/* ==========================================================================
   EMBEDX – Embedded Systems and Automation Club
   Official Website Design System (Main Core CSS)
   Department of Electrical and Electronics Engineering (EEE)
   SRM TRP Engineering College, Tiruchirappalli
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Rajdhani:wght@500;600;700&family=Space+Grotesk:wght@500;600;700&family=Sora:wght@400;600;700;800&family=JetBrains+Mono:wght@400;500;700&display=swap');

:root {
  /* Controlled Professional Brand Palette */
  --primary-navy: #0B2A6F;
  --secondary-blue: #123F8C;
  --navy-dark: #071C4B;
  --navy-deep: #04102C;
  
  --engineering-green: #146B3A;
  --green-dark: #0E4E2A;
  --green-light: #1E8C4E;
  --green-glow: rgba(20, 107, 58, 0.25);
  
  --accent-blue: #2D72D9;
  --accent-cyan: #00D2FF;
  --blue-glow: rgba(45, 114, 217, 0.25);
  
  --accent-orange: #F47B20;
  --orange-light: #FF8F3D;
  --orange-glow: rgba(244, 123, 32, 0.3);
  
  --bg-primary: #FFFFFF;
  --bg-secondary: #F5F8FC;
  --bg-tertiary: #EDF3FA;
  --bg-card: #FFFFFF;
  --bg-card-hover: #FCFDFF;
  --bg-dark-section: #081738;
  --bg-dark-card: #0F234D;
  
  --border-light: rgba(11, 42, 111, 0.12);
  --border-card: rgba(18, 63, 140, 0.1);
  --border-hover: rgba(45, 114, 217, 0.35);
  --border-glow: rgba(0, 210, 255, 0.4);
  
  --text-dark: #152238;
  --text-primary: #1A2E50;
  --text-muted: #617086;
  --text-light: #8E9EBA;
  --text-white: #FFFFFF;
  
  /* Elevation Shadows */
  --shadow-sm: 0 2px 8px rgba(11, 42, 111, 0.06);
  --shadow-md: 0 8px 24px rgba(11, 42, 111, 0.08);
  --shadow-lg: 0 16px 40px rgba(11, 42, 111, 0.12);
  --shadow-xl: 0 24px 60px rgba(11, 42, 111, 0.16);
  --shadow-glow-blue: 0 0 25px rgba(45, 114, 217, 0.35);
  --shadow-glow-orange: 0 0 25px rgba(244, 123, 32, 0.35);
  --shadow-glow-green: 0 0 25px rgba(20, 107, 58, 0.35);

  /* Typography Fonts */
  --font-heading: 'Space Grotesk', 'Rajdhani', sans-serif;
  --font-subheading: 'Sora', sans-serif;
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --font-code: 'JetBrains Mono', monospace;

  /* Layout Spacing */
  --container-max: 1320px;
  --header-height: 84px;
  --header-compact-height: 70px;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-bounce: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

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

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

body {
  font-family: var(--font-body);
  color: var(--text-dark);
  background-color: var(--bg-secondary);
  line-height: 1.65;
  font-weight: 400;
  overflow-x: hidden;
  position: relative;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Subtle PCB / Grid Blueprint Texture */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    radial-gradient(rgba(11, 42, 111, 0.04) 1px, transparent 1px),
    linear-gradient(to right, rgba(11, 42, 111, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(11, 42, 111, 0.02) 1px, transparent 1px);
  background-size: 40px 40px, 80px 80px, 80px 80px;
  pointer-events: none;
  z-index: -2;
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--primary-navy);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.2rem, 4.5vw, 3.5rem); }
h2 { font-size: clamp(1.8rem, 3vw, 2.5rem); }
h3 { font-size: clamp(1.3rem, 2vw, 1.75rem); }
h4 { font-size: clamp(1.1rem, 1.5vw, 1.35rem); }
h5 { font-size: 1.1rem; }
h6 { font-size: 0.95rem; text-transform: uppercase; letter-spacing: 0.08em; }

p {
  margin-bottom: 1rem;
  color: var(--text-muted);
}

p:last-child {
  margin-bottom: 0;
}

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

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

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

ul, ol {
  list-style-position: inside;
}

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

/* Layout Utilities */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.container-fluid {
  width: 100%;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.section {
  padding-top: clamp(4rem, 8vw, 7rem);
  padding-bottom: clamp(4rem, 8vw, 7rem);
  position: relative;
}

.section-sm {
  padding-top: clamp(2.5rem, 5vw, 4rem);
  padding-bottom: clamp(2.5rem, 5vw, 4rem);
}

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

.section-bg-alt {
  background-color: var(--bg-secondary);
}

.section-bg-dark {
  background-color: var(--bg-dark-section);
  color: var(--text-white);
}

.section-bg-dark h1,
.section-bg-dark h2,
.section-bg-dark h3,
.section-bg-dark h4 {
  color: var(--text-white);
}

.section-bg-dark p {
  color: var(--text-light);
}

/* Section Headers */
.section-header {
  text-align: center;
  max-width: 780px;
  margin: 0 auto clamp(2.5rem, 5vw, 4rem);
}

.section-header.text-left {
  text-align: left;
  margin-left: 0;
}

.section-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--engineering-green);
  background: rgba(20, 107, 58, 0.08);
  border: 1px solid rgba(20, 107, 58, 0.2);
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
}

.section-eyebrow.eyebrow-blue {
  color: var(--accent-blue);
  background: rgba(45, 114, 217, 0.08);
  border-color: rgba(45, 114, 217, 0.2);
}

.section-eyebrow.eyebrow-orange {
  color: var(--accent-orange);
  background: rgba(244, 123, 32, 0.08);
  border-color: rgba(244, 123, 32, 0.2);
}

.section-title {
  margin-bottom: 1rem;
  color: var(--primary-navy);
}

.section-subtitle {
  font-size: clamp(1rem, 1.3vw, 1.15rem);
  color: var(--text-muted);
  line-height: 1.7;
}

/* Tagline Slogan Component */
.slogan-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.15em;
  color: var(--primary-navy);
  background: linear-gradient(135deg, rgba(11, 42, 111, 0.06), rgba(20, 107, 58, 0.06));
  border: 1px solid rgba(11, 42, 111, 0.15);
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-full);
}

.slogan-pill .dot {
  color: var(--accent-orange);
}

/* Circuit Track Decorator Line */
.circuit-line-decor {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin: 1.25rem auto 0;
  width: 120px;
}

.circuit-line-decor::before,
.circuit-line-decor::after {
  content: '';
  height: 2px;
  flex: 1;
  background: linear-gradient(90deg, transparent, var(--accent-blue));
}

.circuit-line-decor::after {
  background: linear-gradient(90deg, var(--accent-blue), transparent);
}

.circuit-line-decor .circuit-node {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--engineering-green);
  border: 2px solid var(--accent-blue);
  box-shadow: 0 0 8px var(--green-light);
}

/* Flex & Grid Helpers */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.gap-4 { gap: 2rem; }

/* Text Utilities */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-navy { color: var(--primary-navy); }
.text-green { color: var(--engineering-green); }
.text-orange { color: var(--accent-orange); }
.text-blue { color: var(--accent-blue); }
.font-mono { font-family: var(--font-code); }
.font-heading { font-family: var(--font-heading); }

/* Focus States for Accessibility */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 3px solid var(--accent-blue);
  outline-offset: 2px;
}