/* ============================================
   Fraction Calculator - CSS Styles
   Neobrutalism Design System
   Multi-fraction support
   ============================================ */

/* Global box-sizing */
.fraction-calculator-container,
.fraction-calculator-container *,
.fraction-calculator-container *::before,
.fraction-calculator-container *::after {
  box-sizing: border-box;
}

/* ============================================
   CSS Variables - Light Mode (Default)
   ============================================ */
.fraction-calculator-container {
  /* Background colors */
  --bg-primary: #f5f5f0;
  --bg-secondary: #fff;
  --bg-section: #fff;
  
  /* Borders */
  --border-color: #333;
  
  /* Text colors */
  --text-primary: #222;
  --text-secondary: #555;
  --text-light: #666;
  
  /* Brand colors */
  --color-accent: #3498db;
  --color-success: #27ae60;
  --color-warning: #f39c12;
  --color-danger: #e74c3c;
  --color-purple: #9b59b6;
  --color-teal: #1abc9c;
  
  /* Shadows (neobrutalism) */
  --shadow-sm: 2px 2px 0 rgba(0,0,0,0.1);
  --shadow-md: 4px 4px 0 rgba(0,0,0,0.15);
  --shadow-lg: 8px 8px 0 rgba(0,0,0,0.15);
  
  /* Border radius */
  --radius-container: 8px;
  --radius-section: 6px;
  --radius-button: 4px;
  --radius-input: 4px;
  
  /* Input focus */
  --input-focus-bg: #fffacd;
  
  /* Header title */
  --title-color: #2c3e50;
  --title-shadow: 2px 2px 0 rgba(255,255,255,0.5);
  
  /* Button hover background */
  --btn-hover-overlay: rgba(0,0,0,0.1);
  
  /* Copy button background */
  --copy-btn-bg: #fff;
  --copy-btn-hover-bg: #f0f0f0;
}

/* ============================================
   CSS Variables - Dark Mode (Manual Toggle)
   ============================================ */
.fraction-calculator-container.dark {
  /* Background colors */
  --bg-primary: #1a1a1a;
  --bg-secondary: #2d2d2d;
  --bg-section: #2d2d2d;
  
  /* Borders */
  --border-color: #e0e0e0;
  
  /* Text colors */
  --text-primary: #e8e8e8;
  --text-secondary: #b0b0b0;
  --text-light: #909090;
  
  /* Brand colors - brighter for dark background */
  --color-accent: #5dade2;
  --color-success: #52c77a;
  --color-warning: #f5b041;
  --color-danger: #ec7063;
  --color-purple: #af7ac5;
  --color-teal: #48d1cc;
  
  /* Shadows - light color */
  --shadow-sm: 2px 2px 0 rgba(255,255,255,0.08);
  --shadow-md: 4px 4px 0 rgba(255,255,255,0.12);
  --shadow-lg: 8px 8px 0 rgba(255,255,255,0.12);
  
  /* Input focus */
  --input-focus-bg: #3a3a3a;
  
  /* Header title */
  --title-color: #7fb3d5;
  --title-shadow: 2px 2px 0 rgba(0,0,0,0.5);
  
  /* Button hover background */
  --btn-hover-overlay: rgba(255,255,255,0.1);
  
  /* Copy button background */
  --copy-btn-bg: #3a3a3a;
  --copy-btn-hover-bg: #4a4a4a;
}

/* ============================================
   System Dark Mode Auto Detection
   ============================================ */
@media (prefers-color-scheme: dark) {
  .fraction-calculator-container:not(.dark):not(.light) {
    /* Background colors */
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-section: #2d2d2d;
    
    /* Borders */
    --border-color: #e0e0e0;
    
    /* Text colors */
    --text-primary: #e8e8e8;
    --text-secondary: #b0b0b0;
    --text-light: #909090;
    
    /* Brand colors */
    --color-accent: #5dade2;
    --color-success: #52c77a;
    --color-warning: #f5b041;
    --color-danger: #ec7063;
    --color-purple: #af7ac5;
    --color-teal: #48d1cc;
    
    /* Shadows */
    --shadow-sm: 2px 2px 0 rgba(255,255,255,0.08);
    --shadow-md: 4px 4px 0 rgba(255,255,255,0.12);
    --shadow-lg: 8px 8px 0 rgba(255,255,255,0.12);
    
    /* Input focus */
    --input-focus-bg: #3a3a3a;
    
    /* Header title */
    --title-color: #7fb3d5;
    --title-shadow: 2px 2px 0 rgba(0,0,0,0.5);
    
