/* ==========================================================
   贝博平台 · Site Kit 共享样式
   /assets/site.css
   版本 1.0
   ========================================================== */

/* ---------- 01 · 变量 ---------- */

:root {
  --color-primary: #0B1B3D;
  --color-primary-deep: #0F2346;
  --color-primary-mid: #1E3A6E;
  --color-gold-start: #D4A84B;
  --color-gold-end: #F2D07B;
  --color-bg-soft: #E8EEF5;
  --color-bg-white: #F5F7FA;
  --color-text: #111827;
  --color-accent-red: #E85D4A;
  --color-accent-cyan: #2BB3B8;

  --gradient-gold: linear-gradient(135deg, #D4A84B, #F2D07B);

  --font-sans: 'PingFang SC', 'Helvetica Neue', 'Microsoft YaHei', sans-serif;
  --fs-display: 56px;
  --fs-h1: 40px;
  --fs-h2: 32px;
  --fs-h3: 24px;
  --fs-body: 16px;
  --fs-caption: 14px;
  --fs-small: 12px;

  --header-h: 72px;
  --header-h-mobile: 60px;
  --container-max: 1200px;
  --container-wide: 1440px;

  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 16px;
  --sp-4: 24px;
  --sp-5: 32px;
  --sp-6: 48px;
  --sp-7: 64px;
  --sp-8: 96px;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-cut: 2px 16px 16px 16px;

  --shadow-card: 0 4px 24px rgba(11, 27, 61, 0.08);
  --shadow-header: 0 2px 20px rgba(11, 27, 61, 0.22);
  --shadow-cta: 0 4px 16px rgba(212, 168, 75, 0.35);

  --ease-ios: cubic-bezier(0.22, 1, 0.36, 1);
  --dur-fast: 0.18s;
  --dur-mid: 0.35s;
  --dur-slow: 0.7s;

  --progress: 0%;
}

/* ---------- 02 · 重置与基础 ---------- */

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-h);
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg-white);
  min-height: 100vh;
  padding-top: var(--header-h);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-accent-cyan);
  text-decoration: none;
  transition: color var(--dur-fast) ease;
}

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

ul,
ol {
  list-style: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--color-primary);
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); }

address {
  font-style: normal;
}

::selection {
  background: rgba(212, 168, 75, 0.3);
  color: var(--color-primary-deep);
}

/* ---------- 03 · 无障碍 ---------- */

.skip-link {
  position: fixed;
  top: -120px;
  left: 16px;
  z-index: 2000;
  padding: 10px 18px;
  background: var(--color-primary);
  color: #fff;
  font-size: var(--fs-caption);
  font-weight: 600;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  text-decoration: none;
  transition: top var(--dur-mid) var(--ease-ios);
}

.skip-link:focus {
  top: 0;
  color: var(--color-gold-end);
}

:focus-visible {
  outline: 2px solid var(--color-accent-cyan);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ---------- 04 · 头部 ---------- */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1000;
  width: 100%;
  height: var(--header-h);
  background-color: rgba(11, 27, 61, 0.5);
  -webkit-backdrop-filter: blur(16px) saturate(1.4);
  backdrop-filter: blur(16px) saturate(1.4);
  transition: background-color var(--dur-mid) ease, box-shadow var(--dur-mid) ease;
}

.site-header[data-scrolled="true"] {
  background-color: rgba(11, 27, 61, 0.97);
  box-shadow: var(--shadow-header);
}

.header-inner {
  display: flex;
  align-items: center;
  width: 100%;
  max-width: var(--container-wide);
  height: 100%;
  margin: 0 auto;
  padding: 0 32px;
  gap: 32px;
}

.brand-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}

.brand-mark {
  position: relative;
  display: inline-block;
  width: 26px;
  height: 26px;
  flex-shrink: 0;
}

.brand-mark::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-gold);
  clip-path: polygon(50% 0%, 100% 50%, 50% 100%, 0% 50%);
}

.brand-mark::after {
  content: '';
  position: absolute;
  inset: 7px;
  background: var(--color-primary);
  clip-path: polygon(50% 0%, 100% 50%, 50% 100%, 0% 50%);
}

.brand-name {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: #fff;
  white-space: nowrap;
}

.header-progress {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 2px;
  width: var(--progress, 0%);
  background: var(--gradient-gold);
  border-radius: 0 2px 2px 0;
  z-index: 2;
  opacity: 0;
  transition: opacity var(--dur-mid) ease;
  pointer-events: none;
}

.site-header[data-scrolled="true"] .header-progress {
  opacity: 1;
}

.primary-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.nav-link {
  display: inline-block;
  position: relative;
  padding: 8px 14px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.02em;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: background-color var(--dur-fast) ease, color var(--dur-fast) ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  background-color: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.nav-link[aria-current="page"] {
  color: var(--color-gold-end);
  font-weight: 600;
}

.nav-link[aria-current="page"]::after {
  content: '';
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 2px;
  height: 2px;
  background: var(--gradient-gold);
  border-radius: 2px;
}

