/* =============================================
   博娱看台 · 全站共享 CSS
   设计系统：深夜蓝 x 奶油白 x 金橙
   ============================================= */

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

:root {
  --color-primary-bg: #0B1A2E;
  --color-secondary-bg: #F5F0E6;
  --color-accent-gold: #F0A030;
  --color-accent-orange: #E85D2A;
  --color-text-dark: #1A1A1A;
  --color-text-light: #EAEAEA;
  --color-link: #4A90E2;
  --color-success: #2E8B57;
  --color-warning: #D32F2F;
  --color-muted: #9AA8B7;

  --font-headline: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;

  --radius-lg: 32px;
  --radius-md: 24px;
  --radius-sm: 12px;

  --container-max: 1280px;
  --content-pad: 24px;

  --header-height: 90px;
  --transition-speed: 300ms;
  --transition-ease: cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-dark);
  background-color: var(--color-primary-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

body > #main-content {
  flex: 1 0 auto;
}

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

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color var(--transition-speed) var(--transition-ease);
}

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

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

ul,
ol {
  list-style: none;
}

:focus-visible {
  outline: 3px solid var(--color-accent-gold);
  outline-offset: 4px;
  border-radius: 4px;
}

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--content-pad);
  padding-right: var(--content-pad);
}

/* ---------- Skip Link ---------- */
.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 2000;
  background-color: var(--color-accent-gold);
  color: var(--color-text-dark);
  padding: 8px 20px;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  font-weight: 700;
  transition: top var(--transition-speed) var(--transition-ease);
}

.skip-link:focus-visible {
  top: 0;
  color: var(--color-text-dark);
}

/* ---------- Announcement Bar ---------- */
.announcement-bar {
  background-color: var(--color-accent-orange);
  color: #fff;
  text-align: center;
  padding: 6px 16px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.02em;
  position: relative;
  z-index: 1001;
}

.announcement-bar p {
  margin: 0;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--color-primary-bg);
  color: var(--color-text-light);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header__main {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
  gap: 24px;
}

/* Brand */
.brand {
  flex-shrink: 0;
}

.brand__link {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--color-text-light);
}

.brand__logo {
  display: inline-flex;
  width: 52px;
  height: 52px;
}

.brand__logo svg {
  width: 100%;
  height: 100%;
  overflow: visible;
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand__name {
  font-family: var(--font-headline);
  font-size: 24px;
  font-weight: 900;
  letter-spacing: 0.04em;
  color: #fff;
}

.brand__sub {
  font-size: 13px;
  color: var(--color-muted);
  letter-spacing: 0.08em;
}

/* Navigation */
.site-nav__list {
  display: flex;
  align-items: center;
  gap: 6px;
}

.site-nav__link {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 100px;
  font-weight: 600;
  font-size: 15px;
  color: var(--color-text-light);
  transition: background-color var(--transition-speed) var(--transition-ease),
    color var(--transition-speed) var(--transition-ease);
}

.site-nav__link:hover {
  background-color: rgba(255, 255, 255, 0.08);
  color: var(--color-accent-gold);
}

.site-nav__link[aria-current="page"] {
  background-color: var(--color-accent-gold);
  color: var(--color-text-dark);
  font-weight: 700;
}

/* Nav Toggle (Mobile) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: var(--radius-sm);
}

.nav-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text-light);
  border-radius: 2px;
  transition: transform var(--transition-speed) var(--transition-ease),
    opacity var(--transition-speed) var(--transition-ease);
}

.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);
}

/* ---------- Footer ---------- */
.site-footer {
  background-color: var(--color-primary-bg);
  color: var(--color-text-light);
  border-top: 2px solid var(--color-accent-gold);
  position: relative;
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 80% 20%, rgba(240, 160, 48, 0.08), transparent 40%);
  pointer-events: none;
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.5fr 1.2fr 1fr;
  gap: 48px;
  padding-top: 64px;
  padding-bottom: 48px;
  position: relative;
}

.footer__brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.footer__logo {
  font-family: var(--font-headline);
  font-size: 72px;
  font-weight: 900;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 2px var(--color-accent-gold);
  text-stroke: 2px var(--color-accent-gold);
  margin-bottom: 8px;
}

.footer__name {
  font-family: var(--font-headline);
  font-size: 32px;
  font-weight: 900;
  color: #fff;
  letter-spacing: 0.06em;
}

