/* ======================== */
/* === Base Variables === */
/* ======================== */
:root {
  /* Typography */
  --font-main: 'Inter', system-ui, sans-serif;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-bold: 600;
  --line-height: 1.65;
  --text-scale: 1.2; /* Minor third scale */
  
  /* Colors */
  --color-primary: #4361ee;
  --color-primary-dark: #3a0ca3;
  --color-secondary: #3f37c9;
  --color-accent: #7209b7;
  --color-text: #2c3e50;
  --color-light: #f8f9fd;
  --color-lighter: #f0f3ff;
  --color-white: #ffffff;
  
  /* Spacing */
  --space-unit: 1rem;
  --space-xxs: calc(var(--space-unit) * 0.125);
  --space-xs: calc(var(--space-unit) * 0.25);
  --space-sm: calc(var(--space-unit) * 0.5);
  --space-md: var(--space-unit);
  --space-lg: calc(var(--space-unit) * 1.5);
  --space-xl: calc(var(--space-unit) * 2);
  
  /* Borders */
  --border-width: 0.125rem;
  --border-radius-sm: 0.25rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  
  /* Shadows */
  --shadow-sm: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.08);
  --shadow-md: 0 0.25rem 0.5rem rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
  --shadow-xl: 0 1rem 2rem rgba(0, 0, 0, 0.2);
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Container Styles */
  --container-width: min(90vw, 50rem);
  --container-padding: var(--space-lg);
  --container-bg: var(--color-white);
  --container-border: var(--border-width) solid rgba(67, 97, 238, 0.1);
}

/* ======================== */
/* === Base Styles === */
/* ======================== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-lg);
}

@media (max-width: 75em) { html { font-size: 93.75%; } }
@media (max-width: 56.25em) { html { font-size: 87.5%; } }
@media (max-width: 37.5em) { html { font-size: 81.25%; } }

body {
  font-family: var(--font-main);
  font-size: var(--space-md);
  line-height: var(--line-height);
  color: var(--color-text);
  background: linear-gradient(135deg, var(--color-light) 0%, var(--color-lighter) 100%);
  min-height: 100vh;
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* ======================== */
/* === Layout Containers === */
/* ======================== */
.container {
  width: var(--container-width);
  max-width: 100%;
  background: var(--container-bg);
  border-radius: var(--border-radius-xl);
  box-shadow: var(--shadow-md);
  padding: var(--container-padding);
  margin-bottom: var(--space-lg);
  border: var(--container-border);
  position: relative;
  overflow: hidden;
}

.container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 0.25rem;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  opacity: 0.1;
}

.section {
  background: rgba(255, 255, 255, 0.7);
  border-radius: var(--border-radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  border: var(--border-width) solid rgba(67, 97, 238, 0.05);
  box-shadow: var(--shadow-sm);
}

.card {
  background: var(--color-white);
  border-radius: var(--border-radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-md);
  border: var(--border-width) solid rgba(67, 97, 238, 0.08);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.card:hover {
  transform: translateY(-0.125rem);
  box-shadow: var(--shadow-md);
  border-color: rgba(67, 97, 238, 0.15);
}

/* ===================== */
/* === Intro Section === */
/* ===================== */
.intro {
  background: var(--color-white);
  border-radius: var(--border-radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
  box-shadow: var(--shadow-sm);
  border: var(--border-width) solid rgba(67, 97, 238, 0.05);
  text-align: center;
}

.intro h1 {
  margin-top: 0;
  border-bottom: none;
  padding-bottom: 0;
}

.intro p {
  max-width: 80ch;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: var(--space-md);
}

.intro p:last-child {
  margin-bottom: 0;
}

/* ===================== */
/* === Typography === */
/* ===================== */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: 1.2;
  margin: var(--space-lg) 0 var(--space-md);
  color: var(--color-primary-dark);
}

h1 {
  font-size: calc(var(--space-md) * 2);
  background: linear-gradient(45deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  padding-bottom: var(--space-xs);
  border-bottom: var(--border-width) solid rgba(67, 97, 238, 0.1);
}

h2 {
  font-size: calc(var(--space-md) * 1.5);
  position: relative;
  padding-left: var(--space-md);
}

h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.25em;
  height: 1em;
  width: 0.25rem;
  background: var(--color-primary);
  border-radius: var(--border-radius-sm);
}

/* ===================== */
/* === Img Components === */
/* ===================== */

.image-gallery {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
  margin: 20px 0;
}

.image-container {
  max-width: 400px;
  margin: 0 auto;
  text-align: center;
}

.image-container img {
  max-width: 100%;
  height: auto;
  border: 1px solid #ddd;
  border-radius: 4px;
  padding: 5px;
}

figcaption {
  font-size: 0.9em;
  color: #666;
  margin-top: 8px;
}

/* ===================== */
/* === UI Components === */
/* ===================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-sm) var(--space-lg);
  background: linear-gradient(45deg, var(--color-primary), var(--color-secondary));
  color: white;
  border-radius: var(--border-radius-md);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  border: none;
  cursor: pointer;
}

.btn:hover {
  transform: translateY(-0.125rem);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  border: var(--border-width) solid var(--color-primary);
  color: var(--color-primary);
}

/* ===================== */
/* === Responsive Design === */
/* ===================== */
@media (max-width: 48em) {
  .container {
    padding: var(--space-md);
    border-radius: var(--border-radius-lg);
  }
  
  .section, .card {
    padding: var(--space-md);
  }
  
  h1 { font-size: calc(var(--space-md) * 1.75); }
  h2 { font-size: calc(var(--space-md) * 1.25); }
}

@media (max-width: 30em) {
  .container {
    padding: var(--space-sm);
    border-radius: var(--border-radius-md);
  }
  
  body {
    padding: var(--space-sm);
  }
}

/* ===================== */
/* === MathJax Design === */
/* ===================== *//* MathJax Container Styling */
.MathJax {
  font-size: 1.1em !important;
  line-height: 1.5 !important;
}

/* Equation container styling */
.equation-container {
  margin: 1em 0;
  padding: 1em;
  background-color: #f8f9fa;
  border-radius: 6px;
  border-left: 4px solid #4285f4;
}

/* Spacing between equations */
.equation {
  display: block;
  margin: 0.8em 0;
}

/* Card specific adjustments */
.card .equation-container {
  margin: 0.5em 0;
  padding: 0.8em;
}

/* Formula box adjustments */
.formula-box {
  line-height: 1.6;
}

/* Step-by-step calculation spacing */
.calculation-steps .equation {
  margin: 0.5em 0;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .equation-container {
    padding: 0.8em;
    overflow-x: auto;
  }
  
  .MathJax {
    font-size: 1em !important;
  }
}

/* ===================== */
/* === Intro Section === */
/* ===================== */
.intro {
  margin-bottom: var(--space-xl);
  text-align: center;
}

.intro p {
  max-width: 80ch;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: var(--space-md);
}

/* ===================== */
/* === Calculator Link === */
/* ===================== */
.calculator-section > p {
  margin-bottom: var(--space-lg);
  text-align: center;
}

.calculator-section > p a {
  color: var(--color-primary);
  font-weight: var(--font-weight-medium);
  transition: color var(--transition-fast);
}

.calculator-section > p a:hover {
  color: var(--color-accent);
}