/* =====================================================
   乐鱼官方中文站 / LIVE LEYU
   Site Core Stylesheet — /assets/site.css
   设计语言：直播控制台 × 专题研究板
   ===================================================== */

/* ---------- 1. CSS 变量 ---------- */
:root {
  --c-bg: #0A1E2A;
  --c-bg-deep: #050F16;
  --c-bg-raise: #123B4E;
  --c-green: #00FFC6;
  --c-orange: #FF5A36;
  --c-blue: #00D4FF;
  --c-violet: #9B51E0;
  --c-text: #F5F7FA;
  --c-text-dim: #B0C4DE;
  --c-border: #2B3A4A;

  --font-display: 'Impact', 'Arial Black', 'Noto Sans SC', 'PingFang SC', sans-serif;
  --font-body: 'Open Sans', 'Segoe UI', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'Roboto Mono', 'Consolas', 'Courier New', monospace;

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

  --header-w: 96px;
  --header-h: 64px;
  --container-w: 1240px;
  --radius-sm: 2px;
  --radius-md: 6px;
  --radius-lg: 12px;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ---------- 2. Reset 与基础元素 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background: var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease, text-decoration-color 0.2s ease;
}

ul,
ol {
  list-style: none;
}

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

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: 0.01em;
  color: var(--c-text);
}

h1 { font-size: clamp(32px, 6vw, 56px); }
h2 { font-size: clamp(25px, 4vw, 40px); }
h3 { font-size: clamp(20px, 3vw, 28px); }
h4 { font-size: clamp(16px, 2vw, 20px); }

p {
  line-height: 1.75;
  color: var(--c-text);
}

small {
  font-size: 12px;
  color: var(--c-text-dim);
}

code,
.mono {
  font-family: var(--font-mono);
  font-size: 0.92em;
  padding: 0.1em 0.4em;
  background: var(--c-bg-raise);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
}

hr {
  border: none;
  height: 1px;
  margin-block: var(--space-5);
  background: linear-gradient(90deg, var(--c-border), transparent);
}

::selection {
  background: var(--c-green);
  color: var(--c-bg-deep);
}

:focus-visible {
  outline: 2px solid var(--c-blue);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
  background: var(--c-bg-deep);
}

::-webkit-scrollbar-thumb {
  background: var(--c-border);
  border-radius: 0;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--c-blue);
}

/* ---------- 3. 通用工具与容器 ---------- */
.container {
  width: min(100% - clamp(20px, 5vw, 64px), var(--container-w));
  margin-inline: auto;
}

.section {
  padding-block: clamp(48px, 9vw, 96px);
}

.section--tight {
  padding-block: clamp(32px, 6vw, 64px);
}

.u-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;
}

[data-year] {
  font-variant-numeric: tabular-nums;
}

#main-content {
  display: block;
  flex: 1 0 auto;
}

[data-reveal] {
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
}

html.js [data-reveal]:not([data-visible]) {
  opacity: 0;
  transform: translateY(18px);
}

/* ---------- 4. 按钮与标签 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 24px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-align: center;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn--primary {
  background: var(--c-green);
  color: var(--c-bg-deep);
  box-shadow: 0 4px 16px rgba(0, 255, 198, 0.25);
}

.btn--primary:hover {
  background: #7dffe0;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0, 255, 198, 0.4);
}

.btn--ghost {
  background: transparent;
  border: 1px solid var(--c-border);
  color: var(--c-text);
}

.btn--ghost:hover {
  border-color: var(--c-blue);
  color: var(--c-blue);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 10px;
  background: var(--c-bg-raise);
  color: var(--c-blue);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  border: 1px solid var(--c-border);
  border-radius: 999px;
  white-space: nowrap;
}

.badge--hot {
  color: var(--c-orange);
  border-color: rgba(255, 90, 54, 0.4);
  background: rgba(255, 90, 54, 0.1);
}

/* ---------- 5. 面包屑 ---------- */
.breadcrumb {
  font-size: 13px;
  color: var(--c-text-dim);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