    /* Button hover background */
    --btn-hover-overlay: rgba(255,255,255,0.1);
    
    /* Copy button background */
    --copy-btn-bg: #3a3a3a;
    --copy-btn-hover-bg: #4a4a4a;
  }
}

/* ============================================
   Main Container
   ============================================ */
.fraction-calculator-container {
  position: relative;
  max-width: 900px;
  width: 100%;
  margin: 8px auto;
  padding: 8px;
  background: var(--bg-primary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-container);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Malgun Gothic', sans-serif;
  color: var(--text-primary);
  box-shadow: var(--shadow-lg);
  line-height: 1.5;
}

/* ============================================
   Dark Mode Toggle Button
   ============================================ */
.dark-mode-toggle {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 6px 10px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-button);
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: var(--shadow-sm);
  font-size: 15.5px;
  font-weight: 600;
  color: var(--text-primary);
  z-index: 10;
}

.dark-mode-toggle:hover {
  transform: translate(0.5px, 0.5px);
  box-shadow: 1.5px 1.5px 0 rgba(0,0,0,0.15);
}

.dark-mode-toggle:active {
  transform: translate(2px, 2px);
  box-shadow: none;
}

/* ============================================
   Header
   ============================================ */
.calculator-header {
  text-align: center;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.main-title {
  font-size: 28px;
  font-weight: 800;
  color: var(--title-color);
  text-shadow: var(--title-shadow);
  margin: 0 0 4px 0;
}

.subtitle {
  font-size: 13.5px;
  color: var(--text-secondary);
  margin: 0;
}

/* ============================================
   2-Column Grid Layout
   ============================================ */
.main-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

/* ============================================
   Sections (Input / Result)
   ============================================ */
.input-section,
.result-section {
  background: var(--bg-section);
  padding: 8px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-section);
  box-shadow: var(--shadow-md);
}

.section-header {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 8px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--border-color);
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
}

.section-header svg {
  width: 18px;
  height: 18px;
  stroke: var(--color-accent);
}

.fraction-count {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-light);
  margin-left: auto;
}

/* ============================================
   Fractions Container (Multiple Fractions)
   ============================================ */
.fractions-container {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

/* ============================================
   Fraction Item (Single Fraction Row)
   ============================================ */
.fraction-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-input);
  box-shadow: var(--shadow-sm);
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fraction-item.removing {
  animation: fadeOut 0.2s ease forwards;
}

@keyframes fadeOut {
  from {
    opacity: 1;
    transform: translateY(0);
  }
  to {
    opacity: 0;
    transform: translateY(-10px);
  }
}

/* Fraction Number Badge - Always first */
.fraction-number {
  min-width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  border-radius: 50%;
  flex-shrink: 0;
  order: 0;
}

/* Operator Selector - After number */
.operator-select {
  padding: 6px 8px;
  font-size: 16px;
  font-weight: 700;
  background: var(--bg-primary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-button);
  cursor: pointer;
  min-width: 50px;
  text-align: center;
  flex-shrink: 0;
  order: 1;
}

/* Placeholder for first item (no operator) */
.operator-placeholder {
  min-width: 50px;
  flex-shrink: 0;
  order: 1;
}

.operator-select:focus {
  outline: none;
  border-color: var(--color-accent);
}

/* Fraction Input Box */
.fraction-box {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 6px 10px;
  background: var(--bg-primary);
  border-radius: var(--radius-input);
  order: 2;
}

.fraction-input {
  width: 100%;
  max-width: 80px;
  padding: 6px 8px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-input);
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 16px;
  font-family: 'Courier New', monospace;
  font-weight: 600;
  text-align: center;
  transition: all 0.2s;
}

.fraction-input:focus {
  outline: none;
  border-color: var(--color-accent);
  background: var(--input-focus-bg);
  box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.15);
}

.fraction-input::placeholder {
  color: var(--text-light);
  font-weight: 400;
  font-size: 12px;
}

.fraction-line {
  width: 100%;
  max-width: 80px;
  height: 2px;
  background: var(--border-color);
  border-radius: 1px;
}

/* Delete Fraction Button */
.delete-fraction-btn {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-danger);
  color: #fff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-button);
  cursor: pointer;
  transition: all 0.15s;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
  order: 3;
}

.delete-fraction-btn svg {
  stroke: #fff;
}

.delete-fraction-btn:hover {
  filter: brightness(1.1);
  transform: scale(1.05);
}

