/* ═══════════════════════════════════════════════════════════
   Pool Volume — Calculator Component Styles
   These styles support the client-side calculator (app.js)
   ═══════════════════════════════════════════════════════════ */

/* ─── Pool Type Toggle ─────────────────────────────────── */
.pool-type-selector {
  display: flex; justify-content: center;
  padding: var(--space-xl) 0 0;
}
.pool-type-toggle {
  display: flex; background: var(--bg-tertiary);
  border-radius: var(--radius-full); padding: 3px;
  border: 1px solid var(--border-color);
}
.pool-type-toggle button {
  padding: 8px 24px; font-size: 0.88rem; font-weight: 600;
  border: none; border-radius: var(--radius-full);
  background: transparent; color: var(--text-secondary);
  cursor: pointer; transition: all var(--transition-fast); white-space: nowrap;
}
.pool-type-toggle button.active {
  background: hsl(210,80%,42%); color: #fff; box-shadow: var(--shadow-sm);
}
.pool-type-toggle button:hover:not(.active) { color: var(--text-primary); background: var(--bg-card-hover); }

/* Shape card wrapper (for tooltip positioning) */
.shape-card-wrapper { position: relative; }
.shape-card-wrapper .shape-card { width: 100%; }

/* Disabled shape card (above-ground mode) */
.shape-card.shape-disabled {
  opacity: 0.4; cursor: not-allowed;
  filter: grayscale(0.5); pointer-events: none;
  transition: opacity 0.3s ease, filter 0.3s ease;
}
.shape-card-wrapper:has(.shape-disabled) { pointer-events: auto; cursor: not-allowed; }

/* Tooltip for disabled shapes */
.shape-card-wrapper .shape-tooltip {
  display: none; position: absolute; bottom: calc(100% + 8px); left: 50%;
  transform: translateX(-50%); padding: 6px 12px;
  background: hsl(220,15%,20%); color: #fff;
  font-size: 0.72rem; font-weight: 500; white-space: nowrap;
  border-radius: var(--radius-sm); pointer-events: none;
  z-index: 10; box-shadow: var(--shadow-md);
}
.shape-card-wrapper .shape-tooltip::after {
  content: ''; position: absolute; top: 100%; left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent; border-top-color: hsl(220,15%,20%);
}
.shape-card-wrapper:has(.shape-disabled):hover .shape-tooltip { display: block; }

/* Above-ground depth info note */
.above-ground-depth-note {
  display: flex; align-items: flex-start; gap: 6px;
  margin-top: var(--space-xs); padding: 8px 12px;
  background: hsl(45,80%,95%); border: 1px solid hsl(45,60%,82%);
  border-radius: var(--radius-sm); font-size: 0.76rem;
  font-weight: 500; color: hsl(35,40%,35%); line-height: 1.45;
}
.above-ground-depth-note svg { width: 14px; height: 14px; flex-shrink: 0; color: hsl(35,60%,50%); margin-top: 1px; }
[data-theme="dark"] .above-ground-depth-note {
  background: hsl(45,30%,14%); border-color: hsl(45,25%,22%); color: hsl(45,25%,65%);
}
[data-theme="dark"] .above-ground-depth-note svg { color: hsl(45,40%,50%); }

/* Smooth transition for depth field changes */
.depth-section { transition: all 0.3s ease; }

/* ─── Shape Selector ───────────────────────────────────── */
.shape-selector { padding: var(--space-xl) 0 var(--space-md); }
.shape-selector-label {
  text-align: center; font-size: 0.85rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--text-secondary); margin-bottom: var(--space-md);
}
.shape-grid {
  display: grid; grid-template-columns: repeat(7, 1fr);
  gap: var(--space-sm); max-width: 920px; margin: 0 auto;
}
@media (max-width: 900px) { .shape-grid { grid-template-columns: repeat(4, 1fr); } }
@media (max-width: 600px) { .shape-grid { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 400px) { .shape-grid { grid-template-columns: repeat(2, 1fr); } }

