@import url('https://fonts.googleapis.com/css2?family=Bebas+Neue&family=Source+Sans+3:wght@300;400;500;600;700&display=swap');

:root {
  --ink: #000000;
  --paper: #ffffff;
  --mute: rgba(0, 0, 0, 0.55);
  --mute-inv: rgba(255, 255, 255, 0.62);
  --hair: rgba(0, 0, 0, 0.14);
  --pad: clamp(1.15rem, 4vw, 4.5rem);
  --display: 'Bebas Neue', 'Source Sans 3', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --text: 'Source Sans 3', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', system-ui, sans-serif;
}

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

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--text);
  font-size: 17px;
  line-height: 1.75;
  overflow-x: hidden;
  font-weight: 400;
}

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

a {
  color: inherit;
}

h1,
h2,
h3 {
  margin: 0;
  font-family: var(--display);
  font-weight: 900;
  line-height: 0.95;
  letter-spacing: -0.045em;
  overflow-wrap: break-word;
}

p {
  margin: 0 0 1.1rem;
}

/* ---------- 骨架 ---------- */

.shell {
  display: grid;
  grid-template-columns: clamp(210px, 22vw, 300px) minmax(0, 1fr);
  align-items: stretch;
}

.stage {
  min-width: 0;
}

/* ---------- 左栏 ---------- */

.rail {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: auto;
  background: var(--ink);
  color: var(--paper);
  display: flex;
  flex-direction: column;
  gap: 1.35rem;
  padding: 1.4rem var(--pad) 1.6rem;
  -webkit-overflow-scrolling: touch;
}

.brand {
  display: inline-block;
  padding: 0.5rem 0;
  min-height: 44px;
  color: #ffffff;
  text-decoration: none;
  font-family: var(--display);
  font-size: clamp(1.05rem, 1.6vw, 1.3rem);
  font-weight: 900;
  letter-spacing: 0.22em;
}

.rail-top {
  display: grid;
  gap: 0.45rem;
}

.rail-h {
  color: #ffffff;
  font-size: clamp(1.7rem, 2.7vw, 2.5rem);
}

.subtitle {
  margin: 0;
  font-size: 16px;
  letter-spacing: 0.05em;
  color: var(--mute-inv);
}

.nav {
  margin-top: auto;
}

.nav summary {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  min-height: 48px;
  padding: 0.6rem 0;
  cursor: pointer;
  color: #ffffff;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.28em;
}

.nav summary::-webkit-details-marker {
  display: none;
}

.nav summary::before {
  content: '';
  width: 14px;
  height: 2px;
  background: #ffffff;
  transition: transform 0.25s ease;
}

.nav[open] summary::before {
  transform: rotate(90deg);
}

.nav menu {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.1rem;
}

.nav menu a {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  min-height: 44px;
  padding: 0.72rem 0;
  color: #ffffff;
  font-size: 16px;
  text-decoration: none;
  transition: transform 0.2s ease;
}

.nav menu a:hover,
.nav menu a:focus-visible {
  transform: translateX(6px);
}

.dot {
  width: 6px;
  height: 6px;
  flex: 0 0 6px;
  background: currentColor;
  border-radius: 1px;
  opacity: 0.55;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.nav menu a:hover .dot {
  opacity: 1;
  transform: scale(1.6);
}

/* ---------- 顶部细条 ---------- */

.ticker {
  background: var(--ink);
  color: var(--paper);
  overflow: hidden;
  padding: 0.6rem 0;
}

.tk-track {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  width: max-content;
  white-space: nowrap;
  animation: slide 28s linear infinite;
}

.tk {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.34em;
  padding-left: 0.34em;
}

@keyframes slide {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-50%);
  }
}

/* ---------- 首屏 ---------- */

.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  background: var(--ink);
  color: var(--paper);
  display: flex;
  align-items: flex-end;
  justify-content: flex-end;
  padding: clamp(2rem, 7vw, 6rem) var(--pad);
  overflow: hidden;
}

.hero-shots {
  position: absolute;
  inset: 0;
}

.shot {
  position: absolute;
  object-fit: cover;
  width: clamp(130px, 24vw, 330px);
  border-radius: 10px;
  filter: grayscale(1) contrast(1.06);
  box-shadow: 0 40px 70px -40px rgba(0, 0, 0, 0.95);
}

.shot.s1 {
  top: 8%;
  left: 5%;
  transform: rotate(-3.2deg);
}

.shot.s2 {
  bottom: 15%;
  left: 30%;
  transform: rotate(2.4deg);
}

.hero-copy {
  position: relative;
  z-index: 2;
  text-align: right;
  max-width: 100%;
}

.hero h1 {
  color: #ffffff;
  font-size: clamp(3rem, 9.5vw, 9rem);
  text-align: right;
}

