/**
 * Step-by-Step Solver CSS
 * Styles the StepByStepSolver component for chemistry calculators
 * BEM naming convention with CSS custom properties
 */

/* ==========================================================================
   CSS CUSTOM PROPERTIES
   ========================================================================== */

/* Base CSS variables for step-by-step solver */
:root {
  /**
   * Step-by-Step Solver colors
   */
  --sbs-primary: #28a745;
  --sbs-primary-dark: #218838;
  --sbs-primary-light: #48c765;
  --sbs-gradient-start: #28a745;
  --sbs-gradient-end: #34dcb3;
  --sbs-success: #28a745;
  --sbs-success-light: #e8f5e9;
  --sbs-warn: #ffc107;
  --sbs-warn-light: #fff8e1;
  --sbs-error: #dc3545;
  --sbs-error-light: #fde8e8;
  --sbs-info: #17a2b8;
  --sbs-info-light: #e0f7fa;

  /**
   * Text colors
   */
  --sbs-text-primary: #212529;
  --sbs-text-secondary: #6c757d;
  --sbs-text-muted: #adb5bd;
  --sbs-text-inverse: #ffffff;

  /**
   * Background colors
   */
  --sbs-bg-primary: #ffffff;
  --sbs-bg-secondary: #f8f9fa;
  --sbs-bg-tertiary: #e9ecef;
  --sbs-bg-light: #fdfdfd;
  --sbs-bg-shadow: rgba(0, 0, 0, 0.1);

  /**
   * Border colors
   */
  --sbs-border-light: #dee2e6;
  --sbs-border-medium: #ced4da;
  --sbs-border-dark: #868e96;
  --sbs-border-focus: #80bdff;

  /**
   * Spacing tokens
   */
  --sbs-spacing-xs: 0.25rem;
  --sbs-spacing-sm: 0.5rem;
  --sbs-spacing-md: 1rem;
  --sbs-spacing-lg: 1.5rem;
  --sbs-spacing-xl: 2rem;
  --sbs-spacing-2xl: 3rem;

  /**
   * Border radius
   */
  --sbs-radius-sm: 0.25rem;
  --sbs-radius-md: 0.5rem;
  --sbs-radius-lg: 1rem;
  --sbs-radius-xl: 1.5rem;
  --sbs-radius-full: 9999px;

  /**
   * Shadows
   */
  --sbs-shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --sbs-shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --sbs-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --sbs-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --sbs-shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  /**
   * Typography
   */
  --sbs-font-family-base:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --sbs-font-family-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  --sbs-font-size-xs: 0.75rem;
  --sbs-font-size-sm: 0.875rem;
  --sbs-font-size-base: 1rem;
  --sbs-font-size-lg: 1.125rem;
  --sbs-font-size-xl: 1.25rem;
  --sbs-font-size-2xl: 1.5rem;
  --sbs-font-size-3xl: 1.875rem;
  --sbs-line-height-tight: 1.25;
  --sbs-line-height-base: 1.5;
  --sbs-line-height-relaxed: 1.625;

  /**
   * Transitions
   */
  --sbs-transition-fast: 150ms ease;
  --sbs-transition-base: 200ms ease;
  --sbs-transition-slow: 300ms ease;

  /**
   * Z-index layers
   */
  --sbs-z-index-base: 1;
  --sbs-z-index-dropdown: 1000;
  --sbs-z-index-sticky: 1020;
  --sbs-z-index-fixed: 1030;
  --sbs-z-index-modal-backdrop: 1040;
  --sbs-z-index-modal: 1050;
  --sbs-z-index-popover: 1060;
  --sbs-z-index-tooltip: 1070;
}

/* ==========================================================================
   DARK MODE SUPPORT
   Use CSS variables for theming
   ========================================================================== */

/* Dark mode override */
@media (prefers-color-scheme: dark) {
  :root {
    --sbs-text-primary: #f8f9fa;
    --sbs-text-secondary: #adb5bd;
    --sbs-text-muted: #6c757d;
    --sbs-text-inverse: #212529;

