/* ============ 变量与基础 ============ */
:root {
  --c-bg: #0B1020;
  --c-panel: #111827;
  --c-panel-alt: #0F2B4C;
  --c-blue: #2B7FFF;
  --c-blue-light: #4FB8FF;
  --c-orange: #FF6B00;
  --c-text: #E8EDF2;
  --c-text-dim: #A0B0C0;
  --c-border: #1E2A3A;
  --c-success: #00D98B;
  --font-sans: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'Roboto Mono', 'Consolas', monospace;
  --r-sm: 10px;
  --r-md: 16px;
  --r-lg: 24px;
  --r-pill: 999px;
  --content-w: 1200px;
  --header-z: 200;
  --nav-z: 300;
  --overlay-z: 250;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  min-width: 320px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-wrap: break-word;
  background:
    radial-gradient(ellipse at 88% -8%, rgba(43, 127, 255, 0.1), transparent 62%),
    radial-gradient(ellipse at -6% 108%, rgba(255, 107, 0, 0.06), transparent 60%),
    var(--c-bg);
  color: var(--c-text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6, p, ul, ol, figure, blockquote, dl, dd {
  margin: 0;
}

ul[class], ol[class] {
  list-style: none;
  padding: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

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

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

::selection {
  background: rgba(43, 127, 255, 0.4);
  color: #fff;
}

:focus {
  outline: none;
}

:focus-visible {
  outline: 3px solid var(--c-orange);
  outline-offset: 3px;
  border-radius: 6px;
}

h1 {
  font-size: clamp(34px, 5vw, 52px);
  font-weight: 300;
  line-height: 1.15;
  letter-spacing: 0.01em;
}

h2 {
  font-size: clamp(26px, 3.2vw, 38px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.01em;
}

h3 {
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 600;
  line-height: 1.25;
}

#main-content {
  scroll-margin-top: 88px;
}

/* ============ 无障碍与导航辅助 ============ */
.skip-link {
  position: fixed;
  top: 14px;
  left: 14px;
  z-index: calc(var(--nav-z) + 100);
  padding: 12px 22px;
  border-radius: var(--r-pill);
  background: var(--c-orange);
  color: #fff;
  font-weight: 600;
  font-size: 15px;
  box-shadow: 0 8px 24px rgba(255, 107, 0, 0.4);
  transform: translateY(-180%);
  transition: transform 0.25s var(--ease);
}

.skip-link:focus-visible {
  transform: translateY(0);
}

/* ============ 头部 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--header-z);
  background:
    linear-gradient(180deg, rgba(43, 127, 255, 0.07), transparent 140px),
    rgba(11, 16, 32, 0.9);
  border-bottom: 1px solid var(--c-border);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.site-header::before {
  content: "";
  position: absolute;
  z-index: 0;
  top: 0;
  left: 0;
  width: 220px;
  height: 100%;
  background: linear-gradient(100deg, rgba(43, 127, 255, 0.1), transparent 72%);
  clip-path: polygon(0 0, 15% 0, 8% 100%, 0 100%);
  pointer-events: none;
}

.header-shell {
  position: relative;
  z-index: 1;
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 0 20px;
}

.header-upper {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 24px;
  padding: 16px 0 0;
}

/* 品牌 */
.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  padding: 8px 14px 8px 8px;
  margin-left: -8px;
  border-radius: var(--r-pill);
  transition: background 0.2s;
}

.brand-link:hover {
  background: rgba(43, 127, 255, 0.08);
}

.brand-symbol {
  width: 46px;
  height: 46px;
  flex: none;
  filter: drop-shadow(0 4px 12px rgba(43, 127, 255, 0.35));
}

.brand-symbol--sm {
  width: 38px;
  height: 38px;
}

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

.brand-name {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.brand-sub {
  font-size: 12px;
  font-weight: 400;
  color: var(--c-text-dim);
  letter-spacing: 0.14em;
}

/* 导读目录 */
.header-directory {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  justify-self: center;
  min-width: 0;
  overflow: hidden;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--c-text-dim);
}

.header-directory-label {
  flex: none;
  padding: 3px 10px;
  border-radius: var(--r-pill);
  background: rgba(43, 127, 255, 0.14);
  color: var(--c-blue-light);
  font-weight: 600;
  font-size: 12px;
  letter-spacing: 0.1em;
}

.header-directory-text {
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 头部操作区 */
.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  justify-self: end;
}

.header-theme-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: var(--r-pill);
  border: 1px solid var(--c-border);
  background: rgba(17, 24, 39, 0.6);
  color: var(--c-text-dim);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.theme-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex: none;
  background: var(--c-blue-light);
  box-shadow: 0 0 10px rgba(79, 184, 255, 0.7);
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  border-radius: var(--r-pill);
  background: var(--c-panel);
  border: 1px solid var(--c-border);
  color: var(--c-text);
  font-size: 14px;
  font-weight: 600;
  white-space: nowrap;
  transition: border-color 0.2s, background 0.2s, box-shadow 0.2s;
}

.nav-toggle:hover {
  border-color: var(--c-blue);
  box-shadow: 0 0 18px rgba(43, 127, 255, 0.2);
}

