:root {
  --color-bg-primary: #050b1a;
  --color-bg-secondary: #0f172a;
  --color-bg-tertiary: #1e293b;
  --color-surface: rgba(15, 23, 42, 0.85);
  --color-surface-soft: rgba(15, 23, 42, 0.65);
  --color-border: rgba(148, 163, 184, 0.4);
  --color-border-strong: rgba(148, 163, 184, 0.7);
  --color-text-primary: #f8fafc;
  --color-text-secondary: #cbd5f5;
  --color-accent: #38bdf8;
  --color-accent-strong: #60a5fa;
  --color-success: #34d399;
  --color-danger: #fb7185;
  --radius-large: 24px;
  --radius-medium: 18px;
  --radius-small: 12px;
  --shadow-soft: 0 20px 45px rgba(3, 7, 18, 0.45);
  --shadow-hard: 0 30px 60px rgba(3, 7, 18, 0.65);
  --blur-amount: 18px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Inter', 'SF Pro Display', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: radial-gradient(circle at 20% 20%, rgba(56, 189, 248, 0.15), transparent 55%),
              radial-gradient(circle at 80% 0%, rgba(96, 165, 250, 0.18), transparent 50%),
              linear-gradient(160deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 55%, var(--color-bg-tertiary) 100%);
  color: var(--color-text-primary);
  min-height: 100vh;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(120deg, rgba(56, 189, 248, 0.08), rgba(99, 102, 241, 0.08));
  opacity: 0.6;
  z-index: 0;
}

a {
  color: inherit;
  text-decoration: none;
}

a:hover,
a:focus {
  text-decoration: none;
}

.site-shell {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 28px 64px;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: 40px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 16px;
  font-weight: 700;
  letter-spacing: -0.02em;
  font-size: 1.125rem;
  color: var(--color-text-primary);
}

.brand img {
  width: 40px;
  height: 40px;
  filter: drop-shadow(0 8px 16px rgba(59, 130, 246, 0.55));
}

.site-nav {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 6px;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.55);
  backdrop-filter: blur(16px);
  border: 1px solid rgba(148, 163, 184, 0.35);
  box-shadow: var(--shadow-soft);
}

.site-nav a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  color: rgba(226, 232, 240, 0.85);
  transition: all 0.25s ease;
  min-height: 44px;
}

.site-nav a:hover,
.site-nav a:focus {
  color: var(--color-text-primary);
  background: rgba(56, 189, 248, 0.18);
  box-shadow: 0 12px 25px rgba(34, 211, 238, 0.25);
}

.site-nav a.active {
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-strong));
  color: #0b1120;
  box-shadow: 0 12px 30px rgba(56, 189, 248, 0.38);
}

.site-main {
  background: var(--color-surface);
  border-radius: var(--radius-large);
  padding: 40px;
  border: 1px solid rgba(148, 163, 184, 0.35);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(var(--blur-amount));
}

.site-main section + section {
  margin-top: 42px;
}

.lede {
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  margin: 12px 0 28px;
  max-width: 680px;
}

.actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin: 32px 0 36px;
}

.action {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 20px;
  border-radius: 16px;
  border: 1px solid rgba(148, 163, 184, 0.35);
  color: var(--color-text-primary);
  background: rgba(15, 23, 42, 0.6);
  font-weight: 600;
  box-shadow: 0 14px 30px rgba(3, 7, 18, 0.45);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.action.primary {
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-strong));
  color: #020617;
  border-color: transparent;
}

.action:hover,
.action:focus {
  transform: translateY(-3px) scale(1.01);
  box-shadow: var(--shadow-hard);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  margin-top: 16px;
}

.card,
.surface-card {
  background: var(--color-surface-soft);
  border-radius: var(--radius-medium);
  padding: 24px;
  border: 1px solid rgba(148, 163, 184, 0.25);
  box-shadow: var(--shadow-soft);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover,
.surface-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hard);
}

.card h3,
.surface-card h3 {
  margin-top: 0;
  margin-bottom: 12px;
  font-size: 1.1rem;
  color: var(--color-text-primary);
}

.card p,
.surface-card p {
  margin: 0;
  color: var(--color-text-secondary);
}

.site-footer {
  margin-top: 56px;
  padding-top: 28px;
  border-top: 1px solid rgba(148, 163, 184, 0.3);
  font-size: 0.85rem;
  color: rgba(226, 232, 240, 0.65);
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
}

.site-footer nav {
  display: flex;
  gap: 16px;
}

.pill-group {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.18);
  color: var(--color-text-secondary);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.metric-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  margin-top: 20px;
}

.metric-card {
  padding: 18px 20px;
  border-radius: var(--radius-medium);
  background: linear-gradient(145deg, rgba(56, 189, 248, 0.15), rgba(59, 130, 246, 0.18));
  border: 1px solid rgba(148, 163, 184, 0.3);
  color: var(--color-text-primary);
  box-shadow: var(--shadow-soft);
}

.metric-card strong {
  display: block;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(226, 232, 240, 0.68);
}

.metric-card span {
  display: block;
  margin-top: 6px;
  font-size: 1.5rem;
  font-weight: 700;
}