    --sbs-bg-primary: #1a1a2e;
    --sbs-bg-secondary: #16213e;
    --sbs-bg-tertiary: #0f3460;
    --sbs-bg-light: #1a1a2e;
    --sbs-bg-shadow: rgba(0, 0, 0, 0.3);

    --sbs-border-light: #3d3d5c;
    --sbs-border-medium: #4a4a6a;
    --sbs-border-dark: #6c6c8c;
    --sbs-border-focus: #5c9eff;

    --sbs-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --sbs-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
  }
}

/* Manual dark mode toggle support */
[data-theme='dark'] {
  --sbs-text-primary: #f8f9fa;
  --sbs-text-secondary: #adb5bd;
  --sbs-text-muted: #6c757d;
  --sbs-text-inverse: #212529;

  --sbs-bg-primary: #1a1a2e;
  --sbs-bg-secondary: #16213e;
  --sbs-bg-tertiary: #0f3460;
  --sbs-bg-light: #1a1a2e;
  --sbs-bg-shadow: rgba(0, 0, 0, 0.3);

  --sbs-border-light: #3d3d5c;
  --sbs-border-medium: #4a4a6a;
  --sbs-border-dark: #6c6c8c;
  --sbs-border-focus: #5c9eff;

  --sbs-shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --sbs-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
}

/* ==========================================================================
   STEP-BY-STEP SOLVER STYLES
   BEM naming convention
   ========================================================================== */

/**
 * Main container
 * .step-by-step-solver
 */
.step-by-step-solver {
  margin: var(--sbs-spacing-lg) 0;
  border-radius: var(--sbs-radius-lg);
  background: var(--sbs-bg-primary);
  box-shadow: var(--sbs-shadow-lg);
  overflow: hidden;
  animation: sbsFadeIn var(--sbs-transition-slow) ease-out;
  border: 1px solid var(--sbs-border-light);
}

/**
 * Header section
 * .step-by-step-solver__header
 */
.step-by-step-solver__header {
  background: linear-gradient(135deg, var(--sbs-gradient-start), var(--sbs-gradient-end));
  color: var(--sbs-text-inverse);
  padding: var(--sbs-spacing-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--sbs-spacing-md);
}

.step-by-step-solver__header h3 {
  margin: 0;
  font-size: var(--sbs-font-size-xl);
  font-weight: 600;
  line-height: var(--sbs-line-height-tight);
  display: flex;
  align-items: center;
  gap: var(--sbs-spacing-sm);
}

.step-by-step-solver__header h3::before {
  content: '📝';
  font-size: 1.2em;
}

/**
 * Step count badge
 * .step-by-step-solver__count
 */
.step-count {
  background: rgba(255, 255, 255, 0.25);
  color: var(--sbs-text-inverse);
  padding: var(--sbs-spacing-xs) var(--sbs-spacing-sm);
  border-radius: var(--sbs-radius-full);
  font-size: var(--sbs-font-size-sm);
  font-weight: 500;
  backdrop-filter: blur(10px);
}

/**
 * Toggle button
 * .step-by-step-solver__toggle-solver
 */
.toggle-solver {
  background: rgba(255, 255, 255, 0.25);
  border: 2px solid rgba(255, 255, 255, 0.5);
  color: var(--sbs-text-inverse);
  padding: var(--sbs-spacing-xs) var(--sbs-spacing-md);
  border-radius: var(--sbs-radius-full);
  font-size: var(--sbs-font-size-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--sbs-transition-fast);
  display: flex;
  align-items: center;
  gap: var(--sbs-spacing-xs);
  background-clip: padding-box;
  backdrop-filter: blur(10px);
}

.toggle-solver:hover,
.toggle-solver:focus {
  background: rgba(255, 255, 255, 0.35);
  border-color: rgba(255, 255, 255, 0.75);
  transform: translateY(-1px);
  box-shadow: var(--sbs-shadow-sm);
  outline: none;
}

