/* Reading surface: dark technical notebook with a tight, deliberate editorial rhythm. */
body {
  min-width: 320px;
  color: var(--ink);
  line-height: 1.78;
  background:
    radial-gradient(circle at 92% 2%, rgba(71, 100, 190, .17), transparent 28rem),
    linear-gradient(90deg, rgba(128, 151, 188, .055) 1px, transparent 1px) 0 0 / 128px 128px,
    var(--canvas);
}

.article-frame { width: min(1180px, calc(100% - 64px)); margin: 0 auto; }
.article-nav { min-height: 70px; }
.article-nav .back-link { color: var(--ink-muted); font-size: .82rem; }
.article-nav .back-link:hover { color: var(--aqua); }

.article-hero {
  position: relative;
  width: min(860px, 100%);
  padding: clamp(48px, 7vw, 88px) 0 38px;
  border-bottom: 1px solid var(--line);
}
.article-hero::before {
  position: absolute;
  top: 43px;
  left: -35px;
  width: 15px;
  height: 15px;
  content: "";
  border: 3px solid var(--cobalt);
  border-radius: 50%;
  background: var(--canvas);
  box-shadow: 0 0 0 6px rgba(124, 156, 255, .14);
}
.label { margin: 0; color: var(--aqua); font-size: .76rem; font-weight: 760; letter-spacing: .025em; }
.article-hero h1 { max-width: 13ch; margin: 16px 0; color: var(--ink-strong); font-family: var(--font-display); font-size: clamp(2.7rem, 5.25vw, 5rem); font-weight: 760; letter-spacing: -.04em; line-height: 1.03; text-wrap: balance; }
.intro { max-width: 63ch; margin: 0; color: var(--ink-muted); font-size: clamp(.98rem, 1.2vw, 1.07rem); line-height: 1.85; text-wrap: pretty; }
.meta { margin: 19px 0 0; color: var(--ink-faint); font-size: .8rem; font-weight: 640; }

.content { position: relative; width: min(790px, 100%); padding: 38px 0 clamp(64px, 8vw, 100px); }
.content::before { position: absolute; top: 38px; bottom: 52px; left: -36px; width: 1px; content: ""; background: linear-gradient(var(--cobalt), var(--line) 8%, var(--line) 92%, transparent); }
.content h2 { max-width: 27ch; margin: 42px 0 13px; color: var(--ink-strong); font-family: var(--font-display); font-size: clamp(1.42rem, 2.45vw, 1.92rem); font-weight: 745; letter-spacing: -.033em; line-height: 1.18; text-wrap: balance; }
.content h2:first-child { margin-top: 0; }
.content p { margin: 0 0 16px; color: var(--ink); text-wrap: pretty; }
.content li { margin: 7px 0; padding-left: 3px; color: var(--ink); }
.content ul, .content ol { margin: 17px 0; padding-left: 1.42rem; }
.content strong { color: var(--ink-strong); }
.content a { color: var(--cobalt-deep); text-decoration: underline; text-decoration-color: rgba(156, 179, 255, .45); text-underline-offset: 3px; }
.content a:hover { color: #c2d0ff; text-decoration-color: currentColor; }

.callout { margin: 26px -24px; padding: 19px 23px; color: #b2e5df; line-height: 1.72; border: 1px solid #2c6861; border-radius: var(--radius); background: linear-gradient(112deg, #102d2c, #101a23 72%); box-shadow: 0 13px 29px rgba(0, 0, 0, .16); }
.callout strong { color: var(--aqua); }
.source { margin-top: 43px; padding: 23px 25px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow-soft); }
.source h2 { margin: 0 0 10px; font-size: 1.17rem; }
.source p { margin: 0; color: var(--ink-muted); font-size: .89rem; line-height: 1.72; }
.article-footer { margin-top: 2px; }
code { padding: .1em .36em; color: #bac9ff; font-family: ui-monospace, "SFMono-Regular", Consolas, monospace; font-size: .88em; border: 1px solid #3a4c75; border-radius: 5px; background: var(--cobalt-soft); }

@media (max-width: 820px) {
  .article-hero::before, .content::before { display: none; }
  .callout { margin-right: 0; margin-left: 0; }
}
@media (max-width: 680px) {
  .article-frame { width: min(100% - 36px, 1180px); }
  .article-nav { min-height: 62px; }
  .article-hero { padding: 44px 0 31px; }
  .article-hero h1 { font-size: clamp(2.45rem, 11vw, 3.9rem); }
  .content { padding-top: 30px; padding-bottom: 68px; }
  .content h2 { margin-top: 35px; }
  .source { padding: 20px; }
}