.nav-toggle[aria-expanded="true"] {
  border-color: var(--c-blue);
  background: rgba(43, 127, 255, 0.12);
  color: var(--c-blue-light);
}

.nav-toggle-icon {
  position: relative;
  display: block;
  width: 16px;
  height: 12px;
  flex: none;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.25s var(--ease), top 0.25s var(--ease);
}

.nav-toggle-icon::before {
  top: 0;
}

.nav-toggle-icon::after {
  top: 10px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before {
  top: 5px;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after {
  top: 5px;
  transform: rotate(-45deg);
}

.nav-toggle-text {
  line-height: 1;
}

/* 主导航 */
.site-nav {
  padding: 12px 0 16px;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 6px;
  width: fit-content;
  max-width: 100%;
  padding: 6px;
  border-radius: var(--r-pill);
  background: rgba(17, 24, 39, 0.72);
  border: 1px solid var(--c-border);
  overflow-x: auto;
  scrollbar-width: none;
}

.nav-list::-webkit-scrollbar {
  display: none;
}

.nav-item {
  flex: none;
}

.nav-link {
  display: block;
  padding: 9px 18px;
  border-radius: var(--r-pill);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--c-text-dim);
  white-space: nowrap;
  transition: background 0.2s, color 0.2s, box-shadow 0.2s;
}

.nav-link:hover {
  background: rgba(43, 127, 255, 0.1);
  color: var(--c-text);
}

.nav-link:focus-visible {
  outline: 2px solid var(--c-orange);
  outline-offset: 2px;
}

.nav-link[aria-current="page"] {
  background: linear-gradient(120deg, var(--c-blue), #1565d9);
  color: #fff;
  font-weight: 600;
  box-shadow: 0 4px 16px rgba(43, 127, 255, 0.35);
}

/* 滚动进度条 */
.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 5;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--c-blue) 0%, var(--c-blue-light) 55%, var(--c-orange) 100%);
  transform: scaleX(0);
  transform-origin: left;
  pointer-events: none;
  will-change: transform;
}

/* ============ 页脚 ============ */
.site-footer {
  position: relative;
  margin-top: 80px;
  background: linear-gradient(160deg, var(--c-panel-alt) 0%, var(--c-bg) 55%, var(--c-panel) 100%);
  border-top: 1px solid var(--c-border);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 46%;
  height: 260px;
  background: linear-gradient(120deg, rgba(43, 127, 255, 0.18), rgba(255, 107, 0, 0.08) 55%, transparent 100%);
  clip-path: polygon(28% 0, 100% 0, 100% 100%, 0% 100%);
  pointer-events: none;
}

.site-footer::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--c-blue), var(--c-orange));
  opacity: 0.7;
  pointer-events: none;
}

.footer-shell {
  position: relative;
  z-index: 1;
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 56px 20px 0;
}

.footer-main {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1.2fr;
  gap: 48px;
}

.footer-brand-link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.footer-brand-name {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.footer-about {
  max-width: 38em;
  margin-bottom: 14px;
  color: var(--c-text-dim);
  font-size: 15px;
}

.footer-trust {
  padding-left: 14px;
  border-left: 3px solid var(--c-blue);
  font-size: 13px;
  color: var(--c-text-dim);
  opacity: 0.78;
}

.footer-heading {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.footer-heading::before {
  content: "";
  width: 8px;
  height: 8px;
  flex: none;
  border-radius: 2px;
  background: var(--c-orange);
  transform: rotate(45deg);
}

.footer-nav-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-nav-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 15px;
  color: var(--c-text-dim);
  transition: color 0.2s, transform 0.2s;
}

.footer-nav-list a::before {
  content: "";
  width: 4px;
  height: 4px;
  border-radius: 50%;
  flex: none;
  background: var(--c-border);
  transition: background 0.2s;
}

.footer-nav-list a:hover {
  color: var(--c-blue-light);
  transform: translateX(4px);
}

.footer-nav-list a:hover::before {
  background: var(--c-orange);
}

.footer-contact-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 20px;
}

.footer-contact-list li {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.contact-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--c-text-dim);
  opacity: 0.72;
}

.contact-value {
  font-size: 15px;
  color: var(--c-text);
}

.footer-contact-note {
  margin-bottom: 18px;
  font-size: 13px;
  color: var(--c-text-dim);
  opacity: 0.8;
}

.footer-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--r-pill);
  background: linear-gradient(120deg, var(--c-blue), #1565d9);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  box-shadow: 0 4px 14px rgba(43, 127, 255, 0.3);
  transition: transform 0.2s, box-shadow 0.2s;
}

.footer-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(43, 127, 255, 0.42);
}

.footer-cta-arrow {
  transition: transform 0.2s;
}

.footer-cta:hover .footer-cta-arrow {
  transform: translateX(4px);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 24px;
  margin-top: 48px;
  padding: 24px 0;
  border-top: 1px solid var(--c-border);
  font-size: 13px;
  color: var(--c-text-dim);
}

.footer-copyright {
  margin-right: auto;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-legal a {
  color: var(--c-text-dim);
  transition: color 0.2s;
}

