:root {
  color-scheme: light;
  --ink: #111827;
  --muted: #5b6472;
  --line: #d9e0ea;
  --panel: #ffffff;
  --accent: #2563eb;
  --accent-2: #7c3aed;
  --bg: #f5f7fb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.hero {
  min-height: 360px;
  padding: 24px clamp(20px, 5vw, 72px) 72px;
  background:
    linear-gradient(135deg, rgba(37, 99, 235, 0.92), rgba(124, 58, 237, 0.88)),
    radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.38), transparent 32%);
  color: white;
}

nav {
  display: flex;
  align-items: center;
  gap: 20px;
}

nav a {
  color: rgba(255, 255, 255, 0.84);
  text-decoration: none;
}

.hero section {
  max-width: 860px;
  margin-top: 64px;
}

.eyebrow {
  margin: 0 0 12px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.78rem;
  opacity: 0.84;
}

h1 {
  margin: 0;
  max-width: 760px;
  font-size: clamp(2.4rem, 7vw, 5.4rem);
  line-height: 0.98;
}

.lede {
  max-width: 680px;
  margin-top: 24px;
  font-size: 1.12rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.88);
}

main {
  width: min(1120px, calc(100% - 32px));
  margin: -42px auto 72px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.panel {
  margin-bottom: 18px;
  padding: 22px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
}

.controls {
  display: flex;
  gap: 16px;
}

label {
  display: grid;
  flex: 1;
  gap: 8px;
  color: var(--muted);
  font-size: 0.9rem;
}

select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: white;
  color: var(--ink);
  font: inherit;
}

h2 {
  margin: 0 0 16px;
  font-size: 1.05rem;
}

.delta-item {
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

.delta-item:first-child {
  border-top: 0;
}

.tag {
  display: inline-block;
  margin-bottom: 6px;
  padding: 3px 8px;
  border-radius: 999px;
  background: #eff6ff;
  color: var(--accent);
  font-size: 0.76rem;
  font-weight: 700;
}

ul {
  padding-left: 18px;
}

li {
  margin: 8px 0;
  color: var(--muted);
}

code {
  color: var(--accent-2);
}

.timeline {
  display: grid;
  grid-template-columns: repeat(6, minmax(120px, 1fr));
  gap: 10px;
  overflow-x: auto;
}

.step {
  min-height: 118px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdff;
}

.step strong {
  display: block;
  margin-bottom: 8px;
}

.step span {
  color: var(--muted);
  font-size: 0.9rem;
}

@media (max-width: 780px) {
  .grid,
  .controls {
    grid-template-columns: 1fr;
    display: grid;
  }

  .hero {
    min-height: 440px;
  }
}