/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { min-height: 100vh; line-height: 1.6; -webkit-font-smoothing: antialiased; }
img, picture, video, canvas, svg { display: block; max-width: 100%; }
input, button, textarea, select { font: inherit; }
ul, ol { list-style: none; }
a { text-decoration: none; color: inherit; }
:focus-visible { outline: 2px solid #D4A843; outline-offset: 2px; }

/* ===== CSS VARIABLES ===== */
:root {
  --clr-primary-deep-blue: #0B1D3A;
  --clr-primary-gold: #D4A843;
  --clr-accent-red: #E63946;
  --clr-background-dark: #0A1424;
  --clr-surface-dark: #111D33;
  --clr-text-light: #F0F4F8;
  --clr-text-muted: #9AA8B9;
  --clr-border-subtle: #2A3B54;
  --clr-success: #2ECC71;
  --clr-warning: #F39C12;
  --font-heading: 'Oswald', 'Impact', 'Arial Black', sans-serif;
  --font-body: 'PT Serif', 'Georgia', 'Times New Roman', serif;
  --font-mono: 'Source Code Pro', 'Consolas', 'Courier New', monospace;
  --size-xs: 0.75rem;
  --size-sm: 0.875rem;
  --size-base: 1rem;
  --size-lg: 1.125rem;
  --size-xl: 1.5rem;
  --size-2xl: 2rem;
  --size-3xl: 2.75rem;
  --size-4xl: 3.75rem;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --max-width: 1280px;
  --header-height: 80px;
  --transition: 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --border-radius: 0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto; }
}

/* ===== TYPOGRAPHY ===== */
body { font-family: var(--font-body); font-size: var(--size-base); color: var(--clr-text-light); background: var(--clr-background-dark); }
h1, h2, h3, h4, h5, h6 { font-family: var(--font-heading); font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; line-height: 1.15; }
h1 { font-size: var(--size-4xl); }
h2 { font-size: var(--size-3xl); }
h3 { font-size: var(--size-2xl); }
h4 { font-size: var(--size-xl); }
p { margin-bottom: var(--space-md); max-width: 70ch; }
a { color: var(--clr-primary-gold); transition: color var(--transition); }
a:hover { color: #e8c15a; }

/* ===== SKIP LINK ===== */
.skip-link {
  position: fixed; top: -100%; left: 50%; transform: translateX(-50%);
  background: var(--clr-primary-gold); color: var(--clr-background-dark);
  padding: var(--space-sm) var(--space-lg); font-family: var(--font-heading);
  font-size: var(--size-sm); text-transform: uppercase; letter-spacing: 0.05em;
  z-index: 10000; border-radius: 0; transition: top 0.3s;
}
.skip-link:focus { top: var(--space-sm); }

/* ===== CONTAINER ===== */
.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-lg); }

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  font-family: var(--font-heading); font-size: var(--size-sm); font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.08em; padding: var(--space-sm) var(--space-xl);
  border: 2px solid var(--clr-border-subtle); background: transparent; color: var(--clr-text-light);
  cursor: pointer; transition: all var(--transition); border-radius: var(--border-radius);
  min-height: 48px; text-decoration: none;
}
.btn:hover { border-color: var(--clr-primary-gold); color: var(--clr-primary-gold); background: rgba(212, 168, 67, 0.08); }
.btn--primary { background: var(--clr-primary-gold); border-color: var(--clr-primary-gold); color: var(--clr-background-dark); }
.btn--primary:hover { background: #e8c15a; border-color: #e8c15a; color: var(--clr-background-dark); }
.btn--accent { border-color: var(--clr-accent-red); color: var(--clr-accent-red); }
.btn--accent:hover { background: var(--clr-accent-red); color: var(--clr-text-light); }

/* ===== BREADCRUMB ===== */
.breadcrumb {
  display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-xs);
  font-family: var(--font-heading); font-size: var(--size-xs); text-transform: uppercase;
  letter-spacing: 0.05em; color: var(--clr-text-muted); padding: var(--space-md) 0;
}
.breadcrumb__item { display: flex; align-items: center; gap: var(--space-xs); }
.breadcrumb__item + .breadcrumb__item::before { content: '/'; color: var(--clr-border-subtle); margin-right: var(--space-xs); }
.breadcrumb__item a { color: var(--clr-text-muted); }
.breadcrumb__item a:hover { color: var(--clr-primary-gold); }
.breadcrumb__item[aria-current="page"] { color: var(--clr-primary-gold); }

