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

:root {
  /* Light mode colors */
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border-color: #e2e8f0;
  --accent: #0ea5e9;
  --accent-hover: #0284c7;
  --accent-light: #e0f2fe;
  --success: #22c55e;
  --success-light: #dcfce7;
  --warning: #f59e0b;
  --error: #ef4444;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;

  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* Font */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;

  /* Timer bar height */
  --timer-height: 80px;
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #64748b;
    --border-color: #334155;
    --accent-light: #0c4a6e;
    --success-light: #14532d;
  }
}

html {
  font-size: 16px;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  padding-bottom: calc(var(--timer-height) + env(safe-area-inset-bottom, 16px));
}

/* Typography */
h1 {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.2;
}

h2 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-secondary);
}

h3 {
  font-size: 1rem;
  font-weight: 600;
}

/* App Container */
.app-container {
  max-width: 600px;
  margin: 0 auto;
  padding: var(--spacing-md);
}

/* Tab Navigation */
.tab-nav {
  display: flex;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  background: var(--bg-secondary);
  padding: var(--spacing-xs);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
}

.tab-btn {
  flex: 1;
  padding: var(--spacing-sm) var(--spacing-md);
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.15s ease;
}

.tab-btn.active {
  background: var(--accent);
  color: white;
}

.tab-btn:not(.active):hover {
  background: var(--bg-tertiary);
}

/* View Container */
.view {
  display: none;
}

.view.active {
  display: block;
}

/* Day Header */
.day-header {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.day-header .day-name {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-xs);
}

.day-header h1 {
  margin-bottom: var(--spacing-xs);
}

.day-header .week-label {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Program Loop Banner */
.loop-banner {
  background: var(--warning);
  color: #000;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  font-size: 0.75rem;
  text-align: center;
  margin-bottom: var(--spacing-md);
}

/* Rest Day */
.rest-day {
  text-align: center;
  padding: var(--spacing-xl) var(--spacing-md);
}

.rest-day h2 {
  font-size: 2rem;
  color: var(--text-primary);
  margin-bottom: var(--spacing-md);
}

.rest-day p {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* Block */
.block {
  margin-bottom: var(--spacing-xl);
}

.block-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--accent);
}

.block-header h3 {
  color: var(--accent);
}

.block-header .block-info {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.block-description {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
  font-style: italic;
}

/* Exercise Card */
.exercise-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-md);
}

.exercise-info {
  flex: 1;
  min-width: 0;
}

.exercise-name {
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.exercise-name .timed-badge {
  font-size: 0.625rem;
  background: var(--accent-light);
  color: var(--accent);
  padding: 2px 6px;
  border-radius: var(--radius-full);
  font-weight: 500;
}

.exercise-details {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.exercise-details span {
  display: inline-block;
}

.exercise-details span:not(:last-child)::after {
  content: '•';
  margin: 0 var(--spacing-sm);
  color: var(--text-muted);
}

.exercise-actions {
  display: flex;
  gap: var(--spacing-sm);
  flex-shrink: 0;
}

/* YouTube Button */
.youtube-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.75rem;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.youtube-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* Timer Button for timed exercises */
.timer-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--accent-light);
  border: none;
  border-radius: var(--radius-sm);
  color: var(--accent);
  cursor: pointer;
  transition: all 0.15s ease;
}

.timer-btn:hover {
  background: var(--accent);
  color: white;
}

/* Round Checkboxes */
.rounds-container {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
  padding: var(--spacing-md);
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  flex-wrap: wrap;
}

.rounds-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
  margin-right: var(--spacing-sm);
}

.round-checkbox {
  position: relative;
  width: 44px;
  height: 44px;
}

.round-checkbox input {
  position: absolute;
  opacity: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
  z-index: 1;
  margin: 0;
}

.round-checkbox .round-display {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-secondary);
  transition: all 0.15s ease;
}

.round-checkbox input:checked + .round-display {
  background: var(--success);
  border-color: var(--success);
  color: white;
}

.round-checkbox input:focus + .round-display {
  box-shadow: 0 0 0 3px var(--accent-light);
}

/* Week View */
.week-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: var(--spacing-sm);
}

@media (max-width: 480px) {
  .week-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .week-grid .week-cell:nth-child(n+5) {
    grid-column: span 1;
  }
}

.week-cell {
  background: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: var(--spacing-sm);
  text-align: center;
  cursor: pointer;
  transition: all 0.15s ease;
  min-height: 80px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.week-cell:hover {
  border-color: var(--accent);
}

.week-cell.today {
  border-color: var(--accent);
  border-width: 3px;
}

.week-cell.selected {
  background: var(--accent-light);
}

.week-cell .day-abbr {
  font-size: 0.625rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.week-cell .date {
  font-size: 1.25rem;
  font-weight: 700;
  margin: var(--spacing-xs) 0;
}

.week-cell .workout-type {
  font-size: 0.625rem;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.week-cell.rest .workout-type {
  color: var(--text-muted);
}

/* Timer Bar */
.timer-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  min-height: var(--timer-height);
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  padding-bottom: calc(var(--spacing-sm) + env(safe-area-inset-bottom, 0px));
  z-index: 100;
}

.timer-main {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  width: 100%;
}

.timer-display {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 700;
  min-width: 100px;
  text-align: center;
}

.timer-display.running {
  color: var(--accent);
}

.timer-display.warning {
  color: var(--warning);
}

.timer-controls {
  display: flex;
  gap: var(--spacing-sm);
  align-items: center;
}

.timer-btn-control {
  padding: var(--spacing-xs) var(--spacing-sm);
  border: 1px solid var(--border-color);
  background: transparent;
  border-radius: var(--radius-md);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.timer-btn-control:hover {
  background: var(--bg-tertiary);
}

.timer-btn-control.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.timer-btn-control.primary:hover {
  background: var(--accent-hover);
}

.timer-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 300px;
}

.timer-hint {
  font-size: 0.625rem;
  color: var(--text-muted);
  text-align: left;
}

.timer-mode-toggle {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: 0.625rem;
  color: var(--text-muted);
}

.timer-mode-toggle input {
  cursor: pointer;
}

/* Stopwatch Mode */
.timer-bar.stopwatch .timer-display {
  color: var(--success);
}

/* Desktop adjustments */
@media (min-width: 768px) {
  .app-container {
    padding: var(--spacing-xl);
  }

  h1 {
    font-size: 2rem;
  }

  .week-grid {
    grid-template-columns: repeat(7, 1fr);
  }

  .timer-bar {
    max-width: 600px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    border: 1px solid var(--border-color);
    border-bottom: none;
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
  }
}

/* Focus visible */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

button:focus:not(:focus-visible),
a:focus:not(:focus-visible),
input:focus:not(:focus-visible) {
  outline: none;
}