.nav-cta {
  display: inline-block;
  margin-left: 12px;
  padding: 9px 22px;
  border-radius: 999px;
  background: var(--gradient-gold);
  color: var(--color-primary-deep);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-decoration: none;
  box-shadow: var(--shadow-cta);
  transition: transform var(--dur-fast) ease, box-shadow var(--dur-fast) ease, color var(--dur-fast) ease;
  white-space: nowrap;
}

.nav-cta:hover,
.nav-cta:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(212, 168, 75, 0.45);
  color: var(--color-primary-deep);
}

.nav-cta:active {
  transform: translateY(0);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  margin-left: auto;
  border: 1px solid rgba(255, 255, 255, 0.32);
  border-radius: 10px;
  background: transparent;
  cursor: pointer;
  transition: border-color var(--dur-fast) ease, background-color var(--dur-fast) ease;
}

.nav-toggle:hover {
  border-color: rgba(255, 255, 255, 0.6);
  background-color: rgba(255, 255, 255, 0.08);
}

.nav-toggle[aria-expanded="true"] {
  border-color: var(--color-gold-start);
}

.nav-toggle-line {
  display: block;
  width: 18px;
  height: 2px;
  background-color: #fff;
  border-radius: 2px;
  transition: transform var(--dur-fast) ease, opacity var(--dur-fast) ease;
}

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

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

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 05 · 页脚 ---------- */

.site-footer {
  position: relative;
  margin-top: var(--sp-8);
  padding-top: var(--sp-7);
  background-color: var(--color-primary-deep);
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
  background-size: 44px 44px;
  color: rgba(255, 255, 255, 0.72);
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-gold-start) 0%, var(--color-gold-end) 35%, transparent 100%);
}

.site-footer::after {
  content: '贝博';
  position: absolute;
  right: -20px;
  bottom: -50px;
  font-size: 200px;
  font-weight: 800;
  letter-spacing: 0.1em;
  line-height: 1;
  color: rgba(255, 255, 255, 0.025);
  pointer-events: none;
  user-select: none;
}

.footer-shell {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--container-wide);
  margin: 0 auto;
  padding: 0 32px;
}

.footer-main {
  display: grid;
  grid-template-columns: 3fr 2fr 2fr;
  gap: var(--sp-6);
  padding-bottom: var(--sp-6);
}

.footer-brand {
  max-width: 480px;
}

.footer-logo {
  margin-bottom: var(--sp-3);
}

.footer-logo .brand-name {
  font-size: 18px;
}

.footer-about,
.footer-trust {
  margin-top: var(--sp-3);
  font-size: var(--fs-caption);
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.62);
}

.footer-trust {
  padding-left: var(--sp-3);
  border-left: 2px solid rgba(212, 168, 75, 0.55);
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer-heading {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: var(--sp-2);
  font-size: 16px;
  font-weight: 700;
  color: #fff;
}

.footer-heading::before {
  content: '';
  width: 18px;
  height: 2px;
  background: var(--gradient-gold);
  border-radius: 2px;
}

.footer-link {
  display: inline-block;
  width: fit-content;
  color: rgba(255, 255, 255, 0.7);
  font-size: var(--fs-caption);
  text-decoration: none;
  transition: color var(--dur-fast) ease, transform var(--dur-fast) ease;
}

.footer-link:hover {
  color: var(--color-gold-end);
  transform: translateX(4px);
}

.footer-contact-line,
.footer-address,
.footer-hours {
  font-size: var(--fs-caption);
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.62);
}

.footer-address,
.footer-hours {
  margin-top: var(--sp-2);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--sp-3);
  padding: var(--sp-3) 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-copy {
  font-size: var(--fs-small);
  color: rgba(255, 255, 255, 0.5);
}

.footer-legal {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--sp-3);
}

.footer-legal-link {
  color: rgba(255, 255, 255, 0.5);
  font-size: var(--fs-small);
  text-decoration: none;
  transition: color var(--dur-fast) ease;
}

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

.footer-icp {
  display: inline-block;
  margin-left: var(--sp-2);
  padding-left: var(--sp-3);
  border-left: 1px solid rgba(255, 255, 255, 0.15);
  font-size: var(--fs-small);
  color: rgba(255, 255, 255, 0.4);
}

/* ---------- 06 · 返回顶部 ---------- */

.back-top {
  position: fixed;
  right: 28px;
  bottom: 28px;
  z-index: 900;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--color-primary);
  color: var(--color-gold-end);
  box-shadow: 0 4px 16px rgba(11, 27, 61, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity var(--dur-mid) ease, transform var(--dur-mid) ease, visibility var(--dur-mid) ease, background-color var(--dur-fast) ease;
}

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

.back-top:hover {
  background: var(--color-primary-mid);
  transform: translateY(-2px);
}

.back-top-arrow {
  display: block;
  width: 10px;
  height: 10px;
  margin-top: 4px;
  border-top: 2px solid var(--color-gold-end);
  border-left: 2px solid var(--color-gold-end);
  transform: rotate(45deg);
}

