/* UnitSnap - Fluent Design System Styles */

/* CSS Custom Properties (Variables) - Palette Chiara e Luminosa */
:root {
  /* Light Theme - Colori chiari e luminosi */
  --primary-color: #FF6B9D; /* Rosa coral luminoso */
  --primary-hover: #FF5722; /* Rosa più intenso per hover */
  --primary-active: #E53935; /* Rosa scuro per active */
  --primary-light: #FFB3E6; /* Rosa pastello chiaro */
  --primary-lighter: #FFE1F3; /* Rosa cristallino */
  
  /* Colori secondari luminosi e freschi */
  --secondary-color: #4ECDC4; /* Turchese menta */
  --secondary-hover: #26A69A;
  --accent-color: #FFD93D; /* Giallo sole brillante */
  --accent-hover: #FFC107;
  --tertiary-color: #A8E6CF; /* Verde menta pastello */
  --tertiary-hover: #81C784;
  
  /* Status colors con tinte chiare */
  --success-color: #66BB6A; /* Verde fresco */
  --success-hover: #4CAF50;
  --warning-color: #FFAB40; /* Arancione pastello */
  --warning-hover: #FF9800;
  --error-color: #EF5350; /* Rosso corallo */
  --error-hover: #F44336;
  --info-color: #42A5F5; /* Azzurro cielo */
  --info-hover: #2196F3;
  
  /* Gradienti chiari e luminosi */
  --gradient-primary: linear-gradient(135deg, #FF6B9D 0%, #FFB3E6 100%);
  --gradient-secondary: linear-gradient(135deg, #4ECDC4 0%, #A8E6CF 100%);
  --gradient-accent: linear-gradient(135deg, #FFD93D 0%, #FFAB40 100%);
  --gradient-warm: linear-gradient(135deg, #FF6B9D 0%, #FFD93D 100%);
  --gradient-cool: linear-gradient(135deg, #4ECDC4 0%, #42A5F5 100%);
  --gradient-pastel: linear-gradient(135deg, #FFE1F3 0%, #E1F5FE 100%);
  
  /* Testo e sfondi chiari */
  --text-primary: #2E2E2E; /* Grigio scuro per leggibilità */
  --text-secondary: #5E5E5E; /* Grigio medio */
  --text-light: #8E8E8E; /* Grigio chiaro */
  --text-white: #FFFFFF;
  
  /* Sfondi neutri luminosi */
  --background-primary: #FEFEFE; /* Bianco purissimo */
  --background-secondary: #F8F9FA; /* Grigio chiarissimo */
  --background-tertiary: #F3F4F6; /* Grigio perla */
  --background-glass: rgba(255, 255, 255, 0.7); /* Glass effect luminoso */
  
  /* Bordi e separatori delicati */
  --border-color: rgba(255, 107, 157, 0.2);
  --border-hover: rgba(255, 107, 157, 0.4);
  --divider-color: rgba(46, 46, 46, 0.1);
  
  /* Ombre delicate */
  --shadow-light: 0 2px 8px rgba(255, 107, 157, 0.15);
  --shadow-medium: 0 4px 16px rgba(255, 107, 157, 0.2);
  --shadow-heavy: 0 8px 32px rgba(255, 107, 157, 0.25);
  --glass-shadow: 0 8px 32px rgba(255, 255, 255, 0.3);
  
  /* Enhanced Neutral Colors */
  --neutral-foreground-rest: #1F2937;
  --neutral-foreground-hover: #111827;
  --neutral-background: #FFFFFF;
  --neutral-background-hover: #F8FAFC;
  --neutral-background-pressed: #F1F5F9;
  --neutral-stroke-rest: #E2E8F0;
  --neutral-stroke-hover: #CBD5E1;
  --neutral-layer-floating: rgba(255, 255, 255, 0.95);
  --neutral-layer-card: rgba(248, 250, 252, 0.8);
  
  /* Glass Effect Colors */
  --glass-background: rgba(255, 255, 255, 0.1);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-shadow: 0 8px 32px rgba(31, 38, 135, 0.37);
  
  /* Semantic Colors */
  --card-background: rgba(255, 255, 255, 0.85);
  --card-border: rgba(148, 163, 184, 0.1);
  --overlay-background: rgba(15, 23, 42, 0.5);
  
  /* Typography */
  --font-family-primary: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-family-monospace: 'Cascadia Code', 'Consolas', monospace;
  
  /* Font Sizes */
  --font-size-caption: 12px;
  --font-size-body: 14px;
  --font-size-body-large: 16px;
  --font-size-subtitle: 20px;
  --font-size-title: 28px;
  --font-size-display: 34px;
  
