:root {
  color-scheme: dark;
  --bg: #000000;
  --ink: #ffffff;
  --muted: rgba(255, 255, 255, 0.62);
  --faint: rgba(255, 255, 255, 0.40);
  --line: rgba(255, 255, 255, 0.26);
  --glass: rgba(255, 255, 255, 0.08);
  --edge: rgba(255, 255, 255, 0.18);
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.55);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  letter-spacing: 0;
}

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

.page {
  position: relative;
  min-height: 100vh;
  overflow: hidden;
}

.page::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.18;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='96' height='96' viewBox='0 0 96 96'%3E%3Cg fill='%23fff'%3E%3Ccircle cx='12' cy='18' r='1' opacity='.34'/%3E%3Ccircle cx='46' cy='10' r='1' opacity='.18'/%3E%3Ccircle cx='76' cy='30' r='1' opacity='.28'/%3E%3Ccircle cx='28' cy='62' r='1' opacity='.22'/%3E%3Ccircle cx='66' cy='76' r='1' opacity='.30'/%3E%3C/g%3E%3C/svg%3E");
  mix-blend-mode: screen;
}

.intro {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 76px 0 48px;
  animation: enter-main 900ms ease 90ms both;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--faint);
  font-size: 14px;
  font-weight: 760;
}

h1 {
  max-width: 820px;
  margin: 0;
  font-size: 76px;
  line-height: 0.94;
  letter-spacing: 0;
}

.intro-copy {
  max-width: 620px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.8;
}

.timeline-wrap {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 26px 0 96px;
  animation: enter-main 900ms ease 190ms both;
}

.timeline {
  position: relative;
  display: grid;
  gap: 14px;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 2px;
  transform: translateX(-50%);
  background: var(--line);
  box-shadow: 0 0 34px rgba(255, 255, 255, 0.18);
}

.timeline-item {
  position: relative;
  min-height: 250px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  opacity: 0;
  filter: blur(8px);
  transform: translateY(30px) scale(0.985);
  transition:
    opacity 640ms ease,
    filter 640ms ease,
    transform 640ms ease;
}

.timeline-item.is-visible {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0) scale(1);
}

.timeline-item.is-visible .line-reveal {
  clip-path: inset(0 0 0 0);
  opacity: 1;
  transform: translateX(0);
}

.timeline-item--left .timeline-card {
  grid-column: 1;
  margin-right: 48px;
}

.timeline-item--right .timeline-card {
  grid-column: 2;
  margin-left: 48px;
}

.timeline-dot {
  position: absolute;
  top: 34px;
  left: 50%;
  width: 16px;
  height: 16px;
  border: 3px solid var(--bg);
  border-radius: 99px;
  transform: translateX(-50%);
  background: #ffffff;
  overflow: visible;
  box-shadow:
    0 0 0 7px rgba(255, 255, 255, 0.08),
    0 0 28px rgba(255, 255, 255, 0.20);
}

.timeline-item--major .timeline-dot {
  top: 31px;
  width: 22px;
  height: 22px;
  box-shadow:
    0 0 0 9px rgba(255, 255, 255, 0.09),
    0 0 42px rgba(255, 255, 255, 0.28);
}

.timeline-item--major .timeline-dot::before,
.timeline-item--major .timeline-dot::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 46px;
  height: 46px;
  border: 1px solid rgba(255, 255, 255, 0.34);
  border-radius: 99px;
  opacity: 0;
  transform: translate(-50%, -50%) scale(0.42);
  animation: major-ripple 2.8s ease-out infinite;
}

.timeline-item--major .timeline-dot::after {
  animation-delay: 1.4s;
}

.timeline-item--minor .timeline-dot {
  width: 12px;
  height: 12px;
  background: rgba(255, 255, 255, 0.72);
  box-shadow:
    0 0 0 6px rgba(255, 255, 255, 0.06),
    0 0 22px rgba(255, 255, 255, 0.16);
}

.timeline-card {
  position: relative;
  border: 1px solid var(--edge);
  border-radius: 8px;
  background: var(--glass);
  backdrop-filter: blur(28px);
  padding: 28px;
  box-shadow: var(--shadow);
  overflow: hidden;
  isolation: isolate;
}

