/* ==========================================================================
   CONE VOLUME FORMULA & 3D CALCULATOR - COMPREHENSIVE DESIGN SYSTEM
   Modern, Responsive, Glassmorphic UI with Dark/Light Themes
   ========================================================================== */

:root {
  color-scheme: dark;
  /* Color Palette - Vibrant Jewel & Slate Tones */
  --bg-base: #090d16;
  --bg-surface: #0f172a;
  --bg-card: rgba(15, 23, 42, 0.75);
  --bg-card-hover: rgba(30, 41, 59, 0.85);
  --card-border: rgba(255, 255, 255, 0.08);
  --card-border-hover: rgba(99, 102, 241, 0.4);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --primary-light: #818cf8;
  --primary-glow: rgba(99, 102, 241, 0.35);
  
  --secondary: #06b6d4;
  --secondary-hover: #0891b2;
  --secondary-glow: rgba(6, 182, 212, 0.3);
  
  --accent-amber: #f59e0b;
  --accent-amber-light: #fbbf24;
  --accent-emerald: #10b981;
  --accent-emerald-light: #34d399;
  --accent-rose: #f43f5e;
  --accent-purple: #8b5cf6;
  
  --input-bg: rgba(30, 41, 59, 0.8);
  --input-border: rgba(255, 255, 255, 0.12);
  --input-focus: #6366f1;
  
  --nav-bg: rgba(9, 13, 22, 0.85);
  
  /* Fonts */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-heading: 'Outfit', var(--font-sans);
  --font-mono: 'JetBrains Mono', monospace;

  /* Shadows & Radius */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 35px rgba(99, 102, 241, 0.25);
  
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Permanent Dark Theme - Enforced */

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Ambient Background Glows */
.ambient-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(140px);
  pointer-events: none;
  z-index: 0;
  opacity: 0.45;
  transition: opacity 0.5s ease;
}

.glow-1 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, #8b5cf6 0%, rgba(99, 102, 241, 0) 70%);
  top: -100px;
  right: -100px;
}

.glow-2 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, #06b6d4 0%, rgba(6, 182, 212, 0) 70%);
  bottom: 10%;
  left: -200px;
}

/* Glass Card Foundation */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: var(--transition);
}

.glass-card:hover {
  border-color: var(--card-border-hover);
}

/* Typography Helpers */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-main);
}

.gradient-text {
  background: linear-gradient(135deg, #a78bfa 0%, #38bdf8 50%, #34d399 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

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

.hidden {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* KaTeX adjustments */
.katex {
  font-size: 1.08em;
}

.katex-display {
  margin: 0.8rem 0;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.2rem 0;
}

/* Section Header Styles */
.section-header {
  max-width: 780px;
  margin: 0 auto 3rem auto;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary-light);
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.25);
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  margin-bottom: 1rem;
}

.section-title {
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Buttons System */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.75rem 1.4rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition);
  user-select: none;
  white-space: nowrap;
}

.btn-sm {
  padding: 0.45rem 0.9rem;
  font-size: 0.85rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 0.9rem 1.8rem;
  font-size: 1.05rem;
  border-radius: var(--radius-md);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-hover) 100%);
  color: #ffffff;
  box-shadow: 0 4px 15px var(--primary-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px var(--primary-glow);
}

.btn-secondary {
  background: linear-gradient(135deg, var(--secondary) 0%, var(--secondary-hover) 100%);
  color: #ffffff;
  box-shadow: 0 4px 15px var(--secondary-glow);
}

.btn-secondary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px var(--secondary-glow);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-main);
  border-color: var(--card-border);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--card-border-hover);
  transform: translateY(-2px);
}

.btn-icon {
  width: 1.2rem;
  height: 1.2rem;
}

.icon-btn, .icon-btn-sm {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--card-border);
  color: var(--text-main);
  cursor: pointer;
  transition: var(--transition);
}

.icon-btn {
  width: 42px;
  height: 42px;
}

.icon-btn-sm {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
}

.icon-btn:hover, .icon-btn-sm:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--primary-light);
  transform: scale(1.05);
}

