@import url('https://fonts.googleapis.com/css2?family=Lora:wght@400;500;600;700&family=Raleway:wght@300;400;500;600;700&display=swap');

:root {
  --ink: #000000;
  --panel: #121212;
  --mid: #1d2b4d;
  --line: rgba(148, 172, 224, 0.14);
  --line-strong: rgba(150, 185, 255, 0.34);
  --txt: #e3e7ef;
  --dim: #a9b3c4;
  --glow: rgba(120, 162, 255, 0.42);
  --gold: #c8a86a;
  --serif: "Lora", Georgia, "Songti SC", "SimSun", serif;
  --sans: "Raleway", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

html {
  color-scheme: dark;
  scroll-behavior: smooth;
  background: #000000;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  background:
    radial-gradient(880px 520px at 80% -14%, rgba(38, 72, 148, 0.3), transparent 70%),
    radial-gradient(680px 420px at 4% 6%, rgba(24, 42, 92, 0.22), transparent 72%),
    #000000;
  color: var(--txt);
  font-family: var(--sans);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.72;
  letter-spacing: 0.012em;
}

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

a {
  color: #9fbcff;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

a:hover {
  color: #cddcff;
}

:focus-visible {
  outline: 2px solid #8fb4ff;
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 70;
  padding: 12px 18px;
  background: #0b1220;
  border: 1px solid var(--line-strong);
  color: #e6ecff;
  text-decoration: none;
}

.skip:focus {
  left: 10px;
  top: 10px;
}

header.top {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 7px 16px;
  background: rgba(0, 0, 0, 0.74);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
}

.mark {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  overflow: hidden;
  border: 1px solid var(--line);
  background: linear-gradient(150deg, rgba(92, 132, 232, 0.2), rgba(255, 255, 255, 0.02));
  color: #dfe7ff;
  font-family: var(--serif);
  font-size: 15px;
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: border-color 0.2s ease, box-shadow 0.25s ease;
}

.mark img {
  width: 26px;
  height: 26px;
  object-fit: contain;
}

.mark:hover {
  border-color: rgba(140, 175, 255, 0.6);
  box-shadow: 0 0 16px rgba(92, 140, 255, 0.3);
}

.top-nav {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  justify-content: flex-end;
}

.top-nav ol {
  display: flex;
  align-items: center;
  gap: 2px;
  margin: 0;
  padding: 0 2px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.top-nav li {
  flex: 0 0 auto;
}

.top-nav a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  border-bottom: 2px solid transparent;
  color: #b9c2d2;
  font-size: 16px;
  white-space: nowrap;
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, text-shadow 0.25s ease;
}

.top-nav a:hover,
.top-nav a:focus-visible {
  color: #ffffff;
  border-bottom-color: #6f9dff;
  text-shadow: 0 0 12px var(--glow);
}

.top-nav a[aria-current="true"] {
  color: #ffffff;
  border-bottom-color: var(--gold);
}

main.shell {
  display: grid;
  grid-template-columns: 212px minmax(0, 1fr);
  align-items: start;
  gap: 38px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 34px 22px 92px;
}

aside.rail {
  position: sticky;
  top: 78px;
  padding: 16px 16px 18px;
  border: 1px solid var(--line);
  background: linear-gradient(
    165deg,
    rgba(255, 255, 255, 0.06),
    rgba(255, 255, 255, 0.012) 55%,
    rgba(30, 60, 130, 0.1)
  );
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

aside.rail h2 {
  margin: 0;
  color: #cfd8e8;
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.3em;
}

hr {
  height: 1px;
  margin: 10px 0 14px;
  border: 0;
  background: linear-gradient(90deg, rgba(120, 160, 255, 0.6), rgba(120, 160, 255, 0.04));
}

aside ul {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
}

aside a {
  display: flex;
  align-items: center;
  min-height: 42px;
  padding: 4px 10px;
  border-left: 1px solid rgba(120, 160, 255, 0.22);
  color: var(--dim);
  font-size: 16px;
  text-decoration: none;
  transition: color 0.2s ease, background 0.25s ease, border-color 0.2s ease, text-shadow 0.25s ease;
}

aside a:hover,
aside a:focus-visible {
  color: #ffffff;
  border-left-color: #7fa7ff;
  background: linear-gradient(90deg, rgba(92, 136, 235, 0.18), transparent);
  text-shadow: 0 0 10px var(--glow);
}

section.doc {
  min-width: 0;
}

section > div {
  padding: 26px 24px;
  border: 1px solid rgba(140, 175, 255, 0.13);
  background: linear-gradient(
    160deg,
    rgba(255, 255, 255, 0.052),
    rgba(255, 255, 255, 0.012) 60%,
    rgba(30, 60, 130, 0.1)
  );
  backdrop-filter: blur(9px);
  -webkit-backdrop-filter: blur(9px);
  scroll-margin-top: 96px;
  transition: border-color 0.25s ease, opacity 0.5s ease, transform 0.5s ease;
}

section > div + div {
  margin-top: 26px;
}

section > div:hover {
  border-color: var(--line-strong);
}

.hero {
  position: relative;
  isolation: isolate;
  display: grid;
  place-items: center;
  min-height: 70vh;
  padding: 58px 18px 46px;
  overflow: hidden;
  text-align: center;
  background: linear-gradient(180deg, rgba(12, 20, 38, 0.72), rgba(0, 0, 0, 0.34));
}

.hero-img {
  position: absolute;
  z-index: 0;
  object-fit: cover;
  border: 1px solid rgba(120, 160, 255, 0.16);
  filter: brightness(0.62) saturate(0.5) contrast(1.06);
  opacity: 0.72;
}

