/* ============ 1. CSS Variables ============ */
:root {
  --deep-blue: #0B2545;
  --deep-blue-dark: #071A33;
  --gold: #C9A227;
  --gold-light: #DDBB4A;
  --cream: #F4F1E8;
  --cream-dark: #E6E1D3;
  --rock-gray: #8A8D7C;
  --moss-green: #5A6B53;
  --terracotta: #B36A4B;
  --orange: #E86A33;
  --ink: #111111;
  --white: #FFFFFF;

  --font-headline: "Source Han Sans CN", "Noto Sans CJK SC", "思源黑体", "Microsoft YaHei", sans-serif;
  --font-data: "Roboto Mono", "SFMono-Regular", "Cascadia Mono", "Consolas", monospace;
  --font-body: "Source Han Serif CN", "Noto Serif CJK SC", "思源宋体", "Georgia", serif;

  --border-thick: 4px;
  --border-med: 2px;
  --border-thin: 1px;

  --shadow-hard: 5px 5px 0 rgba(17, 17, 17, 0.28);
  --shadow-hard-blue: 5px 5px 0 rgba(11, 37, 69, 0.25);

  --header-height: 72px;
  --header-height-mobile: 60px;
  --container-width: 1200px;
  --content-pad: 24px;
  --breakpoint-lg: 1080px;
  --breakpoint-md: 960px;
  --breakpoint-sm: 640px;

  --transition-fast: 0.18s ease;
  --transition-med: 0.3s ease;
  --transition-slow: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ============ 2. Reset & Base ============ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  background: var(--cream);
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--deep-blue);
  background: var(--cream);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.nav-open {
  overflow: hidden;
}

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

h1,
h2,
h3,
h4 {
  font-family: var(--font-headline);
  line-height: 1.2;
  font-weight: 900;
  color: var(--deep-blue);
}

h1 { font-size: clamp(40px, 6vw, 72px); }
h2 { font-size: clamp(28px, 3.6vw, 44px); }
h3 { font-size: clamp(20px, 2vw, 26px); }
h4 { font-size: 18px; }

a {
  color: var(--deep-blue);
  text-underline-offset: 4px;
}

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

button {
  font-family: inherit;
}

::selection {
  background: var(--gold);
  color: var(--deep-blue);
}

@media (max-width: 960px) {
  html {
    scroll-padding-top: calc(var(--header-height-mobile) + 12px);
  }
}

/* ============ 3. Container & Utilities ============ */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: var(--content-pad);
}

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.mono {
  font-family: var(--font-data);
  letter-spacing: 0.02em;
}

.vertical-note {
  writing-mode: vertical-rl;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.25em;
  color: var(--rock-gray);
  text-transform: uppercase;
}

.divider {
  display: block;
  height: 4px;
  border: 0;
  background: linear-gradient(90deg, var(--gold) 0%, var(--gold) 60%, transparent 100%);
}

.number-texture {
  position: relative;
  background-image:
    repeating-linear-gradient(
      0deg,
      rgba(201, 162, 39, 0.04) 0,
      rgba(201, 162, 39, 0.04) 1px,
      transparent 1px,
      transparent 32px
    ),
    repeating-linear-gradient(
      90deg,
      rgba(201, 162, 39, 0.03) 0,
      rgba(201, 162, 39, 0.03) 1px,
      transparent 1px,
      transparent 56px
    );
}

/* ============ 4. Buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border: 2px solid var(--ink);
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 14px;
  line-height: 1;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-med), color var(--transition-med);
  color: var(--ink);
  background: var(--cream);
}

.btn:hover {
  transform: translate(-1px, -1px);
  box-shadow: 7px 7px 0 var(--ink);
  color: var(--ink);
}

.btn:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--ink);
}

.btn-primary {
  background: var(--orange);
  color: var(--cream);
  border-color: var(--ink);
  box-shadow: 4px 4px 0 var(--ink);
}

.btn-primary:hover {
  background: var(--orange);
  box-shadow: 7px 7px 0 var(--ink);
  color: var(--cream);
}

.btn-ghost {
  background: transparent;
  border-color: var(--gold);
  color: var(--gold);
  box-shadow: 4px 4px 0 rgba(201, 162, 39, 0.35);
}

.btn-ghost:hover {
  background: rgba(201, 162, 39, 0.08);
  border-color: var(--gold-light);
  color: var(--gold-light);
  box-shadow: 7px 7px 0 rgba(201, 162, 39, 0.3);
}

