/* ============================================================
   ANVAYA'26 - Official College Tech Symposium Stylesheet
   Ethiraj College for Women (Autonomous), Chennai - MCA Department
   Visual Language: Deep Cyber-Nature Fusion (Emerald + Cyan/Teal)
   ============================================================ */

:root {
  /* Color Palette */
  --bg-dark: #030a16;
  --bg-darker: #02070f;
  --bg-surface: #061528;
  --bg-card: rgba(8, 25, 45, 0.72);
  --bg-card-hover: rgba(12, 34, 60, 0.88);
  --bg-glass: rgba(6, 21, 38, 0.65);
  --bg-glass-elevated: rgba(9, 29, 52, 0.85);

  /* Emerald Nature Accents */
  --emerald-300: #6ee7b7;
  --emerald-400: #34d399;
  --emerald-500: #10b981;
  --emerald-600: #059669;
  --emerald-glow: rgba(16, 185, 129, 0.28);
  --emerald-border: rgba(16, 185, 129, 0.24);

  /* Cyan / Tech Teal Accents */
  --cyan-300: #67e8f9;
  --cyan-400: #22d3ee;
  --cyan-500: #06b6d4;
  --cyan-600: #0891b2;
  --cyan-glow: rgba(6, 182, 212, 0.28);
  --cyan-border: rgba(6, 182, 212, 0.24);

  /* Text Colors */
  --text-main: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #849ab0;
  --text-dim: #4e657e;

  /* Borders & Dividers */
  --border-glass: rgba(148, 163, 184, 0.12);
  --border-light: rgba(255, 255, 255, 0.08);

  /* Gradients */
  --grad-nature-tech: linear-gradient(135deg, #10b981 0%, #06b6d4 100%);
  --grad-tech-nature: linear-gradient(135deg, #06b6d4 0%, #10b981 100%);
  --grad-hero-text: linear-gradient(135deg, #ffffff 30%, #a7f3d0 70%, #67e8f9 100%);
  --grad-card-border: linear-gradient(135deg, rgba(16, 185, 129, 0.35), rgba(6, 182, 212, 0.35));

  /* Typography */
  --font-body: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-heading: 'Outfit', 'Plus Jakarta Sans', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Layout */
  --container-max: 1240px;
  --nav-height: 76px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.5);
  --shadow-glow-cyan: 0 0 25px rgba(6, 182, 212, 0.3);
  --shadow-glow-emerald: 0 0 25px rgba(16, 185, 129, 0.3);
  /* Modal border glow (was undefined, fixed) */
  --border-glow: rgba(6, 182, 212, 0.35);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  color-scheme: dark;
  overflow-x: hidden;
  max-width: 100vw;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  max-width: 100vw;
  position: relative;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Subtle Geometric Cyber-Nature Grid Background */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    radial-gradient(circle at 15% 20%, rgba(16, 185, 129, 0.08) 0%, transparent 45%),
    radial-gradient(circle at 85% 65%, rgba(6, 182, 212, 0.09) 0%, transparent 50%),
    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: 100% 100%, 100% 100%, 64px 64px, 64px 64px;
  background-position: center;
  pointer-events: none;
  z-index: -1;
}

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

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

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

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

/* Section Headings */
.section {
  padding: 6rem 0;
  position: relative;
}

.section-alt {
  background: linear-gradient(180deg, rgba(6, 21, 40, 0.4) 0%, rgba(3, 10, 22, 0.8) 100%);
  border-top: 1px solid var(--border-glass);
  border-bottom: 1px solid var(--border-glass);
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 3.5rem auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid var(--emerald-border);
  border-radius: var(--radius-full);
  font-size: 0.825rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--emerald-400);
  margin-bottom: 1rem;
}

.section-tag.cyan {
  background: rgba(6, 182, 212, 0.1);
  border-color: var(--cyan-border);
  color: var(--cyan-400);
}

.section-title {
  font-size: clamp(2rem, 3.5vw, 2.75rem);
  margin-bottom: 1rem;
  font-weight: 800;
}

.section-title .gradient-text {
  background: var(--grad-nature-tech);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-desc {
  font-size: 1.075rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* Notice & Placeholder Banners */
.placeholder-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(245, 158, 11, 0.12);
  border: 1px dashed rgba(245, 158, 11, 0.45);
  color: #fbbf24;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  font-size: 0.775rem;
  font-weight: 500;
}

.official-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: rgba(16, 185, 129, 0.14);
  border: 1px solid var(--emerald-border);
  color: var(--emerald-300);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  font-size: 0.775rem;
  font-weight: 600;
}

/* Accessibility / Focus */
:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 3px;
}

/* Selection */
::selection {
  background: rgba(16, 185, 129, 0.35);
  color: #ffffff;
}