  /* Font Weights */
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  /* Spacing */
  --spacing-xs: 4px;
  --spacing-s: 8px;
  --spacing-m: 12px;
  --spacing-l: 16px;
  --spacing-xl: 20px;
  --spacing-xxl: 24px;
  --spacing-xxxl: 32px;
  
  /* Border Radius */
  --radius-none: 0;
  --radius-small: 4px;
  --radius-medium: 8px;
  --radius-large: 12px;
  --radius-circular: 50%;
  
  /* Shadows */
  --shadow-2: 0 1px 2px rgba(0, 0, 0, 0.14), 0 0px 2px rgba(0, 0, 0, 0.12);
  --shadow-4: 0 2px 4px rgba(0, 0, 0, 0.14), 0 0px 2px rgba(0, 0, 0, 0.12);
  --shadow-8: 0 4px 8px rgba(0, 0, 0, 0.14), 0 0px 2px rgba(0, 0, 0, 0.12);
  --shadow-16: 0 8px 16px rgba(0, 0, 0, 0.14), 0 0px 2px rgba(0, 0, 0, 0.12);
  --shadow-28: 0 14px 28px rgba(0, 0, 0, 0.24), 0 0px 8px rgba(0, 0, 0, 0.20);
  
  /* Animations */
  --duration-ultra-fast: 50ms;
  --duration-faster: 100ms;
  --duration-fast: 150ms;
  --duration-normal: 200ms;
  --duration-gentle: 250ms;
  --duration-slow: 300ms;
  --duration-slower: 400ms;
  
  --curve-accelerate-mid: cubic-bezier(0.7, 0, 1, 0.5);
  --curve-decelerate-mid: cubic-bezier(0.1, 0.9, 0.2, 1);
  --curve-easy-ease: cubic-bezier(0.33, 0, 0.67, 1);
  --curve-linear: linear;
}

/* Dark Theme - Palette Chiara adattata per dark mode */
[data-theme="dark"] {
  /* Colori chiari adattati per dark mode */
  --primary-color: #FF8BA7; /* Rosa coral più luminoso per dark */
  --primary-hover: #FF6B9D; /* Rosa originale per hover */
  --primary-active: #FF5722; /* Rosa più scuro per active */
  --primary-light: #FFB3E6; /* Rosa pastello */
  --primary-lighter: #FFE1F3; /* Rosa cristallino */
  
  /* Colori secondari per dark mode */
  --secondary-color: #5FDDD6; /* Turchese più luminoso */
  --secondary-hover: #4ECDC4;
  --accent-color: #FFE135; /* Giallo più brillante per dark */
  --accent-hover: #FFD93D;
  --tertiary-color: #B8F5D1; /* Verde menta più chiaro */
  --tertiary-hover: #A8E6CF;
  
  /* Status colors adattati per dark */
  --success-color: #81C784; /* Verde più luminoso */
  --warning-color: #FFCC02; /* Giallo più brillante */
  --error-color: #FF7043; /* Rosso corallo luminoso */
  --info-color: #64B5F6; /* Azzurro più chiaro */
  
  /* Sfondi dark con palette chiara */
  --background-primary: #121212; /* Nero soft */
  --background-secondary: #1E1E1E; /* Grigio scuro */
  --background-tertiary: #2A2A2A; /* Grigio medio scuro */
  --background-glass: rgba(255, 107, 157, 0.1); /* Glass rosa per dark */
  
  /* Testi per dark mode */
  --text-primary: #FFFFFF; /* Bianco per dark */
  --text-secondary: #E0E0E0; /* Grigio chiaro */
  --text-light: #BDBDBD; /* Grigio medio */
  --text-white: #FFFFFF;
  
  /* Bordi dark */
  --border-color: rgba(255, 139, 167, 0.3);
  --border-hover: rgba(255, 139, 167, 0.5);
  --divider-color: rgba(255, 255, 255, 0.1);
  
  /* Ombre dark con tinte rosa */
  --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.5);
  --shadow-heavy: 0 8px 32px rgba(0, 0, 0, 0.6);
  --glass-shadow: 0 8px 32px rgba(255, 107, 157, 0.2);
  
  --neutral-foreground-rest: #F8FAFC;
  --neutral-foreground-hover: #E2E8F0;
  --neutral-background: #0F172A; /* Slate profondo */
  --neutral-background-hover: #1E293B;
  --neutral-background-pressed: #334155;
  --neutral-stroke-rest: #475569;
  --neutral-stroke-hover: #64748B;
  --neutral-layer-floating: rgba(30, 41, 59, 0.95);
  --neutral-layer-card: rgba(15, 23, 42, 0.8);
  