.btn-block {
  display: flex;
  width: 100%;
}

/* ============ 5. Header ============ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: transparent;
  transition: background 0.35s ease, box-shadow 0.35s ease;
}

.site-header[data-scrolled="true"] {
  background: var(--deep-blue);
  box-shadow: 0 4px 24px rgba(7, 26, 51, 0.35);
}

.site-header[data-scrolled="true"]::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--gold) 0%, rgba(201, 162, 39, 0.35) 45%, transparent 100%);
  pointer-events: none;
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: var(--header-height);
}

.skip-link {
  position: fixed;
  top: -60px;
  left: 16px;
  z-index: 1000;
  padding: 12px 20px;
  background: var(--gold);
  color: var(--ink);
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
  border: 2px solid var(--ink);
  box-shadow: 4px 4px 0 var(--ink);
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 16px;
}

/* --- Brand --- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--cream);
  flex-shrink: 0;
}

.brand:hover {
  color: var(--gold);
}

.brand-mark {
  display: grid;
  grid-template-columns: repeat(2, 9px);
  grid-template-rows: repeat(2, 9px);
  gap: 3px;
  width: 22px;
  height: 22px;
  padding: 2px;
  border: 2px solid var(--gold);
  background: rgba(11, 37, 69, 0.55);
}

.brand-dot {
  border-radius: 2px;
  background: var(--gold);
}

.brand-dot:nth-child(2),
.brand-dot:nth-child(3) {
  background: transparent;
  border: 1px solid var(--gold);
}

.brand-text {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 24px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--cream);
  text-shadow: 0 1px 8px rgba(7, 26, 51, 0.4);
}

.brand-suffix {
  font-family: var(--font-data);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--gold);
  border: 1px solid var(--gold);
  padding: 3px 5px;
  line-height: 1;
  border-radius: 2px;
  align-self: center;
}

/* --- Navigation --- */
.main-nav {
  flex: 1;
  display: flex;
  justify-content: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
}

.nav-link {
  position: relative;
  display: block;
  padding: 12px 14px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 600;
  color: var(--cream);
  text-decoration: none;
  letter-spacing: 0.06em;
  white-space: nowrap;
  transition: color var(--transition-fast);
  text-shadow: 0 1px 8px rgba(7, 26, 51, 0.35);
}

.nav-link::after {
  content: '';
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 4px;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.25s cubic-bezier(0.22, 1, 0.36, 1);
}

.nav-link:hover {
  color: var(--gold);
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
}

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

/* --- Header CTA --- */
.header-cta {
  margin-left: 8px;
  padding: 10px 18px;
  white-space: nowrap;
}

/* --- Scroll progress --- */
.scroll-progress {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--gold) 0%, var(--orange) 90%);
  z-index: 105;
  pointer-events: none;
  transition: width 0.08s linear;
}

/* --- Mobile Nav Toggle --- */
.nav-toggle {
  display: none;
  position: relative;
  z-index: 120;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: transparent;
  border: 2px solid var(--gold);
  border-radius: 2px;
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  transition: background var(--transition-fast);
}

.nav-toggle:hover {
  background: rgba(201, 162, 39, 0.1);
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--gold);
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1), opacity 0.2s;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) 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(-7px) rotate(-45deg);
}

@media (max-width: 960px) {
  .header-inner {
    height: var(--header-height-mobile);
  }

  .nav-toggle {
    display: flex;
  }

  .header-cta {
    margin-left: auto;
    padding: 8px 14px;
    font-size: 13px;
  }

  .main-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 110;
    width: min(340px, 84vw);
    background: var(--deep-blue-dark);
    border-left: 3px solid var(--gold);
    box-shadow: -12px 0 36px rgba(0, 0, 0, 0.4);
    padding: calc(var(--header-height-mobile) + 32px) 32px 40px;
    transform: translateX(100%);
    transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    flex-direction: column;
    overflow-y: auto;
    flex: none;
    justify-content: flex-start;
  }

  .main-nav[data-open="true"] {
    transform: translateX(0);
  }

  .nav-list {
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    width: 100%;
  }

  .nav-item {
    width: 100%;
  }

  .nav-link {
    display: block;
    width: 100%;
    padding: 16px 0;
    font-size: 18px;
    border-bottom: 1px solid rgba(201, 162, 39, 0.15);
    text-shadow: none;
  }

  .nav-link::after {
    display: none;
  }
}

@media (max-width: 480px) {
  .header-cta {
    padding: 8px 12px;
    font-size: 12px;
  }

