:root {
  /* Slate Purple + Amber theme */
  --color-bg: #14131a;
  --color-surface: #1e1c28;
  --color-primary: #c4b5fd;
  --color-primary-hover: #d8ccfe;
  --color-primary-light: rgba(196, 181, 253, 0.10);
  --color-secondary: #fbbf24;
  --color-secondary-hover: #fcd34d;
  --color-secondary-light: rgba(251, 191, 36, 0.10);
  --color-tertiary: #f9a8d4;
  --color-tertiary-hover: #fbcfe8;
  --color-tertiary-light: rgba(249, 168, 212, 0.10);
  --color-text: #e4e2ec;
  --color-text-muted: #7a7590;
  --color-label: #ffffff;
  --color-border: #33303f;
  --color-danger: #f87171;
  --color-danger-hover: #ef4444;
  --radius: 6px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-text);
  background: var(--color-bg);
  min-height: 100vh;
}

/* =============================================================================
   LAYOUT
   ============================================================================= */

header {
  position: sticky;
  top: 0;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

main {
  padding: 16px;
  max-width: 500px;
  margin: 0 auto;
}

.hidden { display: none !important; }
.page { display: none; }
.page.active { display: block; }

/* =============================================================================
   CARDS (shared)
   ============================================================================= */

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px;
}

.card--inset {
  background: var(--color-bg);
}

.card--compact {
  padding: 12px;
}

.card--active {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary-light);
}

.exercise-card,
.program-card,
.program-selector,
.previous-measurements,
.program-day-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.exercise-card,
.program-card,
.program-selector {
  padding: 16px;
}

.previous-measurements,
.program-day-card {
  padding: 12px;
}

.program-day-card {
  background: var(--color-bg);
}

.exercise-card {
  box-shadow: var(--shadow);
}

/* =============================================================================
   BUTTONS
   ============================================================================= */

button {
  font-family: inherit;
  cursor: pointer;
  border-radius: var(--radius);
  transition: all 0.15s ease;
}

/* Base */
.btn {
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 500;
  border: 1px solid transparent;
  background: var(--color-surface);
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn:hover {
  border-color: var(--color-text-muted);
}

/* Accent */
.btn.accent {
  background: var(--color-secondary);
  color: var(--color-bg);
  border-color: var(--color-secondary);
}

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

/* Outline accent */
.btn.outline-accent {
  background: var(--color-surface);
  color: var(--color-secondary);
  border-color: var(--color-border);
  border-style: dashed;
}

.btn.outline-accent:hover {
  border-color: var(--color-secondary);
  background: var(--color-secondary-light);
}

/* Danger */
.btn.danger {
  background: transparent;
  color: var(--color-danger);
  border-color: var(--color-danger);
}

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

/* Ghost */
.btn.ghost {
  background: transparent;
  color: var(--color-text-muted);
  border-color: var(--color-border);
  padding: 6px 10px;
  font-size: 13px;
}

.btn.ghost:hover {
  border-color: var(--color-text-muted);
  color: var(--color-text);
}

/* Small */
.btn.sm {
  padding: 4px 8px;
  font-size: 12px;
}

/* Full width */
.btn.full {
  width: 100%;
}

/* Disabled */
.btn:disabled {
  background: var(--color-text-muted);
  border-color: var(--color-text-muted);
  color: var(--color-bg);
  cursor: default;
  opacity: 0.6;
}

/* =============================================================================
   FORMS
   ============================================================================= */

form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

label {
  font-weight: 500;
  font-size: 15px;
  color: var(--color-label);
}

input[type="number"],
input[type="text"],
select {
  width: 100%;
  padding: 10px 12px;
  font-size: 15px;
  font-family: inherit;
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-surface);
  transition: border-color 0.15s, box-shadow 0.15s;
}

input:focus,
select:focus {
  outline: none;
  border-color: var(--color-secondary);
  box-shadow: 0 0 0 2px var(--color-secondary-light);
}

input::placeholder {
  color: var(--color-text-muted);
}

.set-row input::placeholder {
  color: var(--color-primary);
  opacity: 0.7;
}

.form-buttons {
  display: flex;
  gap: 8px;
}

.form-buttons .btn:first-child {
  flex: 1;
}

/* =============================================================================
   TABS
   ============================================================================= */

.tabs {
  display: flex;
}

.tab {
  flex: 1;
  padding: 14px;
  border: none;
  background: transparent;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-muted);
  border-bottom: 2px solid transparent;
}

.tab:hover {
  color: var(--color-text);
}

.tab.active {
  background: var(--color-secondary-light);
  color: var(--color-secondary);
  border-bottom-color: var(--color-secondary);
}

/* Sub-tabs */
.sub-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
}

.sub-tab {
  flex: 1;
  padding: 10px 14px;
  border: 1px solid var(--color-border);
  background: transparent;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-muted);
}

.sub-tab:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
}

.sub-tab.active {
  background: var(--color-surface);
  color: var(--color-secondary);
  border-color: var(--color-secondary);
}

.sub-page { display: none; }
.sub-page.active { display: block; }

/* =============================================================================
   MEASUREMENTS
   ============================================================================= */

