/* General Styles */
:root {
    --primary-color: #0056b3;
    --secondary-color: #004494;
    --accent-color: #e7f1ff;
    --text-color: #333;
    --light-text: #666;
    --bg-color: #fff;
    --section-bg: #f8f9fa;
    --border-color: #dee2e6;
    --font-main: 'Roboto', sans-serif;
    --font-header: 'Lato', sans-serif;
}

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

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

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

a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.container {
    width: 90%;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background-color: var(--primary-color);
    background-image: 
        linear-gradient(rgba(255, 255, 255, 0.07) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.07) 1px, transparent 1px),
        linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    background-size: 30px 30px, 30px 30px, 100% 100%;
    background-attachment: fixed;
    
    color: #fff;
    padding: 80px 0; 
    text-align: center;
    position: relative;
    overflow: hidden;
}

header::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 60%);
    pointer-events: none; /* 确保不影响点击 */
}

/* header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
    padding: 60px 0;
    text-align: center;
} */

header h1 {
    font-family: var(--font-header);
    font-size: 2.5rem;
    margin-bottom: 10px;
    line-height: 1.2;
}

header h2 {
    font-size: 1.5rem;
    font-weight: 300;
    opacity: 0.9;
    margin-bottom: 20px;
}

.date-location {
    font-size: 1.1rem;
    margin-top: 15px;
    opacity: 0.9;
}

.conference-info {
    font-size: 1rem;
    margin-top: 5px;
    font-style: italic;
    opacity: 0.8;
}

.speaker a {
    text-decoration: none;
    color: inherit;
    display: block;
}

.speaker a:hover i.fa-user-circle {
    color: var(--primary-color);
    transform: scale(1.1);
    transition: all 0.3s ease;
}

.speaker img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 15px;
    background-color: #eee;
    transition: transform 0.3s ease;
}

.speaker a:hover img {
    transform: scale(1.1);
}

/* Navigation */
nav {
    background-color: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    padding: 15px 0;
}

nav ul li {
    margin: 0 15px;
}

nav ul li a {
    color: var(--text-color);
    font-weight: 700;
    text-transform: uppercase;
    font-size: 0.9rem;
    text-decoration: none;
}

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

/* Sections */
section {
    padding: 60px 0;
    border-bottom: 1px solid var(--border-color);
}

section:last-child {
    border-bottom: none;
}

section h3 {
    font-family: var(--font-header);
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 30px;
    text-align: center;
    position: relative;
    padding-bottom: 15px;
}

section h3::after {
    content: '';
    display: block;
    width: 50px;
    height: 3px;
    background-color: var(--secondary-color);
    margin: 10px auto 0;
}

section h4 {
    font-family: var(--font-header);
    font-size: 1.4rem;
    margin-top: 30px;
    margin-bottom: 15px;
    color: var(--secondary-color);
}

section p, section li {
    font-size: 1.05rem;
    margin-bottom: 15px;
}

section ul, section ol {
    padding-left: 20px;
    margin-bottom: 15px;
}

section ul li, section ol li {
    margin-bottom: 5px;
}

/* Tracks */
.tracks {
    display: flex;
    gap: 30px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.track {
    flex: 1;
    background: var(--section-bg);
    padding: 25px;
    border-radius: 8px;
    min-width: 300px;
    border: 1px solid var(--border-color);
}

.track h4 {
    margin-top: 0;
}

/* Lists */
ul.dates {
    list-style: none;
    padding-left: 0;
}

ul.dates li {
    padding: 10px 0;
    border-bottom: 1px dashed var(--border-color);
}

/* Speakers */
.speaker-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    text-align: center;
    margin-top: 30px;
}

.speaker {
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    transition: transform 0.3s;
}

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

.speaker img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 15px;
    background-color: #eee;
}

.speaker h4 {
    font-size: 1.1rem;
    margin: 10px 0 5px;
    color: var(--text-color);
}

.speaker p {
    font-size: 0.9rem;
    color: var(--light-text);
    margin-bottom: 0;
}

/* Schedule */
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    background: #fff;
}

th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: var(--section-bg);
    font-weight: 700;
}

tr:hover {
    background-color: var(--accent-color);
}

/* Organizers */
.organizer-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.organizer-list p {
    margin-bottom: 5px;
}

/* Footer */
footer {
    background-color: #333;
    color: #fff;
    padding: 30px 0;
    text-align: center;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.8rem;
    }
    
    nav ul {
        flex-direction: column;
        align-items: center;
    }

    nav ul li {
        margin: 5px 0;
    }

    .tracks {
        flex-direction: column;
    }
}