* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: #f0f4f8;
  color: #333;
  min-height: 100vh;
}

.container {
  max-width: 700px;
  margin: 0 auto;
  padding: 16px;
}

h1 {
  font-size: 1.6rem;
  color: #1a56db;
  margin-bottom: 20px;
  text-align: center;
  letter-spacing: 0.05em;
}

h2 {
  font-size: 1rem;
  color: #374151;
  margin-bottom: 12px;
  font-weight: 600;
}

section {
  background: #fff;
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}

.form-group {
  margin-bottom: 12px;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  color: #6b7280;
  margin-bottom: 4px;
}

.form-group input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  font-size: 1rem;
  transition: border-color 0.2s;
}

.form-group input:focus {
  outline: none;
  border-color: #1a56db;
  box-shadow: 0 0 0 3px rgba(26,86,219,0.1);
}

.form-row {
  display: flex;
  gap: 10px;
}

.form-row .form-group {
  flex: 1;
}

.btn-primary {
  width: 100%;
  padding: 12px;
  background: #1a56db;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

.btn-primary:hover {
  background: #1e40af;
}

.btn-secondary {
  padding: 8px 14px;
  background: #e5e7eb;
  color: #374151;
  border: none;
  border-radius: 8px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.2s;
  white-space: nowrap;
}

.btn-secondary:hover {
  background: #d1d5db;
}

.filter-row {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}

.filter-row input {
  flex: 1;
  min-width: 120px;
  padding: 8px 12px;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  font-size: 0.9rem;
}

.filter-row input:focus {
  outline: none;
  border-color: #1a56db;
}

/* Compare section */
.compare-card {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 10px;
  padding: 14px;
}

.compare-card .exercise-name {
  font-weight: 700;
  font-size: 1rem;
  color: #1e40af;
  margin-bottom: 10px;
}

.compare-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.compare-box {
  flex: 1;
  min-width: 120px;
  background: #fff;
  border-radius: 8px;
  padding: 10px;
  text-align: center;
}

.compare-box .label {
  font-size: 0.75rem;
  color: #6b7280;
  margin-bottom: 6px;
}

.compare-box .value {
  font-size: 1.1rem;
  font-weight: 700;
  color: #111827;
}

.diff-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: 20px;
  padding: 2px 8px;
  margin-top: 4px;
}

.diff-up {
  background: #dcfce7;
  color: #15803d;
}

.diff-down {
  background: #fee2e2;
  color: #b91c1c;
}

.diff-same {
  background: #f3f4f6;
  color: #6b7280;
}

/* Records list */
.date-group {
  margin-bottom: 16px;
}

.date-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: #6b7280;
  margin-bottom: 8px;
  padding-left: 4px;
}

.record-card {
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  padding: 12px 14px;
  margin-bottom: 8px;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 8px;
}

.record-info {
  flex: 1;
}

.record-exercise {
  font-size: 1rem;
  font-weight: 700;
  color: #1a56db;
  margin-bottom: 4px;
}

.record-stats {
  font-size: 0.9rem;
  color: #374151;
}

.record-stats span {
  margin-right: 12px;
}

.record-note {
  font-size: 0.8rem;
  color: #9ca3af;
  margin-top: 4px;
}

.record-time {
  font-size: 0.75rem;
  color: #9ca3af;
  white-space: nowrap;
}

.btn-delete {
  background: none;
  border: none;
  color: #d1d5db;
  font-size: 1.2rem;
  cursor: pointer;
  padding: 0 4px;
  line-height: 1;
  transition: color 0.2s;
}

.btn-delete:hover {
  color: #ef4444;
}

.empty-msg {
  text-align: center;
  color: #9ca3af;
  font-size: 0.95rem;
  padding: 24px 0;
}

@media (max-width: 480px) {
  h1 { font-size: 1.3rem; }
  .form-row { flex-direction: column; gap: 0; }
  .compare-row { flex-direction: column; }
}