.hero-grid {
  display: grid;
  gap: 32px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  align-items: center;
}

.hero-card {
  padding: 24px;
  border-radius: var(--radius-medium);
  background: rgba(15, 23, 42, 0.55);
  border: 1px solid rgba(148, 163, 184, 0.3);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(var(--blur-amount));
}

.hero-card h2 {
  margin: 0 0 12px;
  font-size: 1.35rem;
}

.hero-card p {
  margin: 0;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.stats-ring {
  display: flex;
  align-items: center;
  gap: 16px;
}

.stats-ring .value {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: conic-gradient(from 160deg, rgba(14, 165, 233, 0.65) 0%, rgba(56, 189, 248, 0.55) 70%, rgba(15, 23, 42, 0.4) 100%);
  color: #0b1120;
  font-size: 1.6rem;
  font-weight: 700;
  box-shadow: 0 14px 30px rgba(14, 165, 233, 0.35);
}

.stats-ring .label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.18);
  border: 1px solid rgba(56, 189, 248, 0.25);
  color: var(--color-text-primary);
  font-weight: 600;
  font-size: 0.8rem;
}

.surface-section {
  margin-top: 36px;
  padding: 32px;
  border-radius: var(--radius-large);
  background: rgba(15, 23, 42, 0.55);
  border: 1px solid rgba(148, 163, 184, 0.35);
  box-shadow: var(--shadow-soft);
}

.section-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
}

.section-title {
  font-size: 1.45rem;
  margin: 0;
  color: var(--color-text-primary);
}

.section-lede {
  color: var(--color-text-secondary);
  margin: 0;
  font-size: 0.95rem;
}

.strava-panel {
  display: grid;
  gap: 24px;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.3), rgba(2, 132, 199, 0.26));
  border-radius: var(--radius-large);
  padding: 32px;
  border: 1px solid rgba(56, 189, 248, 0.3);
  box-shadow: var(--shadow-soft);
}

.strava-panel h3 {
  margin: 0 0 12px;
  font-size: 1.35rem;
}

.strava-panel p {
  margin: 0;
  color: rgba(226, 232, 240, 0.76);
}

.strava-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.strava-actions button,
.manual-btn,
.strava-panel button {
  background: #0ea5e9;
  border: none;
  padding: 12px 20px;
  border-radius: var(--radius-small);
  color: #020617;
  font-weight: 600;
  cursor: pointer;
  box-shadow: var(--shadow-soft);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  min-height: 44px;
}

.manual-btn.secondary,
.strava-panel button.secondary {
  background: rgba(15, 23, 42, 0.7);
  color: var(--color-text-primary);
  border: 1px solid rgba(148, 163, 184, 0.3);
}

.strava-panel button:hover,
.manual-btn:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hard);
}

.manual-btn:first-of-type {
  margin-left: 0;
}

.stats-summary {
  display: none;
  margin-top: 28px;
  padding: 24px;
  border-radius: var(--radius-large);
  background: rgba(148, 163, 184, 0.12);
  border: 1px solid rgba(148, 163, 184, 0.25);
  box-shadow: var(--shadow-soft);
}

.sorting-controls {
  display: none;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 28px;
  padding: 18px 22px;
  border-radius: var(--radius-medium);
  background: rgba(15, 23, 42, 0.55);
  border: 1px solid rgba(148, 163, 184, 0.25);
}

.sorting-controls select,
.sorting-controls button,
.custom-workout-form input,
.custom-workout-form select,
#manualWorkoutForm input,
#manualWorkoutForm textarea {
  background: rgba(15, 23, 42, 0.75);
  color: var(--color-text-primary);
  border: 1px solid rgba(148, 163, 184, 0.35);
  border-radius: var(--radius-small);
  padding: 12px;
  font-size: 0.95rem;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  min-height: 44px;
}

.sorting-controls select:focus,
.custom-workout-form input:focus,
.custom-workout-form select:focus,
#manualWorkoutForm input:focus,
#manualWorkoutForm textarea:focus {
  outline: none;
  border-color: rgba(56, 189, 248, 0.65);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.18);
}

.sorting-controls button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: rgba(56, 189, 248, 0.2);
  color: var(--color-text-primary);
  cursor: pointer;
  font-weight: 600;
  border-radius: var(--radius-small);
}

.gap-item,
.session-item {
  background: rgba(15, 23, 42, 0.6);
  border-radius: var(--radius-medium);
  padding: 22px;
  border: 1px solid rgba(148, 163, 184, 0.25);
  box-shadow: var(--shadow-soft);
  margin-top: 18px;
}

.gap-item .gap-percent {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-accent);
  display: inline-block;
  margin-left: 12px;
}

.pace-comparison {
  margin-top: 12px;
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

#manualModal {
  display: none;
}

.modal {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(2, 6, 23, 0.65);
  backdrop-filter: blur(10px);
  z-index: 50;
}