/* ===== STATUS DOT ===== */
.status-dot {
  display: inline-block; width: 8px; height: 8px; border-radius: 0;
  background: var(--clr-border-subtle); flex-shrink: 0;
}
.status-dot--gold { background: var(--clr-primary-gold); }
.status-dot--red { background: var(--clr-accent-red); }
.status-dot--green { background: var(--clr-success); }

/* ===== FRAME BOX (框景) ===== */
.frame-box {
  position: relative; border: 2px solid var(--clr-border-subtle);
  padding: var(--space-2xl); background: var(--clr-surface-dark);
}
.frame-box::before {
  content: ''; position: absolute; inset: -6px;
  border: 1px solid rgba(212, 168, 67, 0.15); pointer-events: none;
}
.frame-box__label {
  position: absolute; top: -0.6em; left: var(--space-lg);
  background: var(--clr-surface-dark); padding: 0 var(--space-sm);
  font-family: var(--font-heading); font-size: var(--size-xs);
  text-transform: uppercase; letter-spacing: 0.1em; color: var(--clr-primary-gold);
}
.frame-box__scale {
  position: absolute; bottom: var(--space-sm); right: var(--space-lg);
  display: flex; gap: 6px; align-items: flex-end;
}
.frame-box__scale span {
  display: block; width: 2px; height: 12px; background: var(--clr-border-subtle);
}
.frame-box__scale span:nth-child(odd) { height: 8px; }
.frame-box__scale span:last-child { height: 16px; background: var(--clr-primary-gold); }

/* ===== DATA PANEL ===== */
.data-panel {
  background: var(--clr-surface-dark); border: 1px solid var(--clr-border-subtle);
  padding: var(--space-lg);
}
.data-panel__header {
  display: flex; justify-content: space-between; align-items: center;
  padding-bottom: var(--space-sm); border-bottom: 1px solid var(--clr-border-subtle);
  margin-bottom: var(--space-md); font-family: var(--font-heading);
  font-size: var(--size-sm); text-transform: uppercase; letter-spacing: 0.05em;
}
.data-panel__title { color: var(--clr-primary-gold); }
.data-panel__grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: var(--space-md); }

/* ===== PROGRESS BAR (固定顶部) ===== */
.progress-bar {
  position: fixed; top: 0; left: 0; width: 0; height: 3px;
  background: var(--clr-primary-gold); z-index: 9999;
  transition: width 0.1s linear;
}
@media (prefers-reduced-motion: reduce) { .progress-bar { display: none; } }

/* ===== BACK TO TOP ===== */
.back-to-top {
  position: fixed; bottom: var(--space-2xl); right: var(--space-2xl);
  width: 48px; height: 48px; background: var(--clr-surface-dark);
  border: 1px solid var(--clr-border-subtle); color: var(--clr-primary-gold);
  font-size: var(--size-xl); display: flex; align-items: center; justify-content: center;
  cursor: pointer; opacity: 0; visibility: hidden; transition: all var(--transition);
  z-index: 100; font-family: var(--font-mono);
}
.back-to-top.is-visible { opacity: 1; visibility: visible; }
.back-to-top:hover { background: var(--clr-primary-gold); color: var(--clr-background-dark); border-color: var(--clr-primary-gold); }

/* ===== SITE HEADER ===== */
.site-header {
  position: sticky; top: 0; z-index: 1000;
  background: var(--clr-primary-deep-blue); border-bottom: 2px solid var(--clr-border-subtle);
  min-height: var(--header-height); font-family: var(--font-heading);
}
.header__inner {
  max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-lg);
  display: flex; align-items: center; justify-content: space-between;
  height: var(--header-height); gap: var(--space-lg);
}
.header__brand { display: flex; align-items: center; gap: var(--space-md); flex-shrink: 0; }
.brand__logo { display: flex; align-items: center; gap: var(--space-sm); color: var(--clr-primary-gold); font-size: var(--size-xl); letter-spacing: 0.08em; text-transform: uppercase; font-weight: 700; transition: none; }
.brand__logo:hover { color: var(--clr-primary-gold); }
.brand__logo-text { line-height: 1; }
.brand__logo-dash { display: block; width: 32px; height: 3px; background: var(--clr-primary-gold); transform: skewX(-15deg); }
.brand__slogan { display: none; font-size: var(--size-xs); color: var(--clr-text-muted); letter-spacing: 0.03em; max-width: 160px; text-transform: none; font-family: var(--font-body); }
@media (min-width: 640px) { .brand__slogan { display: block; } }

