/* Color Palette & Global Variables */
:root {
    --bg-main: #ffffff;         /* Pure white background */
    --bg-card: #f8f9fa;         /* Very light gray for cards/sections */
    --text-main: #212529;       /* Dark gray/almost black for text */
    --text-muted: #555555;      /* Medium gray for paragraphs */
    --ieee-blue: #00629B;       /* Official IEEE Blue */
    --ieee-blue-hover: #004c7a; /* Darker blue for hover states */
    --border: #e9ecef;          /* Light gray borders */
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
}

/* --- Navigation Bar --- */
header {
    background-color: #ffffff;
    border-bottom: 3px solid var(--ieee-blue); /* Strong IEEE Blue border */
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.2rem 2rem;
}

.logo strong {
    font-size: 1.5rem;
    color: var(--ieee-blue);
    letter-spacing: 1px;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 1.5rem;
    flex-wrap: wrap; 
}

nav a {
    color: var(--text-main);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 600;
    transition: color 0.2s ease;
}

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

/* --- Main Content & Typography --- */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    min-height: 80vh;
}

section {
    margin-bottom: 4rem;
}

h1, h2, h3 {
    margin-bottom: 1rem;
    color: var(--ieee-blue); /* Headers match the IEEE branding */
}

h1 {
    font-size: 3rem;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

h2 {
    font-size: 2rem;
    border-bottom: 2px solid var(--border);
    padding-bottom: 0.5rem;
    margin-bottom: 2rem;
}

p, ul, ol {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

ul, ol {
    padding-left: 2rem;
}

/* --- Standard Text Links --- */
main a {
    color: var(--ieee-blue);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s ease;
}

main a:hover {
    color: var(--ieee-blue-hover);
    text-decoration: underline;
}

/* Ensure buttons don't get underlined on hover */
main a.btn-primary:hover, main a.btn-secondary:hover {
    text-decoration: none;
}

/* --- Hero Section (Landing Page) --- */
.hero {
    text-align: center;
    padding: 6rem 2rem;
    background-color: var(--ieee-blue); /* Solid blue background */
    color: #ffffff;
    border-radius: 12px;
    margin-top: 2rem;
    box-shadow: 0 10px 20px rgba(0, 98, 155, 0.15);
}

.hero h1, .hero p {
    color: #ffffff; /* Forces text to be white inside the blue hero */
}

.hero p {
    max-width: 600px;
    margin: 0 auto 2.5rem auto;
    font-size: 1.2rem;
}

/* --- Buttons --- */
.btn-primary, .btn-secondary {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-right: 1rem;
    margin-bottom: 1rem;
}

/* White button for the Blue Hero section */
.hero .btn-primary {
    background-color: #ffffff;
    color: var(--ieee-blue) !important;
}

.hero .btn-primary:hover {
    background-color: #f8f9fa;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* Standard blue button for the rest of the site */
.btn-primary {
    background-color: var(--ieee-blue);
    color: #ffffff !important;
}

.btn-primary:hover {
    background-color: var(--ieee-blue-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 98, 155, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--ieee-blue) !important;
    border: 2px solid var(--ieee-blue);
}

.btn-secondary:hover {
    background-color: var(--ieee-blue);
    color: #ffffff !important;
}

/* --- Cards & Grids (Projects, Officers, News) --- */
.news-card, .project-card, .officer-card, .merch-item {
    background-color: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.news-card:hover, .project-card:hover {
    transform: translateY(-5px);
    border-color: var(--ieee-blue);
    box-shadow: 0 8px 24px rgba(0, 98, 155, 0.1);
}

.officer-grid, .merch-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.officer-card {
    text-align: center;
}

.officer-card img, .merch-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    background-color: #e9ecef; /* Light gray placeholder */
}

/* --- Footer --- */
footer {
    text-align: center;
    padding: 2rem;
    border-top: 1px solid var(--border);
    margin-top: 4rem;
    background-color: #f8f9fa;
    color: var(--text-muted);
}
/* --- Scroll Reveal Animations --- */
.hidden-state {
    opacity: 0;
    transform: translateY(40px);
}

