/* ========================================
   Design Tokens & CSS Custom Properties
   ======================================== */
:root {
  /* Color Palette from PRD */
  --azure-mist: #cddddd;
  --graphite: #2e2f2f;
  --pastel-petal: #f4cae0ff;
  --turquoise: #55d6beff;
  --aquamarine: #acfcd9ff;
  --blue-bell: #058ed9ff;

  /* Extended palette */
  --pastel-petal-dark: #e8b0c9;
  --pastel-petal-light: #f9dfe9;
  --white: #ffffff;
  --shadow-soft: rgba(46, 47, 47, 0.08);
  --shadow-medium: rgba(46, 47, 47, 0.15);
  --shadow-strong: rgba(46, 47, 47, 0.25);

  /* Typography */
  --font-display: 'Playfair Display', Georgia, serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 12px;
  --space-lg: 16px;
  --space-xl: 24px;
  --space-2xl: 32px;

  /* Borders */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-medium: 0.25s ease;
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========================================
   Reset & Base Styles
   ======================================== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font-body);
  color: var(--graphite);
  background: var(--azure-mist);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

#root {
  height: 100%;
}

/* ========================================
   App Layout
   ======================================== */
.app-container {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* ========================================
   Main Visualization Area
   ======================================== */
.main-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
  min-width: 0;
}

/* Title */
.graph-title {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3.5vw, 3rem);
  font-weight: 700;
  color: var(--graphite);
  text-align: center;
  padding: var(--space-lg) var(--space-xl);
  letter-spacing: 0.02em;
  position: relative;
  z-index: 2;
  text-shadow: 0 1px 2px rgba(255, 255, 255, 0.5);
}

/* Graph container */
.graph-container {
  flex: 1;
  position: relative;
  overflow: hidden;
  padding: 0 var(--space-xl) var(--space-xl);
  display: flex;
  flex-direction: row;
  gap: var(--space-lg);
}

.graph-plane-area {
  flex: 1;
  min-width: 0;
  display: flex;
}

.graph-svg-wrapper {
  width: 100%;
  height: 100%;
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: inset 0 0 0 1px rgba(46, 47, 47, 0.1);
}

.graph-svg-wrapper svg {
  display: block;
  width: 100%;
  height: 100%;
}

/* ========================================
   Home Page
   ======================================== */
.home-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-2xl);
  text-align: center;
  animation: fadeInUp 0.8s ease forwards;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.home-title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  color: var(--graphite);
  margin-bottom: var(--space-lg);
  line-height: 1.1;
}

.home-subtitle {
  font-size: 1.15rem;
  font-weight: 300;
  color: var(--graphite);
  opacity: 0.7;
  max-width: 560px;
  line-height: 1.7;
  margin-bottom: var(--space-2xl);
}

.home-formula {
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--blue-bell);
  margin-bottom: var(--space-2xl);
  font-family: var(--font-display);
  letter-spacing: 0.03em;
}

.cta-button {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-lg) var(--space-2xl);
  background: linear-gradient(135deg, var(--turquoise), var(--blue-bell));
  color: white;
  border: none;
  border-radius: var(--radius-xl);
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-medium);
  box-shadow: 0 4px 20px rgba(5, 142, 217, 0.3);
  letter-spacing: 0.02em;
}

.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(5, 142, 217, 0.4);
}

.cta-button:active {
  transform: translateY(0);
}

.cta-button svg {
  transition: transform var(--transition-fast);
}

.cta-button:hover svg {
  transform: translateX(3px);
}

/* Feature cards */
.feature-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  margin-top: var(--space-2xl);
  max-width: 700px;
  width: 100%;
}

.feature-card {
  background: rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  border: 1px solid rgba(255, 255, 255, 0.6);
  transition: all var(--transition-medium);
}

.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px var(--shadow-soft);
}

.feature-card-icon {
  font-size: 1.6rem;
  margin-bottom: var(--space-sm);
}

.feature-card-title {
  font-weight: 600;
  font-size: 0.85rem;
  margin-bottom: var(--space-xs);
}