  .brand-text {
    font-size: 20px;
  }

  .brand-suffix {
    display: none;
  }
}

/* ============ 6. Page Hero & Main ============ */
.page-hero {
  background: var(--deep-blue);
  color: var(--cream);
  padding: calc(var(--header-height) + 72px) 0 64px;
  position: relative;
  overflow: hidden;
  min-height: 460px;
  display: flex;
  align-items: flex-end;
}

.page-hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(
      90deg,
      rgba(201, 162, 39, 0.03) 0,
      rgba(201, 162, 39, 0.03) 1px,
      transparent 1px,
      transparent 60px
    ),
    repeating-linear-gradient(
      0deg,
      rgba(201, 162, 39, 0.02) 0,
      rgba(201, 162, 39, 0.02) 1px,
      transparent 1px,
      transparent 44px
    );
  pointer-events: none;
}

.page-hero > * {
  position: relative;
  z-index: 1;
}

@media (max-width: 960px) {
  .page-hero {
    padding: calc(var(--header-height-mobile) + 48px) 0 48px;
    min-height: 360px;
  }
}

#main-content {
  display: block;
  scroll-margin-top: calc(var(--header-height) + 16px);
}

@media (max-width: 960px) {
  #main-content {
    scroll-margin-top: calc(var(--header-height-mobile) + 12px);
  }
}

/* ============ 7. Breadcrumb ============ */
.breadcrumb {
  padding: 20px 0 4px;
  font-family: var(--font-data);
  font-size: 13px;
  color: var(--rock-gray);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.breadcrumb-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb-item + .breadcrumb-item::before {
  content: "→";
  color: var(--gold);
  font-family: var(--font-data);
  font-size: 12px;
}

.breadcrumb-link {
  color: var(--rock-gray);
  text-decoration: none;
  font-size: 13px;
  letter-spacing: 0.04em;
  transition: color var(--transition-fast);
}

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

.breadcrumb-item[aria-current="page"] {
  color: var(--deep-blue);
  font-weight: 700;
}

/* ============ 8. Sections & Grids ============ */
.section {
  padding-block: clamp(64px, 12vh, 112px);
  position: relative;
}

.section-heading {
  display: grid;
  gap: 8px;
  margin-bottom: 48px;
  padding-left: 20px;
  border-left: 6px solid var(--gold);
}

.section-title {
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.15;
  margin: 0;
  letter-spacing: 0.01em;
}

.section-note {
  font-family: var(--font-data);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--rock-gray);
  margin: 0;
}

.content-grid {
  display: grid;
  gap: 32px;
}

.content-main,
.content-side {
  min-width: 0;
}

@media (min-width: 768px) {
  .content-grid {
    grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
    column-gap: 48px;
    row-gap: 32px;
  }
}

.grid-2,
.grid-3 {
  display: grid;
  gap: 24px;
}

@media (min-width: 640px) {
  .grid-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .grid-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .grid-3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .grid-2 {
    gap: 32px;
  }

  .grid-3 {
    gap: 32px;
  }
}

/* ============ 9. Data Components ============ */
.data-card {
  background: var(--cream);
  border: 1px solid var(--ink);
  border-top: 4px solid var(--gold);
  box-shadow: var(--shadow-hard);
  padding: 24px;
  display: grid;
  gap: 8px;
  transition: transform var(--transition-med), box-shadow var(--transition-med);
}

.data-card:hover {
  transform: translate(-2px, -2px);
  box-shadow: 8px 8px 0 rgba(11, 37, 69, 0.3);
}

.data-card-label {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--rock-gray);
  text-transform: uppercase;
}

.data-card-value {
  font-family: var(--font-data);
  font-size: clamp(28px, 3vw, 40px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--deep-blue);
  letter-spacing: -0.01em;
}

.data-card-value[data-trend="up"] {
  color: var(--moss-green);
}

.data-card-value[data-trend="down"] {
  color: var(--terracotta);
}

.stat-row {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid rgba(11, 37, 69, 0.15);
}

.stat-row .stat-label {
  font-family: var(--font-body);
  font-size: 14px;
  color: var(--rock-gray);
}

.stat-row .stat-value {
  font-family: var(--font-data);
  font-size: 20px;
  font-weight: 700;
  color: var(--deep-blue);
}