/* ==========================================================================
   Header Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--card-border);
  transition: var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  text-decoration: none;
  color: var(--text-main);
}

.logo-icon-wrapper {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 15px rgba(99, 102, 241, 0.2);
}

.logo-svg {
  width: 28px;
  height: 28px;
}

.brand-title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.2rem;
  display: block;
  line-height: 1.1;
  letter-spacing: -0.01em;
}

.brand-tag {
  font-size: 0.75rem;
  color: var(--secondary);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  display: block;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: 1.4rem;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
  padding: 0.4rem 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-main);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--primary-light);
  border-radius: 2px;
  transition: width 0.25s ease;
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  flex-shrink: 0;
}

.calculate-quick-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  height: 36px;
  padding: 0 1rem;
  font-size: 0.84rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  white-space: nowrap;
  flex-shrink: 0;
  border-radius: var(--radius-sm, 6px);
  line-height: 1;
  box-shadow: 0 2px 10px rgba(99, 102, 241, 0.3);
}

.calculate-quick-btn span {
  white-space: nowrap;
  display: inline-block;
}

.btn-arrow,
.calculate-quick-btn .btn-arrow {
  width: 14px;
  height: 14px;
  flex-shrink: 0;
  display: inline-block;
  vertical-align: middle;
  transition: transform 0.2s ease;
}

.calculate-quick-btn:hover .btn-arrow {
  transform: translateX(3px);
}

@media (max-width: 1200px) and (min-width: 769px) {
  .nav-list {
    gap: 0.85rem;
  }
  .nav-link {
    font-size: 0.85rem;
  }
  .calculate-quick-btn {
    height: 34px;
    padding: 0 0.8rem;
    font-size: 0.8rem;
    gap: 0.35rem;
  }
}


/* Mobile Toggle Hamburger */
.mobile-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: transparent;
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  padding: 8px;
}

.hamburger-bar {
  width: 100%;
  height: 2px;
  background-color: var(--text-main);
  border-radius: 2px;
  transition: var(--transition);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 4.5rem 0 3.5rem 0;
  z-index: 1;
}

.hero-container {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 3.5rem;
}

.badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.25);
  color: var(--primary-light);
  padding: 0.4rem 1rem;
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 500;
  margin-bottom: 1.25rem;
}

.badge-sparkle {
  color: var(--accent-amber);
}

.hero-title {
  font-size: clamp(2.4rem, 4.2vw, 3.5rem);
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 1.75rem;
}

/* Primary Formula Hero Card */
.formula-hero-card {
  background: rgba(30, 41, 59, 0.6);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--radius-md);
  padding: 1.2rem 1.6rem;
  margin-bottom: 1.8rem;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
  position: relative;
  overflow: hidden;
}

.formula-hero-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(to bottom, #8b5cf6, #06b6d4);
}

.formula-hero-label {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  text-transform: uppercase;
  color: var(--secondary);
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 0.4rem;
}

.formula-hero-math {
  font-size: 1.35rem;
  color: var(--text-main);
  margin-bottom: 0.6rem;
}

.formula-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.formula-hero-meta strong {
  color: var(--text-main);
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.2rem;
}

.hero-stats {
  display: flex;
  align-items: center;
  gap: 1.8rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--card-border);
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-item-link {
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.2s ease;
}

.stat-item-link:hover .stat-number {
  color: var(--secondary);
}

.stat-item-link:hover .stat-desc {
  color: var(--text-main);
}

.stat-number {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.6rem;
  color: var(--text-main);
  line-height: 1.1;
}

.stat-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.stat-divider {
  width: 1px;
  height: 36px;
  background-color: var(--card-border);
}

/* Hero 3D Card */
.hero-visual {
  display: flex;
  justify-content: center;
}

.hero-cone-card {
  width: 100%;
  max-width: 440px;
  padding: 1.4rem;
  position: relative;
  display: flex;
  flex-direction: column;
}

.card-header-subtle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.8rem;
}

.card-pill {
  font-size: 0.78rem;
  font-family: var(--font-mono);
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-muted);
  border: 1px solid var(--card-border);
}

