/* ---------- colors: light, then dark (by system setting or ?theme=dark) ---------- */
:root {
  --bg: #f3f4f7; --card: #ffffff; --text: #181b22; --muted: #5d6270; --line: #dde0e7;
  --accent: #3d6fd8; --accent-soft: #e6edfb; --on-accent: #ffffff;
  --error: #d2463a;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111318; --card: #1a1d24; --text: #e9ebf0; --muted: #9a9fab; --line: #2c303a;
    --accent: #7ea4ff; --accent-soft: #1b2438; --on-accent: #0b0e14;
    --error: #ff7a6b;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #111318; --card: #1a1d24; --text: #e9ebf0; --muted: #9a9fab; --line: #2c303a;
  --accent: #7ea4ff; --accent-soft: #1b2438; --on-accent: #0b0e14;
  --error: #ff7a6b;
  color-scheme: dark;
}

/* ---------- page ---------- */
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 "Geist", system-ui, -apple-system, "Segoe UI", sans-serif;
}
a { color: var(--accent); }
.wrap { max-width: 760px; margin: 0 auto; padding: 40px 16px 32px; }

header { margin-bottom: 20px; }
h1 { margin: 0; font-size: 2rem; letter-spacing: -0.02em; line-height: 1.1; }
h1 span { color: var(--accent); }
.tagline { margin: 8px 0 0; color: var(--muted); }
h3 { margin: 0; font-size: 1.05rem; letter-spacing: -0.01em; }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 20px;
  margin-bottom: 14px;
  box-shadow: 0 1px 2px rgb(0 0 0 / 4%), 0 8px 24px rgb(0 0 0 / 5%);
}
.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
footer { margin-top: 18px; text-align: center; }

/* ---------- buttons and pill choices ---------- */
.btn {
  font: inherit; font-weight: 600;
  border-radius: 10px; padding: 10px 14px;
  border: 1px solid transparent; cursor: pointer;
  display: inline-flex; align-items: center; justify-content: center; gap: 6px; white-space: nowrap;
}
.btn.ghost { background: transparent; color: var(--text); border-color: var(--line); } /* the Install app button */
.btn.ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn.primary { background: var(--accent); color: var(--on-accent); margin-top: 16px; width: 100%; }
.btn.primary:hover { filter: brightness(1.08); }
.btn:disabled { opacity: .5; cursor: wait; }

.seg { display: flex; gap: 4px; }
.seg label { position: relative; }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg span {
  display: inline-block; padding: 4px 10px; font-size: 0.8rem;
  border: 1px solid var(--line); border-radius: 999px; cursor: pointer; user-select: none;
}
.seg input:checked + span { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.seg input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ---------- form ---------- */
.modes { flex-wrap: wrap; }
.modes span { font-size: 0.9rem; padding: 6px 14px; }

.field { display: flex; flex-direction: column; gap: 4px; margin-top: 14px; min-width: 0; }
.field > span { font-size: 0.8rem; color: var(--muted); }
input[type="time"], input[type="number"] {
  font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--line); border-radius: 10px;
  padding: 10px 12px; width: 100%; min-height: 46px;
}
input:focus-visible, .btn:focus-visible, .opt:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: 0 10px; }
.now .two { grid-template-columns: 1fr; }
.now #time-field { display: none; }
@media (max-width: 520px) { .two { grid-template-columns: 1fr; } }

.sub { margin: 4px 0 14px; }

/* ---------- sleep and wake options ---------- */
.options { margin: 0; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
@media (max-width: 560px) { .options { grid-template-columns: 1fr 1fr; } }
.opt {
  width: 100%; font: inherit; color: var(--text); text-align: left; cursor: pointer;
  background: var(--bg); border: 1px solid var(--line); border-radius: 10px; padding: 12px;
  display: flex; flex-direction: column; gap: 2px;
}
.opt:hover { border-color: var(--accent); }
.opt .t { font-size: 1.35rem; font-weight: 600; font-variant-numeric: tabular-nums; letter-spacing: -0.01em; }
.opt .d { font-size: 0.8rem; color: var(--muted); }
.opt .tag { font-size: 0.7rem; font-weight: 500; color: var(--accent); min-height: 1.1em; }
.opt[aria-pressed="true"] { border-color: var(--accent); background: var(--accent-soft); }

/* ---------- day chart and timeline ---------- */
.chart svg { display: block; width: 100%; height: auto; overflow: visible; }
.chart .curve { fill: none; stroke: var(--accent); stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
.chart .area { fill: var(--accent-soft); }
.chart .band { fill: var(--text); opacity: .06; }
.chart .axis { stroke: var(--line); stroke-width: 1; }
.chart text { fill: var(--muted); font: 11px "Geist Mono", ui-monospace, monospace; }
.chart text.lbl { fill: var(--text); font: 500 11px "Geist", system-ui, sans-serif; }
.chart .now { stroke: var(--text); stroke-width: 1; stroke-dasharray: 3 3; opacity: .6; }

.timeline { margin: 14px 0 0; padding: 0; list-style: none; }
.timeline li { display: grid; grid-template-columns: 128px 1fr; gap: 12px; padding: 10px 0; border-top: 1px solid var(--line); }
.timeline li:first-child { border-top: 0; }
.timeline .when { white-space: pre-line; font: 500 0.85rem/1.5 "Geist Mono", ui-monospace, monospace; font-variant-numeric: tabular-nums; color: var(--muted); }
.timeline strong { display: block; font-weight: 600; }
.timeline p { margin: 2px 0 0; color: var(--muted); font-size: 0.9rem; }
.timeline .key strong { color: var(--accent); }
@media (max-width: 520px) { .timeline li { grid-template-columns: 1fr; gap: 2px; } }

/* ---------- embedded in the site page (../circadian.html) ---------- */
.embedded body { background: transparent; }
.embedded .wrap { max-width: none; padding: 0; }
.embedded header { display: none; }
.embedded footer { margin-bottom: 4px; }