.modal-content {
  background: rgba(15, 23, 42, 0.92);
  border-radius: var(--radius-large);
  width: min(520px, 92vw);
  border: 1px solid rgba(148, 163, 184, 0.3);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 28px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.22), rgba(96, 165, 250, 0.18));
  border-bottom: 1px solid rgba(148, 163, 184, 0.35);
}

.modal-header h2 {
  margin: 0;
  font-size: 1.35rem;
}

.close {
  color: var(--color-text-primary);
  font-size: 28px;
  cursor: pointer;
  opacity: 0.55;
  transition: opacity 0.2s ease;
}

.close:hover {
  opacity: 0.9;
}

.modal-body {
  padding: 28px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  color: var(--color-text-secondary);
}

.form-help {
  display: block;
  margin-top: 6px;
  color: rgba(226, 232, 240, 0.55);
  font-size: 0.8rem;
}

.form-actions {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
  margin-top: 24px;
}

.cancel-btn {
  background: rgba(148, 163, 184, 0.25);
  color: var(--color-text-primary);
  border: 1px solid rgba(148, 163, 184, 0.4);
}

.submit-btn {
  background: linear-gradient(135deg, var(--color-success), #10b981);
  color: #022c22;
  border: none;
}

.empty-state {
  text-align: center;
  color: var(--color-text-secondary);
  padding: 18px;
  border-radius: var(--radius-small);
  background: rgba(148, 163, 184, 0.12);
}

.loading {
  text-align: center;
  color: var(--color-text-secondary);
  padding: 24px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(30, 64, 175, 0.35);
  border: 1px solid rgba(99, 102, 241, 0.45);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: rgba(226, 232, 240, 0.72);
}

@media (max-width: 720px) {
  .site-shell {
    padding: 24px 16px 48px; /* Adjust padding for smaller screens */
  }

  .site-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .site-nav {
    width: 100%;
    justify-content: center;
    padding: 8px;
  }

  .site-nav a {
    padding: 8px 14px;
    font-size: 0.85rem;
  }

  .site-main {
    padding: 24px 18px;
  }

  .section-heading {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .section-title {
    font-size: 1.25rem;
  }

  .section-lede {
    font-size: 0.85rem;
  }

  .pill-group {
    justify-content: flex-start;
  }

  .strava-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .strava-actions button,
  .manual-btn {
    width: 100%;
    font-size: 1rem;
    padding: 14px 20px;
  }

  .sorting-controls {
    flex-direction: column;
    align-items: stretch;
    padding: 14px 18px;
  }

  .sorting-controls .sort-options,
  .sorting-controls .sort-direction {
    width: 100%;
  }

  .sorting-controls select,
  .sorting-controls button {
    width: 100%;
    padding: 10px;
  }

  .gap-item,
  .session-item {
    padding: 18px;
    margin-top: 14px;
  }

  .gap-item .gap-percent {
    font-size: 1.2rem;
  }

  .modal-content {
    width: 95vw;
  }

  .modal-header h2 {
    font-size: 1.2rem;
  }

  .form-group label {
    font-size: 0.9rem;
  }

  .form-help {
    font-size: 0.75rem;
  }

  .challenge-grid {
    grid-template-columns: 1fr; /* Single column on small screens */
  }

  .actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-grid {
    grid-template-columns: 1fr;
  }
}

/* Phones <= 480px */
@media (max-width: 480px) {
  .site-shell {
    padding: 24px calc(14px + env(safe-area-inset-right)) 48px calc(14px + env(safe-area-inset-left));
  }
  
  .site-main {
    padding: 20px 14px;
    border-radius: var(--radius-small);
  }
  
  .site-header { 
    gap: 12px; 
  }
  
  .site-nav {
    width: 100%;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
  }
  
  .site-nav a {
    flex: 1 1 auto;
    padding: 10px 12px;
  }
  
  .section-heading {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }
  
  .strava-actions { 
    flex-direction: column; 
  }
  
  .strava-actions button,
  .manual-btn { 
    width: 100%; 
    font-size: 1rem; 
    padding: 14px 18px; 
  }
  
  .sorting-controls { 
    flex-direction: column; 
    align-items: stretch; 
    gap: 10px; 
  }
  
  .sort-options, 
  .sort-direction { 
    width: 100%; 
  }
  
  .sort-direction button { 
    width: 100%; 
  }
  
  .cards { 
    grid-template-columns: 1fr; 
    gap: 16px; 
  }
  
  .metric-grid { 
    grid-template-columns: 1fr; 
  }
  
  .gap-item, 
  .surface-card { 
    padding: 16px; 
  }
  
  .gap-item .gap-percent { 
    font-size: 1.1rem; 
  }
  
  .custom-workout-form input,
  .custom-workout-form select,
  #manualWorkoutForm input,
  #manualWorkoutForm textarea { 
    font-size: 16px; 
  }
}

/* Small phones <= 360px */
@media (max-width: 360px) {
  .site-shell { 
    padding: 20px calc(12px + env(safe-area-inset-right)) 40px calc(12px + env(safe-area-inset-left)); 
  }
  
  .site-main { 
    padding: 16px 12px; 
  }
  
  .site-nav a { 
    padding: 10px 10px; 
    font-size: 0.9rem; 
  }
}