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

:root {
    --primary-color: #0066cc;
    --primary-dark: #004999;
    --secondary-color: #336799;
    --text-color: #333333;
    --text-light: #666666;
    --background-color: #ffffff;
    --background-light: #f8f9fa;
    --border-color: #e0e0e0;
    --accent-color: #00a8e8;
    --error-color: #dc3545;
    --success-color: #28a745;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 20px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--background-color);
}

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

/* Navigation */
.navbar {
    background-color: var(--background-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand a {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--primary-color);
}

.btn-register {
    background-color: var(--primary-color);
    color: white !important;
    padding: 0.5rem 1.5rem;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.btn-register:hover {
    background-color: var(--primary-dark);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    transition: all 0.3s ease;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    text-align: center;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
}

.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: white;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 8rem 2rem;
    text-align: center;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: bold;
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.75rem;
    font-weight: 300;
    margin-bottom: 1.5rem;
}

.hero-description {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 3rem;
}

.hero-details {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.detail-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.detail-icon {
    font-size: 1.5rem;
}

/* Section Styles */
section {
    padding: 5rem 2rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: bold;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1.125rem;
    margin-bottom: 3rem;
}

/* About Section */
.about {
    background-color: var(--background-light);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.about-text h3 {
    font-size: 1.5rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.feature-list {
    list-style: none;
    margin-top: 1rem;
}

.feature-list li {
    padding: 0.5rem 0;
    position: relative;
    padding-left: 1.5rem;
}

.feature-list li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.image-placeholder {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    height: 300px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
    font-weight: bold;
}

/* Speakers Section */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.speaker-card {
    background-color: white;
    border-radius: 10px;
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.speaker-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.speaker-placeholder {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    margin: 0 auto 1rem;
}

.speaker-name {
    font-size: 1.25rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.speaker-title {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1rem;
}

.speaker-bio {
    color: var(--text-light);
    font-size: 0.9rem;
}

.section-cta {
    text-align: center;
    margin-top: 2rem;
}

/* Schedule Section */
.schedule {
    background-color: var(--background-light);
}

.schedule-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.tab-btn {
    padding: 0.75rem 2rem;
    border: 2px solid var(--primary-color);
    background-color: white;
    color: var(--primary-color);
    border-radius: 5px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.tab-btn:hover,
.tab-btn.active {
    background-color: var(--primary-color);
    color: white;
}

.schedule-content {
    max-width: 900px;
    margin: 0 auto;
}

.schedule-item {
    background-color: white;
    border-radius: 10px;
    padding: 2rem;
    margin-bottom: 1rem;
    display: grid;
    grid-template-columns: 150px 1fr;
    gap: 2rem;
    box-shadow: var(--shadow);
}

.schedule-time {
    font-weight: bold;
    color: var(--primary-color);
    font-size: 1.125rem;
}

.schedule-details h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.schedule-speaker {
    color: var(--text-light);
    margin-top: 0.5rem;
}

/* Sponsors Section */
.sponsors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.sponsor-card {
    background-color: white;
    border-radius: 10px;
    padding: 3rem 2rem;
    text-align: center;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.sponsor-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.sponsor-placeholder {
    color: var(--text-light);
    font-weight: bold;
}

/* Register Section */
.register {
    background-color: var(--background-light);
}

.register-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.pricing-card {
    background-color: white;
    border-radius: 10px;
    padding: 2.5rem;
    text-align: center;
    box-shadow: var(--shadow);
    position: relative;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.pricing-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.pricing-card.featured {
    border: 3px solid var(--primary-color);
}

.badge {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--primary-color);
    color: white;
    padding: 0.5rem 1.5rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: bold;
}

.pricing-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.price {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.pricing-features {
    list-style: none;
    margin: 2rem 0;
    text-align: left;
}

.pricing-features li {
    padding: 0.75rem 0;
    position: relative;
    padding-left: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.pricing-features li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Footer */
.footer {
    background-color: #1a1a1a;
    color: white;
    padding: 3rem 2rem 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

/* Contact Form */
.contact-section {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-color);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    resize: vertical;
    min-height: 150px;
}

.form-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

/* Responsive Design */
@media (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: var(--shadow);
        padding: 2rem 0;
    }

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

    .hamburger {
        display: flex;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

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

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .hero-details {
        flex-direction: column;
        gap: 1rem;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .speakers-grid,
    .sponsors-grid,
    .register-content {
        grid-template-columns: 1fr;
    }

    .schedule-item {
        grid-template-columns: 1fr;
    }

    .section-title {
        font-size: 2rem;
    }

    .hero {
        padding: 5rem 1rem;
    }

    section {
        padding: 3rem 1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .btn {
        padding: 0.625rem 1.5rem;
        font-size: 0.875rem;
    }
}