:root {
  color-scheme: light dark;
  --bg: #faf6f4;
  --surface: #ffffff;
  --surface-2: #f4eeec;
  --ink: #2b2330;
  --ink-2: #5d5463;
  --muted: #847a89;
  --line: #e9e1df;
  --period: #cf3f66;
  --period-soft: #f9dde5;
  --period-ink: #ffffff;
  --fertile: #1f8f8a;
  --fertile-soft: #d6efed;
  --focus: #6d4fc4;
  --danger: #b3261e;
  --shadow: 0 1px 2px rgb(43 35 48 / 6%), 0 4px 16px rgb(43 35 48 / 5%);
  --radius: 18px;
  --tabs-height: 64px;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", system-ui, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #18141b;
    --surface: #221d26;
    --surface-2: #2c2631;
    --ink: #f2ecf3;
    --ink-2: #c3b9c7;
    --muted: #9a8f9f;
    --line: #3a3340;
    --period: #ee6b8d;
    --period-soft: #4b2534;
    --period-ink: #1e0b12;
    --fertile: #4cc4bd;
    --fertile-soft: #183937;
    --focus: #a991f0;
    --danger: #ff8a80;
    --shadow: none;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.45;
  -webkit-tap-highlight-color: transparent;
}

button, input, select { font: inherit; color: inherit; }

:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }

h1, h2 { margin: 0; line-height: 1.2; }
h2 { font-size: 1.05rem; font-weight: 600; }

.topbar {
  display: flex;
  align-items: center;
  gap: 10px;
  max-width: 560px;
  margin: 0 auto;
  padding: calc(env(safe-area-inset-top) + 14px) 16px 6px;
}
.topbar h1 { font-size: 1.35rem; font-weight: 700; letter-spacing: -0.01em; }

.badge {
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--ink-2);
  font-size: 0.8rem;
  font-weight: 600;
}

main {
  max-width: 560px;
  margin: 0 auto;
  padding: 8px 16px calc(var(--tabs-height) + env(safe-area-inset-bottom) + 24px);
}

.view { display: grid; gap: 14px; }
.view[hidden] { display: none; }

.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}
.card > h2 + .subtitle { margin-top: 4px; }

.subtitle { margin: 0 0 14px; color: var(--muted); font-size: 0.9rem; }
.footnote { margin: 0; padding: 0 4px; color: var(--muted); font-size: 0.8rem; text-align: center; }

.banner {
  margin: 0 0 12px;
  padding: 10px 14px;
  border-radius: 12px;
  background: var(--surface-2);
  color: var(--ink);
  font-size: 0.9rem;
}
.banner.error { color: var(--danger); }

/* Today */

.hero { text-align: center; padding: 26px 18px 22px; }
.hero .eyebrow { margin: 0; color: var(--muted); font-size: 0.85rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; }
.hero .figure { margin: 4px 0 2px; font-size: 3.4rem; font-weight: 700; letter-spacing: -0.03em; line-height: 1.05; font-variant-numeric: tabular-nums; }
.hero .figure small { font-size: 1.1rem; font-weight: 600; color: var(--ink-2); letter-spacing: 0; }
.hero .lead { margin: 6px 0 0; font-size: 1.05rem; font-weight: 600; }
.hero .detail { margin: 2px 0 0; color: var(--ink-2); font-size: 0.92rem; }
.hero .note { margin: 14px auto 0; max-width: 34ch; color: var(--muted); font-size: 0.85rem; }
.hero.on-period .figure { color: var(--period); }

.facts { display: grid; gap: 10px; margin: 18px 0 0; padding: 16px 0 0; border-top: 1px solid var(--line); text-align: left; }
.fact { display: flex; align-items: center; gap: 12px; }
.fact .key { flex: none; }
.fact div { display: grid; }
.fact strong { font-size: 0.95rem; font-weight: 600; }
.fact span { color: var(--ink-2); font-size: 0.88rem; }

