/* ========================================
   Design System & CSS Variables
   ======================================== */
:root {
  /* Colors - White Modern Theme */
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F8FAFC;
  --color-bg-tertiary: #F1F5F9;
  --color-text-primary: #0F172A;
  --color-text-secondary: #475569;
  --color-text-muted: #64748B;
  --color-accent-primary: #3B82F6;
  --color-accent-secondary: #0EA5E9;
  --color-accent-gold: #D97706;
  --color-border: #E2E8F0;
  --color-shadow: rgba(15, 23, 42, 0.08);
  --color-success: #10B981;
  --color-error: #EF4444;

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-heading: 'Plus Jakarta Sans', 'Inter', sans-serif;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 0.75rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;

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

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --container-max-width: 1200px;
  --header-height: 70px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  overflow-x: hidden;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: clamp(2rem, 5vw, 3rem);
}

h2 {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
}

h3 {
  font-size: clamp(1.5rem, 3vw, 1.875rem);
}

h4 {
  font-size: 1.25rem;
}

h5 {
  font-size: 1.125rem;
}

h6 {
  font-size: 1rem;
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
}

a {
  color: var(--color-accent-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-accent-secondary);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul,
ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-xl);
}

li {
  margin-bottom: var(--spacing-xs);
  color: var(--color-text-secondary);
}

/* ========================================
   Utility Classes
   ======================================== */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.section {
  padding: var(--spacing-3xl) 0;
}

.text-center {
  text-align: center;
}

.text-muted {
  color: var(--color-text-muted);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-xl);
  font-family: var(--font-primary);
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: white;
}

.btn-secondary {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.btn-secondary:hover {
  background: var(--color-border);
}

/* ========================================
   Header & Navigation
   ======================================== */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  height: var(--header-height);
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text-primary);
  text-decoration: none;
}

.logo svg {
  width: 36px;
  height: 36px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link:hover {
  color: var(--color-accent-primary);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent-primary);
  transition: width var(--transition-base);
}

.nav-link:hover::after {
  width: 100%;
}

/* Dropdown */
.dropdown {
  position: relative;
}

.dropdown-toggle {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  cursor: pointer;
}

.dropdown-menu {
  position: absolute;
  top: calc(100% + 1rem);
  left: 0;
  min-width: 280px;
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all var(--transition-base);
  padding: var(--spacing-sm);
  list-style: none;
  margin: 0;
}

.dropdown:hover .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  margin: 0;
}

.dropdown-link {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  font-size: 0.9375rem;
}

.dropdown-link:hover {
  background: var(--color-bg-secondary);
  color: var(--color-accent-primary);
  transform: translateX(4px);
}

/* Mobile Menu Toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.menu-toggle span {
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  transition: all var(--transition-base);
  border-radius: 2px;
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
  background: linear-gradient(135deg, #F0F9FF 0%, #E0F2FE 50%, #F8FAFC 100%);
  padding: var(--spacing-xl) 0 var(--spacing-3xl);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  animation: float 20s ease-in-out infinite;
}

@keyframes float {

  0%,
  100% {
    transform: translate(0, 0) rotate(0deg);
  }

  33% {
    transform: translate(30px, -30px) rotate(120deg);
  }

  66% {
    transform: translate(-20px, 20px) rotate(240deg);
  }
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  margin-bottom: var(--spacing-2xl);
}

.hero h1 {
  margin-bottom: var(--spacing-lg);
  background: linear-gradient(135deg, var(--color-text-primary), var(--color-accent-primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto var(--spacing-xl);
}

/* Calculator Card */
.calculator-card {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: var(--radius-2xl);
  padding: var(--spacing-2xl);
  box-shadow: var(--shadow-xl);
  max-width: 600px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.calculator-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-2xl);
  padding: 2px;
  background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  mask-composite: exclude;
  opacity: 0.5;
  pointer-events: none;
}

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
  font-size: 0.9375rem;
}

.form-input {
  width: 100%;
  padding: var(--spacing-md);
  font-family: var(--font-primary);
  font-size: 1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  transition: all var(--transition-base);
}

.form-input:focus {
  outline: none;
  border-color: var(--color-accent-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.results-grid {
  margin-top: var(--spacing-xl);
}

