/* ==========================================================================
   Components: buttons, chips, cards, inputs, hero, nav, footer, sticky bar
   ========================================================================== */

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  min-height: 48px;
  padding: 14px 24px;
  border-radius: var(--radius-md);
  font-family: var(--font-zh);
  font-size: var(--fs-label-md);
  font-weight: 500;
  letter-spacing: 0.02em;
  line-height: 1.4;
  text-align: center;
  transition: background var(--duration-base) var(--ease-out),
              color var(--duration-base) var(--ease-out),
              transform var(--duration-base) var(--ease-out),
              box-shadow var(--duration-base) var(--ease-out);
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
}

.btn:focus-visible {
  outline: 2px solid var(--color-brand-300);
  outline-offset: 2px;
}

.btn-primary {
  background: var(--color-brand-400);
  color: var(--color-surface);
  border: 1.5px solid var(--color-brand-400);
}
.btn-primary:hover,
.btn-primary:active {
  background: var(--color-brand-500);
  border-color: var(--color-brand-500);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-brand-400);
  border: 1.5px solid var(--color-brand-400);
}
.btn-secondary:hover {
  background: var(--color-brand-50);
  color: var(--color-brand-500);
  border-color: var(--color-brand-500);
}

.btn-line {
  background: var(--color-line);
  color: var(--color-surface);
  border: 1.5px solid var(--color-line);
}
.btn-line:hover {
  filter: brightness(0.92);
}

.btn-ghost {
  background: transparent;
  color: var(--color-brand-400);
  padding: 12px 16px;
  min-height: auto;
}
.btn-ghost:hover {
  background: var(--color-brand-50);
  color: var(--color-brand-500);
}

.btn-on-dark.btn-secondary {
  background: transparent;
  color: var(--color-surface);
  border-color: var(--color-surface);
}
.btn-on-dark.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--color-surface);
  border-color: var(--color-surface);
}

.btn-block {
  width: 100%;
}

.btn[disabled],
.btn[aria-disabled="true"] {
  background: var(--color-brand-100);
  color: var(--color-surface);
  border-color: var(--color-brand-100);
  opacity: 0.7;
  cursor: not-allowed;
  pointer-events: none;
}

.btn-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--color-ink);
  transition: background var(--duration-base) var(--ease-out);
}
.btn-icon:hover {
  background: var(--color-brand-50);
}

/* === Chips === */
.chip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  padding: 6px 12px;
  border-radius: var(--radius-full);
  font-family: var(--font-zh);
  font-size: var(--fs-label-sm);
  font-weight: 500;
  letter-spacing: 0.04em;
  line-height: 1.4;
}

.chip-available {
  background: var(--color-brand-400);
  color: var(--color-surface);
}

.chip-coming-soon {
  background: var(--color-brand-100);
  color: var(--color-brand-500);
}

.chip-filter {
  background: var(--color-surface);
  color: var(--color-brand-400);
  border: 1px solid var(--color-brand-400);
  padding: 8px 16px;
  cursor: pointer;
  transition: all var(--duration-base) var(--ease-out);
}
.chip-filter:hover {
  background: var(--color-brand-50);
}
.chip-filter[aria-pressed="true"],
.chip-filter.is-active {
  background: var(--color-brand-400);
  color: var(--color-surface);
}

/* === Cards === */
.card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  border: 1px solid var(--color-border);
}

.card-product {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  border: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  transition: box-shadow var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}
.card-product:hover {
  box-shadow: var(--shadow-sm);
  transform: translateY(-4px);
}

.card-feature {
  background: var(--color-surface-alt);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}

.card-coming-soon {
  background: var(--color-brand-50);
  background-image: linear-gradient(180deg, var(--color-brand-100) 0%, var(--color-surface) 100%);
  color: var(--color-brand-500);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
}

/* === Inputs === */
.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}
.field-label {
  font-family: var(--font-zh);
  font-size: var(--fs-label-md);
  font-weight: 500;
  color: var(--color-ink-soft);
}
.input-text {
  background: var(--color-surface);
  color: var(--color-ink);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  height: 48px;
  font-family: var(--font-zh);
  font-size: var(--fs-body-md);
  transition: border-color var(--duration-base) var(--ease-out),
              box-shadow var(--duration-base) var(--ease-out);
}
.input-text:focus {
  outline: none;
  border-color: var(--color-brand-400);
  box-shadow: 0 0 0 2px var(--color-brand-100);
}
.helper-text {
  font-family: var(--font-zh);
  font-size: var(--fs-caption);
  color: var(--color-ink-muted);
}