  --glass-background: rgba(15, 23, 42, 0.2);
  --glass-border: rgba(148, 163, 184, 0.1);
  
  --card-background: rgba(30, 41, 59, 0.85);
  --card-border: rgba(148, 163, 184, 0.1);
  --overlay-background: rgba(0, 0, 0, 0.7);
}

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

html {
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-family-primary);
  font-size: var(--font-size-body-large);
  font-weight: var(--font-weight-regular);
  color: var(--text-primary, #023047);
  background: var(--background-primary, #F8FDFF);
  overflow-x: hidden;
}

/* App Container */
.app-container {
  min-height: 100vh;
  background: var(--gradient-primary);
  background-attachment: fixed;
  position: relative;
}

.app-container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at 20% 80%, var(--primary-light) 0%, transparent 50%),
              radial-gradient(circle at 80% 20%, var(--accent-color) 0%, transparent 50%),
              radial-gradient(circle at 40% 40%, var(--tertiary-color) 0%, transparent 50%);
  opacity: 0.1;
  pointer-events: none;
}

/* Header con nuovi colori chiari e luminosi */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  backdrop-filter: blur(20px) saturate(180%);
  background: var(--background-glass, rgba(255, 255, 255, 0.7));
  border-bottom: 1px solid var(--border-color, rgba(255, 107, 157, 0.2));
  box-shadow: var(--shadow-medium, 0 4px 16px rgba(255, 107, 157, 0.2));
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-l);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-l);
}

.logo-section {
  display: flex;
  align-items: center;
  gap: var(--spacing-m);
}

.logo-icon {
  width: 48px;
  height: 48px;
  background: var(--gradient-primary);
  border-radius: var(--radius-medium);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-white, #ffffff);
  font-size: 24px;
  box-shadow: var(--shadow-medium);
}

.logo-text .app-title {
  font-size: var(--font-size-title);
  font-weight: var(--font-weight-bold);
  color: var(--text-primary, #023047);
  margin: 0;
}

.logo-text .app-tagline {
  font-size: var(--font-size-body);
  color: var(--text-secondary, #0077B6);
  margin: 0;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-s);
}

.control-button {
  /* Dimensioni fisse e forzate */
  width: 45px !important;
  height: 45px !important;
  min-width: 45px !important;
  min-height: 45px !important;
  
  /* Layout e posizionamento */
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  position: relative !important;
  
  /* Sfondo solido con fallback multipli */
  background: #FF6B9D !important;
  background: rgba(255, 107, 157, 0.9) !important;
  background: var(--primary-color, #FF6B9D) !important;
  
  /* Bordo visibile */
  border: 2px solid rgba(255, 255, 255, 0.4) !important;
  border-radius: 12px !important;
  
  /* Colore del testo */
  color: #ffffff !important;
  
  /* Effetti glass */
  backdrop-filter: blur(10px) !important;
  -webkit-backdrop-filter: blur(10px) !important;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2) !important;
  
  /* Interazione */
  cursor: pointer !important;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1) !important;
  
  /* Font e testo */
  font-size: 1.2rem !important;
  font-family: inherit !important;
  
  /* Visibilità forzata */
  opacity: 1 !important;
  visibility: visible !important;
  z-index: 1000 !important;
  
  /* Reset */
  margin: 0 !important;
  padding: 0 !important;
  outline: none !important;
}

.control-button:hover {
  background: #FF5722 !important;
  background: rgba(255, 87, 34, 0.95) !important;
  color: #ffffff !important;
  border-color: rgba(255, 255, 255, 0.6) !important;
  transform: translateY(-2px) scale(1.05) !important;
  box-shadow: 0 8px 25px rgba(255, 107, 157, 0.4) !important;
}

.control-button:active {
  background: #E53935 !important;
  transform: translateY(0) scale(0.98) !important;
  box-shadow: 0 2px 10px rgba(255, 107, 157, 0.3) !important;
}

.control-button i {
  font-size: 1.2rem !important;
  color: inherit !important;
  pointer-events: none !important;
}

/* Theme Icons - Gestione visibilità basata sul tema */
.theme-icon-light {
  display: block !important;
}