.live-dot {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.8rem;
  color: var(--accent-emerald-light);
  font-weight: 500;
}

.pulse {
  width: 8px;
  height: 8px;
  background-color: var(--accent-emerald);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--accent-emerald);
  animation: pulse-glow 2s infinite ease-in-out;
}

@keyframes pulse-glow {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.3); opacity: 0.6; }
}

.hero-canvas-wrapper {
  position: relative;
  width: 100%;
  height: 360px;
  background: radial-gradient(circle at 50% 50%, rgba(99, 102, 241, 0.1) 0%, transparent 70%);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

#hero-cone-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.hero-cone-controls {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
  justify-content: center;
}

.mini-control-btn {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--card-border);
  color: var(--text-muted);
  padding: 0.35rem 0.8rem;
  border-radius: 999px;
  font-size: 0.78rem;
  cursor: pointer;
  transition: var(--transition);
}

.mini-control-btn:hover {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.1);
}

.mini-control-btn.active {
  background: var(--primary);
  border-color: var(--primary-light);
  color: #ffffff;
  box-shadow: 0 0 12px var(--primary-glow);
}

/* ==========================================================================
   Calculator Section & Grid
   ========================================================================== */
.calculator-section {
  position: relative;
  padding: 5rem 0 4rem 0;
  z-index: 1;
}

/* Mode Selection Tabs */
.calc-mode-nav-wrapper {
  margin-bottom: 2.2rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
}

.calc-mode-nav {
  display: flex;
  gap: 0.75rem;
  min-width: max-content;
  background: rgba(15, 23, 42, 0.5);
  padding: 0.5rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--card-border);
}

.mode-tab-btn {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.2rem;
  background: transparent;
  border: 1px solid transparent;
  padding: 0.75rem 1.2rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
}

.tab-badge {
  font-size: 0.72rem;
  font-family: var(--font-mono);
  text-transform: uppercase;
  color: var(--text-dim);
  font-weight: 600;
  letter-spacing: 0.05em;
}

.tab-label {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
}

.mode-tab-btn:hover {
  background: rgba(255, 255, 255, 0.04);
}

.mode-tab-btn.active {
  background: var(--bg-card);
  border-color: var(--primary-light);
  box-shadow: 0 4px 20px var(--primary-glow);
}

.mode-tab-btn.active .tab-badge {
  color: var(--secondary);
}

.mode-tab-btn.active .tab-label {
  color: var(--text-main);
}

/* Main 2-Column Grid */
.calc-main-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

/* Left Panel: Inputs */
.calc-inputs-panel {
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.panel-header {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--card-border);
}

.panel-title {
  font-size: 1.35rem;
  margin-bottom: 0.25rem;
}

.panel-hint {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Presets & Custom Dropdowns */
.custom-select {
  background-color: var(--input-bg);
  color: var(--text-main);
  border: 1px solid var(--input-border);
  border-radius: var(--radius-sm);
  padding: 0.65rem 1rem;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  cursor: pointer;
  outline: none;
  transition: var(--transition);
  color-scheme: dark;
}

.custom-select:focus {
  border-color: var(--input-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.25);
}

select option {
  background-color: #0b0f19;
  color: #f8fafc;
}

.preset-select {
  width: 100%;
  font-weight: 500;
  border-color: rgba(99, 102, 241, 0.45);
  background-color: #000000 !important;
  color: #ffffff !important;
  color-scheme: dark !important;
}

.preset-select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.35);
}

.preset-select option {
  background-color: #000000 !important;
  color: #ffffff !important;
  padding: 10px 14px;
}

.preset-select option:disabled {
  background-color: #080b12 !important;
  color: #818cf8 !important;
  font-weight: 600;
}

.preset-select option:hover,
.preset-select option:checked {
  background-color: #1e1b4b !important;
  color: #a5b4fc !important;
}

/* Form Rows */
.calc-form {
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
}

.form-row {
  display: flex;
  gap: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.flex-1 {
  flex: 1;
}

.label-with-tooltip {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.label-with-tooltip label {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-main);
}

.math-symbol-tag {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  background: rgba(255, 255, 255, 0.06);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  color: var(--secondary);
  font-weight: 600;
}

