:root {
  --bg: #f7f7f5;
  --ink: #222;
  --muted: #555;
  --line: #ddd;
  --card: #fff;
  --accent: #1f4b8f;
  --accent-soft: #e8eef8;
  --font: "IBM Plex Sans", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font);
  font-size: 1.05rem;
  line-height: 1.55;
  background: var(--bg);
}

a { color: var(--accent); }
a:hover { text-decoration: underline; }

code {
  font-family: ui-monospace, "Cascadia Mono", Consolas, monospace;
  font-size: 0.92em;
  background: #eee;
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

.top {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.85rem 5vw;
  border-bottom: 1px solid var(--line);
  background: rgba(247, 247, 245, 0.95);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--ink);
  text-decoration: none;
}

.top nav {
  margin-left: auto;
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
}
.top nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
}
.top nav a:hover { color: var(--ink); }

.lang { display: flex; gap: 0.25rem; }
.lang button {
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 4px;
  padding: 0.25rem 0.55rem;
  cursor: pointer;
  font: inherit;
  color: var(--muted);
}
.lang button.active {
  background: var(--accent-soft);
  border-color: #b7c7e0;
  color: var(--accent);
}

main {
  max-width: 860px;
  margin: 0 auto;
  padding: 2.25rem 5vw 3.5rem;
}

.intro {
  display: grid;
  gap: 1.5rem;
  margin-bottom: 2.75rem;
}

.kicker {
  margin: 0 0 0.5rem;
  color: var(--muted);
  font-size: 0.9rem;
}

h1 {
  font-size: clamp(2.2rem, 5vw, 2.8rem);
  margin: 0 0 0.7rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.lede {
  margin: 0 0 1.1rem;
  color: var(--muted);
  max-width: 38rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  margin: 0;
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  padding: 0.6rem 1rem;
  border-radius: 6px;
  font-weight: 600;
}
.btn:hover { filter: brightness(1.06); text-decoration: none; }

.link {
  color: var(--ink);
  font-weight: 500;
}

.intro-photo {
  margin: 0;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 6px;
  overflow: hidden;
}
.intro-photo img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}
.intro-photo figcaption {
  padding: 0.65rem 0.85rem 0.8rem;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--line);
}

.block { margin-bottom: 2.4rem; }
.block h2 {
  font-size: 1.35rem;
  margin: 0 0 0.7rem;
  font-weight: 700;
}
.sub { margin: -0.15rem 0 0.9rem; color: var(--muted); }

.plain {
  margin: 0;
  padding-left: 1.15rem;
}
.plain li { margin: 0.4rem 0; }

.preset-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.8rem;
}
.preset {
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 6px;
  padding: 0.4rem 0.75rem;
  cursor: pointer;
  font: inherit;
}
.preset.active {
  border-color: #9db3d6;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.preset-box {
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 6px;
  padding: 0.95rem 1rem;
}
.preset-box dl {
  margin: 0 0 0.7rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.7rem;
}
.preset-box dt {
  color: var(--muted);
  font-size: 0.85rem;
}
.preset-box dd {
  margin: 0.15rem 0 0;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}
.preset-box p { margin: 0; color: var(--muted); }

ol {
  margin: 0;
  padding-left: 1.2rem;
}
ol li { margin: 0.35rem 0; }

.note p {
  margin: 0;
  color: var(--muted);
  max-width: 40rem;
}

footer {
  max-width: 860px;
  margin: 0 auto;
  padding: 1.1rem 5vw 2.25rem;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 0.92rem;
}
footer a { color: var(--muted); }

@media (max-width: 700px) {
  .top nav { display: none; }
  .preset-box dl { grid-template-columns: 1fr; }
}