.shape-card {
  display: flex; flex-direction: column; align-items: center;
  justify-content: center; gap: var(--space-sm);
  padding: var(--space-md) var(--space-sm);
  background: var(--bg-card); border: 2px solid var(--border-color);
  border-radius: var(--radius-md); cursor: pointer;
  transition: all var(--transition-base);
  box-shadow: var(--shadow-card); position: relative; overflow: hidden;
}
.shape-card::before {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(135deg, hsl(210,80%,52%), hsl(180,60%,48%));
  opacity: 0; transition: opacity var(--transition-base);
}
.shape-card:hover {
  border-color: hsl(205,85%,65%); transform: translateY(-2px);
  box-shadow: var(--shadow-md), var(--shadow-glow);
}
.shape-card.active {
  border-color: hsl(210,80%,52%); background: hsl(205,100%,96%);
  box-shadow: var(--shadow-md), 0 0 0 3px rgba(59,130,246,0.15);
}
[data-theme="dark"] .shape-card.active { background: var(--bg-card-hover); }
.shape-card svg {
  width: 44px; height: 44px; color: hsl(210,80%,52%);
  transition: transform var(--transition-base); position: relative; z-index: 1;
}
.shape-card:hover svg { transform: scale(1.08); }
.shape-card.active svg { color: hsl(210,80%,42%); }
.shape-card-label {
  font-size: 0.75rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.05em; color: var(--text-secondary);
  position: relative; z-index: 1; transition: color var(--transition-fast); text-align: center;
}
.shape-card.active .shape-card-label { color: hsl(210,85%,35%); }
[data-theme="dark"] .shape-card.active .shape-card-label { color: hsl(205,85%,65%); }

/* ─── Calculator Layout ────────────────────────────────── */
.calculator-section { padding: var(--space-lg) 0 var(--space-3xl); }
.calculator-layout {
  display: grid; grid-template-columns: 1fr 380px;
  gap: var(--space-xl); align-items: start;
  max-width: var(--max-width); margin: 0 auto;
}
@media (max-width: 960px) { .calculator-layout { grid-template-columns: 1fr; gap: var(--space-lg); } }

/* ─── Input Panel ──────────────────────────────────────── */
.input-panel {
  background: var(--bg-card); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md); border: 1px solid var(--border-color); overflow: hidden;
}
.input-panel-header {
  display: flex; align-items: center; gap: var(--space-sm);
  padding: var(--space-lg) var(--space-lg) var(--space-md); flex-wrap: wrap;
}
.input-panel-header svg { width: 24px; height: 24px; color: hsl(210,80%,52%); flex-shrink: 0; }
.input-panel-header h2 { font-size: 1.15rem; font-weight: 700; flex: 1; }

/* Unit toggle */
.unit-toggle {
  display: flex; background: var(--bg-tertiary);
  border-radius: var(--radius-full); padding: 3px;
  border: 1px solid var(--border-color);
}
.unit-toggle button {
  padding: 6px 16px; font-size: 0.82rem; font-weight: 600;
  border: none; border-radius: var(--radius-full);
  background: transparent; color: var(--text-secondary);
  cursor: pointer; transition: all var(--transition-fast); white-space: nowrap;
}
.unit-toggle button.active {
  background: hsl(210,80%,42%); color: #fff; box-shadow: var(--shadow-sm);
}
.unit-toggle button:hover:not(.active) { color: var(--text-primary); background: var(--bg-card-hover); }

/* Pool Diagram */
.pool-diagram {
  display: flex; justify-content: center; align-items: center;
  padding: var(--space-md) var(--space-lg); min-height: 180px;
}
.pool-diagram svg { width: 100%; max-width: 320px; height: auto; }