.input-with-slider {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.input-unit-group {
  display: flex;
  position: relative;
}

.calc-input {
  flex: 1;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-right: none;
  border-top-left-radius: var(--radius-sm);
  border-bottom-left-radius: var(--radius-sm);
  color: var(--text-main);
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 500;
  padding: 0.75rem 1rem;
  outline: none;
  transition: var(--transition);
}

.calc-input:focus {
  border-color: var(--input-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.unit-select {
  width: 90px;
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
  font-weight: 600;
  border-left: 1px solid var(--card-border);
}

/* Custom Range Sliders */
.calc-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}

.calc-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);
  cursor: pointer;
  box-shadow: 0 0 8px var(--primary-glow);
  transition: transform 0.15s ease;
}

.calc-slider::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);
  cursor: pointer;
  box-shadow: 0 0 8px var(--primary-glow);
  border: none;
}

.calc-slider::-webkit-slider-thumb:hover {
  transform: scale(1.25);
}

/* Settings Row */
.form-row-settings {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  padding: 1.1rem 0;
  border-top: 1px solid var(--card-border);
  border-bottom: 1px solid var(--card-border);
}

.setting-item {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.setting-item label {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-muted);
}

.setting-item select {
  font-size: 0.85rem;
  padding: 0.55rem 0.8rem;
}

/* Actions Row */
.form-actions {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
}

/* Right Panel: Visualizer & Results */
.calc-visual-panel {
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
}

.visualizer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.tab-pill-group {
  display: flex;
  background: rgba(0, 0, 0, 0.25);
  padding: 0.25rem;
  border-radius: 999px;
  border: 1px solid var(--card-border);
}

.visual-toggle-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  cursor: pointer;
  transition: var(--transition);
}

.visual-toggle-btn.active {
  background: var(--primary);
  color: #ffffff;
  box-shadow: 0 2px 10px var(--primary-glow);
}

/* Interactive Canvas Container */
.interactive-canvas-container {
  position: relative;
  width: 100%;
  height: 310px;
  background: radial-gradient(circle at 50% 50%, rgba(99, 102, 241, 0.08) 0%, transparent 75%);
  border-radius: var(--radius-md);
  border: 1px solid var(--card-border);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: grab;
}

.interactive-canvas-container:active {
  cursor: grabbing;
}

#cone-main-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* Live Floating Dimension Badges */
.canvas-tag {
  position: absolute;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
  backdrop-filter: blur(8px);
  pointer-events: none;
  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.tag-height {
  top: 40%;
  left: 18%;
  background: rgba(245, 158, 11, 0.2);
  border: 1px solid rgba(245, 158, 11, 0.5);
  color: var(--accent-amber-light);
}

.tag-radius {
  bottom: 18%;
  left: 45%;
  background: rgba(16, 185, 129, 0.2);
  border: 1px solid rgba(16, 185, 129, 0.5);
  color: var(--accent-emerald-light);
}

.tag-slant {
  top: 36%;
  right: 18%;
  background: rgba(6, 182, 212, 0.2);
  border: 1px solid rgba(6, 182, 212, 0.5);
  color: var(--secondary);
}

.canvas-hint-overlay {
  position: absolute;
  bottom: 8px;
  right: 12px;
  font-size: 0.72rem;
  color: var(--text-dim);
  background: rgba(15, 23, 42, 0.7);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  pointer-events: none;
}

/* Primary Result Banner */
.calc-result-banner {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15) 0%, rgba(6, 182, 212, 0.15) 100%);
  border: 1px solid rgba(99, 102, 241, 0.4);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  text-align: center;
  box-shadow: 0 8px 30px rgba(99, 102, 241, 0.15);
}

.result-lead {
  font-size: 0.88rem;
  color: var(--secondary);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.35rem;
}

.result-primary-number {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.5rem;
}

.value-highlight {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.unit-highlight {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--primary-light);
}

.result-exact-pi {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-top: 0.4rem;
  font-family: var(--font-mono);
}

.result-exact-pi strong {
  color: var(--accent-amber-light);
}

/* Companion Stats 4-Card Grid */
.companion-stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.8rem;
}