.log-section + .log-section { margin-top: 18px; }
.log-section h3 { margin: 0 0 10px; color: var(--ink-2); font-size: 0.85rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; }

.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  min-height: 40px;
  padding: 8px 14px;
  border: 1.5px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  font-size: 0.92rem;
  font-weight: 500;
  cursor: pointer;
  touch-action: manipulation;
}
.chip[aria-pressed="true"] { border-color: var(--period); background: var(--period); color: var(--period-ink); }
.chip.symptom[aria-pressed="true"] { border-color: var(--ink); background: var(--ink); color: var(--surface); }
.chip:disabled { cursor: default; }
.chip:disabled:not([aria-pressed="true"]) { opacity: 0.55; }

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

/* Buttons */

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 18px;
  border: 0;
  border-radius: 12px;
  background: var(--period);
  color: var(--period-ink);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
}
.button.secondary { background: var(--surface-2); color: var(--ink); }
.button:disabled { opacity: 0.6; cursor: default; }
.button-row { display: flex; flex-wrap: wrap; gap: 10px; }

.icon-button {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border: 0;
  border-radius: 999px;
  background: var(--surface-2);
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
}

.link-button {
  display: block;
  margin: 12px auto 0;
  padding: 6px 10px;
  border: 0;
  background: none;
  color: var(--ink-2);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
}

/* Calendar */

.month-nav { display: flex; align-items: center; justify-content: space-between; margin-bottom: 12px; }
.month-nav h2 { font-size: 1.1rem; }

.weekdays, .month-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 4px; }
.weekdays span { color: var(--muted); font-size: 0.75rem; font-weight: 600; text-align: center; }
.month-grid { margin-top: 6px; }

.day {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  min-width: 0;
  border: 0;
  border-radius: 999px;
  background: transparent;
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
  cursor: pointer;
  touch-action: manipulation;
}
.day.outside { visibility: hidden; }
.day.future { cursor: default; }
.day.fertile { background: var(--fertile-soft); }
.day.predicted { box-shadow: inset 0 0 0 2px var(--period); background: var(--period-soft); }
.day.period { background: var(--period); color: var(--period-ink); font-weight: 600; }
.day.today::after {
  content: "";
  position: absolute;
  inset: -3px;
  border: 2px solid var(--ink);
  border-radius: 999px;
}
.day .marks { position: absolute; bottom: 12%; display: flex; gap: 3px; }
.day .mark { width: 5px; height: 5px; border-radius: 999px; }
.mark.ovulation { background: var(--fertile); }
.mark.spotting { background: var(--period); }
.mark.symptoms { background: var(--muted); }
.day.period .mark.symptoms { background: var(--period-ink); }

.legend { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 10px 16px; margin: 0; list-style: none; font-size: 0.9rem; color: var(--ink-2); }
.legend li { display: flex; align-items: center; gap: 10px; }

.key { display: inline-block; width: 16px; height: 16px; border-radius: 999px; }
.key-period { background: var(--period); }
.key-predicted { background: var(--period-soft); box-shadow: inset 0 0 0 2px var(--period); }
.key-fertile { background: var(--fertile-soft); }
.key-ovulation { position: relative; background: var(--fertile-soft); }
.key-ovulation::after { content: ""; position: absolute; inset: 5px; border-radius: 999px; background: var(--fertile); }
.key-spotting, .key-symptoms { position: relative; }
.key-spotting::after, .key-symptoms::after { content: ""; position: absolute; inset: 5px; border-radius: 999px; }
.key-spotting::after { background: var(--period); }
.key-symptoms::after { background: var(--muted); }

/* Stats */

.tiles { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.tile { background: var(--surface); border-radius: var(--radius); padding: 14px 16px; box-shadow: var(--shadow); }
.tile .label { margin: 0; color: var(--ink-2); font-size: 0.85rem; }
.tile .value { margin: 2px 0 0; font-size: 1.6rem; font-weight: 650; letter-spacing: -0.01em; font-variant-numeric: tabular-nums; }
.tile .value small { font-size: 0.95rem; font-weight: 500; color: var(--ink-2); }