.footer__tagline {
  font-size: 16px;
  color: var(--color-accent-gold);
  margin-top: 4px;
  font-weight: 600;
}

.footer__desc {
  color: var(--color-muted);
  font-size: 14px;
  margin: 16px 0 24px;
  max-width: 360px;
  line-height: 1.6;
}

.footer__title {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-accent-gold);
  margin-bottom: 16px;
  position: relative;
}

.footer__title::after {
  content: "";
  display: block;
  width: 32px;
  height: 3px;
  background: var(--color-accent-orange);
  margin-top: 8px;
  border-radius: 2px;
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 15px;
}

.footer__list a {
  color: var(--color-text-light);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-speed) var(--transition-ease),
    color var(--transition-speed) var(--transition-ease);
}

.footer__list a:hover {
  color: var(--color-accent-gold);
  border-bottom-color: var(--color-accent-gold);
}

.footer__note {
  font-size: 13px;
  color: var(--color-muted);
  margin-top: 16px;
  line-height: 1.5;
  border-left: 3px solid var(--color-accent-orange);
  padding-left: 12px;
}

.footer__icp {
  display: inline-block;
  margin-top: 20px;
  padding: 4px 12px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 100px;
  font-size: 12px;
  color: var(--color-muted);
}

.footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 20px var(--content-pad);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 8px;
  font-size: 13px;
  color: var(--color-muted);
  position: relative;
}

.footer__legal-note {
  max-width: 720px;
  margin: 0 auto;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 100px;
  font-weight: 700;
  font-size: 15px;
  line-height: 1;
  transition: background-color var(--transition-speed) var(--transition-ease),
    color var(--transition-speed) var(--transition-ease),
    border-color var(--transition-speed) var(--transition-ease),
    transform var(--transition-speed) var(--transition-ease);
  text-align: center;
  white-space: nowrap;
}

.btn--primary {
  background-color: var(--color-accent-gold);
  color: var(--color-text-dark);
  border: 2px solid var(--color-accent-gold);
}

.btn--primary:hover {
  background-color: #f0b04c;
  border-color: #f0b04c;
  color: var(--color-text-dark);
  transform: translateY(-2px);
}

.btn--ghost {
  background-color: transparent;
  color: var(--color-text-light);
  border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn--ghost:hover {
  border-color: var(--color-accent-gold);
  color: var(--color-accent-gold);
}

.btn--sm {
  padding: 10px 20px;
  font-size: 14px;
}

/* ---------- Section & Chapter System ---------- */
.section {
  padding: 64px 0;
}

.section__header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding-bottom: 16px;
}

.section__title {
  font-family: var(--font-headline);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: 0.02em;
}

.chapter-number {
  font-family: var(--font-headline);
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 900;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 2px var(--color-accent-gold);
  text-stroke: 2px var(--color-accent-gold);
  user-select: none;
}

/* ---------- Exhibition Labels & Typography ---------- */
.vertical-rl {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  letter-spacing: 0.3em;
  font-weight: 500;
  color: var(--color-muted);
  font-size: 14px;
}

.exhibit-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-accent-gold);
}

.exhibit-label::before {
  content: "";
  display: inline-block;
  width: 24px;
  height: 2px;
  background: var(--color-accent-orange);
  border-radius: 2px;
}

.desc-plate {
  border: 1px dashed rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-muted);
  background-color: rgba(0, 0, 0, 0.15);
  line-height: 1.5;
}

/* ---------- Cards ---------- */
.card {
  background-color: var(--color-secondary-bg);
  border-radius: var(--radius-lg);
  padding: 28px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 40px -20px rgba(0, 0, 0, 0.4);
}

.card--collage {
  border-radius: var(--radius-md);
  padding: 24px;
  min-height: 220px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform var(--transition-speed) var(--transition-ease),
    box-shadow var(--transition-speed) var(--transition-ease);
}

.card--collage:hover {
  transform: translateY(-6px);
  box-shadow: 0 30px 60px -20px rgba(0, 0, 0, 0.5);
}

.card__title {
  font-family: var(--font-headline);
  font-size: 20px;
  font-weight: 900;
  line-height: 1.3;
  margin-bottom: 8px;
}

.card__text {
  color: var(--color-text-dark);
  opacity: 0.8;
  font-size: 15px;
  line-height: 1.6;
}

