:root {
  --底色: oklch(0.065 0.012 18);
  --表面: oklch(0.115 0.025 20);
  --墨色: oklch(0.96 0.015 30);
  --猩红: oklch(0.56 0.22 28);
  --余烬: oklch(0.72 0.17 46);
  --低语: oklch(0.71 0.035 22);
  --衬线: "STSong", "Songti SC", "Noto Serif SC", serif;
  --无衬线: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
}

* { box-sizing: border-box; }

html { background: var(--底色); }

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  background:
    linear-gradient(112deg, oklch(0.065 0.012 18) 4%, oklch(0.085 0.024 21) 52%, oklch(0.052 0.006 18) 100%);
  color: var(--墨色);
  font-family: var(--无衬线);
}

button, a { -webkit-tap-highlight-color: transparent; }

button { font: inherit; }

.页面 {
  position: relative;
  z-index: 1;
  display: grid;
  min-height: 100svh;
  padding: clamp(1.25rem, 3vw, 2.75rem) clamp(1.25rem, 5.5vw, 6.5rem) 1.25rem;
}

.噪点 {
  position: fixed;
  z-index: 0;
  inset: 0;
  pointer-events: none;
  opacity: .12;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 180 180' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.9'/%3E%3C/svg%3E");
  mix-blend-mode: screen;
}

.光晕 {
  position: fixed;
  z-index: 0;
  width: min(62vw, 52rem);
  aspect-ratio: 1;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(34px);
  opacity: .25;
  background: radial-gradient(circle, oklch(0.56 .22 28 / .62), transparent 66%);
  animation: 呼吸 12s ease-in-out infinite alternate;
}

.光晕--一 { top: -30vw; left: -17vw; }
.光晕--二 { right: -26vw; bottom: -32vw; opacity: .15; animation-delay: -6s; }

.页首, .页脚 {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.页首 { min-height: 2rem; }

.标识 {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  color: var(--墨色);
  font-family: var(--衬线);
  font-size: 1.1rem;
  letter-spacing: .22em;
  text-decoration: none;
}

.标识__点 {
  width: .5rem;
  height: .5rem;
  border-radius: 50%;
  background: var(--猩红);
  box-shadow: 0 0 1rem oklch(0.56 .22 28 / .85);
}

.页首__编号, .眉题, .播放器__参数, .页脚 {
  color: var(--低语);
  font-size: .72rem;
  letter-spacing: .12em;
}

.页首__编号 { margin: 0; }

.首屏 {
  display: grid;
  grid-template-columns: minmax(13rem, 1fr) minmax(16rem, 25vw) minmax(13rem, 1fr);
  align-items: center;
  gap: clamp(1.5rem, 5vw, 6rem);
  width: min(100%, 106rem);
  margin: 0 auto;
}

.首屏__文案 { align-self: center; padding-bottom: 4.5rem; }

.眉题 {
  margin: 0 0 1.1rem;
  color: var(--余烬);
}

h1 {
  max-width: 7ch;
  margin: 0;
  font-family: var(--衬线);
  font-size: clamp(3.6rem, 7.5vw, 7.5rem);
  font-weight: 500;
  line-height: .88;
  letter-spacing: -.07em;
  text-wrap: balance;
}

h1 em {
  position: relative;
  display: inline-block;
  color: oklch(.76 .18 30);
  font-style: normal;
  transform: translateX(.24em);
}

h1 em::after {
  position: absolute;
  right: -.1em;
  bottom: .06em;
  left: -.18em;
  height: .14em;
  content: "";
  background: var(--猩红);
  opacity: .72;
  transform: skewX(-21deg);
}

.导语 {
  max-width: 21rem;
  margin: 2rem 0 0;
  color: oklch(.84 .03 25);
  font-size: clamp(.94rem, 1.1vw, 1.05rem);
  line-height: 1.9;
}

.播放器 {
  position: relative;
  width: 100%;
  margin: 0;
  aspect-ratio: 9 / 16;
  isolation: isolate;
  overflow: hidden;
  background: #050303;
  box-shadow: 0 1.75rem 7rem oklch(.05 .02 20 / .84), 0 0 0 1px oklch(.75 .16 30 / .32);
}

.播放器__边框 {
  position: absolute;
  z-index: 3;
  inset: 0;
  pointer-events: none;
  border: 1px solid oklch(.78 .17 32 / .6);
  box-shadow: inset 0 0 0 5px oklch(.08 .01 20 / .2), inset 0 0 3.5rem oklch(.5 .21 28 / .26);
}