/* Results Table */
.results-table {
  width: 100%;
  border-collapse: collapse;
  background: white;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  margin-top: var(--spacing-xl);
  font-size: 0.875rem;
}

.results-table thead {
  background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
  color: white;
}

.results-table th {
  padding: var(--spacing-sm) var(--spacing-md);
  text-align: left;
  font-weight: 600;
  font-size: 0.8125rem;
  white-space: nowrap;
}

.results-table td {
  padding: var(--spacing-sm) var(--spacing-md);
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  line-height: 1.4;
}

.results-table tbody tr {
  transition: background-color var(--transition-fast);
}

.results-table tbody tr:nth-child(even) {
  background: rgba(59, 130, 246, 0.02);
}

.results-table tbody tr:hover {
  background: var(--color-bg-secondary);
}

.results-table tbody tr:last-child td {
  border-bottom: none;
}

.jawa-label {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  font-weight: 400;
}

/* WhatsApp Share Button */
.share-container {
  grid-column: 1 / -1;
  display: flex;
  justify-content: center;
  margin-top: var(--spacing-lg);
}

.btn-whatsapp {
  background: linear-gradient(135deg, #25D366, #128C7E);
  color: white;
  padding: var(--spacing-md) var(--spacing-xl);
  border: none;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-md);
}

.btn-whatsapp:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  background: linear-gradient(135deg, #128C7E, #075E54);
}

/* ========================================
   Content Section
   ======================================== */
.content-section {
  background: var(--color-bg-primary);
}

.content-wrapper {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--spacing-2xl);
  align-items: start;
}

.main-content {
  background: white;
  padding: var(--spacing-2xl);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
}

.article-content h2 {
  margin-top: var(--spacing-xl);
  padding-bottom: var(--spacing-sm);
  border-bottom: 3px solid var(--color-bg-tertiary);
}

.article-content h3 {
  margin-top: var(--spacing-lg);
  color: var(--color-accent-primary);
}

/* Table of Contents */
.toc-sidebar {
  position: sticky;
  top: calc(var(--header-height) + var(--spacing-lg));
}

.toc-card {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-sm);
}

.toc-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}

.toc-toggle {
  transition: transform var(--transition-base);
}

.toc-toggle.active {
  transform: rotate(180deg);
}

.toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
  max-height: 500px;
  overflow-y: auto;
}

.toc-item {
  margin-bottom: var(--spacing-sm);
}

.toc-link {
  display: block;
  padding: var(--spacing-sm);
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  font-size: 0.9375rem;
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
}

.toc-link:hover,
.toc-link.active {
  background: var(--color-bg-secondary);
  color: var(--color-accent-primary);
  border-left-color: var(--color-accent-primary);
  transform: translateX(4px);
}

/* Blockquote */
.article-content blockquote {
  margin: var(--spacing-xl) 0;
  padding: var(--spacing-lg);
  background: linear-gradient(135deg, #FEF3C7 0%, #FDE68A 100%);
  border-left: 4px solid var(--color-accent-gold);
  border-radius: var(--radius-lg);
  font-style: italic;
  position: relative;
}

.article-content blockquote::before {
  content: '"';
  position: absolute;
  top: -10px;
  left: 10px;
  font-size: 4rem;
  color: var(--color-accent-gold);
  opacity: 0.3;
  font-family: Georgia, serif;
}

.article-content blockquote p {
  margin: 0;
  color: var(--color-text-primary);
  font-weight: 500;
}

/* Table */
.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--spacing-xl) 0;
  background: white;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.article-content thead {
  background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
  color: white;
}

.article-content th {
  padding: var(--spacing-md);
  text-align: left;
  font-weight: 600;
  font-size: 0.9375rem;
}

.article-content td {
  padding: var(--spacing-md);
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-secondary);
}

.article-content tbody tr:hover {
  background: var(--color-bg-secondary);
}

.article-content tbody tr:last-child td {
  border-bottom: none;
}

/* Highlight Box */
.highlight-box {
  background: linear-gradient(135deg, #DBEAFE 0%, #BFDBFE 100%);
  border: 2px solid var(--color-accent-primary);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  margin: var(--spacing-xl) 0;
}

.highlight-box h4 {
  color: var(--color-accent-primary);
  margin-bottom: var(--spacing-sm);
}

