/* ===== CSS VARIABLES ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Arial', sans-serif;
}

body {
    background-color: #fff;
    line-height: 1.6;
}

:root {
    --ieee-blue: #0066cc;
    --ieee-dark-blue: #003d7a;
    --ieee-light-blue: #4d9fff;
    --white: #ffffff;
    --light-gray: #f8f9fa;
    --dark-gray: #6c757d;
    --text-dark: #212529;
    --border-light: #dee2e6;
    --shadow-light: 0 2px 10px rgba(0,0,0,0.1);
    --shadow-medium: 0 5px 20px rgba(0,0,0,0.15);
    --shadow-heavy: 0 10px 30px rgba(0,0,0,0.2);
    --gradient-primary: linear-gradient(135deg, var(--ieee-blue), var(--ieee-dark-blue));
    --gradient-light: linear-gradient(135deg, var(--ieee-light-blue), var(--ieee-blue));
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
}

/* Navigation Styles */
.navbar {
    background: var(--gradient-primary);
    padding: 15px 0;
    box-shadow: var(--shadow-light);
    transition: all 0.3s ease;
}

.navbar.scrolled {
   background: var(--gradient-primary);
    background: rgba(0, 102, 204, 0.95);
    backdrop-filter: blur(10px);
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--white) !important;
}

.brand-text {
    display: inline-block;
}

@media (max-width: 576px) {
    .brand-text {
        font-size: 0.9rem;
    }
}

.navbar-nav .nav-link {
    color: var(--white) !important;
    font-weight: 500;
    margin: 0 10px;
    position: relative;
    transition: all 0.3s ease;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
    color: var(--ieee-light-blue) !important;
}

.navbar-nav .nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 50%;
    background: var(--ieee-light-blue);
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.navbar-nav .nav-link:hover::after,
.navbar-nav .nav-link.active::after {
    width: 100%;
}

.ieee-main-logo {
    max-width: 180px;
    height: auto;
}

/* Events Main Section */
.events-main {
    padding-top: 80px;
    min-height: 100vh;
}

/* Events Hero Section */
.events-hero {
    background: linear-gradient(135deg, var(--ieee-blue), var(--ieee-dark-blue));
    color: var(--white);
    padding: 4rem 0;
    position: relative;
    overflow: hidden;
}

.events-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.events-hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    position: relative;
    z-index: 2;
}

.events-hero-subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 0;
    position: relative;
    z-index: 2;
}

/* Events Section */
.events-section {
    padding: 4rem 0;
    background: var(--light-gray);
}

/* Event Filter Tabs */
.event-filter-tabs {
    background: var(--white);
    border-radius: 50px;
    padding: 0.5rem;
    box-shadow: var(--shadow-light);
}

.event-filter-tabs .nav-link {
    border: none;
    border-radius: 25px;
    color: var(--text-dark);
    font-weight: 500;
    padding: 0.75rem 1.5rem;
    transition: all 0.3s ease;
    background: transparent;
}

.event-filter-tabs .nav-link.active {
    background: var(--gradient-primary);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.event-filter-tabs .nav-link:hover:not(.active) {
    color: var(--ieee-blue);
    background: rgba(0, 102, 204, 0.1);
}

/*Event Cards */
.event-card {
    background: var(--white);
    border: none;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow-light);
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    position: relative;
}

.event-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-heavy);
}

.event-image-container {
    position: relative;
    overflow: hidden;
    height: 220px;
}

.event-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.event-card:hover .event-image {
    transform: scale(1.1);
}

.event-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(0, 102, 204, 0.8), rgba(0, 61, 122, 0.9));
    opacity: 0;
    transition: opacity 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.event-card:hover .event-overlay {
    opacity: 1;
}

.event-date {
    color: var(--white);
    text-align: center;
    font-weight: bold;
}

.event-date .day {
    display: block;
    font-size: 2.5rem;
    line-height: 1;
}

.event-date .month {
    display: block;
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.event-status {
    position: absolute;
    top: 15px;
    right: 15px;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    z-index: 10;
}

.event-status.upcoming {
    background: var(--success-color);
    color: var(--white);
}

.event-status.past {
    background: var(--dark-gray);
    color: var(--white);
}

