:root {
  --background: #f1f1ed;
  --surface: #ffffff;
  --text: #111111;
  --muted: #72757a;
  --border: #ddddda;
  --accent: #111111;
  --success: #14532d;
  --success-bg: #dcfce7;
  --error: #991b1b;
  --error-bg: #fee2e2;
  --radius: 20px;
}

* { box-sizing: border-box; }

html { background: var(--background); }

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--background);
  color: var(--text);
}

button, input { font: inherit; }

button { cursor: pointer; }

.app-shell {
  width: min(760px, 100%);
  margin: 0 auto;
  padding: max(22px, env(safe-area-inset-top)) 16px max(44px, env(safe-area-inset-bottom));
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 18px;
}

.eyebrow {
  margin: 0 0 4px;
  color: var(--muted);
  font-size: .76rem;
  font-weight: 800;
  letter-spacing: .12em;
}

h1 {
  margin: 0;
  font-size: clamp(1.7rem, 5vw, 2.2rem);
  letter-spacing: -.045em;
}

.subtitle {
  margin: 5px 0 0;
  color: var(--muted);
  font-size: .95rem;
}

.date-card,
.exercise-card,
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 28px rgba(0, 0, 0, .035);
}

.date-card {
  padding: 15px;
  margin-bottom: 14px;
}

label {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: .78rem;
  font-weight: 800;
}

input {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 13px;
  padding: 12px;
  color: var(--text);
  background: var(--surface);
  outline: none;
}

input:focus {
  border-color: #9d9d97;
  box-shadow: 0 0 0 3px rgba(0, 0, 0, .06);
}

.exercise-list {
  display: grid;
  gap: 12px;
}

.exercise-card {
  padding: 15px;
}

.exercise-card.completed {
  opacity: .66;
}

.exercise-card.completed .exercise-name {
  text-decoration: line-through;
}

.exercise-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}

.exercise-name {
  font-size: 1.08rem;
  font-weight: 850;
}

.exercise-meta {
  margin-top: 3px;
  color: var(--muted);
  font-size: .84rem;
}

.exercise-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.done-checkbox {
  appearance: none;
  width: 28px;
  height: 28px;
  margin: 0;
  border: 2px solid #c6c8c4;
  border-radius: 50%;
  position: relative;
}

.done-checkbox:checked {
  background: var(--accent);
  border-color: var(--accent);
}

.done-checkbox:checked::after {
  content: "✓";
  position: absolute;
  left: 5px;
  top: 0;
  color: white;
  font-size: 17px;
  font-weight: 900;
}

.icon-button {
  border: 0;
  background: transparent;
  color: var(--muted);
  padding: 4px 6px;
  font-size: 1.05rem;
}

.exercise-fields,
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.form-grid .full { grid-column: 1 / -1; }

.main-actions,
.backup-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 16px;
}

.primary-button,
.secondary-button,
.ghost-button {
  border-radius: 14px;
  padding: 14px 16px;
  font-weight: 850;
}

.primary-button {
  border: 0;
  color: white;
  background: var(--accent);
}

.secondary-button,
.ghost-button {
  border: 1px solid var(--border);
  color: var(--text);
  background: var(--surface);
}

.full-button {
  width: 100%;
  margin-top: 12px;
}

.hidden { display: none; }

.status-message {
  display: none;
  margin-top: 12px;
  border-radius: 13px;
  padding: 11px 13px;
  font-size: .9rem;
  font-weight: 750;
}

.status-message.visible { display: block; }
.status-message.success { color: var(--success); background: var(--success-bg); }
.status-message.error { color: var(--error); background: var(--error-bg); }

.panel {
  margin-top: 16px;
  overflow: hidden;
}

.panel summary {
  list-style: none;
  padding: 15px;
  font-weight: 850;
}

.panel summary::-webkit-details-marker { display: none; }

.panel-content {
  border-top: 1px solid var(--border);
  padding: 14px;
}

.history-day {
  padding: 13px 0;
  border-bottom: 1px solid var(--border);
}

.history-day:last-child { border-bottom: 0; }

.history-date {
  margin-bottom: 8px;
  font-weight: 850;
}

.history-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  padding: 4px 0;
  color: var(--muted);
  font-size: .9rem;
}

.empty-state,
.helper-text,
.footer-note {
  color: var(--muted);
  font-size: .84rem;
  line-height: 1.5;
}

.footer-note { margin-top: 16px; }

@media (max-width: 540px) {
  .main-actions,
  .backup-actions {
    grid-template-columns: 1fr;
  }
}