/* ================================
   ICEPME 2026 - CSS Stylesheet
   ================================ */

/* CSS Variables / Color Palette */
:root {
    --primary: #0a1f44;
    --secondary: #1565c0;
    --accent: #f9a825;
    --light-bg: #f5f3ee;
    --white: #ffffff;
    --text-main: #212529;
    --text-muted: #6c757d;
    --gradient-hero: linear-gradient(135deg, #0a1f44 0%, #1565c0 60%, #0a3d91 100%);
    --shadow-card: 0 4px 20px rgba(10, 31, 68, 0.1);
    --shadow-hover: 0 8px 30px rgba(10, 31, 68, 0.15);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-main);
    background-color: var(--white);
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }

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

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

/* ================================
   Navigation
   ================================ */
.navbar {
    background-color: var(--primary) !important;
    padding: 1rem 0;
    box-shadow: var(--shadow-card);
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--white) !important;
    display: flex;
    align-items: center;
}

.navbar-brand img {
    height: 40px;
    width: auto;
}

.navbar-brand span {
    color: var(--accent);
}

.navbar-dark .navbar-nav .nav-link {
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
    padding: 0.75rem 1rem;
    transition: var(--transition);
}

.navbar-dark .navbar-nav .nav-link:hover,
.navbar-dark .navbar-nav .nav-link.active {
    color: var(--accent);
}

.navbar-toggler {
    border-color: var(--accent);
}

.navbar-toggler-icon {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28255, 255, 255, 0.9%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ================================
   Hero Section
   ================================ */
.hero {
    background: linear-gradient(135deg, rgba(10, 31, 68, 0.85) 0%, rgba(21, 101, 192, 0.75) 100%),
                url('../images/hero-bg.jpg') center center / cover no-repeat;
    color: var(--white);
    padding: 120px 0 100px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(ellipse at center, rgba(255, 255, 255, 0.05) 0%, transparent 70%);
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: linear-gradient(to bottom, transparent, rgba(10, 31, 68, 0.3));
}

.hero-content {
    position: relative;
    z-index: 1;
    background: rgba(10, 31, 68, 0.25);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 60px 40px 50px;
    border: 1px solid rgba(255, 255, 255, 0.15);
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.25);
}

.hero h1 {
    font-size: clamp(3.2rem, 8vw, 5rem);
    color: var(--accent);
    margin-bottom: 1.2rem;
    text-shadow: 3px 3px 12px rgba(0, 0, 0, 0.6), 0 0 40px rgba(249, 168, 37, 0.25);
    letter-spacing: 0.06em;
    font-weight: 800;
}

.hero .subtitle {
    font-family: Georgia, 'Times New Roman', serif;
    font-size: 2.2rem;
    font-weight: 300;
    opacity: 0.95;
    margin-bottom: 2rem;
    line-height: 1.5;
    letter-spacing: 0.02em;
    text-shadow: 1px 1px 6px rgba(0, 0, 0, 0.5);
}

.hero-meta {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.hero-meta-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.15rem;
    background: rgba(255, 255, 255, 0.08);
    padding: 8px 18px;
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.12);
}

.hero-meta-item i {
    color: var(--accent);
    font-size: 1.3rem;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

/* Buttons */
.btn-primary-custom {
    background: var(--accent);
    color: var(--primary);
    border: none;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary-custom:hover {
    background: #e6970c;
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(249, 168, 37, 0.4);
}

.btn-secondary-custom {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--white);
    padding: 12px 30px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 50px;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-secondary-custom:hover {
    background: var(--white);
    color: var(--primary);
    transform: translateY(-3px);
}

/* ================================
   Stats Bar
   ================================ */
.stats-bar {
    background: var(--secondary);
    padding: 40px 0;
    color: var(--white);
}

.stats-item {
    text-align: center;
    padding: 15px;
}

.stats-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent);
    display: block;
}

.stats-label {
    font-size: 0.95rem;
    opacity: 0.9;
    margin-top: 5px;
}

/* ================================
   Section Common Styles
   ================================ */
.section {
    padding: 80px 0;
}

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

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

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    text-align: center;
    margin-bottom: 1rem;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--accent);
    border-radius: 2px;
    margin: 15px auto 0;
}

.section-subtitle {
    text-align: center;
    color: var(--text-muted);
    max-width: 700px;
    margin: 0 auto 50px;
    font-size: 1.1rem;
}