.comp-stat-card {
  background: rgba(30, 41, 59, 0.4);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.comp-stat-card .stat-title {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
}

.comp-stat-card .stat-value {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
}

.comp-stat-card .stat-formula {
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* ==========================================================================
   Step-by-Step Breakdown Panel
   ========================================================================== */
.step-solution-panel {
  padding: 2rem;
  margin-top: 1rem;
}

.step-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--card-border);
  margin-bottom: 1.5rem;
}

.step-header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.step-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.3);
  color: var(--accent-emerald-light);
  display: flex;
  align-items: center;
  justify-content: center;
}

.step-icon svg {
  width: 24px;
  height: 24px;
}

.step-title {
  font-size: 1.25rem;
}

.step-subtitle {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.step-content-body {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
  margin-bottom: 2rem;
}

.step-item {
  background: rgba(30, 41, 59, 0.35);
  border: 1px solid var(--card-border);
  border-left: 3px solid var(--primary-light);
  border-radius: var(--radius-sm);
  padding: 1.2rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.step-item-title {
  font-weight: 600;
  font-size: 1rem;
  color: var(--primary-light);
}

.step-item-math {
  font-size: 1.05rem;
  padding: 0.4rem 0;
}

.step-item-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Equivalent Unit Conversions Grid */
.unit-conversion-wrapper {
  padding-top: 1.5rem;
  border-top: 1px solid var(--card-border);
}

.conversions-title {
  font-size: 0.95rem;
  margin-bottom: 1rem;
  color: var(--text-muted);
  font-weight: 600;
}

.conversions-chips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 0.75rem;
}

.conversion-chip {
  background: rgba(30, 41, 59, 0.4);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.conv-unit-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  font-weight: 500;
}

.conv-unit-value {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
}

/* ==========================================================================
   Water Pouring Proof Section
   ========================================================================== */
.derivation-section {
  position: relative;
  padding: 5rem 0;
  z-index: 1;
}

.proof-interactive-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2rem;
  align-items: start;
}

.proof-simulator-card, .proof-explanation-card {
  padding: 2.2rem;
}

.sim-title, .expl-title {
  font-size: 1.35rem;
  margin-bottom: 0.4rem;
}

.sim-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.sim-canvas-stage {
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.sim-stage-visual {
  display: flex;
  align-items: center;
  justify-content: space-around;
  position: relative;
  min-height: 240px;
}

.sim-cone-station, .sim-cylinder-station {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.station-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.sim-svg-cone, .sim-svg-cylinder {
  width: 140px;
  height: 180px;
  overflow: visible;
}

.station-meta {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--secondary);
  font-weight: 500;
}

/* Pour Stream Line Animation */
.pour-stream-line {
  position: absolute;
  top: 70px;
  left: 36%;
  width: 28%;
  height: 4px;
  background: linear-gradient(90deg, #38bdf8 0%, #0284c7 100%);
  border-radius: 4px;
  opacity: 0;
  transform: rotate(20deg);
  transition: opacity 0.3s ease;
  box-shadow: 0 0 10px #38bdf8;
}

.pour-stream-line.pouring {
  opacity: 1;
  animation: streamFlow 0.4s infinite linear;
}

@keyframes streamFlow {
  0% { transform: rotate(20deg) scaleX(0.8); }
  50% { transform: rotate(20deg) scaleX(1); }
  100% { transform: rotate(20deg) scaleX(0.8); }
}

.sim-action-controls {
  display: flex;
  gap: 1rem;
}

/* Mathematical Proof Card */
.expl-method-block {
  margin-top: 1.25rem;
  padding: 1.25rem;
  background: rgba(30, 41, 59, 0.4);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
}

.method-tag {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--primary-light);
  font-weight: 600;
  text-transform: uppercase;
  margin-bottom: 0.6rem;
}

.method-text {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.math-block {
  padding: 0.6rem 0;
  font-size: 1.05rem;
}

.method-conclusion {
  font-size: 0.9rem;
  color: var(--accent-amber-light);
  font-weight: 600;
  margin-top: 0.5rem;
}