.theme-icon-dark {
  display: none !important;
}

[data-theme="dark"] .theme-icon-light {
  display: none !important;
}

[data-theme="dark"] .theme-icon-dark {
  display: block !important;
}

/* Language Selector */
.language-selector {
  display: flex;
  align-items: center;
  gap: var(--spacing-s);
  background: var(--glass-background);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-medium);
  padding: var(--spacing-s);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  backdrop-filter: blur(20px) saturate(180%);
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.language-selector:hover {
  background: var(--neutral-background-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-4);
}

.language-label {
  display: flex;
  align-items: center;
  color: var(--neutral-foreground-rest);
  font-size: 16px;
  cursor: pointer;
}

.language-select {
  border: none;
  background: transparent;
  font-size: var(--font-size-body);
  color: var(--neutral-foreground-rest);
  cursor: pointer;
  outline: none;
  font-weight: var(--font-weight-medium);
  min-width: 100px;
}

.language-select option {
  background: var(--neutral-layer-floating);
  color: var(--neutral-foreground-rest);
  padding: var(--spacing-s);
}

.language-select:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
  border-radius: var(--radius-small);
}

/* Main Content */
.main-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-xxxl) var(--spacing-l);
}

/* Category Section */
.category-section {
  margin-bottom: var(--spacing-xxxl);
}

.category-section h2 {
  font-size: var(--font-size-subtitle);
  font-weight: var(--font-weight-semibold);
  color: white;
  margin-bottom: var(--spacing-xl);
  text-align: center;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-l);
}

.category-card {
  background: var(--card-background);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-large);
  padding: var(--spacing-xl);
  display: flex;
  align-items: center;
  gap: var(--spacing-l);
  cursor: pointer;
  transition: all var(--duration-normal) var(--curve-decelerate-mid);
  text-align: left;
  width: 100%;
}

.category-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-8);
  background: var(--neutral-background-hover);
}

.category-card:active {
  transform: translateY(-2px);
}

.category-card.active {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 2px rgba(0, 120, 212, 0.2);
  background: var(--neutral-background);
}

.category-icon {
  width: 48px;
  height: 48px;
  background: var(--gradient-primary);
  border-radius: var(--radius-medium);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 20px;
  flex-shrink: 0;
  transition: all var(--duration-normal) var(--curve-decelerate-mid);
  box-shadow: var(--shadow-4);
}

/* Colori chiari e luminosi per le categorie */
.category-card:nth-child(1) .category-icon { 
  background: linear-gradient(135deg, #FF6B9D 0%, #FFB3E6 100%); /* Rosa coral per Lunghezza */
}
.category-card:nth-child(2) .category-icon { 
  background: linear-gradient(135deg, #4ECDC4 0%, #A8E6CF 100%); /* Turchese menta per Peso */
}
.category-card:nth-child(3) .category-icon { 
  background: linear-gradient(135deg, #FFD93D 0%, #FFAB40 100%); /* Giallo sole per Valute */
}
.category-card:nth-child(4) .category-icon { 
  background: linear-gradient(135deg, #EF5350 0%, #FF8A80 100%); /* Rosso corallo per Temperatura */
}
.category-card:nth-child(5) .category-icon { 
  background: linear-gradient(135deg, #66BB6A 0%, #A5D6A7 100%); /* Verde fresco per Tempo */
}
.category-card:nth-child(6) .category-icon { 
  background: linear-gradient(135deg, #42A5F5 0%, #90CAF9 100%); /* Azzurro cielo per Energia */
}
.category-card:nth-child(7) .category-icon { 
  background: linear-gradient(135deg, #AB47BC 0%, #CE93D8 100%); /* Viola pastello per Potenza */
}
.category-card:nth-child(8) .category-icon { 
  background: linear-gradient(135deg, #26A69A 0%, #80CBC4 100%); /* Turchese profondo per Volume */
}

.category-card.active .category-icon {
  transform: scale(1.15) !important;
  animation: pulseStrong 2s infinite !important;
  box-shadow: 0 8px 25px rgba(255, 107, 157, 0.4) !important;
  filter: brightness(1.1) saturate(1.2) !important;
}

.category-card:hover .category-icon {
  transform: scale(1.08) !important;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3) !important;
  filter: brightness(1.05) saturate(1.1) !important;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1) !important;
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

@keyframes pulseStrong {
  0% { 
    transform: scale(1.15); 
    box-shadow: 0 8px 25px rgba(255, 107, 157, 0.4);
  }
  50% { 
    transform: scale(1.2); 
    box-shadow: 0 12px 30px rgba(255, 107, 157, 0.6);
  }
  100% { 
    transform: scale(1.15);
    box-shadow: 0 8px 25px rgba(255, 107, 157, 0.4);
  }
}