.footer-legal a:hover {
  color: var(--c-blue-light);
}

.footer-icp {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

/* ============ 页面通用组件 ============ */
.page-container {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 0 20px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 24px 0;
  list-style: none;
  font-size: 14px;
  color: var(--c-text-dim);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 6px;
}

.breadcrumb li + li::before {
  content: "/";
  font-family: var(--font-mono);
  color: var(--c-border);
}

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

.breadcrumb a:hover {
  color: var(--c-blue-light);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--r-pill);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.2;
  cursor: pointer;
  border: 1px solid transparent;
  text-decoration: none;
  transition: background 0.2s, box-shadow 0.2s, transform 0.2s, border-color 0.2s;
}

.btn--primary {
  background: linear-gradient(120deg, var(--c-orange) 0%, #E05200 100%);
  color: #fff;
  box-shadow: 0 6px 20px rgba(255, 107, 0, 0.32);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(255, 107, 0, 0.42);
}

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

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

.panel {
  background: var(--c-panel);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: 28px;
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.2);
}

.stack-panel {
  position: relative;
  background: var(--c-panel);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: 32px;
  overflow: hidden;
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.2);
}

.stack-panel::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--c-blue), transparent 70%);
  pointer-events: none;
}

.stack-panel + .stack-panel {
  margin-top: 20px;
}

.grid {
  display: grid;
  gap: 24px;
}

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

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

.index-label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 16px;
  border-radius: var(--r-pill);
  background: rgba(43, 127, 255, 0.12);
  border: 1px solid rgba(43, 127, 255, 0.28);
  color: var(--c-blue-light);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
}

.index-label::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  flex: none;
  background: var(--c-orange);
  box-shadow: 0 0 10px rgba(255, 107, 0, 0.6);
}

.media-frame {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  background:
    radial-gradient(circle at 28% 22%, rgba(43, 127, 255, 0.16), transparent 55%),
    radial-gradient(circle at 72% 78%, rgba(255, 107, 0, 0.12), transparent 45%),
    linear-gradient(135deg, var(--c-panel-alt), var(--c-bg));
}

.media-frame--wide {
  aspect-ratio: 21 / 9;
}

.media-frame--square {
  aspect-ratio: 1 / 1;
}

.media-frame > img {
  position: absolute;
  inset: 0;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame__caption {
  position: absolute;
  bottom: 12px;
  left: 12px;
  z-index: 2;
  padding: 5px 14px;
  border-radius: var(--r-pill);
  background: rgba(11, 16, 32, 0.76);
  border: 1px solid var(--c-border);
  color: var(--c-text-dim);
  font-size: 12px;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.data-mono {
  font-family: var(--font-mono);
  font-size: 0.92em;
  letter-spacing: 0.02em;
}

/* ============ 响应式 ============ */
@media (max-width: 1080px) {
  .grid--3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 1000px) {
  .header-directory {
    display: none;
  }
}

@media (max-width: 860px) {
  .header-upper {
    grid-template-columns: 1fr auto;
    padding: 12px 0;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(340px, 88vw);
    z-index: var(--nav-z);
    margin: 0;
    padding: 28px 20px;
    background: var(--c-panel);
    border-left: 1px solid var(--c-border);
    border-radius: 24px 0 0 24px;
    box-shadow: -16px 0 40px rgba(0, 0, 0, 0.5);
    overflow-y: auto;
    transform: translateX(100%);
    transition: transform 0.35s var(--ease);
  }

  .site-nav[data-open] {
    transform: translateX(0);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    width: auto;
    max-width: none;
    padding: 0;
    background: transparent;
    border: none;
    border-radius: 0;
    gap: 4px;
    overflow: visible;
  }

  .nav-link {
    display: block;
    padding: 14px 18px;
    font-size: 16px;
    border-radius: var(--r-md);
    color: var(--c-text);
  }

  .nav-link:hover {
    background: rgba(43, 127, 255, 0.08);
    color: var(--c-text);
  }

  .nav-link[aria-current="page"] {
    background: var(--c-blue);
    color: #fff;
    box-shadow: 0 4px 14px rgba(43, 127, 255, 0.3);
  }

  body[data-nav-open] {
    overflow: hidden;
  }

  body[data-nav-open]::after {
    content: "";
    position: fixed;
    inset: 0;
    z-index: var(--overlay-z);
    background: rgba(11, 16, 32, 0.66);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
  }

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

  .site-footer {
    margin-top: 48px;
  }

  .footer-shell {
    padding: 40px 20px 0;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .footer-copyright {
    margin-right: 0;
  }

  .footer-legal {
    flex-wrap: wrap;
  }
}

@media (max-width: 480px) {
  .brand-symbol {
    width: 38px;
    height: 38px;
  }

  .brand-name {
    font-size: 19px;
  }

  .brand-sub {
    font-size: 11px;
  }

  .header-theme-label {
    display: none;
  }

  .panel {
    padding: 20px;
  }

  .stack-panel {
    padding: 24px;
  }
}

/* ============ 动效偏好 ============ */
@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;
  }

  .skip-link,
  .site-nav {
    transition: none;
  }
}