/* Internal Links */
.internal-link {
  color: var(--color-accent-primary);
  font-weight: 600;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
  transition: all var(--transition-fast);
}

.internal-link:hover {
  color: var(--color-accent-secondary);
  text-decoration-color: var(--color-accent-secondary);
}

/* References */
.references {
  margin-top: var(--spacing-2xl);
  padding-top: var(--spacing-xl);
  border-top: 2px solid var(--color-border);
}

.references h3 {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-md);
}

.references ol {
  padding-left: var(--spacing-lg);
}

.references li {
  margin-bottom: var(--spacing-sm);
  line-height: 1.6;
}

.references a {
  word-break: break-all;
}

/* Related Articles */
.related-articles {
  margin-top: var(--spacing-2xl);
  padding: var(--spacing-xl);
  background: var(--color-bg-secondary);
  border-radius: var(--radius-xl);
}

.related-articles h3 {
  margin-bottom: var(--spacing-lg);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: var(--spacing-md);
}

.related-card {
  background: white;
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition-base);
  text-decoration: none;
  display: block;
}

.related-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-accent-primary);
}

.related-card h4 {
  font-size: 1rem;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
}

.related-card p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin: 0;
}

/* ========================================
   Footer
   ======================================== */
.footer {
  background: var(--color-text-primary);
  color: white;
  padding: var(--spacing-2xl) 0 var(--spacing-lg);
  margin-top: var(--spacing-3xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer-section h4 {
  color: white;
  margin-bottom: var(--spacing-md);
  font-size: 1.125rem;
}

.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-links li {
  margin-bottom: var(--spacing-sm);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: white;
}

.footer-disclaimer {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-lg);
  background: rgba(217, 119, 6, 0.15);
  border: 1px solid rgba(217, 119, 6, 0.3);
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  line-height: 1.6;
}

.footer-disclaimer p {
  margin: 0;
  color: rgba(255, 255, 255, 0.85);
}

.footer-disclaimer strong {
  color: #FCD34D;
}

.footer-bottom {
  padding-top: var(--spacing-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.875rem;
}

/* ========================================
   Back to Top Button
   ======================================== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--color-accent-primary), var(--color-accent-secondary));
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-base);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
  .content-wrapper {
    grid-template-columns: 1fr;
  }

  .toc-sidebar {
    position: static;
    order: -1;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 60px;
  }

  .menu-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    align-items: stretch;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-xl);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    gap: 0;
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-menu li {
    margin-bottom: var(--spacing-md);
  }

  .dropdown-menu {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    border: none;
    margin-top: var(--spacing-sm);
    padding-left: var(--spacing-md);
    display: none;
  }

  .dropdown.active .dropdown-menu {
    display: block;
  }

  .hero {
    padding: var(--spacing-md) 0 var(--spacing-xl);
  }

  .calculator-card {
    padding: var(--spacing-lg);
  }

  .results-grid {
    margin-top: var(--spacing-md);
  }

  .results-table {
    font-size: 0.8125rem;
  }

  .results-table th,
  .results-table td {
    padding: var(--spacing-xs) var(--spacing-sm);
  }

  .results-table th {
    font-size: 0.75rem;
  }

  .results-table td {
    font-size: 0.8125rem;
  }

  .jawa-label {
    font-size: 0.6875rem;
    display: block;
    margin-top: 2px;
  }

  .main-content {
    padding: var(--spacing-lg);
  }

  .related-grid {
    grid-template-columns: 1fr;
  }

  .back-to-top {
    bottom: 1rem;
    right: 1rem;
    width: 45px;
    height: 45px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-md);
  }

  .section {
    padding: var(--spacing-xl) 0;
  }

  .footer-content {
    grid-template-columns: 1fr;
  }
}

/* ========================================
   Loading Animation
   ======================================== */
@keyframes pulse {

  0%,
  100% {
    opacity: 1;
  }

  50% {
    opacity: 0.5;
  }
}

.loading {
  animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* ========================================
   Print Styles
   ======================================== */
@media print {

  .header,
  .footer,
  .back-to-top,
  .toc-sidebar {
    display: none;
  }

  .main-content {
    box-shadow: none;
  }
}