.category-info h3 {
  font-size: var(--font-size-body-large);
  font-weight: var(--font-weight-semibold);
  color: var(--neutral-foreground-rest);
  margin-bottom: var(--spacing-xs);
}

.category-info p {
  font-size: var(--font-size-body);
  color: var(--neutral-foreground-hover);
}

/* Conversion Section - Enhanced UI */
.conversion-section {
  margin-bottom: var(--spacing-xxxl);
}

.conversion-card {
  background: var(--card-background);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-large);
  padding: var(--spacing-xxxl);
  margin-bottom: var(--spacing-xl);
  box-shadow: var(--shadow-medium);
  transition: all var(--duration-normal) var(--curve-easy-ease);
}

.conversion-card:hover {
  box-shadow: var(--shadow-heavy);
  transform: translateY(-2px);
}

.conversion-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-l);
  border-bottom: 2px solid var(--primary-lighter);
}

.conversion-title {
  font-size: var(--font-size-title);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  margin: 0 0 var(--spacing-s) 0;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.conversion-subtitle {
  font-size: var(--font-size-body);
  color: var(--text-secondary);
  margin: 0;
  opacity: 0.8;
}

.conversion-inputs {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--spacing-xl);
  align-items: center;
  margin-bottom: var(--spacing-xl);
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-m);
  position: relative;
}

.input-label-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-s);
}

.input-label {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-semibold);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.input-info {
  color: var(--text-light);
  cursor: help;
  opacity: 0.7;
  transition: opacity var(--duration-fast) var(--curve-easy-ease);
}

.input-info:hover {
  opacity: 1;
  color: var(--primary-color);
}

.conversion-result-badge {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  background: var(--success-color);
  color: white;
  padding: var(--spacing-xs) var(--spacing-s);
  border-radius: var(--radius-small);
  font-size: var(--font-size-caption);
  font-weight: var(--font-weight-medium);
  animation: slideInDown 0.3s var(--curve-easy-ease);
}

.input-container {
  position: relative;
  display: flex;
  gap: var(--spacing-s);
  background: var(--background-primary);
  border: 2px solid transparent;
  border-radius: var(--radius-medium);
  overflow: hidden;
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.input-wrapper {
  position: relative;
  flex: 1;
  display: flex;
  align-items: center;
}

.input-overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.input-focus-ring {
  position: absolute;
  inset: -2px;
  border: 2px solid transparent;
  border-radius: var(--radius-medium);
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.input-container:focus-within .input-focus-ring {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(255, 107, 157, 0.2);
}

.input-container:hover:not(:focus-within) {
  background: var(--background-secondary);
  border-color: var(--border-hover);
}

.conversion-input {
  width: 100%;
  border: none;
  background: transparent;
  font-size: var(--font-size-body-large);
  font-weight: var(--font-weight-medium);
  color: var(--text-primary);
  outline: none;
  padding: var(--spacing-l);
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.conversion-input::placeholder {
  color: var(--text-light);
  font-style: italic;
}

.conversion-input:focus::placeholder {
  opacity: 0.5;
}

.copy-button {
  position: absolute;
  right: var(--spacing-s);
  top: 50%;
  transform: translateY(-50%);
  width: 32px;
  height: 32px;
  border: none;
  background: var(--primary-color);
  color: white;
  border-radius: var(--radius-small);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: all var(--duration-fast) var(--curve-easy-ease);
  opacity: 0.8;
}

.copy-button:hover {
  background: var(--primary-hover);
  opacity: 1;
  transform: translateY(-50%) scale(1.1);
}

.unit-selector {
  position: relative;
  border-left: 1px solid var(--border-color);
}

.unit-select {
  border: none;
  background: transparent;
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-medium);
  color: var(--text-primary);
  cursor: pointer;
  outline: none;
  padding: var(--spacing-l);
  min-width: 120px;
  appearance: none;
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
  background-position: right var(--spacing-s) center;
  background-repeat: no-repeat;
  background-size: 16px;
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.unit-select:hover {
  background-color: var(--background-secondary);
}

.unit-select:focus {
  background-color: var(--primary-lighter);
}

.conversion-divider {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-s);
  position: relative;
}

.swap-button {
  width: 56px;
  height: 56px;
  border: none;
  background: var(--gradient-warm);
  color: white;
  border-radius: var(--radius-circular);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  transition: all var(--duration-normal) var(--curve-easy-ease);
  position: relative;
  box-shadow: var(--shadow-light);
}