.hero-img-a {
  top: 7%;
  left: 0;
  width: 34%;
  aspect-ratio: 3 / 4;
  transform: translate(-14%, 0) rotate(-2deg);
}

.hero-img-b {
  right: 0;
  bottom: 6%;
  width: 32%;
  aspect-ratio: 4 / 3;
  transform: translate(12%, 0) rotate(2deg);
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: radial-gradient(closest-side at 50% 55%, rgba(0, 0, 0, 0.32), rgba(0, 0, 0, 0.87));
}

.hero-copy {
  position: relative;
  z-index: 2;
  max-width: 44rem;
}

.badge {
  display: inline-block;
  margin: 0 0 18px;
  padding: 6px 16px;
  border: 1px solid rgba(200, 168, 106, 0.5);
  background: rgba(0, 0, 0, 0.5);
  color: #e8d9b8;
  font-size: 15px;
  letter-spacing: 0.24em;
  box-shadow: 0 0 20px rgba(200, 168, 106, 0.16);
}

h1 {
  margin: 0;
  color: #ffffff;
  font-family: var(--serif);
  font-size: clamp(30px, 5.4vw, 54px);
  font-weight: 600;
  line-height: 1.14;
  letter-spacing: 0.02em;
  text-shadow: 0 0 24px rgba(110, 155, 255, 0.34);
}

.lede {
  max-width: 46ch;
  margin: 18px auto 0;
  color: #b9c3d4;
  font-size: 17px;
}

section h2 {
  margin: 0 0 4px;
  color: #ffffff;
  font-family: var(--serif);
  font-size: clamp(22px, 3.2vw, 32px);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: 0.01em;
}

section h3 {
  margin: 26px 0 4px;
  color: #eaf0ff;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
}

section h2 + hr,
section h3 + hr {
  margin: 12px 0 18px;
  background: linear-gradient(90deg, rgba(200, 168, 106, 0.75), rgba(120, 160, 255, 0.34), transparent);
}

section p {
  max-width: 70ch;
  margin: 14px 0;
  color: #c2cad8;
}

section ul,
section ol {
  padding-left: 22px;
  color: #c2cad8;
}

section li {
  margin: 8px 0;
}

section strong,
section b {
  color: #ffffff;
}

section blockquote {
  margin: 18px 0;
  padding: 12px 18px;
  border-left: 2px solid var(--gold);
  background: rgba(200, 168, 106, 0.07);
  color: #dad3c3;
}

section table {
  width: 100%;
  border-collapse: collapse;
  margin: 18px 0;
  font-size: 16px;
}

section th,
section td {
  padding: 10px 12px;
  border: 1px solid var(--line);
  text-align: left;
}

section th {
  background: rgba(30, 60, 130, 0.22);
  color: #eef3ff;
}

.rv {
  opacity: 0;
  transform: translateY(18px);
}

.rv.in {
  opacity: 1;
  transform: none;
}

footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 22px;
  border-top: 1px solid var(--line);
  background: #040404;
}

.f-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #dfe6f4;
  font-family: var(--serif);
  font-size: 16px;
  letter-spacing: 0.1em;
}

.f-brand img {
  width: 26px;
  height: 26px;
  object-fit: contain;
  border: 1px solid var(--line);
}

.f-nav ol {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.f-nav a {
  display: flex;
  align-items: center;
  min-height: 40px;
  padding: 0 10px;
  color: var(--dim);
  font-size: 16px;
  text-decoration: none;
}

.f-nav a:hover,
.f-nav a:focus-visible {
  color: #ffffff;
  text-shadow: 0 0 10px var(--glow);
}

.f-copy {
  flex: 1 1 auto;
  color: #8b95a7;
  font-size: 16px;
  text-align: center;
}

.totop {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 55;
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid rgba(140, 175, 255, 0.35);
  background: rgba(10, 16, 30, 0.86);
  color: #dbe4f6;
  font-family: var(--sans);
  font-size: 16px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: opacity 0.24s ease, transform 0.24s ease, visibility 0.24s, border-color 0.2s ease;
}

.totop.on {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.totop:hover {
  border-color: #8fb4ff;
  box-shadow: 0 0 18px rgba(110, 155, 255, 0.34);
}

@media (max-width: 900px) {
  main.shell {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
    padding: 18px 14px 74px;
  }

  aside.rail {
    position: static;
    padding: 12px 12px 14px;
  }

  aside ul {
    display: flex;
    gap: 6px;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  aside a {
    min-height: 44px;
    padding: 4px 12px;
    border: 1px solid rgba(120, 160, 255, 0.2);
    border-left-width: 1px;
    white-space: nowrap;
  }

  .hero {
    min-height: 62vh;
    padding: 46px 14px 38px;
  }

  .hero-img-a {
    width: 40%;
    opacity: 0.5;
  }

  .hero-img-b {
    width: 36%;
    opacity: 0.44;
  }

  section > div {
    padding: 22px 16px;
  }

  footer {
    flex-direction: column;
    gap: 8px;
    padding: 18px 14px;
    text-align: center;
  }
}

@media (max-width: 560px) {
  header.top {
    padding: 6px 10px;
  }

  .top-nav a {
    padding: 0 10px;
    font-size: 16px;
  }

  .hero-img-b {
    display: none;
  }

  .hero-img-a {
    width: 46%;
    opacity: 0.42;
  }

  .lede {
    font-size: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .rv {
    opacity: 1;
    transform: none;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}

button[aria-expanded]{min-width:44px;min-height:44px}