/* ============ 10. Decorative ============ */
.ball-motif {
  position: relative;
  width: 72px;
  height: 72px;
  border-radius: 50%;
  border: 2px solid var(--gold);
  background: var(--deep-blue);
  display: grid;
  place-items: center;
  box-shadow: inset -6px -6px 16px rgba(0, 0, 0, 0.28), inset 6px 6px 16px rgba(201, 162, 39, 0.12);
}

.ball-motif::before {
  content: '';
  position: absolute;
  inset: 10px;
  border-radius: 50%;
  border: 1px dashed rgba(201, 162, 39, 0.5);
}

.ball-motif::after {
  content: '★';
  color: var(--gold);
  font-family: var(--font-data);
  font-size: 18px;
  line-height: 1;
}

/* ============ 11. Footer ============ */
.site-footer {
  position: relative;
  background: var(--deep-blue);
  color: var(--cream);
  overflow: hidden;
}

.footer-goldbar {
  display: block;
  height: 4px;
  background: linear-gradient(90deg, var(--gold) 0%, var(--gold) 65%, transparent 100%);
}

.footer-inner {
  padding-block: 64px 32px;
}

.footer-top {
  display: grid;
  gap: 48px;
}

.footer-brand-col {
  display: grid;
  align-content: start;
  gap: 20px;
}

.footer-intro {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.8;
  color: rgba(244, 241, 232, 0.85);
  max-width: 34ch;
}

.footer-trust {
  font-family: var(--font-data);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: rgba(201, 162, 39, 0.8);
  border-left: 2px solid var(--gold);
  padding-left: 14px;
  max-width: 44ch;
  margin-top: 4px;
}

.footer-heading {
  font-family: var(--font-data);
  font-size: 13px;
  letter-spacing: 0.25em;
  color: var(--gold);
  text-transform: uppercase;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(201, 162, 39, 0.3);
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.footer-links a {
  color: rgba(244, 241, 232, 0.85);
  text-decoration: none;
  font-size: 14px;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.footer-links a:hover {
  color: var(--gold);
  padding-left: 6px;
}

.footer-contact {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.footer-contact li {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.6;
  color: rgba(244, 241, 232, 0.8);
}

.footer-contact-label {
  display: block;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--gold);
  margin-bottom: 2px;
}

.footer-note {
  font-family: var(--font-data);
  font-size: 12px;
  line-height: 1.7;
  color: rgba(138, 141, 124, 0.9);
  border: 1px solid rgba(138, 141, 124, 0.3);
  padding: 12px 14px;
  margin-top: 20px;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid rgba(201, 162, 39, 0.2);
  font-family: var(--font-data);
  font-size: 12px;
  color: rgba(138, 141, 124, 0.9);
}

.footer-copy {
  color: rgba(244, 241, 232, 0.6);
}

.footer-icp {
  color: rgba(138, 141, 124, 0.7);
  letter-spacing: 0.05em;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-legal a {
  color: rgba(244, 241, 232, 0.7);
  text-decoration: none;
  font-size: 12px;
  transition: color var(--transition-fast);
}

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

.footer-vertical-note {
  position: absolute;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  writing-mode: vertical-rl;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: 0.4em;
  color: rgba(201, 162, 39, 0.3);
  text-transform: uppercase;
  pointer-events: none;
}

@media (min-width: 961px) {
  .footer-top {
    grid-template-columns: 1.4fr 0.8fr 1.2fr;
    gap: 64px;
  }
}

@media (max-width: 768px) {
  .footer-vertical-note {
    display: none;
  }

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

/* ============ 12. Back to Top ============ */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 90;
  width: 48px;
  height: 48px;
  border: 2px solid var(--gold);
  background: var(--deep-blue);
  color: var(--gold);
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.35);
  display: grid;
  place-items: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity 0.25s ease, visibility 0.25s ease, transform 0.25s ease, background 0.2s ease, color 0.2s ease;
}

.back-to-top[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--gold);
  color: var(--deep-blue);
}

.back-to-top-arrow {
  display: inline-block;
  font-family: var(--font-data);
  font-weight: 700;
}

/* ============ 13. Focus & A11y ============ */
:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 3px;
  border-radius: 2px;
}

a:focus-visible,
button:focus-visible {
  outline-color: var(--orange);
}

.site-header a:focus-visible,
.site-footer a:focus-visible,
.site-footer button:focus-visible {
  outline-color: var(--gold);
}

@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;
  }

  .main-nav,
  .nav-toggle-bar,
  .back-to-top,
  .scroll-progress {
    transition: none !important;
  }
}