/* --- VARIABLES & BASE STYLES --- */
:root {
    --color-primary: #e9d5ff; /* Soft Lavender */
    --color-secondary: #334155; /* Slate Grey */
    --color-white: #ffffff;
    --color-light-grey: #f8fafc;
    --color-text: #334155;
    --color-error: #b91c1c;

    --font-heading: 'Merriweather', serif;
    --font-body: 'Lato', sans-serif;

    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 32px;
    --spacing-xl: 64px;
    --spacing-xxl: 128px;
}

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

html {
    scroll-behavior: smooth;
    font-size: 100%;
}

body {
    font-family: var(--font-body);
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-white);
}

.container {
    width: 100%;
    max-width: 1100px;
    margin-left: auto;
    margin-right: auto;
    padding: 0 var(--spacing-lg);
}

h1, h2, h3, h4, h5 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.3;
    color: var(--color-secondary);
}

h1 { font-size: 3rem; font-weight: 900; }
h2 { font-size: 1.75rem; font-weight: 400; }
h3 { font-size: 2.25rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--color-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--color-primary);
}

.section-title {
    margin-bottom: var(--spacing-xl);
}

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

/* --- ANIMATION ON SCROLL --- */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- HEADER --- */
.main-header {
    padding: var(--spacing-md) 0;
    background-color: rgba(255, 255, 255, 0.9);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid #e2e8f0;
}

.logo {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.5rem;
}

/* --- HERO SECTION --- */
#hero {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    min-height: 90vh;
    padding: var(--spacing-xxl) var(--spacing-lg);
    background-image: linear-gradient(rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0.8)), url('images/hero-bg.webp');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

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

.hero-content h1 {
    color: var(--color-secondary);
    text-shadow: 2px 2px 4px rgba(0,0,0,0.05);
}

.hero-content h2 {
    margin: var(--spacing-md) 0 var(--spacing-lg) 0;
    font-weight: 400;
}

.event-date {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: var(--spacing-lg);
}

.cta-button {
    display: inline-block;
    background-color: var(--color-secondary);
    color: var(--color-white);
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: 50px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: background-color 0.3s ease, transform 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.cta-button:hover {
    background-color: #1e293b;
    color: var(--color-white);
    transform: translateY(-3px);
}

/* --- GENERAL SECTION STYLING --- */
section {
    padding: var(--spacing-xxl) 0;
}

.text-section {
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* --- INTRO & STATS --- */
#intro {
    background-color: var(--color-light-grey);
}

.stats-container {
    display: flex;
    justify-content: space-around;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
    text-align: center;
}

.stat-item {
    flex: 1;
}

.stat-number {
    display: block;
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 900;
    color: var(--color-primary);
}

.stat-label {
    font-size: 0.9rem;
    line-height: 1.4;
}

/* --- AGENDA / TIMELINE --- */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 3px;
    background-color: var(--color-primary);
    top: 0;
    bottom: 0;
    left: 60px;
}

.timeline-item {
    padding: var(--spacing-md) 0 var(--spacing-xl) 100px;
    position: relative;
}

.timeline-time {
    position: absolute;
    left: 0;
    top: 18px;
    font-weight: 700;
    background-color: var(--color-secondary);
    color: var(--color-white);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 4px;
    width: 75px;
    text-align: center;
}

.timeline-content h4 {
    margin-bottom: var(--spacing-sm);
}

/* --- SPEAKERS --- */
#speakers {
    background-color: var(--color-light-grey);
}

.speakers-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
}

.speaker-card {
    text-align: center;
}

.speaker-card img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: var(--spacing-md);
    border: 5px solid var(--color-white);
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.speaker-card h4 {
    margin-bottom: var(--spacing-xs);
}

.speaker-card h5 {
    font-family: var(--font-body);
    font-weight: 400;
    color: #64748b;
    margin-bottom: var(--spacing-sm);
}

/* --- TARGET AUDIENCE --- */
.audience-list {
    list-style: none;
    padding-left: 0;
}

.audience-list li {
    padding-left: 30px;
    position: relative;
    margin-bottom: var(--spacing-md);
}

.audience-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-secondary);
    font-weight: 900;
}

/* --- REGISTRATION FORM --- */
#register {
    background-color: var(--color-secondary);
    color: var(--color-white);
}

.form-card {
    background-color: var(--color-white);
    color: var(--color-text);
    padding: var(--spacing-xl);
    border-radius: 8px;
    max-width: 600px;
    margin: 0 auto;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.form-card h3 {
    text-align: center;
    margin-bottom: var(--spacing-md);
}

.form-card p {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.form-group input[type="text"],
.form-group input[type="email"] {
    width: 100%;
    padding: 12px;
    border: 1px solid #cbd5e1;
    border-radius: 4px;
    font-family: var(--font-body);
    font-size: 1rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--color-secondary);
    box-shadow: 0 0 0 3px rgba(51, 65, 85, 0.1);
}

.form-group-checkbox {
    display: flex;
    align-items: center;
    margin: var(--spacing-lg) 0;
}

.form-group-checkbox input {
    margin-right: var(--spacing-sm);
    width: 18px;
    height: 18px;
}

.form-group-checkbox label {
    font-size: 0.9rem;
}

.form-button {
    width: 100%;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.error-message {
    color: var(--color-error);
    font-size: 0.85rem;
    display: none;
    margin-top: var(--spacing-xs);
}

.form-group.error input {
    border-color: var(--color-error);
}

.form-group.error .error-message,
.form-group-checkbox.error .error-message {
    display: block;
}

#form-success-message {
    text-align: center;
    padding: var(--spacing-md);
    background-color: #f0fdf4;
    color: #166534;
    border-radius: 4px;
    margin-top: var(--spacing-lg);
}

/* --- CONTACT --- */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.map-container iframe {
    border-radius: 8px;
}

/* --- FOOTER --- */
.main-footer {
    background-color: var(--color-secondary);
    color: #cbd5e1;
    padding: var(--spacing-lg) 0;
    font-size: 0.9rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.footer-nav a {
    color: #cbd5e1;
    margin-left: var(--spacing-md);
}

.footer-nav a:hover {
    color: var(--color-white);
}

.disclaimer {
    text-align: center;
    font-size: 0.8rem;
    color: #94a3b8;
    border-top: 1px solid #475569;
    padding-top: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

/* --- RESPONSIVE DESIGN --- */
@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.8rem; }

    section {
        padding: var(--spacing-xl) 0;
    }

    .speakers-grid, .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline::after {
        left: 20px;
    }

    .timeline-item {
        padding-left: 60px;
        padding-bottom: var(--spacing-lg);
    }
    
    .timeline-time {
        left: -15px;
        width: auto;
        padding: 5px 8px;
        font-size: 0.8rem;
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}