/* Dimension hint */
.dimension-hint {
  display: flex; align-items: center; gap: 6px;
  margin: 0 var(--space-lg); padding: 8px 12px;
  background: hsl(210,50%,96%); border: 1px solid hsl(210,40%,88%);
  border-radius: var(--radius-sm); font-size: 0.78rem;
  font-weight: 500; color: hsl(210,30%,42%); letter-spacing: 0.01em;
}
.dimension-hint svg { width: 14px; height: 14px; flex-shrink: 0; color: hsl(210,50%,60%); }
[data-theme="dark"] .dimension-hint {
  background: hsl(210,30%,14%); border-color: hsl(210,25%,22%); color: hsl(210,25%,65%);
}
[data-theme="dark"] .dimension-hint svg { color: hsl(210,40%,50%); }

/* Input Fields */
.input-fields {
  padding: 0 var(--space-lg) var(--space-xl);
  display: flex; flex-direction: column; gap: var(--space-md);
}
.input-group { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-md); }
@media (max-width: 500px) { .input-group { grid-template-columns: 1fr; } }
.input-group.full-width { grid-template-columns: 1fr; }

.field { display: flex; flex-direction: column; gap: var(--space-xs); }
.field label {
  font-size: 0.8rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--text-secondary);
}
.field label .unit-label { font-weight: 400; color: var(--text-tertiary); text-transform: none; letter-spacing: 0; }
.input-wrapper { position: relative; display: flex; align-items: center; }
.input-wrapper input {
  width: 100%; height: var(--input-height); padding: 0 var(--space-md);
  padding-right: 44px; font-size: 1rem; font-weight: 500;
  background: var(--bg-input); color: var(--text-primary);
  border: 2px solid var(--border-color); border-radius: var(--radius-sm);
  transition: all var(--transition-fast); outline: none;
  -moz-appearance: textfield; appearance: textfield;
}
.input-wrapper input::-webkit-inner-spin-button,
.input-wrapper input::-webkit-outer-spin-button { -webkit-appearance: none; margin: 0; }
.input-wrapper input::placeholder { color: var(--text-tertiary); font-weight: 400; }
.input-wrapper input:focus { border-color: var(--border-focus); box-shadow: 0 0 0 3px rgba(59,130,246,0.12); }
.input-wrapper input:hover:not(:focus) { border-color: hsl(210,12%,78%); }
.input-suffix {
  position: absolute; right: var(--space-md);
  font-size: 0.85rem; font-weight: 600; color: var(--text-tertiary); pointer-events: none;
}

/* Depth section */
.depth-section { margin-top: var(--space-sm); padding-top: var(--space-md); border-top: 1px solid var(--border-color); }
.depth-section-label {
  font-size: 0.75rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.08em; color: hsl(210,80%,52%);
  margin-bottom: var(--space-sm); display: flex; align-items: center; gap: var(--space-xs);
}
.depth-section-label svg { width: 16px; height: 16px; }

/* ─── Results Panel ────────────────────────────────────── */
.results-panel { position: sticky; top: 80px; }
@media (max-width: 960px) { .results-panel { position: static; } }

.results-card {
  background: var(--bg-result); border-radius: var(--radius-lg);
  overflow: hidden; box-shadow: var(--shadow-lg);
  transition: transform var(--transition-base);
}
.results-card-inner { padding: var(--space-xl); color: #fff; text-align: center; }
.results-label {
  font-size: 0.8rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.1em; color: rgba(255,255,255,0.7); margin-bottom: var(--space-sm);
}
.results-volume {
  font-family: var(--font-family-heading);
  font-size: clamp(2.5rem, 5vw, 3.5rem); font-weight: 800;
  letter-spacing: -0.03em; line-height: 1.1; margin-bottom: 4px;
  transition: transform var(--transition-base);
}
.results-volume.animate { animation: volumePop 0.4s cubic-bezier(0.16,1,0.3,1); }
@keyframes volumePop {
  0% { transform: scale(0.8); opacity: 0.5; }
  60% { transform: scale(1.05); }
  100% { transform: scale(1); opacity: 1; }
}
.results-unit-main {
  font-size: 1.1rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.08em; color: rgba(255,255,255,0.9); margin-bottom: var(--space-lg);
}
.results-secondary {
  display: flex; justify-content: center; gap: var(--space-lg);
  padding-top: var(--space-md); border-top: 1px solid rgba(255,255,255,0.15);
}
.results-secondary-item { text-align: center; }
.results-secondary-value { font-family: var(--font-family-heading); font-size: 1.2rem; font-weight: 700; }
.results-secondary-unit {
  font-size: 0.72rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.06em; color: rgba(255,255,255,0.65); margin-top: 2px;
}