.event-content {
    padding: 1.5rem;
}

.event-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 0.75rem;
    line-height: 1.3;
}

.event-description {
    color: var(--dark-gray);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.event-meta {
    margin-bottom: 1.5rem;
}

.event-date-text,
.event-location {
    display: flex;
    align-items: center;
    font-size: 0.85rem;
    color: var(--dark-gray);
    margin-bottom: 0.5rem;
}

.event-date-text i,
.event-location i {
    margin-right: 0.5rem;
    color: var(--ieee-blue);
    width: 14px;
}

.event-btn {
    display: inline-flex;
    align-items: center;
    color: var(--ieee-blue);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    position: relative;
}

.event-btn:hover {
    color: var(--ieee-dark-blue);
    transform: translateX(5px);
}

.event-btn i {
    margin-left: 0.5rem;
    transition: transform 0.3s ease;
}

.event-btn:hover i {
    transform: translateX(3px);
}

/* Load More Button */
.load-more-btn {
    border: 2px solid var(--ieee-blue);
    color: var(--ieee-blue);
    padding: 0.75rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.load-more-btn:hover {
    background: var(--ieee-blue);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

/* Responsive Design */
@media (max-width: 1199.98px) {
    .events-hero-title {
        font-size: 3rem;
    }

    .event-image-container {
        height: 200px;
    }
}

@media (max-width: 991.98px) {
    .events-hero-title {
        font-size: 2.5rem;
    }

    .events-hero-subtitle {
        font-size: 1.1rem;
    }

    .event-filter-tabs {
        margin-bottom: 2rem;
    }

    .event-filter-tabs .nav-link {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 767.98px) {
    .events-hero {
        padding: 3rem 0;
    }

    .events-hero-title {
        font-size: 2rem;
    }

    .events-hero-subtitle {
        font-size: 1rem;
    }

    .events-section {
        padding: 3rem 0;
    }

    .event-filter-tabs {
        border-radius: 15px;
    }

    .event-filter-tabs .nav-link {
        padding: 0.5rem 0.75rem;
        font-size: 0.85rem;
        border-radius: 15px;
    }

    .event-card {
        border-radius: 15px;
        margin-bottom: 1.5rem;
    }

    .event-image-container {
        height: 180px;
    }

    .event-content {
        padding: 1.25rem;
    }

    .event-title {
        font-size: 1.1rem;
    }

    .event-description {
        font-size: 0.85rem;
    }

    .event-date-text,
    .event-location {
        font-size: 0.8rem;
    }

    .event-btn {
        font-size: 0.85rem;
    }

    .load-more-btn {
        padding: 0.625rem 1.5rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 575.98px) {
    .events-hero {
        padding: 2.5rem 0;
    }

    .events-hero-title {
        font-size: 1.75rem;
    }

    .events-hero-subtitle {
        font-size: 0.95rem;
    }

    .event-filter-tabs .nav-link {
        padding: 0.4rem 0.6rem;
        font-size: 0.8rem;
    }

    .event-image-container {
        height: 160px;
    }

    .event-content {
        padding: 1rem;
    }

    .event-date .day {
        font-size: 2rem;
    }

    .event-date .month {
        font-size: 0.9rem;
    }

    .event-status {
        padding: 0.2rem 0.6rem;
        font-size: 0.7rem;
    }
}

/* Animation Classes */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.6s ease forwards;
}

.fade-in.delay-1 { animation-delay: 0.1s; }
.fade-in.delay-2 { animation-delay: 0.2s; }
.fade-in.delay-3 { animation-delay: 0.3s; }

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Focus States for Accessibility */
.event-filter-tabs .nav-link:focus,
.event-btn:focus,
.load-more-btn:focus {
    outline: 2px solid var(--ieee-light-blue);
    outline-offset: 2px;
}

/* Loading State */
.loading-spinner {
    display: none;
    margin: 0 auto;
}

.loading-spinner.show {
    display: block;
}

/* Footer Styles */
.footer {
    background: var(--gradient-primary);
    color: var(--white);
    padding: 3rem 0 1rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 0;
}

.social-icons a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
}

.social-icons a:hover {
    background: var(--white);
    color: var(--ieee-blue);
    transform: translateY(-3px);
}

.footer hr {
    border-color: rgba(255, 255, 255, 0.2);
}