.timeline-item--major .timeline-card {
  border-color: rgba(255, 255, 255, 0.34);
  background: rgba(255, 255, 255, 0.105);
  box-shadow:
    0 30px 86px rgba(0, 0, 0, 0.64),
    inset 0 0 0 1px rgba(255, 255, 255, 0.08);
}

.timeline-item--minor .timeline-card {
  border-color: rgba(255, 255, 255, 0.22);
  border-style: dashed;
  background: rgba(255, 255, 255, 0.025);
  backdrop-filter: blur(18px);
  padding: 20px 22px;
  box-shadow:
    0 12px 34px rgba(0, 0, 0, 0.42),
    inset 0 0 0 1px rgba(255, 255, 255, 0.03);
}

.timeline-item--minor .timeline-card::before {
  inset: 8px;
  border-color: rgba(255, 255, 255, 0.06);
  box-shadow: none;
}

.timeline-card::before,
.timeline-card::after {
  content: "";
  position: absolute;
  pointer-events: none;
  z-index: -1;
}

.timeline-card::before {
  inset: 1px;
  border-radius: 7px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.20),
    inset 0 -24px 44px rgba(255, 255, 255, 0.035);
}

.timeline-card::after {
  inset: 0;
  background: rgba(255, 255, 255, 0.035);
  opacity: 0;
  transition: opacity 240ms ease;
}

.timeline-card:hover::after {
  opacity: 1;
}

.card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  color: var(--muted);
  font-size: 13px;
}

.line-reveal {
  clip-path: inset(0 100% 0 0);
  opacity: 0;
  transform: translateX(-18px);
  transition:
    clip-path 680ms ease,
    opacity 680ms ease,
    transform 680ms ease;
  transition-delay: calc(120ms + var(--line-index, 0) * 82ms);
}

.card-meta strong {
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--ink);
  padding: 5px 10px;
  white-space: nowrap;
}

.timeline-item--major .card-meta strong {
  background: #ffffff;
  color: #000000;
  border-color: #ffffff;
}

.timeline-item--minor .card-meta strong {
  background: rgba(255, 255, 255, 0.04);
  color: rgba(255, 255, 255, 0.78);
  border-color: rgba(255, 255, 255, 0.20);
}

.timeline-card h2 {
  margin: 22px 0 12px;
  font-size: 28px;
  line-height: 1.18;
  letter-spacing: 0;
}

.timeline-item--major .timeline-card h2 {
  font-size: 31px;
}

.timeline-item--minor .timeline-card h2 {
  color: rgba(255, 255, 255, 0.88);
  font-size: 22px;
  margin-top: 16px;
}

.timeline-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
}

@media (max-width: 820px) {
  h1 {
    font-size: 56px;
  }

  .intro {
    padding-top: 56px;
  }

  .timeline::before {
    left: 8px;
  }

  .timeline-item {
    min-height: auto;
    grid-template-columns: 1fr;
    padding-left: 32px;
  }

  .timeline-item--left .timeline-card,
  .timeline-item--right .timeline-card {
    grid-column: 1;
    margin: 0;
  }

  .timeline-dot {
    left: 8px;
  }
}

@media (max-width: 560px) {
  .intro,
  .timeline-wrap {
    width: min(100% - 24px, 1120px);
  }

  h1 {
    font-size: 42px;
  }

  .intro-copy {
    font-size: 16px;
  }

  .timeline-card {
    padding: 22px;
  }

  .timeline-card h2 {
    font-size: 23px;
  }

  .card-meta {
    flex-direction: column;
    align-items: flex-start;
  }
}

@keyframes enter-main {
  from {
    opacity: 0;
    transform: translateY(24px);
    filter: blur(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
    filter: blur(0);
  }
}

@keyframes major-ripple {
  0% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.42);
  }
  18% {
    opacity: 0.38;
  }
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(1.55);
  }
}

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

  .timeline-item {
    opacity: 1;
    filter: none;
    transform: none;
    transition: none;
  }

  .line-reveal {
    clip-path: inset(0 0 0 0);
    opacity: 1;
    transform: none;
    transition: none;
  }

  .intro,
  .timeline-wrap {
    animation: none;
  }

  .timeline-item--major .timeline-dot::before,
  .timeline-item--major .timeline-dot::after {
    animation: none;
  }
}