/* ---------- 正文 ---------- */

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: clamp(2.5rem, 7vw, 7rem) var(--pad);
}

.sheet {
  min-width: 0;
}

.page-h1 {
  font-size: clamp(2.6rem, 8vw, 6rem);
  margin-bottom: clamp(1.5rem, 4vw, 3rem);
}

.prose {
  max-width: 64ch;
  font-size: 17px;
}

.prose > div {
  padding-block: clamp(2rem, 5vw, 4rem);
  scroll-margin-top: 120px;
}

.prose > div:first-child {
  padding-top: 0;
}

.prose > div + div {
  margin-top: clamp(1rem, 3vw, 2rem);
}

.prose h2 {
  font-size: clamp(2rem, 5.6vw, 3.6rem);
  margin: 0 0 1.1rem;
}

.prose h3 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  margin: 2.2rem 0 0.8rem;
}

.prose ul,
.prose ol {
  margin: 0 0 1.2rem;
  padding-left: 1.2rem;
}

.prose li {
  margin: 0.35rem 0;
}

.prose a {
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
  transition: background 0.18s ease, color 0.18s ease;
}

.prose a:hover,
.prose a:focus-visible {
  background: var(--ink);
  color: var(--paper);
  text-decoration: none;
}

.prose strong {
  font-weight: 700;
}

.prose blockquote {
  margin: 1.6rem 0;
  padding: 0.2rem 0 0.2rem 1.2rem;
  border-left: 4px solid var(--ink);
  color: var(--mute);
}

.prose img {
  border-radius: 10px;
  margin: 1.4rem 0;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 16px;
  margin: 0 0 1.4rem;
}

.prose th,
.prose td {
  text-align: left;
  padding: 0.6rem 0.5rem;
  border-bottom: 1px solid var(--hair);
}

.prose hr {
  border: 0;
  border-top: 1px solid var(--hair);
  margin: 2rem 0;
}

/* ---------- 页脚 ---------- */

.foot {
  background: var(--ink);
  color: var(--paper);
  padding: clamp(3rem, 7vw, 6rem) var(--pad) 2rem;
  display: grid;
  gap: clamp(2rem, 5vw, 3.5rem);
}

.foot-cta .cta {
  display: inline-block;
  color: #ffffff;
  text-decoration: none;
  font-family: var(--display);
  font-size: clamp(2.4rem, 8.5vw, 6.5rem);
  font-weight: 900;
  line-height: 0.88;
  letter-spacing: -0.05em;
  padding: 0.2rem 0;
}

.foot-links ul {
  margin: 0 0 1.2rem;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.1rem;
}

.foot-links ul a {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  min-height: 44px;
  padding: 0.5rem 0;
  color: var(--mute-inv);
  font-size: 16px;
  text-decoration: none;
  transition: color 0.18s ease, transform 0.18s ease;
}

.foot-links ul a:hover {
  color: #ffffff;
  transform: translateX(4px);
}

.totop {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0.7rem 1.2rem;
  border-radius: 10px;
  background: #ffffff;
  color: #000000;
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
}

.copy {
  margin: 0;
  font-size: 16px;
  color: var(--mute-inv);
}

/* ---------- 动效 ---------- */

.anim .prose > div {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.anim .prose > div.in {
  opacity: 1;
  transform: none;
}

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

  .tk-track {
    animation: none;
  }

  .anim .prose > div {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ---------- 窄屏 ---------- */

@media (max-width: 900px) {
  .shell {
    grid-template-columns: minmax(0, 1fr);
  }

  .rail {
    position: sticky;
    top: 0;
    z-index: 60;
    height: auto;
    max-height: 100svh;
    gap: 0.75rem;
    padding: 0.75rem var(--pad) 1rem;
  }

  .rail-top {
    display: flex;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 0.2rem 0.7rem;
  }

  .rail-h {
    font-size: 1.55rem;
  }

  .subtitle {
    font-size: 16px;
  }

  .nav {
    margin-top: 0;
  }

  .hero {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    min-height: auto;
    padding: clamp(1.6rem, 6vw, 2.6rem) var(--pad) clamp(2rem, 7vw, 3rem);
  }

  .hero-copy {
    order: -1;
    text-align: left;
    margin-bottom: 1.5rem;
  }

  .hero h1 {
    font-size: clamp(2.6rem, 13vw, 4.5rem);
    text-align: left;
  }

  .hero-shots {
    position: relative;
    inset: auto;
    display: flex;
    align-items: flex-start;
    gap: 0.9rem;
    width: 100%;
  }

  .shot {
    position: static;
    width: 48%;
    max-width: 190px;
    border-radius: 10px;
    transform: rotate(-2deg);
  }

  .shot.s2 {
    transform: rotate(2deg);
    margin-top: 1.5rem;
  }

  .prose > div {
    scroll-margin-top: 160px;
  }
}

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