/* ---------- 07 · 通用组件 ---------- */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.container-wide {
  max-width: var(--container-wide);
}

.section {
  position: relative;
  padding: var(--sp-7) 0;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: var(--fs-caption);
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--color-primary);
}

.section-label::before {
  content: '';
  width: 28px;
  height: 2px;
  background: var(--gradient-gold);
  border-radius: 2px;
}

.chapter-num {
  font-size: clamp(64px, 10vw, 128px);
  font-weight: 800;
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: transparent;
  -webkit-text-stroke: 1px rgba(11, 27, 61, 0.18);
  user-select: none;
  pointer-events: none;
}

.card-panel {
  position: relative;
  background: var(--color-bg-white);
  border: 1px solid rgba(11, 27, 61, 0.08);
  border-radius: var(--radius-cut);
  padding: var(--sp-5);
  box-shadow: var(--shadow-card);
  transition: transform var(--dur-mid) var(--ease-ios), box-shadow var(--dur-mid) var(--ease-ios);
}

.card-panel:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(11, 27, 61, 0.12);
}

.card-panel::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 36px;
  height: 36px;
  background: var(--gradient-gold);
  clip-path: polygon(0 0, 0 100%, 100% 0);
  border-radius: 2px 0 0 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 10px;
  font-size: var(--fs-body);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--dur-fast) ease, box-shadow var(--dur-fast) ease, background-color var(--dur-fast) ease, border-color var(--dur-fast) ease;
}

.btn-primary {
  background: var(--gradient-gold);
  color: var(--color-primary-deep);
  box-shadow: var(--shadow-cta);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(212, 168, 75, 0.5);
  color: var(--color-primary-deep);
}

.btn-ghost {
  border: 1px solid rgba(11, 27, 61, 0.3);
  color: var(--color-primary);
  background: transparent;
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  border-color: var(--color-primary);
  background: rgba(11, 27, 61, 0.04);
  color: var(--color-primary);
}

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding: var(--sp-4) 0;
  font-size: var(--fs-caption);
  color: rgba(17, 24, 39, 0.6);
}

.breadcrumb-sep {
  color: rgba(17, 24, 39, 0.3);
}

.breadcrumb-current {
  color: var(--color-primary);
  font-weight: 600;
}

.image-frame {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  background-color: var(--color-bg-soft);
  border-radius: var(--radius-cut);
  aspect-ratio: 16 / 10;
}

.image-frame::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: linear-gradient(var(--color-primary-mid), var(--color-primary-deep));
  opacity: 0.06;
  z-index: 1;
}

.image-frame img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--dur-slow) var(--ease-ios);
}

.image-frame:hover img {
  transform: scale(1.04);
}

/* ---------- 08 · 滚动显现 ---------- */

[data-animate="pending"] {
  opacity: 0;
  transform: translateY(28px);
}

[data-animate="visible"] {
  opacity: 1;
  transform: none;
  transition: opacity var(--dur-slow) var(--ease-ios), transform var(--dur-slow) var(--ease-ios);
}

/* ---------- 09 · 响应式 ---------- */

@media (max-width: 1024px) {
  :root {
    --fs-display: 44px;
    --fs-h1: 32px;
    --fs-h2: 26px;
    --fs-h3: 20px;
  }

  .footer-main {
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--sp-5);
  }
}

@media (max-width: 768px) {
  :root {
    --header-h: var(--header-h-mobile);
  }

  body {
    padding-top: var(--header-h-mobile);
  }

  .site-header {
    height: var(--header-h-mobile);
  }

  .header-inner {
    padding: 0 16px;
    gap: 12px;
  }

  .brand-name {
    font-size: 17px;
  }

  .brand-mark {
    width: 22px;
    height: 22px;
  }

  .brand-mark::after {
    inset: 6px;
  }

  .primary-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    margin: 0;
    padding: 14px 16px 22px;
    background-color: var(--color-primary-deep);
    box-shadow: 0 16px 40px rgba(11, 27, 61, 0.4);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
  }

  .primary-nav[data-open] {
    display: flex;
  }

  .nav-link {
    padding: 12px 16px;
    font-size: 16px;
    border-radius: var(--radius-md);
  }

  .nav-cta {
    margin: 8px 0 0;
    padding: 12px 16px;
    text-align: center;
    border-radius: var(--radius-md);
  }

  .nav-toggle {
    display: flex;
  }

  .container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .section {
    padding: var(--sp-6) 0;
  }

  .footer-shell {
    padding: 0 16px;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: var(--sp-4);
  }

  .footer-brand {
    max-width: 100%;
  }

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

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

@media (max-width: 480px) {
  .nav-cta {
    font-size: 13px;
  }

  .image-frame {
    aspect-ratio: 4 / 3;
  }
}

/* ---------- 10 · 减少运动 ---------- */

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

  html {
    scroll-behavior: auto;
  }

  [data-animate] {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}