.feature-card-desc {
  font-size: 0.75rem;
  opacity: 0.6;
  line-height: 1.4;
}

/* ========================================
   Side Panel
   ======================================== */
.side-panel {
  width: 310px;
  min-width: 310px;
  max-width: 310px;
  background: var(--pastel-petal);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: -4px 0 20px var(--shadow-soft);
  position: relative;
  z-index: 10;
}

.panel-header {
  padding: var(--space-lg) var(--space-lg) var(--space-md);
  border-bottom: 1px solid var(--pastel-petal-dark);
}

.panel-header h2 {
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--graphite);
}

/* Subtabs */
.subtabs {
  display: flex;
  gap: 2px;
  padding: var(--space-sm) var(--space-lg) 0;
}

.subtab {
  flex: 1;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--pastel-petal-dark);
  background: var(--pastel-petal-light);
  color: var(--graphite);
  font-family: var(--font-body);
  font-size: 0.72rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  text-align: center;
}

.subtab.active {
  background: var(--white);
  border-bottom-color: var(--white);
  font-weight: 600;
  box-shadow: 0 -2px 6px var(--shadow-soft);
}

.subtab:hover:not(.active) {
  background: rgba(255, 255, 255, 0.5);
}

/* Panel Body */
.panel-body {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-md) var(--space-lg) var(--space-lg);
  scrollbar-width: thin;
  scrollbar-color: var(--pastel-petal-dark) transparent;
}

.panel-body::-webkit-scrollbar {
  width: 5px;
}

.panel-body::-webkit-scrollbar-track {
  background: transparent;
}

.panel-body::-webkit-scrollbar-thumb {
  background: var(--pastel-petal-dark);
  border-radius: 10px;
}

/* Calculator Sections */
.calc-section {
  margin-bottom: var(--space-md);
  border: 1px solid var(--pastel-petal-dark);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.25);
  overflow: hidden;
  transition: all var(--transition-medium);
}

.calc-section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-sm) var(--space-md);
  cursor: pointer;
  user-select: none;
  transition: background var(--transition-fast);
}

.calc-section-header:hover {
  background: rgba(255, 255, 255, 0.3);
}

.calc-section-header h3 {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--graphite);
  letter-spacing: 0.01em;
}

.collapse-icon {
  font-size: 0.7rem;
  transition: transform var(--transition-medium);
  color: var(--graphite);
  opacity: 0.6;
}

.collapse-icon.collapsed {
  transform: rotate(180deg);
}

.calc-section-body {
  padding: 0 var(--space-md) var(--space-md);
  animation: slideDown 0.25s ease;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.calc-section-body.hidden {
  display: none;
}

/* Input Groups */
.input-row {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

.input-group {
  flex: 1;
}

.input-group label {
  display: block;
  font-size: 0.68rem;
  font-weight: 500;
  color: var(--graphite);
  opacity: 0.7;
  margin-bottom: 3px;
}

.input-group input {
  width: 100%;
  padding: var(--space-sm) var(--space-sm);
  border: 1px solid var(--pastel-petal-dark);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.8rem;
  color: var(--graphite);
  background: var(--white);
  transition: all var(--transition-fast);
  outline: none;
}

.input-group input:focus {
  border-color: var(--blue-bell);
  box-shadow: 0 0 0 3px rgba(5, 142, 217, 0.12);
}

.input-group input::placeholder {
  color: var(--graphite);
  opacity: 0.3;
}

/* Select */
.input-group select {
  width: 100%;
  padding: var(--space-sm);
  border: 1px solid var(--pastel-petal-dark);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.8rem;
  color: var(--graphite);
  background: var(--white);
  cursor: pointer;
  outline: none;
  transition: all var(--transition-fast);
}

.input-group select:focus {
  border-color: var(--blue-bell);
  box-shadow: 0 0 0 3px rgba(5, 142, 217, 0.12);
}

/* Action Buttons */
.calc-btn {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  background: var(--white);
  color: var(--graphite);
  border: 1px solid var(--pastel-petal-dark);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-top: var(--space-xs);
}

.calc-btn:hover {
  background: var(--graphite);
  color: var(--white);
  border-color: var(--graphite);
  transform: translateY(-1px);
  box-shadow: 0 2px 8px var(--shadow-medium);
}