.播放器::after {
  position: absolute;
  z-index: 2;
  inset: 0;
  pointer-events: none;
  content: "";
  background: repeating-linear-gradient(0deg, transparent 0 3px, oklch(0 0 0 / .14) 4px 5px);
  mix-blend-mode: multiply;
}

.播放器__视频 { display: block; width: 100%; height: 100%; object-fit: cover; }

.播放按钮 {
  position: absolute;
  z-index: 4;
  top: 50%;
  left: 50%;
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  padding: .65rem .95rem .65rem .75rem;
  border: 1px solid oklch(.88 .08 32 / .75);
  border-radius: 0;
  color: white;
  background: oklch(.38 .17 27 / .87);
  box-shadow: 0 0 2rem oklch(.49 .22 28 / .55);
  cursor: pointer;
  transform: translate(-50%, -50%);
  transition: opacity .22s ease, transform .22s ease, background .22s ease;
}

.播放按钮:hover { background: oklch(.49 .21 28 / .95); transform: translate(-50%, -50%) scale(1.03); }
.播放按钮:focus-visible, .动态按钮:focus-visible, .全屏按钮:focus-visible { outline: 2px solid white; outline-offset: 4px; }

.播放按钮__图标 {
  width: 0;
  height: 0;
  border-top: .42rem solid transparent;
  border-bottom: .42rem solid transparent;
  border-left: .62rem solid currentColor;
}

.播放按钮__文字 { font-size: .82rem; letter-spacing: .14em; }

.播放器.正在播放 .播放按钮 { opacity: 0; pointer-events: none; transform: translate(-50%, -45%); }
.播放器.暂停中 .播放按钮 { opacity: 1; pointer-events: auto; }

.播放器__参数 {
  position: absolute;
  z-index: 3;
  right: .7rem;
  bottom: .75rem;
  left: .7rem;
  display: flex;
  justify-content: space-between;
  color: oklch(.98 .01 30 / .88);
  text-shadow: 0 1px 4px black;
}

.观看提示 { align-self: end; max-width: 18rem; padding-bottom: 2.4rem; }

.观看提示__标题 {
  margin: 0 0 .6rem;
  color: var(--余烬);
  font-family: var(--衬线);
  font-size: 1.12rem;
  letter-spacing: .08em;
}

.观看提示 p:not(.观看提示__标题) {
  margin: 0;
  color: oklch(.82 .03 24);
  font-size: .9rem;
  line-height: 1.75;
}

.动态按钮, .全屏按钮 {
  margin-top: 1.2rem;
  padding: .55rem 0;
  border: 0;
  border-bottom: 1px solid oklch(.7 .1 28 / .66);
  color: var(--墨色);
  background: transparent;
  cursor: pointer;
}

.动态按钮:hover, .全屏按钮:hover { color: var(--余烬); }
.动态按钮[aria-pressed="true"] { color: var(--余烬); }

.页脚 { align-self: end; padding-top: 1rem; }
.页脚 p { margin: 0; }
.全屏按钮 { margin: 0; color: var(--低语); font-size: .78rem; letter-spacing: .08em; }

body.减少动态 .光晕 { animation-play-state: paused; opacity: .09; }
body.减少动态 .噪点 { opacity: .05; }

@keyframes 呼吸 {
  from { transform: translate3d(-3%, -2%, 0) scale(.92); }
  to { transform: translate3d(5%, 3%, 0) scale(1.08); }
}

@media (max-width: 850px) {
  .页面 { min-height: auto; }
  .首屏 { grid-template-columns: 1fr minmax(14.5rem, 20rem); grid-template-areas: "copy video" "note video"; gap: 1.75rem 2.5rem; padding: 4rem 0 3rem; }
  .首屏__文案 { grid-area: copy; padding: 0; }
  .播放器 { grid-area: video; }
  .观看提示 { grid-area: note; align-self: start; padding: 0; }
}

@media (max-width: 590px) {
  .页面 { padding: 1.15rem 1rem .9rem; }
  .首屏 { display: flex; flex-direction: column; align-items: stretch; padding: 2.75rem 0; }
  .首屏__文案 { align-self: flex-start; }
  h1 { font-size: clamp(3.85rem, 20vw, 5.7rem); }
  .导语 { margin-top: 1.35rem; }
  .播放器 { width: min(100%, 22rem); align-self: center; }
  .观看提示 { align-self: stretch; max-width: none; padding-top: .25rem; }
  .页首__编号 { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .光晕 { display: none; }
}