.breadcrumb__item + .breadcrumb__item::before {
  content: '/';
  margin-right: 6px;
  color: var(--c-border);
}

.breadcrumb__link {
  color: var(--c-text-dim);
  transition: color 0.2s ease;
}

.breadcrumb__link:hover {
  color: var(--c-blue);
}

.breadcrumb__item[aria-current="page"] {
  color: var(--c-text);
  font-weight: 600;
}

/* ---------- 6. 头部 / 侧边轨道导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  width: 100%;
  height: var(--header-h);
  background: rgba(10, 30, 42, 0.96);
  border-bottom: 1px solid var(--c-border);
}

.site-header__inner {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  padding: 0 14px;
}

.site-header__skip {
  position: fixed;
  top: 8px;
  left: 50%;
  z-index: 3000;
  transform: translate(-50%, -240%);
  background: var(--c-green);
  color: var(--c-bg-deep);
  font-weight: 700;
  font-size: 13px;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 16px rgba(0, 255, 198, 0.35);
  transition: transform 0.22s var(--ease-out);
  white-space: nowrap;
}

.site-header__skip:focus-visible {
  transform: translate(-50%, 0);
}

.site-brand {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.site-brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 2px solid var(--c-green);
  background: var(--c-bg-raise);
  color: var(--c-green);
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 900;
  border-radius: var(--radius-sm);
  box-shadow: 0 0 18px rgba(0, 255, 198, 0.22), inset 0 0 8px rgba(0, 255, 198, 0.1);
}

.site-brand__text {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--c-text);
  white-space: nowrap;
}

.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 11px 10px;
  background: var(--c-bg-raise);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-sm);
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

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

.nav-toggle__bar {
  display: block;
  height: 2px;
  background: var(--c-green);
  border-radius: 2px;
  transition: transform 0.3s var(--ease-out), opacity 0.2s 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);
}

.site-nav {
  position: fixed;
  top: var(--header-h);
  left: 0;
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: min(300px, 84vw);
  height: calc(100vh - var(--header-h));
  min-height: 0;
  padding: 28px 20px 24px;
  background: linear-gradient(165deg, var(--c-bg-deep) 0%, var(--c-bg) 45%, var(--c-bg-raise) 140%);
  border-right: 1px solid var(--c-border);
  transform: translateX(-102%);
  transition: transform 0.38s var(--ease-out);
  overflow-y: auto;
}

.site-nav[data-open] {
  transform: translateX(0);
  box-shadow: 20px 0 48px rgba(0, 0, 0, 0.45);
}

body.menu-open::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 998;
  background: rgba(3, 12, 18, 0.72);
  pointer-events: auto;
  animation: scrim-in 0.25s ease-out;
}

@keyframes scrim-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

.site-nav__link {
  position: relative;
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 14px;
  padding: 11px 14px;
  border-radius: var(--radius-md);
  color: var(--c-text-dim);
  transition: color 0.2s ease, background-color 0.2s ease;
}

.site-nav__link:hover {
  color: var(--c-text);
  background: rgba(0, 212, 255, 0.06);
}

.site-nav__link:hover .site-nav__index {
  color: var(--c-green);
}

.site-nav__index {
  font-family: var(--font-mono);
  font-size: 11px;
  min-width: 18px;
  color: var(--c-border);
  transition: color 0.2s ease;
}

.site-nav__name {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.site-nav__link[aria-current="page"] {
  color: var(--c-text);
}

.site-nav__link[aria-current="page"] .site-nav__index {
  color: var(--c-green);
  font-weight: 700;
}

.site-nav__link[aria-current="page"]::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 58%;
  background: var(--c-green);
  border-radius: 0 4px 4px 0;
  box-shadow: 0 0 12px rgba(0, 255, 198, 0.45);
}

.site-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  margin-top: auto;
  padding: 10px 12px;
  background: var(--c-green);
  color: var(--c-bg-deep);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.06em;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 20px rgba(0, 255, 198, 0.28);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