.calc-btn:active {
  transform: translateY(0);
}

/* Result Messages */
.result-message {
  margin-top: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 500;
  line-height: 1.5;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

.result-message.success {
  background: rgba(172, 252, 217, 0.4);
  border: 1px solid var(--turquoise);
  color: #1a6b4f;
}

.result-message.error {
  background: rgba(244, 202, 224, 0.6);
  border: 1px solid var(--pastel-petal-dark);
  color: #8b3a62;
}

.result-message.info {
  background: rgba(5, 142, 217, 0.08);
  border: 1px solid rgba(5, 142, 217, 0.3);
  color: var(--blue-bell);
}

/* Settings Section */
.settings-section {
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--pastel-petal-dark);
}

.settings-section h3 {
  font-size: 0.78rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--graphite);
}

.settings-row {
  display: flex;
  gap: var(--space-md);
}

/* Footer timestamp */
.panel-footer {
  padding: var(--space-sm) var(--space-lg);
  text-align: right;
  font-size: 0.65rem;
  color: var(--graphite);
  opacity: 0.5;
  border-top: 1px solid var(--pastel-petal-dark);
  font-weight: 500;
}

/* ========================================
   SVG Graph Styles
   ======================================== */
.graph-grid-line {
  stroke: var(--graphite);
  stroke-width: 0.3;
  opacity: 0.15;
}

.graph-axis-line {
  stroke: var(--graphite);
  stroke-width: 1;
  opacity: 0.4;
}

.graph-tick-label {
  font-family: var(--font-body);
  font-size: 10px;
  fill: var(--graphite);
  opacity: 0.5;
  user-select: none;
}

/* Triangles */
.triangle-shape {
  stroke-width: 2;
  stroke-linejoin: round;
  transition: opacity var(--transition-medium);
}

.triangle-label {
  font-family: var(--font-body);
  font-size: 12px;
  font-weight: 600;
  fill: var(--graphite);
  text-anchor: middle;
}

/* Draggable shape groups */
.draggable-shape {
  transition: transform 0.2s cubic-bezier(0.4, 0, 0.2, 1),
    filter 0.2s ease;
  cursor: grab;
}

.draggable-shape:hover:not(.dragging) .triangle-shape {
  filter: drop-shadow(0 2px 6px rgba(46, 47, 47, 0.18));
  fill-opacity: 0.65;
}

.draggable-shape.dragging {
  transition: none;
  /* no transition while actively moving */
  cursor: grabbing;
  filter: drop-shadow(0 4px 12px rgba(46, 47, 47, 0.3));
}

.draggable-shape.dragging .triangle-shape {
  fill-opacity: 0.7;
  stroke-width: 3;
}

.draggable-shape.selected .triangle-shape {
  filter: drop-shadow(0 0 8px rgba(5, 142, 217, 0.35));
}

/* ========================================
   Triangle Info Panel
   ======================================== */
.tri-info-panel {
  width: 280px;
  min-width: 280px;
  background: rgba(255, 255, 255, 0.55);
  backdrop-filter: blur(12px);
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.6);
  box-shadow: 0 4px 20px var(--shadow-soft);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  padding: var(--space-lg);
  animation: fadeIn 0.3s ease;
  scrollbar-width: thin;
  scrollbar-color: rgba(46, 47, 47, 0.15) transparent;
  order: -1;
}

.tri-info-panel::-webkit-scrollbar {
  width: 4px;
}

.tri-info-panel::-webkit-scrollbar-thumb {
  background: rgba(46, 47, 47, 0.15);
  border-radius: 10px;
}

.tri-info-empty {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  opacity: 0.5;
  gap: var(--space-sm);
}

.tri-info-empty-icon {
  font-size: 2rem;
  margin-bottom: var(--space-xs);
}

.tri-info-empty p {
  font-size: 0.82rem;
  line-height: 1.6;
  max-width: 180px;
}

.tri-info-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid rgba(46, 47, 47, 0.1);
}

.tri-info-swatch {
  width: 14px;
  height: 14px;
  border-radius: 3px;
  border: 1px solid rgba(46, 47, 47, 0.15);
  flex-shrink: 0;
}

.tri-info-header h3 {
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--graphite);
}