/* Results Actions */
.results-actions {
  display: flex; gap: var(--space-sm);
  padding: var(--space-md) var(--space-xl); background: rgba(0,0,0,0.15);
}
.results-actions button {
  flex: 1; display: flex; align-items: center; justify-content: center; gap: 6px;
  padding: var(--space-sm); border: 1px solid rgba(255,255,255,0.2);
  border-radius: var(--radius-sm); background: rgba(255,255,255,0.08);
  color: rgba(255,255,255,0.85); font-size: 0.78rem; font-weight: 600;
  cursor: pointer; transition: all var(--transition-fast);
}
.results-actions button svg { width: 16px; height: 16px; }
.results-actions button:hover { background: rgba(255,255,255,0.18); color: #fff; }

/* Empty state */
.results-empty { text-align: center; padding: var(--space-2xl) var(--space-xl); color: rgba(255,255,255,0.6); }
.results-empty svg { width: 56px; height: 56px; margin: 0 auto var(--space-md); opacity: 0.4; color: #fff; }
.results-empty p { font-size: 0.9rem; }

/* Formula breakdown */
.formula-breakdown {
  background: var(--bg-card); border-radius: var(--radius-md);
  border: 1px solid var(--border-color); margin-top: var(--space-md); overflow: hidden;
}
.formula-toggle {
  width: 100%; display: flex; align-items: center; justify-content: space-between;
  padding: var(--space-md) var(--space-lg); border: none;
  background: transparent; color: var(--text-primary);
  font-size: 0.88rem; font-weight: 600; cursor: pointer;
  transition: background var(--transition-fast);
}
.formula-toggle:hover { background: var(--bg-tertiary); }
.formula-toggle svg { width: 18px; height: 18px; color: var(--text-tertiary); transition: transform var(--transition-base); }
.formula-toggle.open svg { transform: rotate(180deg); }
.formula-content { padding: 0 var(--space-lg) var(--space-lg); display: none; }
.formula-content.open { display: block; animation: fadeSlideIn 0.3s ease; }
@keyframes fadeSlideIn { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: translateY(0); } }
.formula-formula {
  background: var(--bg-secondary); border-radius: var(--radius-sm);
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-family-mono); font-size: 0.85rem;
  color: hsl(210,80%,42%); margin-bottom: var(--space-md); border: 1px solid var(--border-color);
}
[data-theme="dark"] .formula-formula { color: hsl(205,85%,65%); }
.formula-steps { list-style: none; display: flex; flex-direction: column; gap: var(--space-sm); }
.formula-steps li {
  display: flex; align-items: flex-start; gap: var(--space-sm);
  font-size: 0.85rem; color: var(--text-secondary);
  font-family: var(--font-family-mono); line-height: 1.5;
}
.formula-steps li::before { content: '→'; color: hsl(180,60%,48%); font-weight: 700; flex-shrink: 0; }

/* ─── Bonus Tools ──────────────────────────────────────── */
.bonus-tools-section { padding: var(--space-2xl) 0 var(--space-3xl); }
.bonus-tools-header { text-align: center; margin-bottom: var(--space-xl); }
.bonus-tools-header h2 { font-size: clamp(1.4rem, 3vw, 1.8rem); font-weight: 700; margin-bottom: var(--space-sm); }
.bonus-tools-header p { color: var(--text-secondary); max-width: 500px; margin: 0 auto; font-size: 0.95rem; }
.bonus-tools-grid,
#bonus-tools-container {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: var(--space-md); max-width: var(--max-width); margin: 0 auto;
}
@media (max-width: 500px) { .bonus-tools-grid, #bonus-tools-container { grid-template-columns: 1fr; } }