/* ===== NAVIGATION ===== */
.header__nav { display: none; }
.header__nav[data-open] { display: block; }
@media (min-width: 768px) { .header__nav { display: block; } }

.nav__list {
  display: flex; align-items: center; gap: var(--space-xs);
}
.nav__item { position: relative; }
.nav__link {
  display: inline-flex; align-items: center; gap: 6px;
  padding: var(--space-sm) var(--space-md); color: var(--clr-text-light);
  font-size: var(--size-sm); letter-spacing: 0.05em; text-transform: uppercase;
  border-bottom: 2px solid transparent; transition: all var(--transition);
  white-space: nowrap;
}
.nav__link:hover { color: var(--clr-primary-gold); border-bottom-color: var(--clr-primary-gold); background: rgba(212, 168, 67, 0.06); }
.nav__link[aria-current="page"] {
  color: var(--clr-primary-gold); border-bottom-color: var(--clr-primary-gold);
  position: relative;
}
.nav__link[aria-current="page"]::after {
  content: ''; display: inline-block; width: 6px; height: 6px;
  background: var(--clr-primary-gold); margin-left: 6px;
}

/* ===== NAV TOGGLE (移动) ===== */
.nav__toggle {
  display: flex; flex-direction: column; gap: 5px;
  width: 40px; height: 40px; background: transparent; border: 1px solid var(--clr-border-subtle);
  align-items: center; justify-content: center; cursor: pointer;
  padding: 8px; transition: border-color var(--transition);
}
.nav__toggle:hover { border-color: var(--clr-primary-gold); }
.nav__toggle-bar { display: block; width: 20px; height: 2px; background: var(--clr-text-light); transition: all var(--transition); }
@media (min-width: 768px) { .nav__toggle { display: none; } }

body[data-nav-open] .nav__toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
body[data-nav-open] .nav__toggle-bar:nth-child(2) { opacity: 0; }
body[data-nav-open] .nav__toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== HEADER CTA ===== */
.header__cta { display: none; flex-shrink: 0; }
@media (min-width: 480px) { .header__cta { display: inline-flex; } }

/* ===== MOBILE NAV OVERLAY ===== */
@media (max-width: 767px) {
  .header__nav {
    position: fixed; top: var(--header-height); left: 0; right: 0; bottom: 0;
    background: var(--clr-primary-deep-blue); z-index: 999;
    padding: var(--space-xl) var(--space-lg); border-top: 2px solid var(--clr-border-subtle);
    overflow-y: auto; transform: translateY(-10px); opacity: 0; visibility: hidden;
    transition: all var(--transition);
  }
  .header__nav[data-open] {
    transform: translateY(0); opacity: 1; visibility: visible;
  }
  .nav__list { flex-direction: column; gap: var(--space-xs); align-items: stretch; }
  .nav__link { padding: var(--space-md); border-bottom: 1px solid var(--clr-border-subtle); font-size: var(--size-lg); white-space: normal; }
  .nav__link[aria-current="page"] { border-bottom-color: var(--clr-primary-gold); background: rgba(212, 168, 67, 0.06); }
  .nav__link[aria-current="page"]::after { display: none; }
}

/* ===== SITE FOOTER ===== */
.site-footer {
  background: var(--clr-primary-deep-blue); border-top: 2px solid var(--clr-border-subtle);
  padding: var(--space-3xl) 0 var(--space-xl); color: var(--clr-text-muted);
  font-size: var(--size-sm);
}
.footer__inner {
  max-width: var(--max-width); margin: 0 auto; padding: 0 var(--space-lg);
  display: grid; grid-template-columns: 1fr; gap: var(--space-2xl);
}
@media (min-width: 640px) {
  .footer__inner { grid-template-columns: 1fr 1fr; }
}
@media (min-width: 1024px) {
  .footer__inner { grid-template-columns: 2fr 1fr 1fr 1fr; }
}

