:root {
  color-scheme: light;
  --ink: #263238;
  --muted: #617078;
  --brand: #197d80;
  --brand-dark: #365158;
  --surface: #ffffff;
  --soft: #eef5f4;
  --line: #d9e3e2;
  --shadow: 0 18px 50px rgba(31, 51, 55, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #f5f8f8;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--brand);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

a:hover,
a:focus-visible {
  color: #0d5f62;
}

.skip-link {
  position: absolute;
  top: -80px;
  left: 1rem;
  z-index: 10;
  padding: 0.7rem 1rem;
  background: #ffffff;
  color: var(--ink);
  border-radius: 0.4rem;
}

.skip-link:focus {
  top: 1rem;
}

.site-header {
  background: linear-gradient(135deg, #424c55, var(--brand-dark));
  color: #ffffff;
  border-bottom: 4px solid var(--brand);
}

.brand {
  width: min(100% - 2rem, 1040px);
  margin: 0 auto;
  padding: 1.35rem 0 1.2rem;
}

.brand a {
  color: #ffffff;
  text-decoration: none;
}

.brand-name {
  display: block;
  font-size: clamp(1.35rem, 3vw, 1.85rem);
  font-weight: 650;
  letter-spacing: 0.01em;
}

.brand-role {
  display: block;
  margin-top: 0.15rem;
  font-size: 0.82rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.page-shell {
  width: min(100% - 2rem, 960px);
  margin: 0 auto;
  padding: 1.4rem 0 3.5rem;
}

.breadcrumb {
  margin: 0 0 1rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.breadcrumb a {
  color: inherit;
}

.article-card,
.collection-card {
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 0.85rem;
  box-shadow: var(--shadow);
}

.article-body,
.collection-body {
  padding: clamp(1.35rem, 4vw, 3rem);
}

h1,
h2 {
  color: #263f43;
  line-height: 1.2;
  text-wrap: balance;
}

h1 {
  max-width: 22ch;
  margin: 0 0 0.8rem;
  font-size: clamp(2rem, 6vw, 3.4rem);
  font-weight: 700;
}

h2 {
  margin: 2.4rem 0 1rem;
  font-size: clamp(1.35rem, 3vw, 1.8rem);
}

.article-meta {
  margin: 0 0 1.6rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.lead {
  max-width: 70ch;
  margin: 0 0 1.7rem;
  font-size: 1.08rem;
}

.video-frame {
  overflow: hidden;
  width: 100%;
  margin: 1.6rem 0 1rem;
  background: #111111;
  border-radius: 0.65rem;
  box-shadow: 0 8px 24px rgba(20, 35, 38, 0.16);
  aspect-ratio: 16 / 9;
}

.video-frame iframe {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
}

.video-link {
  margin: 0 0 2rem;
  font-size: 0.92rem;
}

.notice {
  margin: 2rem 0 0;
  padding: 1rem 1.1rem;
  background: var(--soft);
  border-left: 4px solid var(--brand);
  color: #40575a;
  font-size: 0.94rem;
}

.article-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  align-items: center;
  justify-content: space-between;
  margin-top: 2.3rem;
  padding-top: 1.3rem;
  border-top: 1px solid var(--line);
}

.author {
  margin: 0;
  color: var(--muted);
}

.collection-intro {
  max-width: 68ch;
  margin: 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.link-grid a {
  display: flex;
  min-height: 100%;
  align-items: center;
  padding: 1rem 1.05rem;
  background: #fbfdfd;
  color: #2d5155;
  border: 1px solid var(--line);
  border-radius: 0.6rem;
  font-weight: 600;
  text-decoration: none;
}

.link-grid a:hover,
.link-grid a:focus-visible {
  background: var(--soft);
  border-color: #9fc3c2;
}

.site-footer {
  padding: 1.5rem 1rem 2.2rem;
  color: var(--muted);
  font-size: 0.9rem;
  text-align: center;
}

.site-footer p {
  margin: 0.2rem 0;
}

@media (max-width: 680px) {
  body {
    font-size: 16px;
  }

  .page-shell,
  .brand {
    width: min(100% - 1.2rem, 960px);
  }

  .article-body,
  .collection-body {
    padding: 1.2rem;
  }

  .link-grid {
    grid-template-columns: 1fr;
  }
}

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