.bonus-tool-card {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: var(--radius-md); overflow: hidden;
  box-shadow: var(--shadow-card); transition: box-shadow var(--transition-base);
}
.bonus-tool-card:hover { box-shadow: var(--shadow-md); }
.bonus-tool-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--space-md) var(--space-lg); cursor: pointer;
  border: none; background: transparent; width: 100%;
  text-align: left; color: inherit; transition: background var(--transition-fast);
}
.bonus-tool-header:hover { background: var(--bg-tertiary); }
.bonus-tool-header-left { display: flex; align-items: center; gap: var(--space-sm); }
.bonus-tool-icon {
  width: 40px; height: 40px; border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.15rem; flex-shrink: 0;
}
.bonus-tool-icon.chemical { background: hsl(200,80%,92%); color: hsl(200,80%,40%); }
.bonus-tool-icon.fill { background: hsl(210,80%,92%); color: hsl(210,80%,40%); }
.bonus-tool-icon.cost { background: hsl(152,60%,92%); color: hsl(152,60%,35%); }
.bonus-tool-icon.pump { background: hsl(270,60%,93%); color: hsl(270,60%,45%); }
.bonus-tool-icon.heater { background: hsl(25,90%,92%); color: hsl(25,90%,45%); }
[data-theme="dark"] .bonus-tool-icon.chemical { background: hsl(200,50%,18%); color: hsl(200,70%,65%); }
[data-theme="dark"] .bonus-tool-icon.fill { background: hsl(210,50%,18%); color: hsl(210,70%,65%); }
[data-theme="dark"] .bonus-tool-icon.cost { background: hsl(152,40%,16%); color: hsl(152,55%,55%); }
[data-theme="dark"] .bonus-tool-icon.pump { background: hsl(270,40%,18%); color: hsl(270,55%,65%); }
[data-theme="dark"] .bonus-tool-icon.heater { background: hsl(25,55%,18%); color: hsl(25,75%,60%); }
.bonus-tool-title { font-size: 0.95rem; font-weight: 600; }
.bonus-tool-subtitle { font-size: 0.78rem; color: var(--text-tertiary); margin-top: 2px; }
.bonus-tool-chevron {
  width: 20px; height: 20px; color: var(--text-tertiary);
  transition: transform var(--transition-base); flex-shrink: 0;
}
.bonus-tool-card.open .bonus-tool-chevron { transform: rotate(180deg); }
.bonus-tool-body { padding: 0 var(--space-lg) var(--space-lg); display: none; }
.bonus-tool-card.open .bonus-tool-body { display: block; animation: fadeSlideIn 0.3s ease; }
.bonus-tool-body .input-group { margin-bottom: var(--space-md); }
.bonus-tool-result {
  background: var(--bg-secondary); border-radius: var(--radius-sm);
  padding: var(--space-md); margin-top: var(--space-md);
  border: 1px solid var(--border-color);
}
.bonus-tool-result p { font-size: 0.9rem; line-height: 1.7; color: var(--text-secondary); }
.bonus-tool-result strong { color: var(--text-primary); }
.bonus-tool-result .highlight { color: hsl(210,80%,42%); font-weight: 700; }
[data-theme="dark"] .bonus-tool-result .highlight { color: hsl(205,85%,65%); }

.preset-select {
  width: 100%; height: var(--input-height); padding: 0 var(--space-md);
  font-size: 0.9rem; background: var(--bg-input); color: var(--text-primary);
  border: 2px solid var(--border-color); border-radius: var(--radius-sm);
  cursor: pointer; transition: border-color var(--transition-fast); appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%239ca3af' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 12px center;
}
.preset-select:focus { border-color: var(--border-focus); outline: none; box-shadow: 0 0 0 3px rgba(59,130,246,0.12); }