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

.delete-fraction-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
}

/* ============================================
   Add Fraction Button
   ============================================ */
.add-fraction-btn {
  width: 100%;
  padding: 8px;
  margin-top: 6px;
  background: var(--bg-secondary);
  color: var(--color-accent);
  border: 1px dashed var(--color-accent);
  border-radius: var(--radius-button);
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.add-fraction-btn svg {
  stroke: var(--color-accent);
}

.add-fraction-btn:hover {
  background: var(--color-accent);
  color: #fff;
  border-style: solid;
}

.add-fraction-btn:hover svg {
  stroke: #fff;
}

.add-fraction-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  background: var(--bg-secondary);
  color: var(--text-light);
  border-color: var(--text-light);
}

.add-fraction-btn:disabled svg {
  stroke: var(--text-light);
}

/* ============================================
   Calculate Button (Main Action)
   ============================================ */
.calculate-btn {
  width: 100%;
  padding: 10px;
  margin-top: 8px;
  background: var(--color-accent);
  color: #fff;
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-button);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.15s;
  box-shadow: 4px 4px 0 rgba(0,0,0,0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.calculate-btn svg {
  stroke: #fff;
}

.calculate-btn:hover {
  filter: brightness(1.05);
  transform: translate(1px, 1px);
  box-shadow: 3px 3px 0 rgba(0,0,0,0.2);
}

.calculate-btn:active {
  transform: translate(4px, 4px);
  box-shadow: none;
}

/* ============================================
   Secondary Buttons (Sample, Reset)
   ============================================ */
.button-group {
  display: flex;
  gap: 6px;
  margin-top: 6px;
}

.sample-btn,
.reset-btn {
  flex: 1;
  padding: 6px 10px;
  font-size: 13.5px;
  font-weight: 600;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-button);
  cursor: pointer;
  transition: all 0.15s;
  box-shadow: 2px 2px 0 rgba(0,0,0,0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.sample-btn {
  background: var(--color-success);
  color: #fff;
}

.reset-btn {
  background: var(--color-warning);
  color: #fff;
}

.sample-btn svg,
.reset-btn svg {
  stroke: #fff;
}

.sample-btn:hover,
.reset-btn:hover {
  filter: brightness(1.05);
  transform: translate(0.5px, 0.5px);
  box-shadow: 1.5px 1.5px 0 rgba(0,0,0,0.2);
}

.sample-btn:active,
.reset-btn:active {
  transform: translate(2px, 2px);
  box-shadow: none;
}

/* ============================================
   Result Cards
   ============================================ */
.result-card {
  padding: 10px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-section);
  margin-bottom: 8px;
  box-shadow: var(--shadow-sm);
}

.result-card:last-child {
  margin-bottom: 0;
}

.result-label {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 6px;
  font-weight: 600;
}

/* Expression Card */
.expression-display {
  font-size: 15px;
  font-family: 'Courier New', monospace;
  color: var(--text-primary);
  padding: 8px;
  background: var(--bg-primary);
  border-radius: var(--radius-input);
  text-align: center;
  min-height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 6px;
  line-height: 1.8;
}

.placeholder-text {
  color: var(--text-light);
  font-size: 13px;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Malgun Gothic', sans-serif;
}

/* Expression Fraction Display */
.expr-fraction {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  vertical-align: middle;
  margin: 0 2px;
}

.expr-numerator,
.expr-denominator {
  font-size: 14px;
  font-weight: 600;
  line-height: 1.2;
}

.expr-line {
  width: 100%;
  min-width: 18px;
  height: 2px;
  background: var(--border-color);
  margin: 1px 0;
}

.expr-operator {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-accent);
  margin: 0 2px;
}

.expr-equals {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 4px;
}

/* Main Result Display */
.main-result-display {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.result-fraction {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 12px;
  background: var(--bg-primary);
  border-radius: var(--radius-input);
  min-height: 60px;
}

.result-placeholder {
  color: var(--text-light);
  font-size: 13px;
}

/* Result Fraction Display */
.result-frac {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.result-frac .numerator,
.result-frac .denominator {
  font-size: 24px;
  font-weight: 700;
  font-family: 'Courier New', monospace;
  color: var(--color-accent);
  line-height: 1.2;
}

.result-frac .frac-line {
  width: 100%;
  min-width: 40px;
  height: 3px;
  background: var(--color-accent);
  margin: 4px 0;
  border-radius: 2px;
}

.result-whole {
  font-size: 28px;
  font-weight: 700;
  font-family: 'Courier New', monospace;
  color: var(--color-accent);
}

