* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

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

.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    padding: 4rem 0;
    position: relative;
    overflow: hidden;
}

.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"><circle cx="20" cy="20" r="2" fill="rgba(255,255,255,0.1)"/><circle cx="80" cy="40" r="1.5" fill="rgba(255,255,255,0.1)"/><circle cx="40" cy="70" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="90" cy="80" r="2.5" fill="rgba(255,255,255,0.1)"/><circle cx="10" cy="60" r="1.2" fill="rgba(255,255,255,0.1)"/></svg>');
    opacity: 0.3;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 700;
    margin-bottom: 1rem;
    position: relative;
    z-index: 1;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.hero-subtitle {
    font-size: clamp(1.1rem, 3vw, 1.5rem);
    opacity: 0.9;
    position: relative;
    z-index: 1;
    font-weight: 300;
}

.main-content {
    background: white;
    position: relative;
    z-index: 2;
}

section {
    padding: 4rem 0;
}

h2 {
    font-size: clamp(2rem, 5vw, 3rem);
    margin-bottom: 3rem;
    text-align: center;
    color: #2d3748;
    font-weight: 600;
}

.previous-speakers {
    background: #f7fafc;
}

.speakers-grid {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
}

.speaker-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 350px;
}

.speaker-card-link {
    text-decoration: none;
}

.speaker-year-label {
    margin-top: 1rem;
    font-size: 0.9rem;
    color: #718096;
    font-weight: 500;
}

.speaker-card {
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    overflow: hidden;
    min-height: 350px;
    display: flex;
    align-items: end;
}

.speaker-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}

.speaker-overlay {
    background: linear-gradient(to top, rgba(0,0,0,0.95) 0%, rgba(0,0,0,0.8) 40%, transparent 100%);
    padding: 1.5rem 2rem;
    color: white;
    text-align: left;
    width: 100%;
}

.speaker-overlay h3 {
    color: white;
    margin-bottom: 0.3rem;
    text-shadow: 2px 2px 8px rgba(0,0,0,1), 0 0 10px rgba(0,0,0,0.8);
    font-size: 1.3rem;
    font-weight: 700;
}

.speaker-overlay .speaker-topic {
    color: #f7fafc;
    font-weight: 600;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.8);
    margin-bottom: 0.5rem;
}

.speaker-overlay .speaker-bio {
    color: #e2e8f0;
    font-size: 0.9rem;
    line-height: 1.4;
}

.speaker-year {
    display: inline-block;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    padding: 0.4rem 0.8rem;
    border-radius: 50px;
    font-weight: 700;
    font-size: 0.8rem;
    margin-bottom: 0.5rem;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.5);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.4);
}


.speaker-topic {
    color: #667eea;
    font-weight: 600;
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.speaker-bio {
    color: #718096;
    line-height: 1.6;
}

.cta-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-section::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"><polygon points="0,100 30,0 100,20 100,100" fill="rgba(255,255,255,0.05)"/></svg>');
}

.cta-section h2 {
    color: white;
    margin-bottom: 1rem;
}

.cta-section p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    position: relative;
    z-index: 1;
}

.cta-button {
    background: white;
    color: #667eea;
    border: none;
    padding: 1rem 3rem;
    font-size: 1.2rem;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    z-index: 1;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.3);
    background: #f7fafc;
}

.proposals {
    background: #f7fafc;
}

.proposals-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.proposal-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
    transition: transform 0.3s ease;
    border-left: 4px solid #667eea;
}

.proposal-card:hover {
    transform: translateY(-5px);
}

.proposal-card h3 {
    color: #2d3748;
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.proposal-topic {
    color: #667eea;
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.proposal-bio {
    color: #718096;
    line-height: 1.6;
}

.loading, .error, .no-proposals {
    text-align: center;
    padding: 3rem;
    color: #718096;
    font-size: 1.1rem;
    grid-column: 1 / -1;
}

.error {
    color: #e53e3e;
}

.main-content.disabled {
    pointer-events: none;
    opacity: 0.3;
    filter: blur(2px);
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.8);
    z-index: 1000;
    backdrop-filter: blur(5px);
}

.modal-content {
    background: white;
    margin: 5% auto;
    padding: 2rem;
    border-radius: 20px;
    max-width: 500px;
    width: 90%;
    position: relative;
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.close {
    position: absolute;
    top: 1rem;
    right: 1.5rem;
    font-size: 2rem;
    cursor: pointer;
    color: #718096;
    transition: color 0.3s ease;
}

.close:hover {
    color: #2d3748;
}

.modal h2 {
    color: #2d3748;
    margin-bottom: 2rem;
    text-align: center;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #2d3748;
    font-weight: 600;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

.form-group textarea {
    resize: vertical;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.submit-button {
    width: 100%;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    border: none;
    padding: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.submit-button:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.3);
}

.submit-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.success-message {
    position: fixed;
    top: 2rem;
    right: 2rem;
    background: #48bb78;
    color: white;
    padding: 1rem 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(72, 187, 120, 0.3);
    z-index: 1001;
    animation: slideInRight 0.3s ease;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(100px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@media (max-width: 768px) {
    section {
        padding: 3rem 0;
    }
    
    .speakers-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        margin: 10% auto;
        padding: 1.5rem;
    }
    
    .success-message {
        top: 1rem;
        right: 1rem;
        left: 1rem;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 3rem 0;
    }
    
    .speaker-card {
        min-height: 300px;
    }
    
    .speaker-overlay {
        padding: 1rem 1.5rem;
    }
    
    .proposal-card {
        padding: 1.5rem;
    }
    
    .cta-button {
        padding: 0.8rem 2rem;
        font-size: 1.1rem;
    }
}