/* ==========================================================================
   Formulas Reference Section
   ========================================================================== */
.formulas-section {
  position: relative;
  padding: 5rem 0;
  z-index: 1;
}

.formula-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 1.5rem;
}

.formula-card {
  padding: 1.8rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.formula-card:hover {
  transform: translateY(-4px);
  border-color: var(--card-border-hover);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.35);
}

.formula-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-pill.pill-violet {
  background: rgba(139, 92, 246, 0.15);
  color: #c4b5fd;
  border-color: rgba(139, 92, 246, 0.3);
}

.card-pill.pill-cyan {
  background: rgba(6, 182, 212, 0.15);
  color: #67e8f9;
  border-color: rgba(6, 182, 212, 0.3);
}

.card-pill.pill-amber {
  background: rgba(245, 158, 11, 0.15);
  color: #fcd34d;
  border-color: rgba(245, 158, 11, 0.3);
}

.card-pill.pill-emerald {
  background: rgba(16, 185, 129, 0.15);
  color: #6ee7b7;
  border-color: rgba(16, 185, 129, 0.3);
}

.card-pill.pill-rose {
  background: rgba(244, 63, 94, 0.15);
  color: #fda4af;
  border-color: rgba(244, 63, 94, 0.3);
}

.card-abbr {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
}

.formula-expression {
  font-size: 1.35rem;
  background: rgba(0, 0, 0, 0.2);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  border: 1px solid var(--card-border);
}

.formula-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.55;
}

.formula-variables {
  font-size: 0.82rem;
  color: var(--text-dim);
  border-top: 1px solid var(--card-border);
  padding-top: 0.8rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

/* ==========================================================================
   Worked Examples Section
   ========================================================================== */
.examples-section {
  position: relative;
  padding: 5rem 0;
  z-index: 1;
}

.examples-accordion-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: 900px;
  margin: 0 auto;
}

.example-box {
  padding: 1.8rem;
}

.example-box-header {
  margin-bottom: 1.25rem;
}

.example-badge {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--secondary);
  text-transform: uppercase;
  margin-bottom: 0.35rem;
}

.example-title {
  font-size: 1.2rem;
}

.example-solution-flow {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.flow-step {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  background: rgba(30, 41, 59, 0.3);
  padding: 0.9rem 1.2rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--card-border);
}

.flow-step-num {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  background: var(--primary);
  color: #ffffff;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  white-space: nowrap;
}

.flow-step-text {
  font-size: 0.95rem;
  color: var(--text-muted);
}

.flow-step-text strong {
  color: var(--accent-emerald-light);
}

/* ==========================================================================
   Interactive Practice Quiz Section
   ========================================================================== */
.quiz-section {
  position: relative;
  padding: 5rem 0;
  z-index: 1;
}

.quiz-card {
  max-width: 800px;
  margin: 0 auto;
  padding: 2.5rem;
}

.quiz-badge {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--accent-amber);
  font-weight: 600;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.quiz-title {
  font-size: 1.8rem;
  margin-bottom: 0.5rem;
}

.quiz-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.quiz-question-box {
  background: rgba(30, 41, 59, 0.5);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 1.4rem 1.6rem;
  margin-bottom: 1.5rem;
}

.question-meta {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.8rem;
}

.pill-difficulty {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--secondary);
  background: rgba(6, 182, 212, 0.15);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
}

.pill-score {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-emerald-light);
  background: rgba(16, 185, 129, 0.15);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-weight: 600;
}

.question-prompt {
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text-main);
  line-height: 1.55;
}

.quiz-choices-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.quiz-choice-btn {
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: var(--radius-md);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 500;
  padding: 1.1rem 1.3rem;
  cursor: pointer;
  text-align: left;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.quiz-choice-btn:hover:not(:disabled) {
  border-color: var(--primary-light);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.choice-letter {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  background: rgba(255, 255, 255, 0.08);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--secondary);
}

.quiz-choice-btn.correct {
  background: rgba(16, 185, 129, 0.2) !important;
  border-color: var(--accent-emerald) !important;
  color: #ffffff;
}