.chart { position: relative; }
.chart svg { display: block; width: 100%; height: auto; overflow: visible; }
.chart .grid { stroke: var(--line); stroke-width: 1; }
.chart .axis-label { fill: var(--muted); font-size: 11px; }
.chart .bar { fill: var(--period); }
.chart .bar.dim { opacity: 0.35; }
.chart .avg { stroke: var(--ink-2); stroke-width: 1; stroke-dasharray: 3 3; }
.chart .avg-label { fill: var(--ink-2); font-size: 11px; font-weight: 600; }
.chart .hit { fill: transparent; cursor: pointer; }
.chart-empty { margin: 0; color: var(--muted); font-size: 0.92rem; }
.tooltip {
  position: absolute;
  z-index: 2;
  padding: 6px 10px;
  border-radius: 10px;
  background: var(--ink);
  color: var(--surface);
  font-size: 0.82rem;
  white-space: nowrap;
  pointer-events: none;
  transform: translate(-50%, calc(-100% - 8px));
}
.tooltip[hidden] { display: none; }

.table-wrap { margin-top: 12px; overflow-x: auto; }
.history { width: 100%; border-collapse: collapse; font-size: 0.92rem; font-variant-numeric: tabular-nums; }
.history th { padding: 0 0 8px; color: var(--muted); font-size: 0.8rem; font-weight: 600; text-align: left; }
.history td { padding: 9px 0; border-top: 1px solid var(--line); }
.history th:not(:first-child), .history td:not(:first-child) { text-align: right; }
.history .excluded { color: var(--muted); }
.history .excluded small { display: block; font-size: 0.78rem; }

/* Settings */

.switch-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; cursor: pointer; }
.switch-row span { display: grid; gap: 2px; }
.switch-row small { color: var(--muted); font-size: 0.85rem; }
.switch-row input { flex: none; width: 24px; height: 24px; accent-color: var(--period); }

.seed-form { display: grid; gap: 12px; }
.seed-form label { display: grid; gap: 4px; color: var(--ink-2); font-size: 0.88rem; font-weight: 600; }
.seed-form input {
  min-height: 44px;
  padding: 8px 12px;
  border: 1.5px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  font-weight: 400;
}
.seed-dates { display: grid; gap: 8px; }
.seed-form .seed-length { max-width: 120px; }

/* Tabs */

.tabs {
  position: fixed;
  inset: auto 0 0;
  z-index: 5;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 6px max(8px, env(safe-area-inset-left)) calc(6px + env(safe-area-inset-bottom));
  border-top: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
}
.tabs.three { grid-template-columns: repeat(3, 1fr); }
.tabs button {
  display: grid;
  justify-items: center;
  gap: 2px;
  min-height: 52px;
  padding: 4px;
  border: 0;
  background: none;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 600;
  cursor: pointer;
}
.tabs button[hidden] { display: none; }
.tabs svg { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.tabs button[aria-selected="true"] { color: var(--period); }

/* Day sheet */

.sheet {
  width: min(560px, 100%);
  max-width: 100%;
  max-height: 90vh;
  margin: auto auto 0;
  padding: 0;
  border: 0;
  border-radius: 22px 22px 0 0;
  background: var(--surface);
  color: var(--ink);
}
.sheet::backdrop { background: rgb(0 0 0 / 35%); }
.sheet-inner { padding: 18px 18px calc(22px + env(safe-area-inset-bottom)); }
.sheet-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
.sheet-head h2 { font-size: 1.15rem; }
.sheet .prediction-note { margin: 0 0 16px; color: var(--ink-2); font-size: 0.9rem; }

@media (min-width: 600px) {
  .sheet { margin: auto; border-radius: 22px; }
  .tiles { grid-template-columns: repeat(4, 1fr); }
}