:root {
  --bg-main: #090d16;
  --bg-card: #121826;
  --bg-card-elevated: #1a2234;
  --bg-input: #0d1320;
  --border-color: #243049;
  --text-primary: #f3f6fc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #10b981;
  --accent-hover: #059669;
  --accent-soft: rgba(16, 185, 129, 0.14);
  --blue: #3b82f6;
  --blue-soft: rgba(59, 130, 246, 0.15);
  --amber: #f59e0b;
  --amber-soft: rgba(245, 158, 11, 0.15);
  --danger: #ef4444;
  --danger-soft: rgba(239, 68, 68, 0.15);
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  background-color: var(--bg-main);
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Sukhumvit Set", "Prompt", "Kanit", sans-serif;
  font-size: 16px;
  line-height: 1.45;
  overscroll-behavior-y: none;
  min-height: 100vh;
}

.app-shell {
  max-width: 480px;
  margin: 0 auto;
  padding-top: max(14px, env(safe-area-inset-top));
  padding-bottom: calc(88px + env(safe-area-inset-bottom));
  padding-left: 16px;
  padding-right: 16px;
}

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

.btn-sync-pill {
  background: var(--bg-card-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 7px 11px;
  border-radius: var(--radius-md);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
  transition: all 0.15s ease;
}

.btn-sync-pill:active {
  background: var(--accent-soft);
  border-color: var(--accent);
}

/* Header */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, #10b981, #047857);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.25);
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand-sub {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.date-picker-wrap {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 6px 10px;
  border-radius: var(--radius-md);
}

.date-input {
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 600;
  font-family: inherit;
  outline: none;
}

.date-input::-webkit-calendar-picker-indicator {
  filter: invert(1);
  opacity: 0.75;
}

/* Cards */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 16px;
  margin-bottom: 14px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.22);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.card-title {
  font-size: 0.98rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Muscle Category Pills */
.category-scroll {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: 10px;
  scrollbar-width: none;
}
.category-scroll::-webkit-scrollbar {
  display: none;
}

.cat-pill {
  flex-shrink: 0;
  padding: 7px 13px;
  border-radius: 999px;
  background: var(--bg-card-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.cat-pill.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #04130d;
  font-weight: 700;
}

/* Search & Exercise Selector */
.search-row {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
}

.input-field {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 11px 13px;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-family: inherit;
  outline: none;
  transition: border-color 0.15s;
}

.input-field:focus {
  border-color: var(--accent);
}

.exercise-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  max-height: 156px;
  overflow-y: auto;
  padding: 2px 0;
}

.ex-chip {
  padding: 8px 12px;
  border-radius: var(--radius-md);
  background: var(--bg-card-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s;
}

.ex-chip .ex-cat-tag {
  font-size: 0.68rem;
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.06);
  padding: 2px 6px;
  border-radius: 6px;
}

.ex-chip.selected {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: #34d399;
  font-weight: 700;
}

/* Previous Session Banner */
.prev-stats-banner {
  background: linear-gradient(145deg, rgba(59, 130, 246, 0.14), rgba(16, 185, 129, 0.1));
  border: 1px solid rgba(59, 130, 246, 0.38);
  border-radius: var(--radius-md);
  padding: 12px;
  margin-top: 12px;
  margin-bottom: 14px;
}

.prev-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.prev-title {
  font-size: 0.82rem;
  font-weight: 700;
  color: #60a5fa;
  display: flex;
  align-items: center;
  gap: 5px;
}

.prev-date {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.prev-sets-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.prev-set-pill {
  background: rgba(15, 23, 42, 0.75);
  border: 1px solid rgba(148, 163, 184, 0.22);
  border-radius: 8px;
  padding: 5px 9px;
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  gap: 6px;
}

.prev-pr-row {
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px dashed rgba(148, 163, 184, 0.2);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: #fbbf24;
}

.btn-copy-prev {
  background: rgba(59, 130, 246, 0.22);
  border: 1px solid rgba(59, 130, 246, 0.5);
  color: #93c5fd;
  padding: 4px 9px;
  border-radius: 6px;
  font-size: 0.74rem;
  font-weight: 600;
  cursor: pointer;
}

/* Set Input Form */
.set-inputs-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 12px;
}

.input-group label {
  display: block;
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-bottom: 5px;
  font-weight: 600;
}

.stepper-wrap {
  display: flex;
  align-items: center;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.stepper-btn {
  width: 40px;
  height: 44px;
  background: var(--bg-card-elevated);
  border: none;
  color: var(--text-primary);
  font-size: 1.15rem;
  font-weight: 700;
  cursor: pointer;
  flex-shrink: 0;
}

.stepper-btn:active {
  background: var(--accent);
  color: #000;
}

.stepper-input {
  width: 100%;
  background: transparent;
  border: none;
  color: var(--text-primary);
  text-align: center;
  font-size: 1.1rem;
  font-weight: 700;
  font-family: inherit;
  outline: none;
  min-width: 0;
}

/* RPE 1-10 Selector */
.rpe-section {
  margin-bottom: 14px;
}

.rpe-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 7px;
}

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

.rpe-desc {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent);
}

.rpe-grid {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 4px;
}

.rpe-btn {
  height: 38px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: var(--bg-input);
  color: var(--text-secondary);
  font-weight: 700;
  font-size: 0.86rem;
  cursor: pointer;
  transition: all 0.12s;
}

.rpe-btn.active {
  transform: translateY(-2px);
  color: #081018;
  border-color: transparent;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.35);
}

