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

:root {
    --primary-grey: #2c3e50;
    --dark-grey: #1a1a1a;
    --medium-grey: #4a4a4a;
    --light-grey: #f5f5f5;
    --lighter-grey: #e8e8e8;
    --accent-color: #d4a017;
    --accent-dark: #b8860b;
    --white: #ffffff;
    --text-dark: #333333;
    --text-light: #666666;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--white);
    overflow-x: hidden;
}

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

/* Navigation */
.navbar {
    background-color: var(--primary-grey);
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-color);
    letter-spacing: 1px;
}

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

.nav-link {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: var(--accent-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

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

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

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-grey) 0%, var(--dark-grey) 100%);
    position: relative;
    overflow: hidden;
    padding-top: 80px;
}

.hero-decoration {
    position: absolute;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--accent-color) 0%, transparent 70%);
    opacity: 0.1;
    border-radius: 50%;
    top: -250px;
    right: -250px;
    animation: float 20s infinite ease-in-out;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) rotate(0deg);
    }
    50% {
        transform: translate(-50px, 50px) rotate(180deg);
    }
}

.hero-content {
    text-align: center;
    color: var(--white);
    z-index: 1;
    max-width: 800px;
    padding: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: var(--lighter-grey);
    animation: fadeInUp 1s ease 0.2s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 30px;
    text-decoration: none;
    border-radius: 5px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--accent-color);
    color: var(--white);
    box-shadow: 0 4px 15px rgba(212, 160, 23, 0.3);
}

.btn-primary:hover {
    background-color: var(--accent-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(212, 160, 23, 0.4);
}

/* Sections */
.section {
    padding: 80px 0;
    background-color: var(--white);
}

.section-alt {
    background-color: var(--light-grey);
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--primary-grey);
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, transparent, var(--accent-color), transparent);
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 25px rgba(212, 160, 23, 0.2);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    color: var(--primary-grey);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* Speakers Grid */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.speaker-card {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.speaker-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 25px rgba(212, 160, 23, 0.2);
}

.speaker-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-dark));
    color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: bold;
    margin: 0 auto 1rem;
    overflow: hidden;
    border: 3px solid var(--white);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.speaker-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.speaker-card h3 {
    color: var(--primary-grey);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.speaker-role {
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.speaker-bio {
    color: var(--text-light);
    line-height: 1.8;
    font-size: 0.95rem;
}

/* Talks Grid */
.talks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.talk-card {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid var(--accent-color);
}

.talk-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 25px rgba(212, 160, 23, 0.2);
}

.talk-date {
    color: var(--accent-color);
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.talk-card h3 {
    color: var(--primary-grey);
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.talk-speaker {
    color: var(--medium-grey);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.talk-description {
    color: var(--text-light);
    line-height: 1.8;
}

/* Contact Section */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 3rem;
    margin-top: 3rem;
}

.contact-info h3 {
    color: var(--primary-grey);
    margin-bottom: 2rem;
    font-size: 1.5rem;
}

.contact-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    align-items: flex-start;
}

.contact-icon {
    font-size: 1.5rem;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--accent-color);
    color: var(--white);
    border-radius: 50%;
    flex-shrink: 0;
}

.contact-item strong {
    display: block;
    color: var(--primary-grey);
    margin-bottom: 0.3rem;
}

.contact-item p {
    color: var(--text-light);
    margin: 0;
}

/* Contact Form */
.contact-form {
    background-color: var(--white);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
}

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

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--lighter-grey);
    border-radius: 5px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s ease;
}

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

.form-group textarea {
    resize: vertical;
}

.form-message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 5px;
    display: none;
}

.form-message.success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
    display: block;
}

.form-message.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
    display: block;
}

/* Footer */
.footer {
    background-color: var(--primary-grey);
    color: var(--white);
    text-align: center;
    padding: 2rem 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--primary-grey);
        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;
    }

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

    .hero-subtitle {
        font-size: 1.2rem;
    }

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

    .contact-wrapper {
        grid-template-columns: 1fr;
    }

    .features-grid,
    .speakers-grid,
    .talks-grid {
        grid-template-columns: 1fr;
    }
}

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

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

    .section {
        padding: 60px 0;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}