.footer__logo { font-family: var(--font-heading); font-size: var(--size-xl); color: var(--clr-primary-gold); text-transform: uppercase; letter-spacing: 0.05em; font-weight: 700; display: inline-block; margin-bottom: var(--space-sm); }
.footer__logo:hover { color: var(--clr-primary-gold); }
.footer__tagline { font-family: var(--font-body); font-size: var(--size-sm); color: var(--clr-text-muted); margin-bottom: var(--space-md); }
.footer__trust { font-size: var(--size-xs); color: var(--clr-text-muted); line-height: 1.6; max-width: 40ch; font-style: italic; border-left: 2px solid var(--clr-border-subtle); padding-left: var(--space-md); }

.footer__link-title { font-family: var(--font-heading); font-size: var(--size-sm); color: var(--clr-text-light); text-transform: uppercase; letter-spacing: 0.05em; display: block; margin-bottom: var(--space-md); padding-bottom: var(--space-xs); border-bottom: 1px solid var(--clr-border-subtle); }

.footer__link-list { display: flex; flex-direction: column; gap: var(--space-sm); }
.footer__link { color: var(--clr-text-muted); font-size: var(--size-sm); transition: color var(--transition); }
.footer__link:hover { color: var(--clr-primary-gold); }

.footer__contact-list { display: flex; flex-direction: column; gap: var(--space-sm); }
.footer__contact-item { color: var(--clr-text-muted); font-size: var(--size-sm); }
.footer__contact-item[href^="mailto"] { color: var(--clr-text-muted); }
.footer__contact-item[href^="mailto"]:hover { color: var(--clr-primary-gold); }
.footer__note { font-size: var(--size-xs); color: var(--clr-text-muted); margin-top: var(--space-md); font-style: italic; }

.footer__colophon { grid-column: 1 / -1; border-top: 1px solid var(--clr-border-subtle); padding-top: var(--space-lg); display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: var(--space-md); font-size: var(--size-xs); }
.footer__copyright { color: var(--clr-text-muted); margin: 0; }
.footer__icp { color: var(--clr-text-muted); margin: 0; font-family: var(--font-mono); }

/* ===== RESPONSIVE HELPERS ===== */
@media (max-width: 479px) {
  :root { --header-height: 64px; }
  .header__inner { padding: 0 var(--space-md); }
  .brand__logo { font-size: var(--size-lg); }
  .brand__logo-dash { width: 24px; }
}
@media (min-width: 768px) and (max-width: 1023px) {
  .nav__link { padding: var(--space-sm) var(--space-sm); font-size: var(--size-xs); }
}
@media (min-width: 1280px) {
  .brand__slogan { display: block; font-size: var(--size-sm); }
}

/* ===== GRID UTILITY ===== */
.grid { display: grid; gap: var(--space-lg); }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }

/* ===== IMAGE CONTAINER (占位基础) ===== */
.img-container {
  position: relative; overflow: hidden; background: var(--clr-surface-dark);
  border: 1px solid var(--clr-border-subtle); aspect-ratio: 16 / 9;
  display: flex; align-items: center; justify-content: center;
  color: var(--clr-text-muted); font-family: var(--font-mono); font-size: var(--size-xs);
}
.img-container--portrait { aspect-ratio: 3 / 4; }
.img-container--square { aspect-ratio: 1 / 1; }
.img-container--wide { aspect-ratio: 21 / 9; }
.img-container__placeholder { opacity: 0.4; text-transform: uppercase; letter-spacing: 0.05em; }

/* ===== SELECTION ===== */
::selection { background: var(--clr-primary-gold); color: var(--clr-background-dark); }

/* ===== FOCUS VISIBLE ENHANCEMENT ===== */
a:focus-visible, button:focus-visible, .nav__toggle:focus-visible, .btn:focus-visible { outline: 2px solid var(--clr-primary-gold); outline-offset: 2px; }