/* ============================================
   Interactive Electronics Tools - Global Styles
   ============================================ */

/* CSS Variables - Design System */
:root {
 /* Color Palette */
 --color-primary: #0066CC;
 --color-primary-dark: #004080;
 --color-primary-light: #E6F2FF;
 --color-secondary: #00A86B;
 --color-accent: #FF6B35;
 --color-text: #1A1A1A;
 --color-text-secondary: #6C757D;
 --color-background: #F5F7FA;
 --color-surface: #FFFFFF;
 --color-border: #E1E4E8;

 /* Typography */
 --font-family: 'Inter', 'Segoe UI', -apple-system, system-ui, sans-serif;
 --font-size-base: 16px;
 --font-size-sm: 14px;
 --font-size-lg: 18px;
 --font-size-xl: 24px;
 --font-size-2xl: 28px;
 --font-size-3xl: 36px;
 --font-weight-normal: 400;
 --font-weight-medium: 500;
 --font-weight-semibold: 600;
 --font-weight-bold: 700;

 /* Spacing */
 --spacing-xs: 4px;
 --spacing-sm: 8px;
 --spacing-md: 16px;
 --spacing-lg: 24px;
 --spacing-xl: 32px;
 --spacing-2xl: 48px;

 /* Border Radius */
 --radius-sm: 6px;
 --radius-md: 8px;
 --radius-lg: 12px;
 --radius-xl: 16px;

 /* Shadows */
 --shadow-sm: 0 2px 4px rgba(0,0,0,0.06);
 --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
 --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
 --shadow-focus: 0 0 0 3px rgba(0,102,204,0.1);

 /* Transitions */
 --transition-fast: 0.15s ease;
 --transition-base: 0.2s ease;
 --transition-slow: 0.3s ease;
}

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

body {
 font-family: var(--font-family) !important;
 background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-background) 100%);
 color: var(--color-text);
 line-height: 1.6;
 min-height: 100vh;
 padding-top: 72px !important; /* Space for fixed nav */
 padding-bottom: var(--spacing-2xl) !important; /* Bottom spacing */
 overflow-x: hidden;
 overflow-y: auto;
 /* Override inline flex centering styles */
 display: block !important;
 justify-content: unset !important;
 align-items: unset !important;
 margin: 0 !important;
}

/* Navigation Menu */
.site-nav {
 position: fixed;
 top: 0;
 left: 0;
 right: 0;
 background: var(--color-surface);
 border-bottom: 1px solid var(--color-border);
 box-shadow: var(--shadow-md);
 z-index: 1000;
}

.nav-container {
 max-width: 1400px;
 margin: 0 auto;
 padding: 0 var(--spacing-lg);
 display: flex;
 align-items: center;
 /* justify-content: space-between; */
 height: 72px;
}

.nav-brand {
 display: flex;
 align-items: center;
 gap: var(--spacing-md);
 text-decoration: none;
 color: var(--color-text);
 font-weight: var(--font-weight-bold);
 font-size: var(--font-size-lg);
 transition: color var(--transition-base);
}

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

.nav-logo {
 width: 32px;
 height: 32px;
}

.nav-menu {
 display: flex;
 align-items: center;
 gap: var(--spacing-xs);
 list-style: none;
 margin-left: 50px;
}

.nav-item {
 position: relative;
}

.nav-link {
 display: flex;
 align-items: center;
 gap: var(--spacing-xs);
 padding: var(--spacing-sm) var(--spacing-md);
 color: var(--color-text-secondary);
 text-decoration: none;
 font-size: var(--font-size-sm);
 font-weight: var(--font-weight-medium);
 border-radius: var(--radius-md);
 transition: all var(--transition-base);
}

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

.nav-link.active {
 color: var(--color-primary);
 font-weight: var(--font-weight-semibold);
}

/* Dropdown Menu */
.nav-dropdown {
 position: relative;
}

.dropdown-toggle {
 cursor: pointer;
}

.dropdown-menu {
 display: none;
 position: absolute;
 top: 100%;
 left: 0;
 min-width: 240px;
 background: var(--color-surface);
 border-radius: var(--radius-lg);
 box-shadow: var(--shadow-lg);
 border: 1px solid var(--color-border);
 padding: var(--spacing-sm);
 margin-top: 0;
 z-index: 1001;
 opacity: 0;
 transform: translateY(-8px);
 transition: opacity var(--transition-fast), transform var(--transition-fast);
 pointer-events: none;
}

.nav-dropdown:hover .dropdown-menu {
 display: block;
 opacity: 1;
 transform: translateY(0);
 pointer-events: auto;
 transition-delay: 0s;
}

.dropdown-menu:hover {
 display: block;
 opacity: 1;
 pointer-events: auto;
}

.dropdown-menu .nav-link {
 display: block;
 padding: var(--spacing-md);
 border-radius: var(--radius-md);
}

.dropdown-menu .nav-link:hover {
 background: var(--color-primary-light);
}

/* Mobile Menu Toggle */
.nav-toggle {
 display: none;
 background: none;
 border: none;
 font-size: 24px;
 cursor: pointer;
 color: var(--color-text);
 padding: var(--spacing-sm);
}