.tri-info-section {
  margin-bottom: var(--space-md);
}

.tri-info-section h4 {
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--graphite);
  opacity: 0.55;
  margin-bottom: var(--space-xs);
}

.tri-info-table {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.tri-info-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 5px 8px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.5);
  transition: background var(--transition-fast);
}

.tri-info-row:hover {
  background: rgba(255, 255, 255, 0.8);
}

.tri-info-label {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--graphite);
  opacity: 0.75;
}

.tri-info-value {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--graphite);
  font-variant-numeric: tabular-nums;
}

.tri-info-highlight {
  color: var(--blue-bell);
  font-weight: 700;
}

/* Rotation Buttons */
.rotation-buttons {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

.rotation-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  background: var(--turquoise);
  color: var(--graphite);
  border: 1px solid var(--turquoise);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: normal;
  text-align: center;
  line-height: 1.2;
}

.rotation-btn:hover {
  background: var(--graphite);
  color: var(--azure-mist);
  border-color: var(--graphite);
  transform: translateY(-1px);
  box-shadow: 0 2px 8px var(--shadow-medium);
}

.rotation-btn:active {
  transform: translateY(0);
}

.rotation-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.rotation-btn svg {
  flex-shrink: 0;
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 900px) {
  .app-container {
    flex-direction: column;
  }

  .side-panel {
    width: 100%;
    min-width: 100%;
    max-width: 100%;
    max-height: 50vh;
    box-shadow: 0 -4px 20px var(--shadow-soft);
  }

  .graph-container {
    flex-direction: column;
  }

  .tri-info-panel {
    width: 100%;
    min-width: 100%;
    max-height: 140px;
    order: 1;
  }

  .feature-cards {
    grid-template-columns: 1fr;
    max-width: 300px;
  }
}

/* Radio toggle for 45-45-90 */
.radio-row {
  display: flex;
  gap: var(--space-md);
  margin-bottom: var(--space-sm);
}

.radio-option {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  cursor: pointer;
  font-size: 0.73rem;
  font-weight: 500;
}

.radio-option input[type="radio"] {
  accent-color: var(--blue-bell);
  cursor: pointer;
}

/* ========================================
   Themes
   ======================================== */
[data-theme="olive-wood"] {
  --azure-mist: #fefae0ff;
  --graphite: #283618ff;
  --pastel-petal: #dda15eff;
  --turquoise: #606c38ff;
  --aquamarine: #dda15eff;
  --blue-bell: #bc6c25ff;
  --pastel-petal-dark: #bc6c25ff;
  --pastel-petal-light: #fefae0ff;
}

[data-theme="ocean-blue"] {
  --azure-mist: #4cc9f0ff;
  --graphite: #3a0ca3ff;
  --pastel-petal: #8543ee;
  --turquoise: #4361eeff;
  --aquamarine: #7209b7ff;
  --blue-bell: #626eef;
  --pastel-petal-dark: #7209b7ff;
  --pastel-petal-light: #4cc9f0ff;
}

[data-theme="modern-palette"] {
  --azure-mist: #e8eddfff;
  --graphite: #242423ff;
  --pastel-petal: #cfdbd5ff;
  --turquoise: #f5cb5cff;
  --aquamarine: #333533ff;
  --blue-bell: #f0d99b;
  --pastel-petal-dark: #333533;
  --pastel-petal-light: #e8eddfff;
}

[data-theme="watermelon-sugar"] {
  --azure-mist: #06d6a0ff;
  --graphite: #073b4cff;
  --pastel-petal: #ef476fff;
  --turquoise: #ffd166ff;
  --aquamarine: #118ab2ff;
  --blue-bell: #a5ffd6;
  --pastel-petal-dark: #ffd166ff;
  --pastel-petal-light: #ffd166ff;
}

[data-theme="pastel-serenity"] {
  --azure-mist: #eaf2d7ff;
  --graphite: #e27396ff;
  --pastel-petal: #efcfe3ff;
  --turquoise: #b3dee2ff;
  --aquamarine: #ea9ab2ff;
  --blue-bell: #e27396ff;
  --pastel-petal-dark: #ea9ab2ff;
  --pastel-petal-light: #eaf2d7ff;
}