/* Copy Button */
.copy-btn {
  padding: 6px 10px;
  background: var(--copy-btn-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-button);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  gap: 4px;
  box-shadow: var(--shadow-sm);
}

.copy-btn svg {
  stroke: var(--text-secondary);
}

.copy-btn:hover {
  background: var(--copy-btn-hover-bg);
  transform: scale(1.02);
}

.copy-btn:active {
  transform: scale(0.98);
}

/* Info Grid */
.info-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.info-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 8px;
  background: var(--bg-primary);
  border-radius: var(--radius-input);
  text-align: center;
}

.info-item .info-label {
  font-size: 11px;
  color: var(--text-light);
  font-weight: 500;
}

.info-item .info-value {
  font-size: 14px;
  font-weight: 700;
  font-family: 'Courier New', monospace;
  color: var(--text-primary);
}

/* Calculation Steps */
.steps-card {
  max-height: 150px;
  overflow-y: auto;
}

.steps-content {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.step-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  background: var(--bg-primary);
  border-radius: var(--radius-input);
  font-size: 12px;
}

.step-number {
  min-width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-teal);
  color: #fff;
  font-size: 10px;
  font-weight: 700;
  border-radius: 50%;
}

.step-text {
  color: var(--text-secondary);
  font-family: 'Courier New', monospace;
}

/* ============================================
   Info Section (Help)
   ============================================ */
.info-section {
  margin-top: 8px;
  padding: 8px;
  background: var(--bg-section);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-section);
  box-shadow: var(--shadow-sm);
}

.help-content {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 6px;
}

.help-item {
  font-size: 12.5px;
  color: var(--text-secondary);
  padding: 6px 8px;
  background: var(--bg-primary);
  border-radius: var(--radius-input);
  line-height: 1.4;
}

.help-item strong {
  color: var(--text-primary);
}

/* ============================================
   Toast Notification
   ============================================ */
.toast {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-button);
  padding: 10px 15px;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 10px;
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.3s;
  z-index: 1000;
  max-width: 300px;
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.toast svg {
  stroke: var(--color-success);
  flex-shrink: 0;
}

.toast.error svg {
  stroke: var(--color-danger);
}

.toast-content {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.toast-title {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-primary);
}

.toast-value {
  font-size: 12px;
  color: var(--text-secondary);
  font-family: 'Courier New', monospace;
  word-break: break-all;
}

/* ============================================
   Responsive - Tablet (768px or less)
   ============================================ */
@media (max-width: 768px) {
  .fraction-calculator-container {
    margin: 6px 5px;
    padding: 7px;
    width: calc(100% - 10px);
  }
  
  .main-grid {
    grid-template-columns: 1fr;
    gap: 6px;
  }
  
  .main-title {
    font-size: 24px;
  }
  
  .section-header {
    font-size: 15px;
  }
  
  .dark-mode-toggle {
    font-size: 14px;
    padding: 5px 8px;
  }
  
  .help-content {
    grid-template-columns: 1fr;
  }
  
  .info-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ============================================
   Responsive - Mobile (480px or less)
   ============================================ */
@media (max-width: 480px) {
  .fraction-calculator-container {
    padding: 6px;
    border-width: 1px;
  }
  
  .input-section,
  .result-section,
  .info-section {
    padding: 6px;
  }
  
  .main-title {
    font-size: 22px;
  }
  
  .subtitle {
    font-size: 12.5px;
  }
  
  .fraction-item {
    flex-wrap: wrap;
    gap: 4px;
    padding: 6px;
  }
  
  .fraction-number {
    min-width: 20px;
    height: 20px;
    font-size: 10px;
  }
  
  .operator-select {
    min-width: 44px;
    padding: 4px 6px;
    font-size: 14px;
  }
  
  .fraction-box {
    flex: 1;
    min-width: 60px;
  }
  
  .fraction-input {
    font-size: 14px;
    padding: 5px 6px;
    max-width: 70px;
  }
  
  .delete-fraction-btn {
    width: 24px;
    height: 24px;
  }
  
  .info-grid {
    grid-template-columns: 1fr;
    gap: 6px;
  }
  
  .result-frac .numerator,
  .result-frac .denominator {
    font-size: 20px;
  }
  
  .result-whole {
    font-size: 24px;
  }
  
  .expr-numerator,
  .expr-denominator {
    font-size: 12px;
  }
  
  .expr-operator,
  .expr-equals {
    font-size: 14px;
  }
  
  .toast {
    left: 10px;
    right: 10px;
    max-width: none;
  }
}