.swap-button::before {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: var(--radius-circular);
  background: var(--gradient-warm);
  opacity: 0;
  transition: opacity var(--duration-fast) var(--curve-easy-ease);
}

.swap-button:hover {
  transform: scale(1.1) rotate(180deg);
  box-shadow: var(--shadow-medium);
}

.swap-button:hover::before {
  opacity: 0.3;
}

.swap-button:active {
  transform: scale(1.05) rotate(180deg);
}

.swap-icon {
  z-index: 1;
  position: relative;
}

.swap-tooltip {
  position: absolute;
  bottom: -32px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--text-primary);
  color: white;
  padding: var(--spacing-xs) var(--spacing-s);
  border-radius: var(--radius-small);
  font-size: var(--font-size-caption);
  font-weight: var(--font-weight-medium);
  opacity: 0;
  pointer-events: none;
  transition: all var(--duration-fast) var(--curve-easy-ease);
  white-space: nowrap;
}

.swap-button:hover .swap-tooltip {
  opacity: 1;
  transform: translateX(-50%) translateY(-4px);
}

/* Enhanced states for input groups */
.from-group .input-container {
  border-color: var(--primary-light);
}

.to-group .input-container {
  border-color: var(--secondary-color);
}

.from-group .conversion-input:focus {
  background: linear-gradient(90deg, transparent 0%, rgba(255, 107, 157, 0.05) 100%);
}

.to-group .conversion-input:focus {
  background: linear-gradient(90deg, rgba(78, 205, 196, 0.05) 0%, transparent 100%);
}

/* Responsive design for mobile */
@media (max-width: 768px) {
  .conversion-inputs {
    grid-template-columns: 1fr;
    gap: var(--spacing-l);
  }
  
  .conversion-divider {
    order: 2;
    flex-direction: row;
    justify-content: center;
    margin: var(--spacing-m) 0;
  }
  
  .swap-button {
    transform: rotate(90deg);
  }
  
  .swap-button:hover {
    transform: scale(1.1) rotate(270deg);
  }
  
  .input-container {
    flex-direction: column;
    gap: 0;
  }
  
  .unit-selector {
    border-left: none;
    border-top: 1px solid var(--border-color);
  }
}

/* Quick Actions */
.quick-actions {
  display: flex;
  justify-content: center;
  gap: var(--spacing-m);
}

.action-button {
  display: flex;
  align-items: center;
  gap: var(--spacing-s);
  padding: var(--spacing-m) var(--spacing-l);
  border: 1px solid var(--neutral-stroke-rest);
  background: var(--neutral-background);
  color: var(--neutral-foreground-rest);
  border-radius: var(--radius-medium);
  cursor: pointer;
  font-size: var(--font-size-body);
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.action-button:hover {
  background: var(--neutral-background-hover);
  border-color: var(--neutral-stroke-hover);
  transform: translateY(-2px);
}

.action-button:active {
  transform: translateY(0);
}

/* Results Grid */
.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-l);
}

.result-card {
  background: var(--card-background);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-medium);
  padding: var(--spacing-l);
  text-align: center;
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.result-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-4);
}

.result-card .unit-name {
  font-size: var(--font-size-body);
  color: var(--neutral-foreground-hover);
  margin-bottom: var(--spacing-xs);
}

.result-card .unit-value {
  font-size: var(--font-size-subtitle);
  font-weight: var(--font-weight-semibold);
  color: var(--neutral-foreground-rest);
  font-family: var(--font-family-monospace);
}

/* Calculator Section */
.calculator-section {
  position: fixed;
  bottom: 80px;
  right: var(--spacing-xl);
  z-index: 1000;
  animation: slideUp var(--duration-normal) var(--curve-decelerate-mid);
}

.calculator-card {
  background: var(--neutral-layer-floating);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-large);
  padding: var(--spacing-l);
  box-shadow: var(--shadow-16);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  backdrop-filter: blur(20px) saturate(180%);
  width: 280px;
}

.calculator-display {
  margin-bottom: var(--spacing-l);
}

.calculator-display input {
  width: 100%;
  padding: var(--spacing-l);
  border: 1px solid var(--neutral-stroke-rest);
  border-radius: var(--radius-medium);
  background: var(--neutral-background);
  font-size: var(--font-size-title);
  font-weight: var(--font-weight-medium);
  font-family: var(--font-family-monospace);
  text-align: right;
  color: var(--neutral-foreground-rest);
}

