/* ==========================================================================
   PROENGINEERING.IN - Core Design System & CSS Variables
   Official Domain: proengineering.in
   Brand Contact: amaresh.das@proengineering.com
   ========================================================================== */

:root {
  /* Color Palette - Precision Industrial Tech */
  --bg-primary: #070B14;
  --bg-secondary: #0D1527;
  --bg-card: rgba(16, 26, 48, 0.85);
  --bg-card-hover: rgba(23, 37, 68, 0.95);
  --bg-surface: #121E36;
  --bg-glass: rgba(16, 26, 48, 0.7);

  /* Accents & Brand Tones */
  --primary: #00F0FF;
  --primary-glow: rgba(0, 240, 255, 0.25);
  --primary-dark: #00B8D4;
  --accent-blue: #0066FF;
  --accent-indigo: #4F46E5;
  --accent-green: #10B981;
  --accent-amber: #F59E0B;
  --accent-red: #EF4444;

  /* Text & Contrast */
  --text-main: #FFFFFF;
  --text-muted: #94A3B8;
  --text-dim: #64748B;
  --text-highlight: #E2E8F0;

  /* Borders & Grids */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(0, 240, 255, 0.6);
  --border-cyan: rgba(0, 240, 255, 0.3);

  /* Elevation & Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.7);
  --shadow-glow: 0 0 25px rgba(0, 240, 255, 0.2);

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Roboto Mono', 'Fira Code', monospace;

  /* Spacing */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --transition-fast: 150ms ease;
  --transition-normal: 250ms cubic-bezier(0.16, 1, 0.3, 1);
}

/* Light Mode Overrides (Controlled Technical Theme) */
[data-theme="light"] {
  --bg-primary: #F8FAFC;
  --bg-secondary: #EDF2F7;
  --bg-card: rgba(255, 255, 255, 0.95);
  --bg-card-hover: rgba(255, 255, 255, 1);
  --bg-surface: #E2E8F0;
  --bg-glass: rgba(255, 255, 255, 0.85);

  --primary: #0066FF;
  --primary-glow: rgba(0, 102, 255, 0.15);
  --primary-dark: #004ecc;
  --accent-blue: #0052CC;

  --text-main: #0F172A;
  --text-muted: #475569;
  --text-dim: #64748B;
  --text-highlight: #1E293B;

  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-focus: rgba(0, 102, 255, 0.6);
  --border-cyan: rgba(0, 102, 255, 0.3);

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.12);
  --shadow-glow: 0 0 25px rgba(0, 102, 255, 0.15);
}

/* Reset & Box Sizing */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  background-image: 
    radial-gradient(circle at 15% 10%, rgba(0, 240, 255, 0.04) 0%, transparent 40%),
    radial-gradient(circle at 85% 60%, rgba(79, 70, 229, 0.05) 0%, transparent 45%),
    linear-gradient(to bottom, transparent, rgba(7, 11, 20, 0.8));
}

/* Technical Subtle Grid Pattern */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(rgba(255, 255, 255, 0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.015) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

/* Focus Management - WCAG 2.2 AA */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

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

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* Container */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* Top Notification / Trust Bar */
.top-bar {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0.4rem 1.5rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 101;
}

.top-bar a:hover {
  color: var(--primary);
}

.top-bar-left {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.top-bar-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.badge-trust {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--accent-green);
  font-weight: 500;
}

/* Main Header & Navbar */
.site-header {
  position: sticky;
  top: 0;
  background: var(--bg-glass);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-subtle);
  z-index: 100;
  transition: all var(--transition-fast);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 4.5rem;
}

.logo-wrapper {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-img {
  height: 38px;
  width: auto;
  display: block;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  font-weight: 500;
  font-size: 0.92rem;
  color: var(--text-highlight);
  position: relative;
  padding: 0.5rem 0.25rem;
}

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

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary);
  border-radius: var(--radius-full);
}

/* Currency Switcher & Cart Action */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.currency-toggle {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  display: flex;
  padding: 2px;
}

.curr-btn {
  background: transparent;
  border: none;
  color: var(--text-dim);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.curr-btn.active {
  background: var(--primary);
  color: #070B14;
}

.cart-btn {
  position: relative;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-main);
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.88rem;
  font-weight: 600;
  transition: all var(--transition-fast);
}

.cart-btn:hover {
  border-color: var(--border-cyan);
  box-shadow: var(--shadow-glow);
}

.cart-count {
  background: var(--primary);
  color: #070B14;
  font-size: 0.7rem;
  font-weight: 800;
  padding: 0.1rem 0.4rem;
  border-radius: var(--radius-full);
}

.theme-toggle-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-highlight);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  color: var(--primary);
  border-color: var(--border-cyan);
}

.mobile-menu-toggle {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Standard Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
  border: none;
  text-align: center;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, #0099FF 100%);
  color: #070B14;
  box-shadow: 0 4px 15px rgba(0, 240, 255, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 240, 255, 0.45);
}

.btn-secondary {
  background: var(--bg-surface);
  color: var(--text-main);
  border: 1px solid var(--border-subtle);
}

.btn-secondary:hover {
  border-color: var(--border-cyan);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 1px solid var(--border-cyan);
}

.btn-outline:hover {
  background: rgba(0, 240, 255, 0.1);
  border-color: var(--primary);
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.82rem;
}

.btn-lg {
  padding: 0.85rem 1.8rem;
  font-size: 1.05rem;
}

/* Section Common Styling */
.section {
  padding: 5rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 3.5rem;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 1.5px;
  background: rgba(0, 240, 255, 0.08);
  padding: 0.25rem 0.8rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
  border: 1px solid rgba(0, 240, 255, 0.2);
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.25;
  color: var(--text-main);
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Footer */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  padding: 4.5rem 0 2rem;
  margin-top: 4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.2fr;
  gap: 3rem;
  margin-bottom: 3.5rem;
}

.footer-col-brand p {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin: 1.2rem 0;
  max-width: 380px;
}

.footer-contact-box {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  padding: 1rem;
  border-radius: var(--radius-md);
  margin-top: 1rem;
}

.footer-contact-box .label {
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--text-dim);
  font-family: var(--font-mono);
  display: block;
}

.footer-contact-box .email-link {
  color: var(--primary);
  font-weight: 600;
  font-size: 0.95rem;
  word-break: break-all;
}

.footer-col h4 {
  font-size: 0.95rem;
  color: var(--text-main);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 1.2rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-links a:hover {
  color: var(--primary);
  padding-left: 4px;
}

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