:root {
  --red: #dd1d21;
  --yellow: #fbce07;
  --green: #3d9b4f;
  --bg: #f2f2f7;
  --card: #fff;
  --text: #1c1c1e;
  --muted: #8e8e93;
  --border: #d1d1d6;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000;
    --card: #1c1c1e;
    --text: #f2f2f7;
    --muted: #98989f;
    --border: #38383a;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  padding-bottom: calc(64px + env(safe-area-inset-bottom));
}

.topbar {
  background: var(--red);
  color: #fff;
  padding: calc(12px + env(safe-area-inset-top)) 16px 12px;
  text-align: center;
}

.topbar h1 { margin: 0; font-size: 1.25rem; }
.last-info { font-size: 0.85rem; opacity: 0.9; margin-top: 4px; }

main { padding: 16px; max-width: 520px; margin: 0 auto; }

.view { display: none; }
.view.active { display: block; }

.card {
  background: var(--card);
  border-radius: 12px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-weight: 600;
  font-size: 0.9rem;
}

.unit { color: var(--muted); font-weight: 400; }

input {
  font: inherit;
  font-size: 17px; /* >=16px prevents iOS zoom on focus */
  font-weight: 400;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  width: 100%;
  -webkit-appearance: none;
  appearance: none;
}

input:focus { outline: 2px solid var(--yellow); border-color: transparent; }
input.invalid { border-color: var(--red); }

.preview {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin: 0;
}

.preview div {
  background: var(--bg);
  border-radius: 8px;
  padding: 8px;
  text-align: center;
}

.preview dt { font-size: 0.75rem; color: var(--muted); }
.preview dd { margin: 4px 0 0; font-weight: 600; }

button {
  font: inherit;
  font-size: 1rem;
  border: none;
  border-radius: 10px;
  padding: 12px;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
}

button.primary { background: var(--green); color: #fff; font-weight: 600; }
button:disabled { opacity: 0.5; }

.toolbar { display: flex; justify-content: flex-end; margin-bottom: 12px; }

.history { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; }

.history li {
  background: var(--card);
  border-radius: 12px;
  padding: 12px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.history .main { flex: 1; min-width: 0; }
.history .line1 { display: flex; justify-content: space-between; font-weight: 600; }
.history .line2 { color: var(--muted); font-size: 0.85rem; margin-top: 4px; }
.history .delete { background: transparent; color: var(--red); padding: 8px; }
.history .empty { justify-content: center; color: var(--muted); }

.tabbar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  background: var(--card);
  border-top: 1px solid var(--border);
  padding-bottom: env(safe-area-inset-bottom);
}

.tabbar button {
  flex: 1;
  background: transparent;
  border-radius: 0;
  color: var(--muted);
  padding: 14px 0;
}

.tabbar button.active { color: var(--red); font-weight: 600; }

.toast {
  position: fixed;
  left: 50%;
  bottom: calc(80px + env(safe-area-inset-bottom));
  transform: translateX(-50%);
  background: rgba(0, 0, 0, 0.85);
  color: #fff;
  padding: 10px 16px;
  border-radius: 10px;
  max-width: 90vw;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}

.toast.show { opacity: 1; }
.toast.error { background: var(--red); }