.calculator-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-s);
}

.calc-btn {
  height: 48px;
  border: none;
  border-radius: var(--radius-medium);
  background: var(--neutral-background);
  border: 1px solid var(--neutral-stroke-rest);
  color: var(--neutral-foreground-rest);
  font-size: var(--font-size-body-large);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.calc-btn:hover {
  background: var(--neutral-background-hover);
  transform: scale(1.05);
}

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

.calc-btn.clear-btn {
  background: var(--error-color);
  color: white;
  border-color: var(--error-color);
}

.calc-btn.equals-btn {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
  grid-row: span 2;
}

.calc-btn.zero-btn {
  grid-column: span 2;
}

/* Calculator Toggle - Ultra Robusto */
.calc-toggle {
  /* Posizione fissa */
  position: fixed !important;
  bottom: 30px !important;
  right: 30px !important;
  
  /* Dimensioni fisse */
  width: 64px !important;
  height: 64px !important;
  min-width: 64px !important;
  min-height: 64px !important;
  
  /* Reset e layout */
  border: none !important;
  margin: 0 !important;
  padding: 0 !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  
  /* Sfondo con multipli fallback chiari */
  background: #FF6B9D !important;
  background: var(--gradient-primary) !important;
  background: var(--gradient-warm, linear-gradient(135deg, #FF6B9D 0%, #FFD93D 100%)) !important;
  
  /* Colore e testo */
  color: #ffffff !important;
  font-size: 28px !important;
  
  /* Forma */
  border-radius: 50% !important;
  
  /* Effetti */
  -webkit-backdrop-filter: blur(10px) !important;
  backdrop-filter: blur(10px) !important;
  box-shadow: 0 8px 32px rgba(31, 38, 135, 0.5) !important;
  border: 2px solid rgba(255, 255, 255, 0.3) !important;
  
  /* Visibilità e interazione */
  cursor: pointer !important;
  z-index: 9999 !important;
  opacity: 1 !important;
  visibility: visible !important;
  pointer-events: auto !important;
  
  /* Transizione */
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1) !important;
}

.calc-toggle:hover {
  background: var(--gradient-cool) !important;
  background: linear-gradient(135deg, #4ECDC4 0%, #42A5F5 100%) !important;
  transform: scale(1.15) rotate(5deg) !important;
  box-shadow: 0 12px 40px rgba(255, 107, 157, 0.5) !important;
  animation: calcPulse 1.5s infinite !important;
}

.calc-toggle:active {
  transform: scale(1.1) rotate(0deg);
}

/* Forza la visibilità dei bottoni critici */
.calc-toggle,
.control-button {
  opacity: 1 !important;
  visibility: visible !important;
  pointer-events: auto !important;
}

@keyframes calcPulse {
  0%, 100% { box-shadow: 0 12px 40px rgba(251, 113, 133, 0.4); }
  50% { box-shadow: 0 16px 50px rgba(251, 113, 133, 0.6); }
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--overlay-background);
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-l);
  animation: fadeIn var(--duration-normal) var(--curve-decelerate-mid);
}

.modal-content {
  background: var(--neutral-layer-floating);
  border-radius: var(--radius-large);
  max-width: 600px;
  width: 100%;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-28);
  animation: slideUp var(--duration-normal) var(--curve-decelerate-mid);
}

.modal-header {
  padding: var(--spacing-xl);
  border-bottom: 1px solid var(--card-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h2 {
  font-size: var(--font-size-subtitle);
  font-weight: var(--font-weight-semibold);
  color: var(--neutral-foreground-rest);
}

.modal-close {
  width: 32px;
  height: 32px;
  border: none;
  background: transparent;
  cursor: pointer;
  border-radius: var(--radius-medium);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--neutral-foreground-rest);
  transition: background var(--duration-fast) var(--curve-easy-ease);
}

.modal-close:hover {
  background: var(--neutral-background-hover);
}

.modal-body {
  flex: 1;
  overflow-y: auto;
  padding: var(--spacing-xl);
}

.modal-footer {
  padding: var(--spacing-xl);
  border-top: 1px solid var(--card-border);
  display: flex;
  justify-content: flex-end;
  gap: var(--spacing-m);
}

/* History List */
.history-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-m);
}

.history-item {
  background: var(--neutral-layer-card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-medium);
  padding: var(--spacing-l);
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  transition: all var(--duration-fast) var(--curve-easy-ease);
}

.history-item:hover {
  background: var(--neutral-background-hover);
  transform: translateX(4px);
}

.history-conversion {
  font-family: var(--font-family-monospace);
  font-size: var(--font-size-body);
  color: var(--neutral-foreground-rest);
}

.history-date {
  font-size: var(--font-size-caption);
  color: var(--neutral-foreground-hover);
}