.toggle-solver:focus-visible {
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.5);
}

.toggle-solver::after {
  content: '▼';
  font-size: 0.8em;
  transition: transform var(--sbs-transition-fast);
}

.toggle-solver[aria-expanded='false']::after {
  transform: rotate(-90deg);
}

/**
 * Content area
 * .step-by-step-solver__content
 */
.step-by-step-solver__content {
  padding: var(--sbs-spacing-lg);
  background: var(--sbs-bg-secondary);
}

/**
 * No steps message
 * .step-by-step-solver__no-steps-msg
 */
.no-steps-msg {
  margin: 0;
  color: var(--sbs-text-muted);
  font-style: italic;
  text-align: center;
  padding: var(--sbs-spacing-xl) 0;
  font-size: var(--sbs-font-size-base);
  animation: pulseText var(--sbs-transition-slow) infinite alternate;
}

/**
 * Individual step card
 * .step
 */
.step {
  background: var(--sbs-bg-primary);
  border: 1px solid var(--sbs-border-light);
  border-radius: var(--sbs-radius-md);
  margin-bottom: var(--sbs-spacing-md);
  overflow: hidden;
  transition: all var(--sbs-transition-base);
  animation: stepSlideIn var(--sbs-transition-slow) ease-out backwards;
  animation-fill-mode: both;
}

.step:nth-child(1) {
  animation-delay: 50ms;
}
.step:nth-child(2) {
  animation-delay: 150ms;
}
.step:nth-child(3) {
  animation-delay: 250ms;
}
.step:nth-child(4) {
  animation-delay: 350ms;
}
.step:nth-child(5) {
  animation-delay: 450ms;
}

.step:hover {
  transform: translateX(4px);
  box-shadow: var(--sbs-shadow-md);
  border-color: var(--sbs-primary-light);
}

.step:focus-within {
  box-shadow:
    var(--sbs-shadow-md),
    0 0 0 3px var(--sbs-border-focus);
  border-color: var(--sbs-primary);
}

/**
 * Step header bar
 * .step__header
 */
.step-header {
  display: flex;
  align-items: center;
  gap: var(--sbs-spacing-md);
  padding: var(--sbs-spacing-md);
  background: linear-gradient(90deg, var(--sbs-bg-secondary), transparent);
  border-bottom: 1px solid var(--sbs-border-light);
}

/**
 * Step number badge
 * .step__number
 */
.step-number {
  min-width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--sbs-primary), var(--sbs-primary-dark));
  color: var(--sbs-text-inverse);
  border-radius: var(--sbs-radius-full);
  font-size: var(--sbs-font-size-sm);
  font-weight: 700;
  box-shadow: var(--sbs-shadow-sm);
}

/**
 * Step description text
 * .step__description
 */
.step-description {
  flex: 1;
  font-size: var(--sbs-font-size-base);
  font-weight: 500;
  color: var(--sbs-text-primary);
  line-height: var(--sbs-line-height-tight);
  margin: 0;
}

/**
 * Calculation content area
 * .step__calculation
 */
.step-calculation {
  padding: var(--sbs-spacing-md);
  background: var(--sbs-bg-light);
  border-top: 1px solid var(--sbs-border-light);
}

/**
 * Formula display
 * .calculation__info
 */
.calculation-info {
  margin-bottom: var(--sbs-spacing-sm);
  padding: var(--sbs-spacing-sm) var(--sbs-spacing-md);
  background: var(--sbs-bg-secondary);
  border-left: 4px solid var(--sbs-primary);
  border-radius: var(--sbs-radius-sm);
}

.formula {
  font-family: var(--sbs-font-family-mono);
  font-size: var(--sbs-font-size-sm);
  color: var(--sbs-text-secondary);
}

