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

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

body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
}

img, svg, video { display: block; max-width: 100%; }
button { font: inherit; }
a { color: var(--c-primary); }

::selection { background: var(--c-accent); color: #fff; }

:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 2px;
}

/* ============ Custom Properties ============ */
:root {
  --c-primary: #0F2A5F;
  --c-primary-dark: #0A1E42;
  --c-primary-light: #1A3A7A;
  --c-accent: #FF6B1A;
  --c-gold: #D4A017;
  --c-bg: #FFF8E7;
  --c-text: #241A12;
  --c-text-sub: #6B7B8D;
  --c-hover: #FF9E63;
  --c-red: #C0392B;

  --font-heading: Georgia, 'Noto Serif SC', 'Songti SC', 'STSong', 'SimSun', serif;
  --font-body: 'Noto Sans SC', 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;

  --header-width: 250px;
  --content-max: 1200px;
  --content-pad: clamp(1rem, 3vw, 2.5rem);

  --border-thin: 1px solid rgba(36, 26, 18, 0.12);
  --shadow-micro: 0 2px 8px rgba(36, 26, 18, 0.06);
  --shadow-card: 0 4px 20px rgba(36, 26, 18, 0.08);

  --dur: 300ms;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);

  --r-sm: 4px;
  --r-md: 8px;
  --r-lg: 16px;
}

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

.skip-link {
  position: fixed;
  top: -100%;
  left: 1rem;
  z-index: 2000;
  padding: 0.625rem 1.25rem;
  background: var(--c-accent);
  color: #fff;
  font-weight: 600;
  font-size: 0.875rem;
  text-decoration: none;
  border-radius: 0 0 var(--r-sm) var(--r-sm);
  transition: top 0.2s ease;
}

.skip-link:focus-visible {
  top: 0;
}

#main-content {
  min-height: 60vh;
}

#main-content:focus {
  outline: none;
}

/* ============ Typography ============ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--c-text);
}

h1 { font-size: clamp(2.125rem, 4vw + 0.5rem, 3.25rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.125rem); }
h3 { font-size: 1.25rem; }

p {
  margin: 0;
}

/* ============ Container / Section ============ */
.container {
  max-width: var(--content-max);
  margin: 0 auto;
  padding-inline: var(--content-pad);
}

.section {
  padding: clamp(2.5rem, 6vw, 4.5rem) 0;
}

.section-head {
  display: flex;
  align-items: baseline;
  gap: 0.875rem;
  margin-bottom: 1.5rem;
}

.section-number {
  font-family: var(--font-heading);
  font-style: italic;
  font-size: clamp(2rem, 4vw, 2.75rem);
  line-height: 1;
  color: var(--c-gold);
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw, 2.125rem);
  color: var(--c-text);
}

.section-desc {
  color: var(--c-text-sub);
  font-size: 0.9375rem;
  margin-top: 0.375rem;
}

/* ============ Buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease), transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.btn:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 2px;
}

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

.btn-accent:hover {
  background: var(--c-hover);
  color: var(--c-text);
}

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

.btn-primary:hover {
  background: var(--c-primary-light);
}

.btn-ghost {
  background: transparent;
  border-color: rgba(255, 255, 255, 0.35);
  color: #fff;
}

.btn-ghost:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.btn-block {
  width: 100%;
}

/* ============ Breadcrumb ============ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.375rem;
  list-style: none;
  margin: 0 0 2rem;
  padding: 0;
  font-size: 0.8125rem;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: '/';
  margin-right: 0.375rem;
  color: var(--c-text-sub);
  opacity: 0.6;
}

.breadcrumb-link {
  color: var(--c-text-sub);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.breadcrumb-link:hover {
  color: var(--c-accent);
}

.breadcrumb-current {
  color: var(--c-text);
  font-weight: 500;
}

/* ============ Bento Grid & Cards ============ */
.grid-bento {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: clamp(1rem, 2vw, 1.5rem);
}

.bento-card {
  border: var(--border-thin);
  border-radius: var(--r-md);
  background: #fff;
  padding: 1.5rem;
  box-shadow: var(--shadow-card);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.bento-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(36, 26, 18, 0.12);
}

/* ============ Media Frames ============ */
.media-frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--c-primary-dark), var(--c-primary-light));
  border-radius: var(--r-md);
  aspect-ratio: 16 / 9;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--portrait { aspect-ratio: 3 / 4; }

.media-frame > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ============ Brand ============ */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  text-decoration: none;
  color: inherit;
}

.brand-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  flex-shrink: 0;
  background: var(--c-accent);
  color: #fff;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.0625rem;
  border-radius: var(--r-sm);
  transform: rotate(-6deg);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.25);
}

.brand-name {
  font-family: var(--font-heading);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.brand-inverse {
  color: #fff;
}

/* ============ Header ============ */
.site-header {
  /* children manage their own positioning */
}

.header-topbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: 3.5rem;
  padding: 0 1rem;
  background: var(--c-primary);
  color: #fff;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.header-topbar .brand {
  color: #fff;
}

/* Nav toggle */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0.625rem;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.nav-toggle:hover {
  border-color: var(--c-accent);
}

.nav-toggle-icon {
  display: block;
  width: 1.125rem;
}

.nav-toggle-bar {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: #fff;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.nav-toggle-bar + .nav-toggle-bar {
  margin-top: 0.3125rem;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(0.4375rem) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-0.4375rem) rotate(-45deg);
}