/* ─── Tool Locked State ────────────────────────────────── */
.bonus-tool-locked { opacity: 0.55; pointer-events: none; }
.bonus-tool-locked .bonus-tool-header { cursor: not-allowed; }
.locked-badge {
  font-size: 0.7rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--text-tertiary);
  background: var(--bg-tertiary); padding: 2px 8px; border-radius: var(--radius-full);
}

/* ─── Pool Diagram Colors ──────────────────────────────── */
.pool-shape-fill { fill: hsl(200,80%,90%); stroke: hsl(200,70%,55%); stroke-width: 2; transition: all var(--transition-base); }
[data-theme="dark"] .pool-shape-fill { fill: hsl(200,50%,18%); stroke: hsl(200,60%,45%); }
.pool-dimension-label { font-family: var(--font-family-mono); font-size: 11px; fill: var(--text-secondary); font-weight: 600; }

/* ─── SEO Content Sections ─────────────────────────────── */
.content-section { padding: var(--space-3xl) 0; border-top: 1px solid var(--border-color); }
.content-section h2 { font-size: clamp(1.4rem, 3vw, 1.8rem); font-weight: 700; text-align: center; margin-bottom: var(--space-xl); }

/* Formulas Reference */
.formulas-intro { max-width: 800px; margin: 0 auto var(--space-xl); text-align: center; }
.formulas-intro p { font-size: 1rem; line-height: 1.8; color: var(--text-secondary); }
.formula-legend { margin-bottom: var(--space-xl); max-width: 700px; margin-left: auto; margin-right: auto; }
.formula-legend h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: var(--space-md); text-align: center; }
.legend-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: var(--space-sm); }
.legend-item {
  display: flex; align-items: center; gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-sm);
}
.legend-symbol { font-family: var(--font-family-mono); font-size: 1.1rem; font-weight: 700; color: hsl(210,80%,42%); min-width: 24px; text-align: center; }
[data-theme="dark"] .legend-symbol { color: hsl(205,85%,65%); }
.legend-desc { font-size: 0.85rem; color: var(--text-secondary); }

.formula-shapes-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: var(--space-lg); max-width: var(--max-width); margin: 0 auto;
}
@media (max-width: 500px) { .formula-shapes-grid { grid-template-columns: 1fr; } }
.formula-shape-card {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: var(--radius-md); overflow: hidden; box-shadow: var(--shadow-card);
}
.formula-shape-header {
  display: flex; align-items: center; gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  background: var(--bg-tertiary); border-bottom: 1px solid var(--border-color);
}
.formula-shape-icon { font-size: 1.3rem; line-height: 1; width: 32px; text-align: center; flex-shrink: 0; }
.formula-shape-header h3 { font-size: 1rem; font-weight: 700; margin: 0; }
.formula-shape-body { padding: var(--space-lg); }
.formula-shape-body p { font-size: 0.9rem; line-height: 1.7; color: var(--text-secondary); margin-bottom: var(--space-md); }
.formula-equation {
  background: var(--bg-secondary); border: 1px solid var(--border-color);
  border-radius: var(--radius-sm); padding: var(--space-sm) var(--space-md);
  font-family: var(--font-family-mono); font-size: 0.95rem; font-weight: 600;
  color: hsl(210,80%,42%); margin-bottom: var(--space-md); text-align: center; letter-spacing: 0.01em;
}
[data-theme="dark"] .formula-equation { color: hsl(205,85%,65%); }
.formula-example {
  background: var(--bg-secondary); border-radius: var(--radius-sm);
  padding: var(--space-md); font-size: 0.88rem; line-height: 1.7;
  color: var(--text-secondary); border-left: 3px solid hsl(180,60%,48%);
}
.formula-example ul, .formula-example ol { margin: var(--space-sm) 0 0 var(--space-lg); }
.formula-example li { margin-bottom: 4px; }
.formula-example strong { color: var(--text-primary); }