.site-cta:hover {
  background: #7dffe0;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0, 255, 198, 0.4);
}

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

.site-live {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 6px;
  margin-top: 12px;
  padding-bottom: 2px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--c-text-dim);
}

.site-live__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-orange);
  box-shadow: 0 0 8px rgba(255, 90, 54, 0.7);
  animation: live-pulse 1.6s ease-in-out infinite;
}

.site-live__text {
  font-size: 10px;
  letter-spacing: 0.25em;
}

@keyframes live-pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(0.65); opacity: 0.45; }
}

/* ---------- 7. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: var(--space-7);
  background: linear-gradient(180deg, var(--c-bg) 0%, var(--c-bg-deep) 110%);
  border-top: 1px solid var(--c-border);
  overflow: hidden;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--c-green), var(--c-blue), var(--c-violet), var(--c-orange));
  opacity: 0.55;
  z-index: 1;
}

.site-footer__inner {
  width: min(100% - 32px, var(--container-w));
  margin-inline: auto;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
  padding-block: var(--space-6) var(--space-5);
}

.site-footer__block {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
}

.site-footer__block--brand {
  gap: 0;
}

.site-footer .site-brand {
  flex-direction: row;
  gap: 10px;
}

.site-footer .site-brand__text {
  writing-mode: horizontal-tb;
  font-size: 15px;
  letter-spacing: 0.08em;
  color: var(--c-text);
  white-space: nowrap;
  margin: 0;
}

.site-footer__slogan {
  margin-top: var(--space-3);
  max-width: 34em;
  font-size: 14px;
  color: var(--c-text-dim);
  line-height: 1.7;
}

.site-footer__title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--c-text-dim);
}

.site-footer__title::after {
  content: '';
  height: 1px;
  flex: 1;
  background: linear-gradient(90deg, var(--c-border), transparent);
}

.site-footer__link {
  padding: 3px 0;
  font-size: 14px;
  color: var(--c-text);
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.site-footer__link:hover {
  color: var(--c-green);
  padding-left: 8px;
}

.site-footer__contact-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 13px;
  color: var(--c-text-dim);
  line-height: 1.6;
}

.site-footer__contact-item::before {
  content: '▹';
  flex: none;
  color: var(--c-green);
  font-size: 12px;
  line-height: 1.7;
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px 20px;
  padding: 16px 20px;
  background: rgba(5, 15, 22, 0.35);
  border-top: 1px solid var(--c-border);
  font-size: 12px;
  color: var(--c-text-dim);
}

.site-footer__copy {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--c-text-dim);
}

.site-footer__icp {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
}

.site-footer__legal {
  display: inline-flex;
  gap: 16px;
}

.site-footer__pol {
  color: var(--c-text-dim);
  text-decoration: underline;
  text-decoration-color: var(--c-border);
  text-underline-offset: 3px;
  transition: color 0.2s ease, text-decoration-color 0.2s ease;
}

.site-footer__pol:hover {
  color: var(--c-green);
  text-decoration-color: var(--c-green);
}

/* ---------- 8. 图片媒介容器 ---------- */
.media {
  position: relative;
  overflow: hidden;
  background: var(--c-bg-raise);
  border-radius: var(--radius-md);
}

.media--ratio-16x9 {
  aspect-ratio: 16 / 9;
}

.media--ratio-4x3 {
  aspect-ratio: 4 / 3;
}

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

.media > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 9. 栅格 ---------- */
.grid {
  display: grid;
  gap: var(--space-4);
}

.grid--2 {
  grid-template-columns: repeat(auto-fit, minmax(min(320px, 100%), 1fr));
}

.grid--3 {
  grid-template-columns: repeat(auto-fit, minmax(min(260px, 100%), 1fr));
}

/* ---------- 10. 平板端微调 ---------- */
@media (min-width: 768px) and (max-width: 1023px) {
  .site-footer__inner {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-5) var(--space-4);
  }