/* Side nav (mobile drawer) */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  width: min(320px, 85vw);
  background: linear-gradient(180deg, var(--c-primary-dark), var(--c-primary));
  color: rgba(255, 255, 255, 0.85);
  z-index: 1200;
  transform: translateX(-100%);
  visibility: hidden;
  transition: transform var(--dur) var(--ease), visibility var(--dur);
  overflow-y: auto;
}

.site-nav[data-open="true"] {
  transform: translateX(0);
  visibility: visible;
  box-shadow: 8px 0 32px rgba(10, 30, 66, 0.35);
}

.nav-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 1.5rem 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-close {
  display: none;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  padding: 0;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--r-sm);
  color: #fff;
  font-size: 1.25rem;
  line-height: 1;
  cursor: pointer;
  transition: border-color var(--dur) var(--ease);
}

.nav-close:hover {
  border-color: var(--c-accent);
}

.nav-lead {
  margin: 0;
  padding: 0.75rem 1.5rem 0;
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.45);
}

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0.5rem 0;
  position: relative;
}

.nav-item + .nav-item {
  border-top: 1px solid rgba(255, 255, 255, 0.07);
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 0.875rem;
  padding: 0.875rem 1.5rem;
  color: rgba(255, 255, 255, 0.72);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  border-left: 3px solid transparent;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.nav-link:hover,
.nav-link:focus-visible {
  color: #fff;
  background: rgba(255, 255, 255, 0.04);
}

.nav-link[aria-current="page"] {
  color: #fff;
  background: linear-gradient(90deg, rgba(255, 107, 26, 0.18), transparent);
  border-left-color: var(--c-accent);
}

.nav-num {
  font-family: var(--font-heading);
  font-style: italic;
  font-size: 0.875rem;
  color: var(--c-gold);
  min-width: 1.625rem;
  text-align: right;
}

.nav-link[aria-current="page"] .nav-num {
  color: var(--c-accent);
}

.nav-foot {
  margin-top: auto;
  padding: 1.25rem 1.5rem 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.nav-service {
  margin: 0.75rem 0 0;
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.55);
  text-align: center;
}

/* Backdrop */
.nav-backdrop {
  position: fixed;
  inset: 0;
  z-index: 1100;
  background: rgba(10, 30, 66, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur) var(--ease), visibility var(--dur);
}

.nav-backdrop.is-visible {
  opacity: 1;
  visibility: visible;
}

/* Body scroll lock on mobile drawer */
@media (max-width: 767.98px) {
  body.nav-is-open {
    overflow: hidden;
  }
}

/* ============ Desktop Side Rail ============ */
@media (min-width: 768px) {
  body {
    padding-left: var(--header-width);
  }

  .header-topbar {
    display: none;
  }

  .nav-toggle {
    display: none;
  }

  .site-nav {
    transform: none;
    visibility: visible;
    width: var(--header-width);
    box-shadow: none;
    z-index: 1000;
    background: linear-gradient(180deg, var(--c-primary-dark), var(--c-primary) 80%);
  }

  .site-nav[data-open="true"] {
    box-shadow: none;
  }

  .nav-close {
    display: none;
  }

  .nav-head {
    padding: 1.5rem 1.5rem 1.25rem;
  }

  .nav-lead {
    padding: 0.875rem 1.5rem 0;
  }
}

/* ============ Footer ============ */
.site-footer {
  background: var(--c-primary-dark);
  color: rgba(255, 255, 255, 0.75);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  margin-top: 3rem;
}

.footer-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: clamp(2rem, 5vw, 3.5rem) var(--content-pad) 1.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.5fr;
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

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

.footer-trust {
  margin: 1rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.5);
  max-width: 24rem;
}

.footer-title {
  font-family: var(--font-heading);
  font-size: 0.9375rem;
  font-weight: 700;
  color: #fff;
  margin: 0 0 1rem;
  letter-spacing: 0.06em;
}

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

.footer-list li + li {
  margin-top: 0.5rem;
}

.footer-list a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color var(--dur) var(--ease);
}

.footer-list a:hover,
.footer-list a:focus-visible {
  color: var(--c-accent);
}

.footer-note {
  margin: 0.875rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.5);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 0.625rem 2rem;
  align-items: center;
  justify-content: space-between;
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.4);
}

.footer-bottom p {
  margin: 0;
}

.footer-tagline {
  font-family: var(--font-heading);
  font-style: italic;
  letter-spacing: 0.06em;
}

/* ============ Tabs ============ */
[data-tabs] .tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  padding: 0.3125rem;
  background: #fff;
  border: var(--border-thin);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-micro);
}

[data-tabs] [data-tab-trigger] {
  padding: 0.5rem 1rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--c-text-sub);
  background: transparent;
  border: none;
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}

[data-tabs] [data-tab-trigger]:hover {
  color: var(--c-text);
}

[data-tabs] [data-tab-trigger]:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 1px;
}

[data-tabs] [data-tab-trigger][aria-selected="true"] {
  background: var(--c-primary);
  color: #fff;
}

[data-tabs] [data-tab-panel] {
  padding-top: 1.25rem;
}

[data-tabs] [data-tab-panel][hidden] {
  display: none;
}

/* ============ Scroll Reveal ============ */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.55s var(--ease), transform 0.55s var(--ease);
  will-change: opacity, transform;
}

[data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ============ Responsive Footer ============ */
@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 767.98px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

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

/* ============ Reduced Motion ============ */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
    will-change: auto;
  }

  .site-nav,
  .nav-toggle-bar,
  .nav-backdrop {
    transition: none;
  }
}