/* Guide Columns */
.guide-columns {
  display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-xl);
  max-width: var(--max-width); margin: 0 auto;
}
@media (max-width: 768px) { .guide-columns { grid-template-columns: 1fr; gap: var(--space-lg); } }
.guide-block {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: var(--radius-md); padding: var(--space-xl); box-shadow: var(--shadow-card);
}
.guide-block h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: var(--space-md); }
.guide-block h4 { font-size: 0.95rem; font-weight: 700; margin-top: var(--space-lg); margin-bottom: var(--space-sm); color: hsl(210,80%,42%); }
[data-theme="dark"] .guide-block h4 { color: hsl(205,85%,65%); }
.guide-block p { font-size: 0.9rem; line-height: 1.7; color: var(--text-secondary); margin-bottom: var(--space-sm); }
.guide-block ol, .guide-block ul { margin: var(--space-sm) 0 var(--space-md) var(--space-lg); }
.guide-block li { font-size: 0.9rem; line-height: 1.7; color: var(--text-secondary); margin-bottom: 4px; }

.guide-reasons {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md); margin-top: var(--space-md);
}
.guide-reason {
  display: flex; gap: var(--space-md); padding: var(--space-md);
  background: var(--bg-secondary); border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}
.guide-reason-icon { font-size: 1.5rem; flex-shrink: 0; line-height: 1; margin-top: 2px; }
.guide-reason strong { font-size: 0.95rem; display: block; margin-bottom: 4px; color: var(--text-primary); }
.guide-reason p { font-size: 0.85rem; line-height: 1.6; color: var(--text-secondary); margin: 0; }

/* Conversion Reference */
.conversion-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-lg); max-width: var(--max-width); margin: 0 auto;
}
.conversion-group {
  background: var(--bg-card); border: 1px solid var(--border-color);
  border-radius: var(--radius-md); padding: var(--space-lg); box-shadow: var(--shadow-card);
}
.conversion-group h3 {
  font-size: 1rem; font-weight: 700; margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm); border-bottom: 2px solid hsl(205,95%,90%);
}
[data-theme="dark"] .conversion-group h3 { border-bottom-color: var(--border-color); }
.conversion-table { width: 100%; border-collapse: collapse; font-size: 0.88rem; }
.conversion-table td { padding: 6px 4px; border-bottom: 1px solid var(--border-color); color: var(--text-secondary); }
.conversion-table td:nth-child(2) { text-align: center; color: var(--text-tertiary); font-weight: 600; width: 24px; }
.conversion-table td:nth-child(3) { text-align: right; }
.conversion-table td:nth-child(3) strong { color: var(--text-primary); }
.conversion-table tr:last-child td { border-bottom: none; }
.conversion-note { font-size: 0.88rem; line-height: 1.7; color: var(--text-secondary); }

/* ─── Stagger Animation ───────────────────────────────── */
@keyframes slideUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.stagger > * { animation: slideUp 0.4s cubic-bezier(0.16,1,0.3,1) both; }
.stagger > *:nth-child(1) { animation-delay: 0ms; }
.stagger > *:nth-child(2) { animation-delay: 50ms; }
.stagger > *:nth-child(3) { animation-delay: 100ms; }
.stagger > *:nth-child(4) { animation-delay: 150ms; }
.stagger > *:nth-child(5) { animation-delay: 200ms; }
.stagger > *:nth-child(6) { animation-delay: 250ms; }
.stagger > *:nth-child(7) { animation-delay: 300ms; }

/* ─── Print Styles ─────────────────────────────────────── */
@media print {
  .site-header, .hero, .pool-type-selector, .shape-selector, .bonus-tools-section,
  .content-section, .site-footer, .results-actions, .theme-toggle,
  .unit-toggle { display: none !important; }
  body { background: #fff; color: #000; }
  .calculator-layout { display: block; }
  .results-card { background: #fff !important; color: #000 !important; box-shadow: none !important; border: 2px solid #000; }
  .results-card-inner { color: #000 !important; }
}