.quiz-choice-btn.incorrect {
  background: rgba(244, 63, 94, 0.2) !important;
  border-color: var(--accent-rose) !important;
  color: #ffffff;
}

.quiz-feedback-box {
  border-radius: var(--radius-sm);
  padding: 1rem 1.4rem;
  margin-bottom: 1.5rem;
  background: rgba(30, 41, 59, 0.6);
  border: 1px solid var(--card-border);
  animation: fadeIn 0.3s ease;
}

.feedback-status {
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: 0.35rem;
}

.feedback-explanation {
  font-size: 0.92rem;
  color: var(--text-muted);
}

.feedback-success {
  border-left: 4px solid var(--accent-emerald);
}
.feedback-success .feedback-status {
  color: var(--accent-emerald-light);
}

.feedback-danger {
  border-left: 4px solid var(--accent-rose);
}
.feedback-danger .feedback-status {
  color: var(--accent-rose);
}

.quiz-footer-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq-section {
  position: relative;
  padding: 5rem 0;
  z-index: 1;
}

.faq-accordion {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  background: transparent;
  border: none;
  color: var(--text-main);
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
}

.faq-chevron {
  width: 20px;
  height: 20px;
  color: var(--text-muted);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.faq-item.active .faq-chevron {
  transform: rotate(180deg);
  color: var(--primary-light);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  padding: 0 1.5rem;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding-bottom: 1.4rem;
}

.faq-answer p {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ==========================================================================
   Site Footer
   ========================================================================== */
.site-footer {
  background: rgba(10, 15, 26, 0.95);
  border-top: 1px solid var(--card-border);
  padding: 4.5rem 0 2.5rem 0;
  position: relative;
  z-index: 10;
  width: 100%;
}

.footer-container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.footer-top,
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1.1fr 1fr 1.3fr;
  gap: 2.5rem;
  margin-bottom: 3rem;
  align-items: start;
}

.footer-col,
.footer-links-col,
.footer-formula-col,
.footer-pages-col {
  display: flex;
  flex-direction: column;
}

.footer-math-pill {
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--radius-sm, 8px);
  padding: 0.65rem 1rem;
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-main, #f8fafc);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.footer-math-note {
  font-size: 0.82rem;
  color: var(--text-muted, #94a3b8);
  line-height: 1.5;
}

.footer-brand-col {
  display: flex;
  flex-direction: column;
  max-width: 380px;
}

.brand-logo.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  margin-bottom: 0.5rem;
}

.footer-tagline {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-top: 0.8rem;
}

.footer-heading,
.footer-col-title {
  font-size: 0.98rem;
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1.2rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

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

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.88rem;
  transition: var(--transition);
  display: inline-block;
}

.footer-links a:hover {
  color: var(--primary-light);
  transform: translateX(3px);
}

.footer-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.8rem;
  border-radius: var(--radius-sm);
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.3);
  color: var(--primary-light);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  margin-top: 1rem;
  width: fit-content;
}

.footer-lang-col {
  display: flex;
  flex-direction: column;
}

.footer-lang-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 0.4rem;
  max-width: 270px;
  width: 100%;
}

.lang-btn {
  height: 32px;
  min-width: 36px;
  padding: 0 4px;
  font-size: 0.78rem;
  font-weight: 700;
  font-family: var(--font-sans);
  border-radius: 6px;
  background: rgba(30, 41, 59, 0.7);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: #94a3b8;
  cursor: pointer;
  text-align: center;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-transform: uppercase;
  white-space: nowrap;
  overflow: hidden;
  box-sizing: border-box;
}

.lang-btn:hover {
  background: rgba(51, 65, 85, 0.95);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.lang-btn.active {
  background: #2563eb;
  color: #ffffff;
  border-color: #3b82f6;
  box-shadow: 0 0 14px rgba(37, 99, 235, 0.5);
}

/* Hide Google Translate toolbar banners to keep website pristine */
.goog-te-banner-frame.skiptranslate,
.goog-te-gadget-simple,
#goog-gt-tt,
.goog-te-balloon-frame {
  display: none !important;
}
body {
  top: 0 !important;
}
.skiptranslate {
  display: none !important;
}
#google_translate_element {
  display: none !important;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid var(--card-border);
  font-size: 0.85rem;
  color: var(--text-dim);
}

