/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header and Navigation */
header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar {
    padding: 1rem 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: #2c3e50;
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
}

.nav-menu li {
    margin-left: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.nav-menu a:hover {
    color: #3498db;
}

/* Active link indicator */
.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #3498db;
    transition: width 0.3s ease;
}

.nav-menu a:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    margin: 3px 0;
    background-color: #333;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #e28166 0%, #652cab 100%);
    color: white;
    text-align: center;
    padding: 150px 20px 100px;
    margin-top: 70px;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

/* Sections */
section {
    padding: 80px 0;
}

section h2 {
    text-align: center;
    margin-bottom: 3rem;
    font-size: 2rem;
    color: #2c3e50;
}

/* Submission Section */
.submission {
    background-color: #f8f9fa;
}

.submission .container {
    text-align: center;
}

.submission-deadline {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.submission-info {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

/* Grid Layouts */
.speakers-grid,
.panelists-grid,
.organizers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.speaker-card,
.panelist-card,
.organizer-card {
    text-align: center;
    padding: 1.5rem;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.speaker-card:hover,
.panelist-card:hover,
.organizer-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.15);
}

.speaker-card img,
.panelist-card img,
.organizer-card img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 1rem;
    border: 3px solid #eee;
}

.speaker-card h3,
.panelist-card h3,
.organizer-card h3 {
    margin-bottom: 0.5rem;
    color: #2c3e50;
}

/* Contact Section */
.contact {
    background-color: #f8f9fa;
    text-align: center;
}

.contact a {
    color: #3498db;
    text-decoration: none;
}

.contact a:hover {
    text-decoration: underline;
}

/* Footer */
footer {
    background-color: #2c3e50;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

/* Responsive Design */
@media screen and (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0,0,0,0.05);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu li {
        margin: 1.5rem 0;
    }

    .hamburger {
        display: flex;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    section {
        padding: 60px 0;
    }

    section h2 {
        font-size: 1.8rem;
    }
}

@media screen and (max-width: 480px) {
    .hero {
        padding: 120px 20px 80px;
    }

    .hero h1 {
        font-size: 1.8rem;
    }

    .speakers-grid,
    .panelists-grid,
    .organizers-grid {
        grid-template-columns: 1fr;
    }
}