem;
  color: #333;
  line-height: 1.55;
}

.contact-item a {
  color: #1a1a1a;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

.contact-item a:hover {
  border-bottom-color: #ccc;
  opacity: 1;
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid #ececec;
  padding: 32px 0;
  text-align: center;
  background: #fafafa;
}

.footer p {
  font-size: 0.8rem;
  color: #999;
  margin-bottom: 4px;
}

.footer-domain {
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: #bbb;
}

/* ===== Responsive ===== */
@media (max-width: 700px) {
  .header .container {
    height: 56px;
  }

  .header-right {
    gap: 16px;
  }

  .nav {
    gap: 16px;
  }

  .nav a {
    font-size: 0.8rem;
  }

  .hero {
    padding: 72px 0 56px;
  }

  .section {
    padding: 56px 0;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

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

@media (max-width: 480px) {
  .logo-sub {
    display: none;
  }

  .nav {
    gap: 12px;
  }

  .nav a {
    font-size: 0.75rem;
  }

  .lang-btn {
    padding: 5px 8px;
    font-size: 0.75rem;
  }
}