/* Container & Layout */
.container {
 max-width: 900px;
 margin: var(--spacing-xl) auto;
 padding: var(--spacing-lg);
 background: var(--color-surface);
 border-radius: var(--radius-xl);
 box-shadow: var(--shadow-lg);
 border: 1px solid var(--color-border);
 width: calc(100% - var(--spacing-lg) * 2);
 overflow: visible;
}

.container-wide {
 max-width: 1200px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
 font-weight: var(--font-weight-bold);
 line-height: 1.2;
 margin-bottom: var(--spacing-md);
}

h1 {
 font-size: var(--font-size-2xl);
 color: var(--color-primary-dark);
}

h2 {
 font-size: var(--font-size-xl);
 color: var(--color-primary-dark);
}
h2.category-title a {
 text-decoration: none;
}

h3 {
 font-size: var(--font-size-lg);
 color: var(--color-text);
}

.subtitle {
 color: var(--color-text-secondary);
 font-size: var(--font-size-sm);
 font-weight: var(--font-weight-medium);
 margin-bottom: var(--spacing-xl);
}

/* Form Controls */
input[type="range"] {
 width: 100%;
 height: 8px;
 border-radius: var(--radius-sm);
 background: var(--color-border);
 outline: none;
 appearance: none;
}

input[type="range"]::-webkit-slider-thumb {
 appearance: none;
 width: 22px;
 height: 22px;
 border-radius: 50%;
 background: var(--color-primary);
 cursor: pointer;
 box-shadow: 0 2px 8px rgba(0,102,204,0.3);
 transition: transform var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
 transform: scale(1.1);
}

input[type="text"],
input[type="number"],
select {
 width: 100%;
 padding: var(--spacing-md);
 border: 2px solid var(--color-border);
 border-radius: var(--radius-md);
 font-family: var(--font-family);
 font-size: var(--font-size-base);
 transition: all var(--transition-base);
 margin-top: 20px;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus {
 outline: none;
 border-color: var(--color-primary);
 box-shadow: var(--shadow-focus);
}

label {
 display: block;
 color: var(--color-text);
 font-weight: var(--font-weight-semibold);
 margin-bottom: var(--spacing-sm);
 font-size: var(--font-size-sm);
}

/* Buttons */
button,
.btn {
 padding: var(--spacing-md) var(--spacing-xl);
 background: var(--color-primary);
 color: var(--color-surface);
 border: none;
 border-radius: var(--radius-md);
 font-family: var(--font-family);
 font-size: var(--font-size-base);
 font-weight: var(--font-weight-semibold);
 cursor: pointer;
 transition: all var(--transition-base);
 box-shadow: var(--shadow-sm);
}

button:hover,
.btn:hover {
 background: var(--color-primary-dark);
 transform: translateY(-2px);
 box-shadow: var(--shadow-md);
}

button:active,
.btn:active {
 transform: translateY(0);
}

button:disabled,
.btn:disabled {
 background: var(--color-border);
 cursor: not-allowed;
 transform: none;
}

/* Control Groups */
.control-group {
 background: var(--color-background);
 padding: var(--spacing-md);
 border-radius: var(--radius-lg);
 border: 1px solid var(--color-border);
 margin-bottom: var(--spacing-md);
}

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

.value-display {
 text-align: center;
 font-size: var(--font-size-lg);
 font-weight: var(--font-weight-bold);
 color: var(--color-primary);
 margin-top: var(--spacing-sm);
}

/* Results Display */
.results {
 background: var(--color-primary-light);
 padding: var(--spacing-lg);
 border-radius: var(--radius-lg);
 border: 1px solid var(--color-primary);
 margin-bottom: var(--spacing-lg);
}

.result-row {
 display: flex;
 justify-content: space-between;
 align-items: center;
 padding: var(--spacing-md) 0;
 border-bottom: 1px solid rgba(0,102,204,0.2);
}

.result-row:last-child {
 border-bottom: none;
}

.result-label {
 font-weight: var(--font-weight-semibold);
 color: var(--color-primary-dark);
 font-size: var(--font-size-sm);
}

.result-value {
 font-size: var(--font-size-lg);
 font-weight: var(--font-weight-bold);
 color: var(--color-primary);
}

/* Info Boxes */
.info-box {
 background: var(--color-primary-light);
 padding: var(--spacing-md);
 border-radius: var(--radius-md);
 border-left: 4px solid var(--color-primary);
 margin-top: var(--spacing-lg);
}
.info-box ul {
 margin-left: 40px;
}

.info-title {
 font-weight: var(--font-weight-semibold);
 color: var(--color-primary-dark);
 margin-bottom: var(--spacing-sm);
}

.info-text {
 font-size: var(--font-size-sm);
 color: var(--color-text-secondary);
 line-height: 1.6;
}

/* Responsive Design */
@media (max-width: 768px) {
 body {
  padding-top: 60px;
 }

 .nav-container {
  height: 60px;
 }

 .nav-toggle {
  display: block;
 }

 .nav-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-md);
  flex-direction: column;
  box-shadow: var(--shadow-lg);
 }

 .nav-menu.active {
  display: flex;
 }

 .dropdown-menu {
  position: static;
  box-shadow: none;
  border: none;
  margin-top: 0;
 }

 .container {
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
 }

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

 h1 {
  font-size: var(--font-size-xl);
 }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.hidden { display: none; }