.rpe-btn[data-rpe="1"].active,
.rpe-btn[data-rpe="2"].active,
.rpe-btn[data-rpe="3"].active,
.rpe-btn[data-rpe="4"].active {
  background: #34d399;
}
.rpe-btn[data-rpe="5"].active,
.rpe-btn[data-rpe="6"].active {
  background: #a3e635;
}
.rpe-btn[data-rpe="7"].active,
.rpe-btn[data-rpe="8"].active {
  background: #fbbf24;
}
.rpe-btn[data-rpe="9"].active {
  background: #fb923c;
}
.rpe-btn[data-rpe="10"].active {
  background: #f87171;
  color: #fff;
}

/* Primary Buttons */
.btn-primary {
  width: 100%;
  padding: 13px;
  border-radius: var(--radius-md);
  border: none;
  background: linear-gradient(135deg, #10b981, #059669);
  color: #03150e;
  font-size: 0.96rem;
  font-weight: 800;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.28);
}

.btn-primary:active {
  transform: scale(0.99);
}

.btn-secondary {
  background: var(--bg-card-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 10px 14px;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
}

/* Today's Logged Exercises */
.workout-ex-block {
  background: var(--bg-card-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px;
  margin-bottom: 10px;
}

.workout-ex-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.workout-ex-name {
  font-weight: 700;
  font-size: 0.95rem;
  color: #34d399;
  cursor: pointer;
}

.sets-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}

.sets-table th {
  text-align: left;
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.73rem;
  padding-bottom: 6px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.sets-table td {
  padding: 7px 2px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.rpe-badge {
  display: inline-block;
  padding: 2px 7px;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 700;
}

.btn-del-set {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  cursor: pointer;
  padding: 2px 6px;
}
.btn-del-set:hover {
  color: var(--danger);
}

/* Stats Summary Grid */
.stats-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-bottom: 14px;
}

.stat-box {
  background: var(--bg-card-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px;
  text-align: center;
}

.stat-value {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--accent);
}

.stat-label {
  font-size: 0.72rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* Chart Container */
.chart-wrap {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px;
  margin-bottom: 14px;
}

.chart-tabs {
  display: flex;
  gap: 6px;
  margin-bottom: 10px;
}

.chart-tab {
  flex: 1;
  padding: 6px;
  font-size: 0.76rem;
  font-weight: 600;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  border-radius: 8px;
  cursor: pointer;
}

.chart-tab.active {
  background: var(--blue-soft);
  border-color: var(--blue);
  color: #93c5fd;
}

canvas#progressChart {
  width: 100%;
  height: 190px;
  display: block;
}

/* Bottom Navigation Bar (iPhone Tab Bar style) */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(12, 17, 29, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-around;
  padding-top: 8px;
  padding-bottom: max(10px, env(safe-area-inset-bottom));
  z-index: 100;
}

.nav-item {
  background: none;
  border: none;
  color: var(--text-muted);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  font-size: 0.72rem;
  font-weight: 600;
  cursor: pointer;
  flex: 1;
}

.nav-item .nav-icon {
  font-size: 1.25rem;
}

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

/* Modal */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.72);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 18px;
  z-index: 200;
}

.modal-backdrop.open {
  display: flex;
}

.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 400px;
  padding: 18px;
}

.empty-state {
  text-align: center;
  padding: 24px 12px;
  color: var(--text-muted);
  font-size: 0.88rem;
}

.toast {
  position: fixed;
  top: max(16px, env(safe-area-inset-top));
  left: 50%;
  transform: translateX(-50%) translateY(-80px);
  background: #10b981;
  color: #03150e;
  font-weight: 700;
  font-size: 0.86rem;
  padding: 10px 18px;
  border-radius: 999px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.45);
  transition: transform 0.25s cubic-bezier(0.18, 0.89, 0.32, 1.28);
  z-index: 300;
  pointer-events: none;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
}

/* iPad & Tablet Responsive Layout (Portrait & Landscape) */
@media (min-width: 768px) {
  .app-shell {
    max-width: 1060px;
    padding-top: max(22px, env(safe-area-inset-top));
    padding-bottom: calc(110px + env(safe-area-inset-bottom));
    padding-left: 28px;
    padding-right: 28px;
  }

  .app-header {
    margin-bottom: 22px;
    padding-bottom: 14px;
  }

  .brand-icon {
    width: 44px;
    height: 44px;
    font-size: 22px;
  }

  .brand-title {
    font-size: 1.35rem;
  }

  .brand-sub {
    font-size: 0.84rem;
  }

  .ipad-split-grid {
    display: grid;
    grid-template-columns: 1.12fr 0.88fr;
    gap: 20px;
    align-items: start;
  }

  .ipad-sticky-card {
    position: sticky;
    top: 20px;
    max-height: calc(100vh - 130px);
    overflow-y: auto;
  }

  .days-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
  }

  .days-grid .workout-ex-block {
    margin-bottom: 0;
  }

  .settings-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
    align-items: start;
  }

  .settings-grid .card {
    margin-bottom: 0;
  }

  .exercise-chips {
    max-height: 210px;
  }

  canvas#progressChart {
    height: 270px;
  }

  .bottom-nav {
    max-width: 560px;
    width: calc(100% - 48px);
    left: 0;
    right: 0;
    margin: 0 auto;
    bottom: max(14px, env(safe-area-inset-bottom));
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 10px 14px;
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.55);
  }
}