.footer-meta-links a {
  color: var(--primary-light);
  text-decoration: none;
  font-weight: 500;
}

.footer-meta-links a:hover {
  text-decoration: underline;
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  
  .hero-buttons {
    justify-content: center;
  }
  
  .hero-stats {
    justify-content: center;
  }
  
  .calc-main-grid {
    grid-template-columns: 1fr;
  }
  
  .proof-interactive-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .mobile-toggle {
    display: flex;
  }

  .calculate-quick-btn {
    display: none;
  }

  .nav-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--card-border);
    padding: 1.5rem;
    box-shadow: var(--shadow-lg);
    clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
    transition: clip-path 0.3s ease-in-out;
  }

  .nav-menu.open {
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
  }

  .nav-list {
    flex-direction: column;
    gap: 1rem;
  }

  .quiz-choices-grid {
    grid-template-columns: 1fr;
  }

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

  .form-row-settings {
    grid-template-columns: 1fr;
  }
}

/* ==========================================================================
   More Calculators Section (Homepage)
   ========================================================================== */
.more-calculators-section {
  position: relative;
  padding: 5rem 0 4.5rem 0;
  z-index: 1;
}

.more-calcs-filter-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2.75rem;
}

.more-filter-btn {
  padding: 0.55rem 1.25rem;
  border-radius: 9999px;
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.more-filter-btn:hover {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.2);
  background: rgba(30, 41, 59, 0.85);
}

.more-filter-btn.active {
  background: #2563eb;
  color: #ffffff;
  border-color: #3b82f6;
  box-shadow: 0 0 18px rgba(37, 99, 235, 0.45);
}

.more-calcs-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  margin-bottom: 3rem;
}

@media (max-width: 1100px) {
  .more-calcs-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .more-calcs-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }
}

@media (max-width: 480px) {
  .more-calcs-grid {
    grid-template-columns: 1fr;
  }
}

.home-calc-card {
  background: rgba(15, 23, 42, 0.65);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 18px;
  padding: 1.85rem 1.25rem;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  min-height: 165px;
  gap: 1.15rem;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
  cursor: pointer;
}

.home-calc-card:hover,
.home-calc-card:focus-visible {
  border-color: #3b82f6;
  border-width: 1px;
  box-shadow: 0 0 25px rgba(59, 130, 246, 0.4), inset 0 0 15px rgba(59, 130, 246, 0.1);
  transform: translateY(-4px);
}

.home-calc-icon-wrap {
  width: 68px;
  height: 54px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 0;
  background: transparent;
  border: none;
  border-radius: 0;
}

.home-calc-icon-wrap svg {
  width: 100%;
  height: 100%;
  display: block;
  transition: transform 0.25s ease;
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.35));
}

.home-calc-card:hover .home-calc-icon-wrap svg {
  transform: scale(1.1);
}

.home-calc-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: #f1f5f9;
  margin: 0;
  line-height: 1.35;
  transition: color 0.2s ease;
}

.home-calc-card:hover .home-calc-title {
  color: #ffffff;
}

.more-calcs-cta-box {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.12) 0%, rgba(6, 182, 212, 0.1) 100%);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.2rem;
}

/* ==========================================================================
   Print / PDF Styles
   ========================================================================== */
@media print {
  body {
    background: #ffffff !important;
    color: #000000 !important;
  }

  .site-header, .site-footer, .hero-cone-controls, .form-actions, 
  .ambient-glow, .calc-mode-nav-wrapper, .presets-dropdown-wrapper,
  .calc-slider, .quiz-section, .derivation-section {
    display: none !important;
  }

  .glass-card {
    border: 1px solid #cccccc !important;
    box-shadow: none !important;
    background: #ffffff !important;
  }

  .calc-main-grid {
    grid-template-columns: 1fr !important;
    page-break-inside: avoid;
  }

  .value-highlight, .unit-highlight {
    color: #000000 !important;
  }
}