.fade-in-up {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}
/* --- Custom Page Backgrounds --- */

/* 1. Schematic Dot Grid (Home) */
/* 1. Schematic Dot Grid (Home) */
body.bg-dot-grid {
    /* Changed the dot color from var(--border) to a visible light blue */
    background-image: radial-gradient(rgba(0, 98, 155, 0.25) 1.5px, transparent 1.5px);
    background-size: 24px 24px;
}


/* 2. Soft Ambient Gradients (About Us) */
body.bg-ambient {
    background-color: #ffffff;
    background-image: 
        radial-gradient(at 0% 0%, rgba(0, 98, 155, 0.30) 0px, transparent 50%),
        radial-gradient(at 100% 100%, rgba(56, 189, 248, 0.35) 0px, transparent 50%);
    background-attachment: fixed;
}

/* 3. Interactive Particles (Membership) */
#particles-js {
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: -1; /* Keeps particles safely behind your text */
    background-color: var(--bg-main);
}

body.bg-particles main {
    position: relative;
    z-index: 1;
}

/* 4. Technical Blueprint Grid (Projects) */
/* Straight overlapping lines mimicking an architectural draft */
body.bg-blueprint {
    background-color: #ffffff;
    background-image: 
        linear-gradient(rgba(0, 98, 155, 0.15) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 98, 155, 0.15) 1px, transparent 1px);
    background-size: 40px 40px;
}

/* 5. Sleek Diagonal Motion (Events) */
/* Subtle forward-leaning stripes to represent scheduling and momentum */
body.bg-stripes {
    background-color: #ffffff;
    background-image: repeating-linear-gradient(
        45deg, 
        rgba(0, 98, 155, 0.03) 0, 
        rgba(0, 98, 155, 0.03) 10px, 
        transparent 10px, 
        transparent 20px
    );
}

/* 6. Premium Frosted Glass (Sponsors) */
/* A corporate, heavy diagonal gradient from white to light gray/blue */
body.bg-glass {
    background-color: #f8f9fa;
    background-image: linear-gradient(135deg, #ffffff 0%, rgba(0, 98, 155, 0.08) 100%);
    background-attachment: fixed;
}

/* 7. Hybrid: Glowing Ambient Grid (Resources) */
/* Combines the home page dots with a central cyan glow to look like a server room */
body.bg-ambient-grid {
    background-color: #ffffff;
    background-image: 
        radial-gradient(rgba(0, 98, 155, 0.25) 1.5px, transparent 1.5px),
        radial-gradient(circle at 50% 50%, rgba(56, 189, 248, 0.15) 0%, transparent 60%);
    background-size: 24px 24px, 100% 100%;
    background-attachment: fixed;
}

/* 8. Heritage Mesh (Alumni) */
/* Soft, sweeping corner gradients that feel established and professional */
body.bg-mesh {
    background-color: #ffffff;
    background-image: 
        radial-gradient(at 80% 0%, rgba(0, 98, 155, 0.15) 0px, transparent 60%),
        radial-gradient(at 20% 100%, rgba(0, 98, 155, 0.10) 0px, transparent 60%);
    background-attachment: fixed;
}

/* 9. Radar Waves (Competitions) */
/* Concentric rings expanding outward to represent signals/robotics sensors */
body.bg-radar {
    background-color: #ffffff;
    background-image: repeating-radial-gradient(
        circle at 50% 50%, 
        transparent 0, 
        transparent 40px, 
        rgba(0, 98, 155, 0.05) 40px, 
        rgba(0, 98, 155, 0.05) 41px
    );
    background-attachment: fixed;
}

/* 10. Top Center Spotlight (Shop) */
/* A clean light casting down from the top to make the merchandise cards pop */
body.bg-spotlight {
    background-color: #ffffff;
    background-image: radial-gradient(circle at 50% 0%, rgba(0, 98, 155, 0.12) 0%, transparent 70%);
    background-attachment: fixed;
}