/* ── Design tokens ────────────────────────────────────────────────────────── */
:root {
  --bg:      #f4ede0;   /* page background */
  --card:    #fdf8f0;   /* habit card background */
  --text:    #2d1f0e;   /* primary text */
  --muted:   #8a7463;   /* secondary / placeholder text */
  --accent:  #b87333;   /* copper — buttons, focus rings */
  --border:  #ddd0bb;   /* card borders */
  --done-bg: #ede4d3;   /* completed habit tint */
  --danger:  #b94a2c;   /* terracotta delete button */
  --radius:  12px;
}

/* ── Reset ────────────────────────────────────────────────────────────────── */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ── Base ─────────────────────────────────────────────────────────────────── */
body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, sans-serif;
  display: flex;
  justify-content: center;
  padding: 2.5rem 1rem;
  min-height: 100vh;
}

/* ── Layout container ─────────────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: 520px;
}

/* ── Heading ──────────────────────────────────────────────────────────────── */
h1 {
  text-align: center;
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

/* ── Input row ────────────────────────────────────────────────────────────── */
.input-group {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.input-group input {
  flex: 1;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  color: var(--text);
  background: var(--card);
  outline: none;
  transition: border-color 0.15s;
}

.input-group input:focus {
  border-color: var(--accent);
}

.input-group button {
  padding: 0.75rem 1.25rem;
  background: var(--accent);
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: opacity 0.15s;
  white-space: nowrap;
}

.input-group button:hover {
  opacity: 0.88;
}

/* ── Validation error ─────────────────────────────────────────────────────── */
.error {
  color: var(--danger);
  font-size: 0.85rem;
  min-height: 1.2em;
  margin-bottom: 0.75rem;
}

/* ── Habit list ───────────────────────────────────────────────────────────── */
ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* ── Individual habit card ────────────────────────────────────────────────── */
li {
  background: var(--card);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  transition: background 0.2s, border-color 0.2s;
}

/* Completed state — tinted background */
li.completed {
  background: var(--done-bg);
  border-color: #c7ddf8;
}

/* ── Checkbox + label row ─────────────────────────────────────────────────── */
.habit-label {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  cursor: pointer;
  flex: 1;
  min-width: 0; /* allows text truncation if needed */
}

.habit-label input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent);
  cursor: pointer;
  flex-shrink: 0;
}

.habit-label span {
  font-size: 1rem;
  word-break: break-word;
}

/* Strikethrough on completed habit text */
li.completed .habit-label span {
  text-decoration: line-through;
  color: var(--muted);
}

/* ── Delete button ────────────────────────────────────────────────────────── */
.btn-delete {
  background: transparent;
  border: none;
  color: var(--muted);
  font-size: 1.1rem;
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 6px;
  line-height: 1;
  flex-shrink: 0;
  transition: color 0.15s, background 0.15s;
}

.btn-delete:hover {
  color: var(--danger);
  background: #fee2e2;
}

/* ── Empty state ──────────────────────────────────────────────────────────── */
.empty {
  text-align: center;
  color: var(--muted);
  margin-top: 2.5rem;
  font-size: 0.95rem;
}

/* ── Mobile tweaks (screens narrower than 400px) ──────────────────────────── */
@media (max-width: 400px) {
  h1 { font-size: 1.3rem; }

  .input-group input { font-size: 0.95rem; }

  .input-group button {
    padding: 0.75rem 0.9rem;
    font-size: 0.95rem;
  }
}