/* === Header === */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: saturate(180%) blur(8px);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--gutter-mobile);
  padding-right: var(--gutter-mobile);
}
.site-header__logo {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
}
.site-header__logo img {
  height: 28px;
  width: auto;
}
.site-header__logo-text {
  font-family: var(--font-en);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--color-brand-500);
  text-transform: uppercase;
}
.site-header__nav {
  display: none;
}
.site-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}
.site-header__line-mobile {
  display: inline-flex;
  min-height: 44px;
  padding: 0;
}
.site-header__line-mobile.btn-primary {
  background: var(--color-brand-400);
  color: var(--color-surface);
  border-color: var(--color-brand-400);
}
.site-header__line-mobile.btn-line {
  background: var(--color-line);
  color: var(--color-surface);
  border-color: var(--color-line);
}
.site-header__line-desktop {
  display: none;
}

@media (min-width: 1025px) {
  .site-header__inner {
    height: var(--header-height-desktop);
    padding-left: var(--gutter-desktop);
    padding-right: var(--gutter-desktop);
  }
  .site-header__logo img {
    height: 32px;
  }
  .site-header__nav {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
  }
  .nav-link {
    font-family: var(--font-zh);
    font-size: var(--fs-label-md);
    font-weight: 500;
    color: var(--color-ink);
    position: relative;
    padding: 8px 0;
    transition: color var(--duration-base) var(--ease-out);
  }
  .nav-link:hover {
    color: var(--color-brand-500);
  }
  .nav-link[aria-current="page"] {
    color: var(--color-brand-500);
  }
  .nav-link[aria-current="page"]::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -2px;
    height: 2px;
    background: var(--color-brand-400);
  }
  .site-header__hamburger {
    display: none;
  }
  .site-header__line-mobile {
    display: none;
  }
  .site-header__line-desktop {
    display: inline-flex;
  }
}

/* === Mobile menu (full screen drawer) === */
.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 60;
  background: var(--color-surface);
  transform: translateX(100%);
  transition: transform 250ms var(--ease-out);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}
.mobile-menu.is-open {
  transform: translateX(0);
}
.mobile-menu__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  padding: 0 var(--gutter-mobile);
  border-bottom: 1px solid var(--color-border);
}
.mobile-menu__list {
  list-style: none;
  margin: 0;
  padding: var(--space-lg) var(--gutter-mobile);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  flex: 1;
}
.mobile-menu__list a {
  font-family: var(--font-zh);
  font-size: var(--fs-headline-sm);
  font-weight: 500;
  color: var(--color-ink);
  padding: 12px 0;
  display: block;
}
.mobile-menu__sub {
  list-style: none;
  margin: 0;
  padding-left: var(--space-md);
  border-left: 2px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}
.mobile-menu__sub a {
  font-size: var(--fs-body-md);
  font-weight: 400;
  color: var(--color-ink-soft);
  padding: 8px 0;
}
.mobile-menu__bottom {
  padding: var(--space-lg) var(--gutter-mobile) calc(var(--space-lg) + env(safe-area-inset-bottom));
  border-top: 1px solid var(--color-border);
  background: var(--color-brand-50);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

@media (min-width: 1025px) {
  .mobile-menu {
    display: none;
  }
}

/* === Sticky CTA Bar (mobile) === */
.sticky-cta {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 45;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: saturate(180%) blur(8px);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
  border-top: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  padding: 12px var(--gutter-mobile) calc(12px + env(safe-area-inset-bottom));
  display: flex;
  gap: 12px;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity var(--duration-base) var(--ease-out),
              transform var(--duration-base) var(--ease-out);
}
.sticky-cta.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}
.sticky-cta .btn {
  flex: 1;
  min-height: 48px;
  padding: 12px 16px;
}

@media (min-width: 1025px) {
  .sticky-cta {
    display: none !important;
  }
}

body.has-sticky-cta {
  padding-bottom: 96px;
}
@media (min-width: 1025px) {
  body.has-sticky-cta {
    padding-bottom: 0;
  }
}

/* === Footer === */
.site-footer {
  background: var(--color-brand-500);
  color: var(--color-surface);
  padding: var(--space-2xl) 0 var(--space-lg);
  margin-top: var(--space-3xl);
}
.site-footer a {
  color: var(--color-surface);
  opacity: 0.85;
}
.site-footer a:hover {
  opacity: 1;
  color: var(--color-brand-100);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-xl);
}
.footer-col h4 {
  font-family: var(--font-zh);
  font-size: var(--fs-label-md);
  font-weight: 700;
  letter-spacing: 0.04em;
  margin: 0 0 var(--space-md);
  color: var(--color-brand-100);
  text-transform: uppercase;
}
.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.footer-col p {
  margin: 0 0 var(--space-md);
  line-height: 1.7;
  font-size: var(--fs-body-sm);
}
.footer-brand-logo {
  height: 32px;
  filter: brightness(0) invert(1);
  margin-bottom: var(--space-md);
}
.footer-bottom {
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  font-size: var(--fs-caption);
  opacity: 0.75;
}
.footer-bottom__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