.card--dark {
  background-color: var(--color-primary-bg);
  color: var(--color-text-light);
}

.card--dark .card__text {
  color: var(--color-text-light);
  opacity: 0.7;
}

/* ---------- Tags & Badges ---------- */
.tag {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 100px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.6;
}

.tag--gold {
  background-color: var(--color-accent-gold);
  color: var(--color-text-dark);
}

.tag--orange {
  background-color: var(--color-accent-orange);
  color: #fff;
}

.tag--outline {
  border: 1px solid currentColor;
  background-color: transparent;
}

/* ---------- Image Containers ---------- */
.image-container {
  background-color: #d0d0d0;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.image-container img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.image-container--16x10 {
  aspect-ratio: 16 / 10;
}

.image-container--square {
  aspect-ratio: 1 / 1;
}

.image-container--panorama {
  aspect-ratio: 21 / 9;
}

/* ---------- Hebei Textures (abstract CSS) ---------- */
.theme-texture {
  background:
    radial-gradient(circle at 20% 40%, rgba(240, 160, 48, 0.15), transparent 28%),
    radial-gradient(circle at 80% 70%, rgba(232, 93, 42, 0.1), transparent 32%),
    linear-gradient(135deg, transparent 0%, transparent 48%, rgba(255, 255, 255, 0.03) 50%, transparent 52%);
  background-size: 80px 80px, 120px 120px, 64px 64px;
}

.pattern-greatwall {
  background-color: transparent;
  background-image: linear-gradient(135deg, rgba(255, 255, 255, 0.06) 25%, transparent 25%, transparent 50%, rgba(255, 255, 255, 0.06) 50%, rgba(255, 255, 255, 0.06) 75%, transparent 75%, transparent);
  background-size: 32px 32px;
}

/* ---------- Back to Top ---------- */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 900;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background-color: var(--color-accent-gold);
  color: var(--color-text-dark);
  font-size: 22px;
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: opacity var(--transition-speed) var(--transition-ease),
    transform var(--transition-speed) var(--transition-ease),
    visibility var(--transition-speed) var(--transition-ease);
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background-color: var(--color-accent-orange);
  color: #fff;
}

/* ---------- Scroll Progress Bar ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--color-accent-gold), var(--color-accent-orange));
  z-index: 3000;
  transition: width 0.1s linear;
}

/* ---------- Reveal on Scroll ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--transition-speed) var(--transition-ease),
    transform var(--transition-speed) var(--transition-ease);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Responsive Grid Utilities ---------- */
.grid {
  display: grid;
  gap: 24px;
}

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

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

.col-2-1 {
  grid-column: span 2;
}

.col-1-2 {
  grid-column: span 1;
}

.offset-right {
  transform: translateX(24px);
}

.offset-left {
  transform: translateX(-24px);
}

/* ---------- Responsive Breakpoints ---------- */
@media (max-width: 960px) {
  .nav-toggle {
    display: flex;
  }

  .site-nav__list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: rgba(11, 26, 46, 0.98);
    padding: 16px;
    gap: 8px;
    border-bottom: 1px solid var(--color-accent-gold);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
  }

  .site-nav[data-open="true"] .site-nav__list {
    display: flex;
  }

  .site-nav__link {
    padding: 14px 24px;
    border-radius: var(--radius-sm);
    font-size: 16px;
  }

  .footer__grid {
    grid-template-columns: 1fr;
    gap: 32px;
    padding-top: 40px;
    padding-bottom: 32px;
  }

  .grid--2,
  .grid--3 {
    grid-template-columns: 1fr;
  }

  .col-2-1,
  .col-1-2 {
    grid-column: span 1;
  }

  .offset-right,
  .offset-left {
    transform: none;
  }
}

@media (max-width: 600px) {
  :root {
    --content-pad: 16px;
    --header-height: 70px;
  }

  .brand__logo {
    width: 42px;
    height: 42px;
  }

  .brand__name {
    font-size: 20px;
  }

  .brand__sub {
    display: none;
  }

  .announcement-bar {
    font-size: 12px;
  }

  .section {
    padding: 40px 0;
  }

  .back-to-top {
    right: 16px;
    bottom: 16px;
  }
}

/* ---------- Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

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

  .back-to-top,
  .btn,
  .card--collage,
  .site-nav__link {
    transition: none !important;
  }
}