.measurements-form {
  gap: 8px;
}

.measurement-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.measurement-row label {
  width: 60px;
  flex-shrink: 0;
}

.measurement-row input {
  flex: 1;
}

.measurement-pair {
  display: flex;
  gap: 12px;
}

.measurement-pair .measurement-row {
  flex: 1;
}

.measurements-form .btn {
  margin-top: 8px;
}

.previous-measurements {
  margin-bottom: 16px;
}

.previous-measurements-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
  font-size: 13px;
  color: var(--color-text-muted);
}

#previous-measurements-values {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
}

.measurement-item {
  font-size: 13px;
}

.measurement-item strong {
  color: var(--color-text-muted);
  font-weight: 500;
}

/* =============================================================================
   WORKOUT
   ============================================================================= */

.exercise-header {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-bottom: 12px;
}

.exercise-header input {
  flex: 1;
}

.exercise-header input[readonly] {
  background: transparent;
  border: none;
  color: var(--color-secondary);
  font-weight: 600;
  font-size: 18px;
  padding: 0;
  cursor: default;
  letter-spacing: -0.3px;
}

.exercise-header input[readonly]:focus {
  box-shadow: none;
}

.sets-container {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.set-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.set-label {
  width: 60px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-label);
}

.set-row input {
  flex: 1;
}

#exercises-container {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#exercises-container:empty {
  display: none;
}

/* =============================================================================
   PROGRAM SELECTOR
   ============================================================================= */

.program-selector {
  margin-bottom: 16px;
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 16px;
}

.program-selector .form-group {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 8px;
}

.program-selector .form-group > label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-secondary);
}

.program-selector .form-group > select {
  max-width: 140px;
}

.program-display,
.day-selector {
  display: flex;
  align-items: center;
  gap: 6px;
}

#current-program-name,
#suggested-day {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-label);
}

/* =============================================================================
   PROGRAMS
   ============================================================================= */

#programs-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

#programs-list:empty {
  display: none;
}

.program-card {
  padding: 12px 16px;
}

.program-card.active {
  border-color: var(--color-secondary);
  box-shadow: 0 0 0 1px var(--color-secondary-light);
}

.program-card .program-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}

.program-card .program-header-left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.program-card .expand-icon {
  color: var(--color-text-muted);
  font-size: 12px;
  transition: transform 0.2s;
}

.program-card.expanded .expand-icon {
  transform: rotate(90deg);
}

.program-card .program-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
}

.program-card.active .program-name {
  color: var(--color-secondary);
}

.program-card .program-days {
  font-size: 13px;
  color: var(--color-text-muted);
  background: var(--color-bg);
  padding: 4px 8px;
  border-radius: 4px;
}

.program-card .program-details {
  display: none;
  margin-top: 12px;
}

.program-card.expanded .program-details {
  display: block;
}

.program-actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}

.program-actions button {
  flex: 1;
}

#create-program h3 {
  margin-bottom: 16px;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-secondary);
}

#create-program .form-group {
  margin-bottom: 16px;
}

.empty-message {
  color: var(--color-text-muted);
  text-align: center;
  padding: 24px;
  font-size: 14px;
  background: var(--color-surface);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius);
  margin-bottom: 24px;
}

/* Program days builder */
.program-days-builder {
  margin-bottom: 16px;
}

.program-days-builder > label {
  display: block;
  margin-bottom: 10px;
}

#program-days-container {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 12px;
}

#program-days-container:empty {
  display: none;
}

.program-day-card {
  padding: 14px;
  border-radius: var(--radius);
}

.program-day-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.program-day-label {
  font-weight: 600;
  font-size: 14px;
  color: var(--color-secondary);
}

.program-day-exercises {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 10px;
  min-height: 22px;
}

.exercise-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--color-secondary);
  color: var(--color-bg);
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 13px;
  font-weight: 500;
}

.remove-exercise-btn {
  background: transparent;
  border: none;
  color: var(--color-surface);
  font-size: 14px;
  padding: 0 2px;
  line-height: 1;
  opacity: 0.8;
}

.remove-exercise-btn:hover {
  opacity: 1;
}

.add-exercise-row {
  display: flex;
  gap: 6px;
}

.add-exercise-row input {
  flex: 1;
}

/* Program preview */
.program-days-preview {
  margin-bottom: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.program-day-preview {
  background: var(--color-bg);
  border-radius: var(--radius);
  padding: 10px 12px;
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.program-day-preview strong {
  color: var(--color-secondary);
  font-weight: 600;
  font-size: 13px;
  flex-shrink: 0;
}

.program-day-preview .exercises {
  color: var(--color-text);
  font-size: 13px;
  line-height: 1.4;
}

/* =============================================================================
   EXPORT/IMPORT
   ============================================================================= */

.export-section {
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
  display: flex;
  gap: 8px;
}

.export-section button {
  flex: 1;
}

/* =============================================================================
   TOAST
   ============================================================================= */

.status-toast {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-text);
  color: white;
  padding: 10px 20px;
  border-radius: var(--radius);
  font-size: 14px;
  z-index: 1000;
  opacity: 0;
  transition: opacity 0.2s;
}

.status-toast.visible {
  opacity: 1;
}