/* ============================================
   减脂助手 · FatLoss Pro — CSS
   移动端优先设计
   ============================================ */

:root {
  --primary: #FF6B35;
  --primary-dark: #E8551F;
  --primary-light: #FFF0EB;
  --secondary: #2EC4B6;
  --secondary-light: #E8FAF9;
  --accent: #845EC2;
  --accent-light: #F0EBF8;
  --blue: #3A86FF;
  --blue-light: #EBF3FF;
  --green: #06D6A0;
  --green-light: #E8FBF6;
  --red: #EF233C;
  --red-light: #FEE8EB;
  --orange: #FB8500;
  --orange-light: #FFF4E6;
  --yellow: #FFB703;
  --yellow-light: #FFFBEB;

  --bg: #F5F7FA;
  --surface: #FFFFFF;
  --border: #E8ECF0;
  --text-primary: #1A1A2E;
  --text-secondary: #6B7280;
  --text-muted: #9CA3AF;

  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 4px rgba(0,0,0,0.06);
  --shadow: 0 4px 16px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);

  --transition: 0.2s ease;
  --header-h: 60px;
  --nav-h: 64px;
}

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

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  min-height: 100vh;
  padding-bottom: 80px;
}

/* ============ HEADER ============ */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: linear-gradient(135deg, var(--primary) 0%, #FF8C61 100%);
  height: var(--header-h);
  box-shadow: 0 2px 12px rgba(255,107,53,0.3);
}

.header-inner {
  max-width: 480px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #fff;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.logo-icon {
  font-size: 1.3rem;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
}

.header-subtitle {
  color: rgba(255,255,255,0.85);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
}

/* ============ TAB NAV ============ */
.tab-nav {
  position: sticky;
  top: var(--header-h);
  z-index: 99;
  display: flex;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  max-width: 480px;
  margin: 0 auto;
  width: 100%;
}

/* Make nav full width on mobile */
@media (max-width: 480px) {
  .tab-nav { max-width: 100%; }
}

.tab-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  padding: 10px 4px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.68rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  border-bottom: 2px solid transparent;
  font-family: inherit;
}

.tab-btn i { font-size: 1.1rem; }

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

.tab-btn:active { transform: scale(0.95); }

/* ============ MAIN ============ */
.app-main {
  max-width: 480px;
  margin: 0 auto;
  padding: 16px 12px;
}

/* ============ TAB PANELS ============ */
.tab-panel { display: none; }
.tab-panel.active { display: block; }

.panel-header { margin-bottom: 16px; }

.panel-header h2 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.panel-header h2 i { color: var(--primary); }

.panel-desc {
  margin-top: 4px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* ============ CARD ============ */
.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 14px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
}

.card-title {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.card-title i { color: var(--primary); font-size: 0.9rem; }

.card-desc {
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
  line-height: 1.4;
}

/* ============ FORM ============ */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.unit {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.75rem;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--text-primary);
  background: var(--bg);
  transition: border-color var(--transition), box-shadow var(--transition);
  -webkit-appearance: none;
  appearance: none;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(255,107,53,0.12);
  background: var(--surface);
}

.hint {
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* Gender selector */
.gender-selector {
  display: flex;
  gap: 8px;
}

.gender-btn {
  flex: 1;
  padding: 10px 8px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.gender-btn.active {
  border-color: var(--primary);
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 700;
}

/* Info box */
.info-box {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  background: var(--blue-light);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-size: 0.78rem;
  color: var(--blue);
  line-height: 1.5;
  margin-top: 10px;
}

.info-box i { flex-shrink: 0; margin-top: 1px; }

/* Badge */
.badge {
  font-size: 0.65rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.badge-optional { background: var(--yellow-light); color: var(--yellow); }
.badge-count {
  background: var(--primary);
  color: #fff;
  font-size: 0.7rem;
  min-width: 20px;
  text-align: center;
}

/* Activity list */
.activity-list { display: flex; flex-direction: column; gap: 8px; }

.activity-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
}

.activity-item:has(input:checked) {
  border-color: var(--primary);
  background: var(--primary-light);
}

.activity-item input[type="radio"] { accent-color: var(--primary); width: 16px; height: 16px; flex-shrink: 0; }

.activity-title { font-size: 0.85rem; font-weight: 600; }
.activity-desc { font-size: 0.75rem; color: var(--text-secondary); margin-top: 1px; }

/* ============ BUTTONS ============ */
.btn-primary {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--primary), #FF8C61);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 14px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  box-shadow: 0 4px 14px rgba(255,107,53,0.35);
}

.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(255,107,53,0.4); }
.btn-primary:active { transform: translateY(0); }

.btn-secondary {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--primary-light);
  color: var(--primary);
  border: 1.5px solid var(--primary);
  border-radius: var(--radius);
  padding: 12px 20px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
}

.btn-secondary:hover { background: var(--primary); color: #fff; }

.btn-full { width: 100%; }

.mt-2 { margin-top: 12px; }

/* ============ BMR RESULT ============ */
.result-card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: 20px 16px;
  margin-top: 16px;
  border: 2px solid var(--primary);
  box-shadow: 0 4px 20px rgba(255,107,53,0.12);
}

