:root {
  --brand-1: #ff9a9e;
  --brand-2: #fad0c4;
  --ink: #0b3b58;
  --muted: #66788a;
  --ring: #b3e6ff;


}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  background: #f0f4f8;
  color: #333;
  line-height: 1.6;
}

button:focus, input:focus {
  outline: 3px solid var(--ring);
  outline-offset: 2px;
}

main {
  max-width: 980px;
  margin: 0 auto;
  padding: 20px;
}

header {
  background: linear-gradient(135deg, var(--brand-1), var(--brand-2));
  color: #fff;
  padding: 24px;
  border-radius: 12px;
  margin-bottom: 12px;
}

header h1 {
  margin: 0 0 6px;
}

header p {
  margin: 0;
}

.tip-box {
  background: #e8f9ff;
  border-left: 6px solid var(--brand-1);
  padding: 12px;
  border-radius: 8px;
  margin-bottom: 16px;
}

.add-habit, .tracker, .data-management {
  background: #fff;
  border-radius: 12px;
  padding: 18px;
  margin: 12px 0;
  box-shadow: 0 1px 2px rgba(0,0,0,.04), 0 4px 12px rgba(0,0,0,.04);
}

.add-habit form {
  display: flex;
  gap: 8px;
  align-items: center;
}

.add-habit input {
  flex: 1;
  padding: 10px 12px;
  border: 1px solid #dbe7f0;
  border-radius: 8px;
  outline: none;
}

.add-habit button {
  background: var(--brand-1);
  color: #fff;
  border: none;
  padding: 10px 14px;
  border-radius: 8px;
  cursor: pointer;
}

.tracker-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.tracker-grid {
  overflow-x: auto;
}

.habit-row {
  display: grid;
  grid-template-columns: 1.6fr repeat(7, .9fr) .8fr 1fr;
  align-items: center;
  border-bottom: 1px solid #eef2f6;
}

.header-row {
  font-weight: 600;
  background: #f8fbfe;
}

.habit-row > div {
  padding: 10px;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.data-management .manage-buttons {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.data-management button, .data-management label {
  background: #eef7ff;
  color: #046f95;
  border: none;
  padding: 10px 14px;
  border-radius: 8px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.data-management p {
  color: var(--muted);
  font-size: .95rem;
  margin: 10px 0 0;
}

footer {
  color: var(--muted);
  font-size: .95rem;
  margin: 10px 0 0;
}

/* Habit row buttons */
.habit-row button {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  margin: auto;
  border-radius: 8px;
  border: 1px solid #dbe7f0;
  cursor: pointer;
  user-select: none;
  background: #fff;
  color: inherit;
  font-weight: 400;
}

.habit-row button.completed {
  background: #e9f8ef;
  color: #1e9e4a;
  font-weight: 700;
}

.habit-row button:hover {
  filter: brightness(1.05);
}

/* Streak number alignment */
.habit-row div.streak {
  font-variant-numeric: tabular-nums;
}