/* === Base tokens === */
:root {
  --bg: #0e0f12;
  --panel: #14161b;
  --text: #e7e7ea;
  --muted: #b9bbc6;
  --accent: #8aa7ff;
  --line: #242733;
  --link: #a9c1ff;
  --link-hover: #cfe0ff;

  --font-size: 18px;
  --line-height: 1.75;
  --radius: 8px;
  --shadow: 0 0 0 1px rgba(255,255,255,0.03),
             0 10px 30px rgba(0,0,0,0.35);
}

/* === Reset / base === */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: "Hiragino Sans", "Yu Gothic", "Noto Sans JP",
               "Segoe UI", system-ui, -apple-system,
               "Helvetica Neue", Arial, "Meiryo", sans-serif;
  font-size: var(--font-size);
  line-height: var(--line-height);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--link); text-decoration: none; }
a:hover, a:focus { color: var(--link-hover); text-decoration: underline; }
img { max-width: 100%; height: auto; border-radius: var(--radius); }

.wrap {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 20px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px; height: 1px;
  overflow: hidden;
}
.skip-link:focus {
  position: fixed;
  left: 20px; top: 20px;
  width: auto; height: auto;
  background: var(--panel);
  color: var(--text);
  padding: 10px 14px;
  border-radius: 6px;
  box-shadow: var(--shadow);
  z-index: 1000;
}

/* === Header / Navigation === */
.site-header {
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg,
              rgba(255,255,255,0.02), rgba(255,255,255,0));
  /* Removed sticky positioning */
}
.site-header .wrap {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 16px;
  padding: 18px 20px;
}
.brand .site-title {
  font-size: clamp(20px, 2.2vw + 12px, 28px);
  font-weight: 700;
  letter-spacing: 0.02em;
}
.brand .site-title .en {
  font-weight: 600;
}
.brand .site-tagline {
  margin: 6px 0 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}
.site-nav ul {
  display: flex;
  gap: 14px;
  list-style: none;
  padding: 0; margin: 0;
}
.site-nav a {
  display: inline-block;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid transparent;
}
.site-nav a[aria-current="page"],
.site-nav a:hover {
  background: rgba(255,255,255,0.05);
  border-color: rgba(255,255,255,0.08);
}

/* === Content / Article === */
.content {
  padding: 28px 0 60px;
}
.post {
  background: linear-gradient(180deg,
              rgba(255,255,255,0.02), rgba(255,255,255,0.0));
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 22px;
}
.post-header h1 {
  margin: 0 0 6px;
  font-size: clamp(24px, 2.8vw + 14px, 36px);
  letter-spacing: 0.01em;
}
.meta {
  color: var(--muted);
  margin: 0 0 14px;
  font-size: 0.95rem;
}
.post-section h2 {
  margin-top: 28px;
  margin-bottom: 10px;
  font-size: clamp(20px, 2vw + 10px, 28px);
  border-left: 3px solid var(--accent);
  padding-left: 10px;
}
.post p { margin: 0 0 1em; }

blockquote {
  margin: 1em 0;
  padding: 14px 16px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  color: var(--text);
}
.section-divider {
  border: none;
  border-top: 1px dashed var(--line);
  margin: 28px 0;
}

/* === Figures & captions === */
figure {
  margin: 1.5em 0;
  text-align: center;
}
figure img {
  max-width: 90%;
  height: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
figcaption {
  margin-top: 0.5em;
  font-size: 0.9rem;
  color: var(--muted);
}
figure.tweet-image {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
}
figure.tweet-image img {
  max-width: 100%;
  margin-bottom: 6px;
}
figure.tweet-image figcaption {
  font-size: 0.9rem;
  font-style: italic;
  color: var(--muted);
}

/* Group multiple tweet images neatly */
.tweet-media-group { margin: 0.5em 0 1.25em; }
.tweet-media-group .tweet-image { margin: 1em 0; }

@media (min-width: 820px) {
  .tweet-media-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    align-items: start;
  }
  .tweet-media-group .media-source {
    grid-column: 1 / -1;
  }
}

/* Byline label inside captions */
.byline {
  color: var(--muted);
  font-size: 0.85rem;
  letter-spacing: 0.02em;
}

/* Source line under media */
.media-source {
  margin: 6px 0 0;
  font-size: 0.9rem;
  color: var(--muted);
}

/* === Footer === */
.site-footer {
  border-top: 1px solid var(--line);
  background: linear-gradient(0deg,
              rgba(255,255,255,0.02), rgba(255,255,255,0));
  padding: 26px 0 40px;
  color: var(--muted);
}
.site-footer p { margin: 6px 0; }
.site-footer .en-note { font-size: 0.95rem; }

/* === Utilities === */
@media (max-width: 720px) {
  .site-header .wrap { grid-template-columns: 1fr; }
  .site-nav ul { flex-wrap: wrap; }
  .post { padding: 22px 16px; }
}

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