.formula-tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 20px;
  font-size: 0.72rem;
  font-weight: 600;
  margin-bottom: 14px;
}

.metrics-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.metric-box {
  border-radius: var(--radius-sm);
  padding: 12px 10px;
  text-align: center;
}

.metric-blue { background: var(--blue-light); }
.metric-orange { background: var(--orange-light); }
.metric-green { background: var(--green-light); }
.metric-purple { background: var(--accent-light); }

.metric-label {
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 4px;
  line-height: 1.3;
}

.metric-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
}

.metric-blue .metric-value { color: var(--blue); }
.metric-orange .metric-value { color: var(--orange); }
.metric-green .metric-value { color: var(--green); }
.metric-purple .metric-value { color: var(--accent); }

.metric-unit {
  font-size: 0.68rem;
  color: var(--text-muted);
  margin-top: 2px;
}

/* ============ TOGGLE BAR ============ */
.toggle-bar {
  display: flex;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 4px;
  margin-bottom: 14px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.toggle-btn {
  flex: 1;
  padding: 9px 12px;
  border: none;
  border-radius: calc(var(--radius) - 4px);
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-family: inherit;
}

.toggle-btn.active {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 2px 8px rgba(255,107,53,0.3);
}

/* ============ FOOD GRID ============ */
.food-category-tabs {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: 12px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.food-category-tabs::-webkit-scrollbar { display: none; }

.cat-btn {
  flex-shrink: 0;
  padding: 5px 12px;
  border: 1.5px solid var(--border);
  border-radius: 20px;
  background: var(--bg);
  color: var(--text-secondary);
  font-size: 0.78rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  white-space: nowrap;
}

.cat-btn.active {
  border-color: var(--primary);
  background: var(--primary-light);
  color: var(--primary);
}

.food-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  max-height: 360px;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.food-item {
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 8px 6px;
  cursor: pointer;
  transition: all var(--transition);
  text-align: center;
}

.food-item:active { transform: scale(0.95); }

.food-item.selected {
  border-color: var(--primary);
  background: var(--primary-light);
}

.food-emoji { font-size: 1.4rem; line-height: 1; margin-bottom: 3px; }
.food-name { font-size: 0.72rem; font-weight: 600; color: var(--text-primary); line-height: 1.2; }
.food-cal { font-size: 0.68rem; color: var(--text-muted); margin-top: 2px; }

/* Selected foods list */
.selected-food-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
}

.selected-food-row:last-child { border-bottom: none; }

.sfd-emoji { font-size: 1.2rem; flex-shrink: 0; }

.sfd-info { flex: 1; min-width: 0; }
.sfd-name { font-size: 0.82rem; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.sfd-cal { font-size: 0.72rem; color: var(--text-secondary); }

.sfd-qty {
  display: flex;
  align-items: center;
  gap: 6px;
}

.qty-btn {
  width: 26px; height: 26px;
  border: 1.5px solid var(--border);
  border-radius: 50%;
  background: var(--surface);
  color: var(--text-primary);
  font-size: 1rem;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
  transition: all var(--transition);
  flex-shrink: 0;
}

.qty-btn:active { transform: scale(0.9); background: var(--primary-light); }

.qty-val {
  min-width: 20px;
  text-align: center;
  font-size: 0.85rem;
  font-weight: 600;
}

.sfd-remove {
  color: var(--red);
  background: none;
  border: none;
  font-size: 0.85rem;
  cursor: pointer;
  padding: 4px;
  flex-shrink: 0;
  transition: transform var(--transition);
}

.sfd-remove:active { transform: scale(0.8); }

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 24px 0;
  color: var(--text-muted);
}

.empty-state i { font-size: 2rem; }
.empty-state p { font-size: 0.82rem; }

.total-calories {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 12px;
  margin-top: 12px;
  border-top: 2px solid var(--border);
  font-size: 0.85rem;
  font-weight: 600;
}

.total-val {
  font-size: 1.1rem;
  color: var(--primary);
  font-weight: 700;
}

/* Quick exercise buttons */
.exercise-quick-btns {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-top: 10px;
}

.quick-label {
  width: 100%;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 2px;
}

.quick-btn {
  flex: 1 1 calc(33.33% - 8px);
  min-width: 80px;
  padding: 7px 6px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--text-secondary);
  font-size: 0.7rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  text-align: center;
  line-height: 1.4;
}

.quick-btn:active { background: var(--secondary-light); border-color: var(--secondary); color: var(--secondary); }
.quick-btn.selected { background: var(--secondary-light); border-color: var(--secondary); color: var(--secondary); }

/* ============ RESULT SUMMARY ============ */
.result-summary-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-bottom: 16px;
}

.summary-card {
  border-radius: var(--radius);
  padding: 14px 16px;
  display: flex;
  align-items: center;
  gap: 14px;
  box-shadow: var(--shadow-sm);
}

