:root {
    --primary-color: #0f172a;
    /* Slate 900 */
    --accent-color: #2563eb;
    /* Blue 600 */
    --text-color: #334155;
    /* Slate 700 */
    --bg-light: #f8fafc;
    /* Slate 50 */
    --white: #ffffff;
    --border-color: #e2e8f0;
    --font-family: 'Inter', sans-serif;
}

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

body {
    font-family: var(--font-family);
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--white);
}

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

/* Typography */
h1,
h2,
h3 {
    color: var(--primary-color);
    line-height: 1.2;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
    font-weight: 700;
}

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

.mb-4 {
    margin-bottom: 1.5rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s;
    border: none;
    cursor: pointer;
    text-transform: uppercase;
    font-size: 0.9rem;
    letter-spacing: 0.5px;
}

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

.btn-primary:hover {
    background-color: #1d4ed8;
}

.btn-block {
    display: block;
    width: 100%;
}

/* Header & Hero */
.header {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 20px 0 80px;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 80px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.hero {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-date {
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.hero-title {
    font-size: 3.5rem;
    color: var(--white);
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: #94a3b8;
    margin-bottom: 3rem;
}

.hero-details {
    display: flex;
    justify-content: center;
    gap: 3rem;
    color: #e2e8f0;
}

.detail-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
}

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

.bg-light {
    background-color: var(--bg-light);
}

/* Speakers */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.speaker-card {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 40px 30px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.speaker-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1);
    border-color: var(--accent-color);
}

.speaker-company {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
}

.speaker-info h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--accent-color);
}

/* Info */
.info-content {
    max-width: 800px;
    margin: 0 auto;
}

.agenda-list {
    list-style: none;
    margin-top: 2rem;
    background: var(--white);
    padding: 2rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.agenda-list li {
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    gap: 20px;
}

.agenda-list li:last-child {
    border-bottom: none;
}

.agenda-list li strong {
    color: var(--accent-color);
    min-width: 60px;
}

/* Register Form */
.form-wrapper {
    max-width: 500px;
    margin: 0 auto;
    padding: 40px;
    background: var(--white);
    border-radius: 8px;
    box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    border-top: 5px solid var(--accent-color);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    font-size: 0.95rem;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-message {
    margin-top: 15px;
    text-align: center;
    font-size: 0.9rem;
}

.success {
    color: #16a34a;
}

.error {
    color: #dc2626;
}

/* Footer */
.footer {
    background-color: var(--primary-color);
    color: #64748b;
    padding: 40px 0;
    text-align: center;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .section-title {
        font-size: 2rem;
    }

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

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

    .form-wrapper {
        padding: 20px;
    }
}

/* Checkbox Styling */
.checkbox-group {
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.checkbox-group input[type="checkbox"] {
    width: auto;
    margin-top: 4px;
    /* Align with first line of text */
}

.checkbox-group label {
    font-weight: 400;
    /* Regular weight for consent text */
    font-size: 0.9rem;
    line-height: 1.4;
    color: var(--text-color);
}

.checkbox-group a {
    color: var(--accent-color);
    text-decoration: none;
    border-bottom: 1px dotted var(--accent-color);
}

.checkbox-group a:hover {
    border-bottom-style: solid;
}