.formula strong {
  font-weight: 600;
  color: var(--sbs-text-primary);
}

.formula code {
  background: var(--sbs-bg-tertiary);
  padding: 2px 6px;
  border-radius: var(--sbs-radius-sm);
  font-size: 0.9em;
  color: var(--sbs-primary);
  margin-left: 4px;
}

/**
 * Inputs display section
 * .calculation__inputs
 */
.calculation-inputs {
  margin-bottom: var(--sbs-spacing-md);
}

.inputs-label {
  display: block;
  font-size: var(--sbs-font-size-xs);
  font-weight: 600;
  color: var(--sbs-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: var(--sbs-spacing-xs);
}

.input-item {
  display: inline-block;
  margin: 0 var(--sbs-spacing-xs) var(--sbs-spacing-xs) 0;
  padding: 4px 8px;
  background: var(--sbs-bg-tertiary);
  border-radius: var(--sbs-radius-sm);
  font-size: var(--sbs-font-size-sm);
  color: var(--sbs-text-primary);
}

.input-item strong {
  font-weight: 600;
  color: var(--sbs-primary-dark);
}

/**
 * Result display section
 * .calculation__result
 */
.calculation-result {
  padding: var(--sbs-spacing-md);
  background: linear-gradient(135deg, var(--sbs-success-light), transparent);
  border-radius: var(--sbs-radius-md);
  display: flex;
  align-items: center;
  gap: var(--sbs-spacing-sm);
}

.result-label {
  font-size: var(--sbs-font-size-sm);
  font-weight: 600;
  color: var(--sbs-primary-dark);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.result-value {
  font-size: var(--sbs-font-size-xl);
  font-weight: 700;
  color: var(--sbs-primary);
  font-family: var(--sbs-font-family-mono);
  letter-spacing: -0.5px;
}

.result-unit {
  font-size: var(--sbs-font-size-base);
  color: var(--sbs-text-secondary);
  font-weight: 500;
}

/* ==========================================================================
   ANIMATIONS
   ========================================================================== */

/**
 * Fade in animation
 */
@keyframes sbsFadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/**
 * Slide in animation for steps
 */
@keyframes stepSlideIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/**
 * Pulse animation for emphasis
 */
@keyframes pulseText {
  from {
    opacity: 0.6;
  }
  to {
    opacity: 1;
  }
}

/**
 * Pulse animation for result values
 */
@keyframes resultPulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

/**
 * Bounce animation for new steps
 */
@keyframes stepBounce {
  0%,
  20%,
  50%,
  80%,
  100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-8px);
  }
  60% {
    transform: translateY(-4px);
  }
}

/**
 * Shine animation for headers
 */
@keyframes headerShine {
  from {
    background-position: 200% center;
  }
  to {
    background-position: -200% center;
  }
}

/* ==========================================================================
   RESPONSIVE BREAKPOINTS
   ========================================================================== */

/**
 * Mobile devices (280px+)
 */
@media screen and (min-width: 280px) {
  .step-by-step-solver__header {
    flex-direction: column;
    align-items: flex-start;
  }

  .step-count {
    align-self: flex-start;
  }

  .calculation-result {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--sbs-spacing-xs);
  }
}

/**
 * Tablets and small laptops (768px+)
 */
@media screen and (min-width: 768px) {
  .step-by-step-solver__header {
    flex-direction: row;
  }

  .toggle-solver {
    align-self: center;
  }

  .step {
    margin-bottom: var(--sbs-spacing-lg);
  }

  .step-header {
    padding: var(--sbs-spacing-md) var(--sbs-spacing-lg);
  }

  .step-calculation {
    padding: var(--sbs-spacing-lg);
  }

  .calculation-inputs .input-item {
    margin-right: var(--sbs-spacing-md);
  }
}

/**
 * Desktop and large screens (1024px+)
 */
@media screen and (min-width: 1024px) {
  .step-by-step-solver {
    max-width: 800px;
    margin: var(--sbs-spacing-xl) auto;
  }