.card-red { background: linear-gradient(135deg, #FF6B6B, #EE5A24); color: #fff; }
.card-blue { background: linear-gradient(135deg, #3A86FF, #0073E6); color: #fff; }
.card-green { background: linear-gradient(135deg, #06D6A0, #00B07A); color: #fff; }
.card-orange { background: linear-gradient(135deg, #FB8500, #E67E00); color: #fff; }

.summary-icon { font-size: 1.6rem; flex-shrink: 0; opacity: 0.9; }

.summary-label { font-size: 0.72rem; font-weight: 500; opacity: 0.85; }
.summary-val { font-size: 1.8rem; font-weight: 700; line-height: 1; margin: 2px 0; }
.summary-unit { font-size: 0.7rem; opacity: 0.8; }

/* ============ CHART ============ */
.chart-container {
  position: relative;
  width: 100%;
}

.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 10px;
  justify-content: center;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.legend-dot {
  width: 10px; height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* ============ MACRO BARS ============ */
.macro-bars { display: flex; flex-direction: column; gap: 12px; }

.macro-row { }

.macro-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 5px;
}

.macro-name { font-size: 0.8rem; font-weight: 600; }
.macro-val { font-size: 0.78rem; color: var(--text-secondary); }

.macro-bar-track {
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
}

.macro-bar-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 0.6s ease;
}

.bar-protein { background: var(--blue); }
.bar-fat { background: var(--orange); }
.bar-carb { background: var(--green); }

/* ============ GAP ASSESS ============ */
.gap-assess {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.assess-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
}

.assess-icon { font-size: 1.3rem; flex-shrink: 0; }
.assess-text { line-height: 1.4; }
.assess-label { font-weight: 600; display: block; }
.assess-desc { color: var(--text-secondary); font-size: 0.75rem; }

.assess-danger { background: var(--red-light); color: var(--red); }
.assess-warning { background: var(--yellow-light); color: #92640A; }
.assess-ok { background: var(--green-light); color: #076D50; }
.assess-surplus { background: var(--orange-light); color: var(--orange); }

/* ============ PREDICT ============ */
.predict-milestones {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 14px;
}

.milestone-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 14px 12px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  border: 1.5px solid var(--border);
}

.milestone-card.highlight {
  border-color: var(--primary);
  background: var(--primary-light);
}

.milestone-label { font-size: 0.72rem; color: var(--text-secondary); font-weight: 500; }
.milestone-val { font-size: 1.5rem; font-weight: 700; color: var(--text-primary); margin: 4px 0; }
.milestone-val.text-primary { color: var(--primary); }
.milestone-val.text-blue { color: var(--blue); }
.milestone-val.text-green { color: var(--green); }
.milestone-val.text-secondary-color { color: var(--secondary); }
.milestone-sub { font-size: 0.7rem; color: var(--text-muted); }

/* Milestone table */
.milestone-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}

.milestone-table th {
  background: var(--bg);
  color: var(--text-secondary);
  font-weight: 600;
  padding: 8px 10px;
  text-align: left;
  border-bottom: 1.5px solid var(--border);
}

.milestone-table td {
  padding: 9px 10px;
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
}

.milestone-table tr:last-child td { border-bottom: none; }

.milestone-table tr:nth-child(even) td { background: var(--bg); }

td.highlight-cell { color: var(--primary); font-weight: 700; }

/* Warning card */
.warning-card {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: var(--yellow-light);
  border: 1.5px solid var(--yellow);
}

.warning-card i { color: var(--yellow); font-size: 1.3rem; flex-shrink: 0; margin-top: 2px; }
.warning-card strong { font-size: 0.88rem; display: block; margin-bottom: 4px; }
.warning-card p { font-size: 0.78rem; color: var(--text-secondary); line-height: 1.5; }

/* ============ FOOTER ============ */
.app-footer {
  text-align: center;
  padding: 20px 16px;
  font-size: 0.7rem;
  color: var(--text-muted);
  line-height: 1.8;
  background: var(--surface);
  border-top: 1px solid var(--border);
  margin-top: 8px;
}

/* ============ UTILITY ============ */
.hidden { display: none !important; }

/* Scrollbar */
::-webkit-scrollbar { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

/* ============ DESKTOP ADAPTATION ============ */
@media (min-width: 520px) {
  body {
    background: linear-gradient(135deg, #F5F7FA 0%, #E8ECF4 100%);
  }

  .app-header {
    /* Full-width header on desktop */
  }

  .tab-nav {
    max-width: 520px;
    margin: 0 auto;
    border-radius: 0 0 var(--radius) var(--radius);
  }

  .app-main {
    max-width: 520px;
    margin: 0 auto;
    padding: 20px 16px;
  }

  .metrics-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .predict-milestones {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* Smooth transitions for tab switching */
.tab-panel {
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ LOADING ============ */
.spin {
  animation: spin 0.8s linear infinite;
}

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

/* Number input arrows */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  opacity: 0.6;
}