/* Buttons */
.button {
  padding: var(--spacing-m) var(--spacing-l);
  border-radius: var(--radius-medium);
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all var(--duration-fast) var(--curve-easy-ease);
  border: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-s);
}

.button.primary {
  background: var(--primary-color);
  color: white;
}

.button.primary:hover {
  background: var(--primary-hover);
}

.button.primary:active {
  background: var(--primary-active);
}

.button.secondary {
  background: var(--neutral-background);
  color: var(--neutral-foreground-rest);
  border: 1px solid var(--neutral-stroke-rest);
}

.button.secondary:hover {
  background: var(--neutral-background-hover);
}

/* Toast Notifications */
.toast-container {
  position: fixed;
  top: var(--spacing-xl);
  right: var(--spacing-xl);
  z-index: 3000;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-s);
}

.toast {
  background: var(--neutral-layer-floating);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-medium);
  padding: var(--spacing-l);
  box-shadow: var(--shadow-8);
  display: flex;
  align-items: center;
  gap: var(--spacing-m);
  min-width: 280px;
  animation: slideIn var(--duration-normal) var(--curve-decelerate-mid);
}

.toast.success {
  border-left: 4px solid var(--success-color);
}

.toast.error {
  border-left: 4px solid var(--error-color);
}

.toast.warning {
  border-left: 4px solid var(--warning-color);
}

.toast-icon {
  font-size: 16px;
  color: var(--primary-color);
}

.toast-message {
  flex: 1;
  font-size: var(--font-size-body);
  color: var(--neutral-foreground-rest);
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(100%);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

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

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-8px);
  }
  60% {
    transform: translateY(-4px);
  }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  10%, 30%, 50%, 70%, 90% { transform: translateX(-2px); }
  20%, 40%, 60%, 80% { transform: translateX(2px); }
}

/* Responsive Design */
@media (max-width: 768px) {
  .header-content {
    padding: var(--spacing-m);
    flex-direction: column;
    gap: var(--spacing-m);
  }
  
  .language-selector {
    padding: var(--spacing-xs);
  }
  
  .language-select {
    font-size: var(--font-size-caption);
    min-width: 80px;
  }
  
  .logo-icon {
    width: 40px;
    height: 40px;
    font-size: 20px;
  }
  
  .logo-text .app-title {
    font-size: var(--font-size-subtitle);
  }
  
  .main-content {
    padding: var(--spacing-xl) var(--spacing-m);
  }
  
  .category-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-m);
  }
  
  .category-card {
    padding: var(--spacing-l);
    gap: var(--spacing-m);
  }
  
  .input-section {
    grid-template-columns: 1fr;
    gap: var(--spacing-l);
    text-align: center;
  }
  
  .swap-button {
    align-self: center;
    transform: rotate(90deg);
  }
  
  .swap-button:hover {
    transform: rotate(270deg) scale(1.1);
  }
  
  .quick-actions {
    flex-wrap: wrap;
    gap: var(--spacing-s);
  }
  
  .results-grid {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-m);
  }
  
  .calculator-section {
    position: fixed;
    inset: 0;
    background: var(--overlay-background);
    -webkit-backdrop-filter: blur(4px);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-l);
  }
  
  .calc-toggle {
    bottom: var(--spacing-l);
    right: var(--spacing-l);
    width: 48px;
    height: 48px;
    font-size: 20px;
  }
}

@media (max-width: 480px) {
  .header-content {
    flex-direction: column;
    gap: var(--spacing-m);
  }
  
  .converter-card {
    padding: var(--spacing-xl);
  }
  
  .modal-content {
    margin: var(--spacing-s);
    max-height: calc(100vh - var(--spacing-l));
  }
  
  .toast-container {
    left: var(--spacing-s);
    right: var(--spacing-s);
  }
  
  .toast {
    min-width: auto;
  }
}

/* High contrast mode */
@media (prefers-contrast: high) {
  :root {
    --card-border: rgba(0, 0, 0, 0.2);
    --neutral-stroke-rest: #000000;
  }
  
  [data-theme="dark"] {
    --card-border: rgba(255, 255, 255, 0.2);
    --neutral-stroke-rest: #FFFFFF;
  }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Print styles */
@media print {
  .app-header,
  .calc-toggle,
  .calculator-section,
  .quick-actions,
  .modal-overlay {
    display: none !important;
  }
  
  .main-content {
    padding: 0;
  }
  
  .converter-card {
    box-shadow: none;
    border: 1px solid #000;
  }
}