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

:root {
  --primary: #10b981;
  --primary-dark: #059669;
  --primary-light: #d1fae5;
  --success: #10b981;
  --danger: #f56565;
  --warning: #ed8936;
  --gray-100: #f7fafc;
  --gray-200: #edf2f7;
  --gray-300: #e2e8f0;
  --gray-600: #718096;
  --gray-800: #2d3748;
  --bg: var(--gray-100);
  --card-bg: white;
  --text: var(--gray-800);
  --text-secondary: var(--gray-600);
}

body.dark-mode {
  --bg: #1a202c;
  --card-bg: #2d3748;
  --text: #f7fafc;
  --text-secondary: #a0aec0;
  --gray-100: #2d3748;
  --gray-200: #4a5568;
  --gray-300: #4a5568;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  min-height: 100vh;
  color: var(--text);
  transition: background 0.3s, color 0.3s;
}

.container {
  max-width: 480px;
  margin: 0 auto;
  padding: 16px;
  padding-bottom: 100px;
}

/* Header */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 0;
  margin-bottom: 16px;
}

header h1 {
  font-size: 24px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), #059669);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

.icon-btn {
  width: 40px;
  height: 40px;
  border: none;
  background: var(--card-bg);
  border-radius: 10px;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
  text-decoration: none;
  color: var(--text);
}

.icon-btn:hover {
  background: var(--gray-200);
}

/* Bottom Navigation */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--card-bg);
  display: flex;
  justify-content: space-around;
  padding: 8px 0 12px;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.1);
  z-index: 100;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 11px;
  padding: 4px 8px;
  border-radius: 8px;
  transition: all 0.2s;
  gap: 2px;
}

.nav-item.active {
  color: var(--primary);
}

.nav-icon {
  font-size: 22px;
}

/* Buttons */
.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 24px;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-secondary {
  background: var(--gray-200);
  color: var(--text);
}

.btn-danger {
  background: var(--danger);
  color: white;
}

.btn-success {
  background: var(--success);
  color: white;
}

.btn-block {
  width: 100%;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Cards */
.card {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 16px;
  margin-bottom: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

/* Form */
.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
  font-size: 14px;
  color: var(--text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 14px;
  border: 2px solid var(--gray-200);
  border-radius: 10px;
  font-size: 16px;
  background: var(--card-bg);
  color: var(--text);
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary);
}

/* Loading */
.loading {
  text-align: center;
  padding: 40px;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--gray-200);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 12px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 48px 24px;
  color: var(--text-secondary);
}

.empty-state .empty-icon {
  font-size: 56px;
  margin-bottom: 12px;
}

.empty-state p {
  font-size: 16px;
  margin-bottom: 20px;
}

/* Badges */
.badge {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
}

.badge-strength { background: #dbeafe; color: #1e40af; }
.badge-cardio { background: #fef3c7; color: #92400e; }
.badge-stretching { background: #fce7f3; color: #9d174d; }
.badge-yoga { background: #ede9fe; color: #5b21b6; }
.badge-swimming { background: #cffafe; color: #0e7490; }
.badge-mixed { background: #d1fae5; color: #065f46; }
.badge-other { background: var(--gray-200); color: var(--gray-600); }

/* Muscle group tags */
.tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 11px;
  background: var(--gray-200);
  color: var(--text-secondary);
}

/* Modal / Overlay */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 200;
  display: none;
  align-items: flex-end;
  justify-content: center;
}

.modal-overlay.show {
  display: flex;
}

.modal {
  background: var(--card-bg);
  border-radius: 20px 20px 0 0;
  padding: 24px;
  width: 100%;
  max-width: 480px;
  max-height: 80vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.modal-header h3 {
  font-size: 18px;
}

.modal-close {
  width: 32px;
  height: 32px;
  border: none;
  background: var(--gray-200);
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Search */
.search-input {
  width: 100%;
  padding: 12px 14px 12px 40px;
  border: 2px solid var(--gray-200);
  border-radius: 12px;
  font-size: 15px;
  background: var(--card-bg);
  color: var(--text);
  margin-bottom: 12px;
}

.search-input:focus {
  outline: none;
  border-color: var(--primary);
}

/* Filter Pills */
.filter-pills {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: 12px;
  -webkit-overflow-scrolling: touch;
}

.filter-pill {
  padding: 6px 14px;
  border: 2px solid var(--gray-200);
  background: var(--card-bg);
  border-radius: 20px;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s;
  color: var(--text);
}

.filter-pill.active {
  border-color: var(--primary);
  background: var(--primary);
  color: white;
}

/* Stats */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 16px;
}

.stat-card {
  background: var(--card-bg);
  border-radius: 14px;
  padding: 16px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.stat-value {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary);
}

.stat-label {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Toast */
.toast {
  position: fixed;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gray-800);
  color: white;
  padding: 12px 24px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 500;
  z-index: 300;
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
}

.toast.show {
  opacity: 1;
}

/* App Container */
.app-container {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
}

.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px;
}

.app-header h1 {
  font-size: 24px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), #059669);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.main-content {
  padding: 0 16px 100px;
}

/* Outline button */
.btn-outline {
  background: transparent;
  border: 2px solid var(--gray-300);
  color: var(--text);
}

.btn-outline:hover {
  background: var(--gray-200);
}

/* Calendar */
.calendar-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
  text-align: center;
}

.cal-header {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 4px 0;
}

.cal-day {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  font-size: 13px;
  cursor: pointer;
  transition: background 0.2s;
}

.cal-day.empty {
  cursor: default;
}

.cal-day:not(.empty):hover {
  background: var(--gray-200);
}

.cal-day.today {
  font-weight: 700;
  border: 2px solid var(--primary);
}

.cal-day.has-workout {
  background: var(--primary-light);
  color: var(--primary-dark);
  font-weight: 600;
}

body.dark-mode .cal-day.has-workout {
  background: rgba(16, 185, 129, 0.2);
  color: var(--primary);
}

/* Timer Circle */
.timer-circle {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.timer-display {
  position: absolute;
  font-size: 48px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}

/* Stats page */
.summary-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

.stat-card {
  text-align: center;
}

.stat-icon {
  font-size: 28px;
  margin-bottom: 4px;
}

.stats-section {
  margin-bottom: 20px;
}

.section-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
}

.chart-container {
  background: var(--card-bg);
  border-radius: 14px;
  padding: 16px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.chart-placeholder {
  text-align: center;
  color: var(--text-secondary);
  font-size: 14px;
  padding: 20px 0;
}

.pie-chart-container {
  display: flex;
  align-items: center;
  gap: 20px;
  background: var(--card-bg);
  border-radius: 14px;
  padding: 16px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.pie-legend {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.exercise-select {
  width: 100%;
  padding: 10px 14px;
  border: 2px solid var(--gray-200);
  border-radius: 10px;
  font-size: 14px;
  background: var(--card-bg);
  color: var(--text);
  margin-bottom: 12px;
}

.exercise-select:focus {
  outline: none;
  border-color: var(--primary);
}

.records-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* Border variable */
:root {
  --border: var(--gray-300);
}

/* Workout history item */
.workout-history-item {
  cursor: pointer;
  transition: background 0.2s;
}

.workout-history-item:hover {
  background: var(--gray-200);
}

/* Responsive */
@media (max-width: 400px) {
  .container { padding: 12px; }
  header h1 { font-size: 20px; }
  .btn { padding: 12px 16px; font-size: 14px; }
  .icon-btn { width: 36px; height: 36px; font-size: 16px; }
  .timer-display { font-size: 36px; }
  .summary-cards { grid-template-columns: repeat(2, 1fr); gap: 8px; }
}