/* The tokens and frame of AgingResearch.News (its app/globals.css and docs/brand/design-system.md): a white page and
   black ink in neutral greys, one grotesk, and petrol only for what is active. Dark mode follows the system. */
@font-face {
  font-family: "Host Grotesk";
  src: url("/fonts/host-grotesk.woff2") format("woff2");
  font-weight: 300 800;
  font-display: swap;
}

:root {
  color-scheme: light dark;
  --paper: #ffffff;
  --paper-deep: #f4f4f4;
  --hover: #f7f7f7;
  --ink: #1f1f1f;
  --ink-soft: #2a2a2a;
  --muted: #5f5f5f;
  --rule: #e8e8e8;
  --rule-strong: #d0d0d0;
  --accent: #2e6670;
  --accent-hover: #24545c;
  --on-accent: #ffffff;
  --glow: #cde3e7;
  --sans: "Host Grotesk", "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #242424;
    --paper-deep: #2e2e2e;
    --hover: #2a2a2a;
    --ink: #ececec;
    --ink-soft: #d6d6d6;
    --muted: #a8a8a8;
    --rule: #3a3a3a;
    --rule-strong: #4d4d4d;
    --accent: #7fb5bf;
    --accent-hover: #9cc6ce;
    --on-accent: #1f1f1f;
    --glow: #7fb5bf;
  }
}

* { box-sizing: border-box; }
::selection { background: var(--glow); color: #1f1f1f; }

html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  min-height: 100dvh;
  background: var(--paper);
  color: var(--ink);
  font: 400 15px/1.45 var(--sans);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
a:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; border-radius: 2px; }

.wordmark { font-weight: 700; line-height: 1; letter-spacing: -0.025em; white-space: nowrap; text-decoration: none; }

/* The frame: rail, centre column, sidebar, as on ARN's reader pages; the sidebar appears at 1000px, the rail at 768px. */
.frame { display: flex; justify-content: center; min-height: 100dvh; }
.rail { display: none; }
.sidebar { display: none; }
.column { width: 100%; max-width: 600px; min-height: 100dvh; display: flex; flex-direction: column; }

@media (min-width: 768px) {
  .rail { display: block; width: 240px; flex: none; padding: 22px 16px; }
  .rail .wordmark { display: inline-block; font-size: 17px; padding: 6px 8px; }
  .column { border-left: 1px solid var(--rule); border-right: 1px solid var(--rule); }
}
@media (min-width: 1000px) {
  .sidebar { display: block; width: 350px; flex: none; padding: 12px 20px; }
}

.phone-bar {
  position: sticky; top: 0; z-index: 1;
  display: flex; align-items: center; gap: 10px;
  padding: 12px 16px;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--rule);
}
.phone-bar img { width: 28px; height: 28px; border-radius: 6px; }
.phone-bar .wordmark { font-size: 17px; }
@media (min-width: 768px) { .phone-bar { display: none; } }

/* The tab bar, with its one tab current: the petrol bar under it is the accent's job. */
.tabs {
  position: sticky; top: 0; z-index: 1;
  display: flex;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--rule);
}
@media (max-width: 767px) { .tabs { top: 53px; } }
.tab { flex: 1; text-align: center; padding: 15px 0 0; font-weight: 600; font-size: 14px; }
.tab span { display: inline-block; padding-bottom: 13px; border-bottom: 4px solid var(--accent); border-radius: 0; }

.lead { padding: 28px 20px 24px; border-bottom: 1px solid var(--rule); }
h1 { margin: 0; font-size: 28px; line-height: 1.15; font-weight: 700; letter-spacing: -0.02em; }
.lead p { margin: 14px 0 0; color: var(--ink-soft); font-size: 16px; line-height: 1.5; }


.foot { margin-top: auto; padding: 20px; color: var(--muted); font-size: 13px; }
.foot p { margin: 0; }
.foot p + p { margin-top: 4px; }

/* The sidebar's module, bordered as ARN's are. */
.module { border: 1px solid var(--rule); border-radius: 14px; padding: 14px 16px 16px; }
.module h2 { margin: 0 0 8px; font-size: 17px; font-weight: 700; }
.module p { margin: 0; color: var(--ink-soft); font-size: 14px; }
.module a.go { display: inline-block; margin-top: 12px; color: var(--accent); font-size: 14px; font-weight: 600; text-decoration: none; }
.module a.go:hover { color: var(--accent-hover); }

.phone-only { display: block; }
@media (min-width: 1000px) { .phone-only { display: none; } }
.phone-only .module { margin: 16px 20px 0; }