  .site-footer__block--brand {
    grid-column: 1 / -1;
  }
}

/* ---------- 11. 桌面端：左侧轨道导航 ---------- */
@media (min-width: 1024px) {
  .site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--header-w);
    height: 100vh;
    border-bottom: none;
    background: linear-gradient(
      180deg,
      rgba(0, 255, 198, 0.04) 0%,
      transparent 28%,
      transparent 70%,
      rgba(255, 90, 54, 0.04) 100%
    ), linear-gradient(180deg, var(--c-bg-deep) 0%, var(--c-bg) 100%);
    border-right: 1px solid var(--c-border);
  }

  .site-header::after {
    content: '';
    position: absolute;
    right: -1px;
    top: 0;
    width: 2px;
    height: 100%;
    background: repeating-linear-gradient(
      180deg,
      var(--c-green) 0px,
      var(--c-green) 4px,
      transparent 4px,
      transparent 12px
    );
    opacity: 0.28;
    animation: rail-flow 2.4s linear infinite;
  }

  @keyframes rail-flow {
    from { background-position: 0 0; }
    to { background-position: 0 24px; }
  }

  .site-header__inner {
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    padding: 24px 10px 16px;
  }

  .site-brand {
    flex-direction: column;
    gap: 8px;
  }

  .site-brand__mark {
    width: 40px;
    height: 40px;
    font-size: 16px;
  }

  .site-brand__text {
    writing-mode: vertical-rl;
    text-orientation: mixed;
    font-size: 11px;
    letter-spacing: 0.22em;
    color: var(--c-text-dim);
    white-space: nowrap;
    margin: 0;
  }

  .nav-toggle {
    display: none;
  }

  .site-nav {
    position: static;
    z-index: auto;
    width: auto;
    height: auto;
    min-height: 0;
    flex: 1;
    gap: 4px;
    padding: 28px 0;
    background: none;
    border-right: none;
    transform: none;
    box-shadow: none;
    overflow-x: hidden;
    overflow-y: auto;
  }

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

  .site-nav__link {
    flex-direction: column;
    gap: 2px;
    justify-content: center;
    width: 100%;
    padding: 7px 4px;
    text-align: center;
  }

  .site-nav__index {
    font-size: 10px;
    min-width: 0;
  }

  .site-nav__name {
    font-size: 13px;
  }

  .site-nav__link[aria-current="page"]::before {
    left: -8px;
    height: 38%;
  }

  .site-nav__link:first-of-type {
    margin-top: auto;
  }

  .site-cta {
    width: calc(100% - 8px);
    margin-top: 14px;
    padding: 9px 4px;
    font-size: 12px;
  }

  .site-live {
    justify-content: center;
    margin-top: auto;
    padding-top: 10px;
    padding-bottom: 2px;
  }

  body.menu-open::after {
    display: none;
  }

  #main-content {
    padding-left: var(--header-w);
  }

  .site-footer {
    padding-left: var(--header-w);
  }

  .site-footer__inner {
    grid-template-columns: 2fr 1fr 2fr;
    gap: var(--space-6);
    padding-block: var(--space-7) var(--space-6);
  }

  .site-footer__block--brand {
    grid-column: auto;
  }
}

/* ---------- 12. 正文链接（页面阶段适用） ---------- */
#main-content a:not(.btn) {
  color: var(--c-blue);
  text-decoration: underline;
  text-decoration-color: rgba(0, 212, 255, 0.35);
  text-underline-offset: 3px;
  transition: color 0.2s ease, text-decoration-color 0.2s ease;
}

#main-content a:not(.btn):hover {
  color: var(--c-green);
  text-decoration-color: var(--c-green);
}

/* ---------- 13. 低运动偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    transition-delay: 0ms !important;
    scroll-behavior: auto !important;
  }

  html {
    scroll-behavior: auto;
  }

  [data-reveal],
  html.js [data-reveal]:not([data-visible]) {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}