:root {
  --bg: #fafaf7;
  --card: #ffffff;
  --text: #1d1d1b;
  --muted: #6b6b66;
  --line: #e2e2dc;
  --accent: #2f7d4f;
  --danger: #b3261e;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #161615;
    --card: #20201e;
    --text: #ededea;
    --muted: #a3a39c;
    --line: #34342f;
    --accent: #6cc28f;
    --danger: #f2827a;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
}

main {
  max-width: 34rem;
  margin: 0 auto;
  padding: 2rem 1rem 4rem;
}

h1 {
  margin: 0 0 1.5rem;
  font-size: 1.75rem;
}

form {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

form label {
  flex-basis: 100%;
  color: var(--muted);
  font-size: 0.9rem;
}

#habit-name {
  flex: 1;
  min-width: 0;
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  background: var(--card);
  color: var(--text);
  font: inherit;
}

button {
  padding: 0.6rem 1rem;
  border: 0;
  border-radius: 0.5rem;
  background: var(--accent);
  color: #fff;
  font: inherit;
  cursor: pointer;
}

button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

#empty {
  color: var(--muted);
}

ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

li {
  margin-bottom: 0.75rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  background: var(--card);
}

.habit-head {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.habit-name {
  flex: 1;
  font-weight: 600;
  overflow-wrap: anywhere;
}

.streak {
  color: var(--muted);
  font-size: 0.85rem;
  white-space: nowrap;
}

button.delete {
  padding: 0.25rem 0.5rem;
  background: transparent;
  color: var(--danger);
  font-size: 0.85rem;
}

.week {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 0.25rem;
}

.day {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0;
  border-radius: 0.5rem;
  color: var(--muted);
  font-size: 0.8rem;
}

.day.today {
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--text);
  font-weight: 600;
}

.day input {
  width: 1.5rem;
  height: 1.5rem;
  margin: 0;
  accent-color: var(--accent);
  cursor: pointer;
}