@media (min-width: 1025px) {
  .footer-grid {
    grid-template-columns: 1.4fr 1fr 1fr 1fr;
    gap: var(--space-2xl);
  }
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

/* === Hero shared === */
.hero {
  position: relative;
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
}
.hero--light {
  background: var(--color-brand-50);
}
.hero--dark {
  background: var(--color-brand-500);
  color: var(--color-surface);
}
.hero--text-only {
  background: var(--color-surface);
}
.hero__eyebrow {
  font-family: var(--font-en);
  font-size: var(--fs-english-label);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-brand-400);
  margin-bottom: var(--space-md);
}
.hero--dark .hero__eyebrow {
  color: var(--color-brand-100);
}
.hero__title {
  font-family: var(--font-zh);
  font-size: var(--fs-headline-lg);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.02em;
  margin: 0;
}
.hero__subtitle {
  margin-top: var(--space-md);
  font-size: var(--fs-body-lg);
  line-height: 1.7;
  color: var(--color-ink-soft);
  max-width: 560px;
}
.hero--dark .hero__subtitle {
  color: rgba(255, 255, 255, 0.85);
}
.hero__actions {
  margin-top: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}
.hero__actions .btn {
  width: 100%;
}

@media (min-width: 641px) {
  .hero {
    padding-top: var(--space-3xl);
    padding-bottom: var(--space-3xl);
  }
  .hero__actions {
    flex-direction: row;
    flex-wrap: wrap;
  }
  .hero__actions .btn {
    width: auto;
  }
}
@media (min-width: 1025px) {
  .hero {
    padding-top: var(--space-4xl);
    padding-bottom: var(--space-4xl);
  }
}

/* === Breadcrumb === */
.breadcrumb {
  font-family: var(--font-zh);
  font-size: var(--fs-caption);
  color: var(--color-ink-muted);
  padding: var(--space-md) 0;
}
.breadcrumb a {
  color: var(--color-ink-muted);
}
.breadcrumb a:hover {
  color: var(--color-brand-400);
}
.breadcrumb [aria-current="page"] {
  color: var(--color-ink-soft);
}
.breadcrumb__sep {
  margin: 0 var(--space-xs);
  color: var(--color-border-strong);
}

/* === Section header === */
.section-head {
  text-align: center;
  margin-bottom: var(--space-2xl);
}
.section-head__eyebrow {
  font-family: var(--font-en);
  font-size: var(--fs-english-label);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-brand-300);
  margin-bottom: var(--space-sm);
}
.section-head__title {
  font-family: var(--font-zh);
  font-size: var(--fs-headline-md);
  font-weight: 700;
  letter-spacing: 0.02em;
  margin: 0 0 var(--space-md);
}
.section-head__desc {
  max-width: 560px;
  margin: 0 auto;
  font-size: var(--fs-body-md);
  color: var(--color-ink-soft);
}

/* === CTA section === */
.cta-section {
  padding: var(--space-3xl) 0;
}
.cta-section--dark {
  background: var(--color-brand-500);
  color: var(--color-surface);
}
.cta-section__title {
  font-family: var(--font-zh);
  font-size: var(--fs-headline-md);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: 0.02em;
  margin: 0 0 var(--space-md);
  text-align: center;
}
.cta-section__desc {
  text-align: center;
  max-width: 560px;
  margin: 0 auto var(--space-xl);
  color: var(--color-ink-soft);
  line-height: 1.7;
}
.cta-section--dark .cta-section__desc {
  color: rgba(255, 255, 255, 0.85);
}
.cta-section__actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  max-width: 360px;
  margin: 0 auto;
}
.cta-section__actions .btn {
  width: 100%;
}

@media (min-width: 641px) {
  .cta-section__actions {
    flex-direction: row;
    max-width: 560px;
  }
  .cta-section__actions .btn {
    flex: 1;
  }
}

/* === Brand glyph (placeholder logomark for nav) === */
.brand-glyph {
  font-family: var(--font-en);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.08em;
  color: var(--color-brand-500);
}
/* Language switcher */
.language-switcher { display:flex; align-items:center; gap:6px; white-space:nowrap; font-size:12px; letter-spacing:.08em; }
.language-switcher a { color:var(--color-ink-muted); text-decoration:none; padding:6px 3px; border-radius:4px; }
.language-switcher a[aria-current="true"] { color:var(--color-brand-500); font-weight:700; }
.language-switcher a:focus-visible { outline:2px solid var(--color-brand-300); outline-offset:2px; }
.language-switcher--mobile { justify-content:center; padding:12px 24px 0; font-size:14px; }

@media (max-width: 1100px) { .site-header__actions > .language-switcher:not(.language-switcher--mobile) { display:none; } }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration:.01ms !important; animation-iteration-count:1 !important; transition-duration:.01ms !important; scroll-behavior:auto !important; }
}