  .step-by-step-solver__header h3 {
    font-size: var(--sbs-font-size-2xl);
  }

  .step {
    transform: none;
  }

  .step:hover {
    transform: translateX(8px);
  }

  .step-description {
    font-size: var(--sbs-font-size-lg);
  }

  .step-number {
    min-width: 44px;
    height: 44px;
    font-size: var(--sbs-font-size-base);
  }

  .result-value {
    font-size: var(--sbs-font-size-2xl);
  }

  .toggle-solver {
    padding: var(--sbs-spacing-sm) var(--sbs-spacing-lg);
    font-size: var(--sbs-font-size-base);
  }
}

/**
 * High resolution displays
 */
@media screen and (min-resolution: 2dppx), screen and (min-resolution: 192dpi) {
  .step-by-step-solver {
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }

  .step-number {
    -webkit-font-smoothing: subpixel-antialiased;
  }
}

/* ==========================================================================
   PRINT STYLES
   ========================================================================== */

@media print {
  .step-by-step-solver {
    box-shadow: none;
    border: 1px solid #000;
  }

  .step-by-step-solver__header {
    background: #f0f0f0 !important;
    color: #000 !important;
    print-color-adjust: exact;
    -webkit-print-color-adjust: exact;
  }

  .step {
    break-inside: avoid;
    page-break-inside: avoid;
  }

  .toggle-solver,
  .step-count {
    display: none;
  }

  .step-number {
    background: #333 !important;
    color: #fff !important;
    print-color-adjust: exact;
    -webkit-print-color-adjust: exact;
  }
}

/* ==========================================================================
   REDUCED MOTION
   Respects user's motion preferences
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
  .step-by-step-solver,
  .step,
  .no-steps-msg {
    animation: none;
    transition: none;
  }

  .step:hover,
  .toggle-solver:hover {
    transform: none;
  }
}

/* ==========================================================================
   HIGH CONTRAST MODE
   ========================================================================== */

@media (prefers-contrast: high) {
  :root {
    --sbs-border-light: #000000;
    --sbs-border-medium: #333333;
  }

  .step-number {
    border: 2px solid currentColor;
  }

  .calculation-info {
    border-left-width: 6px;
  }

  .calculation-result {
    border: 2px solid var(--sbs-success);
  }
}

/* ==========================================================================
   COLOUR BLINDNESS SUPPORT
   ========================================================================== */

/* For users with deuteranopia/protanopia, add icons/text to ensure colour isn't the only indicator */
.calculation-result::before {
  content: '✓ ';
  margin-right: var(--sbs-spacing-xs);
}

/* ==========================================================================
   UTILITY CLASSES
   ========================================================================== */

/* Visibility utilities */
.sbs-hidden {
  display: none !important;
}

.sbs-visible {
  display: block !important;
}

/* Text utilities */
.sbs-text-center {
  text-align: center;
}

.sbs-text-right {
  text-align: right;
}

/* Spacing utilities */
.sbs-mt-0 {
  margin-top: 0;
}
.sbs-mt-1 {
  margin-top: var(--sbs-spacing-xs);
}
.sbs-mt-2 {
  margin-top: var(--sbs-spacing-sm);
}
.sbs-mt-3 {
  margin-top: var(--sbs-spacing-md);
}
.sbs-mt-4 {
  margin-top: var(--sbs-spacing-lg);
}
.sbs-mt-5 {
  margin-top: var(--sbs-spacing-xl);
}

.sbs-mb-0 {
  margin-bottom: 0;
}
.sbs-mb-1 {
  margin-bottom: var(--sbs-spacing-xs);
}
.sbs-mb-2 {
  margin-bottom: var(--sbs-spacing-sm);
}
.sbs-mb-3 {
  margin-bottom: var(--sbs-spacing-md);
}
.sbs-mb-4 {
  margin-bottom: var(--sbs-spacing-lg);
}
.sbs-mb-5 {
  margin-bottom: var(--sbs-spacing-xl);
}

/* ==========================================================================
   END OF STYLES
   ========================================================================== */