/* ================================
   About Section
   ================================ */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.about-text p {
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
    color: var(--text-main);
}

.about-highlights {
    background: var(--white);
    padding: 30px;
    border-radius: 15px;
    box-shadow: var(--shadow-card);
}

.highlight-item {
    display: flex;
    align-items: flex-start;
    gap: 15px;
    margin-bottom: 20px;
}

.highlight-item:last-child {
    margin-bottom: 0;
}

.highlight-item i {
    color: var(--accent);
    font-size: 1.3rem;
    margin-top: 3px;
}

.highlight-item h4 {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: var(--primary);
}

.highlight-item p {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* ================================
   Topics / Call for Papers
   ================================ */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.topic-card {
    background: var(--white);
    border-radius: 15px;
    padding: 30px;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
    border-top: 4px solid var(--secondary);
}

.topic-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.topic-icon {
    width: 60px;
    height: 60px;
    background: var(--light-bg);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.topic-icon i {
    font-size: 1.8rem;
    color: var(--secondary);
}

.topic-card h3 {
    color: var(--primary);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.topic-card ul {
    list-style: none;
    padding: 0;
}

.topic-card li {
    padding: 8px 0;
    border-bottom: 1px solid #eee;
    color: var(--text-muted);
    font-size: 0.95rem;
}

.topic-card li:last-child {
    border-bottom: none;
}

.topic-card li::before {
    content: '\f00c';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    color: var(--accent);
    margin-right: 10px;
}

/* ================================
   Important Dates / Timeline
   ================================ */
.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    padding-left: 40px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--accent);
}

.timeline-item {
    position: relative;
    margin-bottom: 40px;
    padding: 25px;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
}

.timeline-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-hover);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -32px;
    top: 30px;
    width: 16px;
    height: 16px;
    background: var(--accent);
    border-radius: 50%;
    border: 3px solid var(--white);
    box-shadow: 0 0 0 3px var(--accent);
}

.timeline-date {
    color: var(--secondary);
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.timeline-title {
    color: var(--primary);
    font-size: 1.2rem;
    margin-bottom: 8px;
}

.timeline-desc {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin: 0;
}

/* ================================
   Submission Guidelines
   ================================ */
.submission-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 50px;
}

.step-card {
    text-align: center;
    padding: 30px;
    background: var(--white);
    border-radius: 15px;
    box-shadow: var(--shadow-card);
    position: relative;
}

.step-number {
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 40px;
    background: var(--accent);
    color: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
}

.step-card i {
    font-size: 2.5rem;
    color: var(--secondary);
    margin-bottom: 20px;
}

.step-card h4 {
    color: var(--primary);
    margin-bottom: 10px;
}

.step-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
}

.submission-cta {
    text-align: center;
    padding: 40px;
    background: var(--light-bg);
    border-radius: 15px;
    margin-top: 30px;
}

.submission-cta h3 {
    color: var(--primary);
    margin-bottom: 15px;
}

/* ================================
   Guidelines Container (New)
   ================================ */
.guidelines-container {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
}

.guidelines-box {
    background: var(--white);
    border-radius: 15px;
    padding: 30px;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
    min-height: 280px;
    display: flex;
    flex-direction: column;
}

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

.guidelines-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--light-bg);
    flex-shrink: 0;
}

.guidelines-header i {
    font-size: 1.8rem;
    color: var(--secondary);
}

.guidelines-header h3 {
    margin: 0;
    font-size: 1.15rem;
    color: var(--primary);
}

.guidelines-list {
    list-style: none;
    padding: 0;
    margin: 0;
    flex-grow: 1;
}

.guidelines-list li {
    padding: 10px 0;
    border-bottom: 1px solid #f0f0f0;
    color: var(--text-main);
    display: flex;
    align-items: flex-start;
    gap: 12px;
    font-size: 0.95rem;
}

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

.guidelines-list li i {
    color: var(--accent);
    margin-top: 3px;
    flex-shrink: 0;
}

.step-badge {
    background: var(--accent);
    color: var(--primary);
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
    flex-shrink: 0;
}

.download-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
    flex-grow: 1;
    justify-content: center;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 18px;
    background: var(--light-bg);
    border-radius: 10px;
    color: var(--primary);
    font-weight: 500;
    transition: var(--transition);
}

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

.download-btn i {
    font-size: 1.3rem;
    color: var(--secondary);
}

.download-btn:hover i {
    color: var(--white);
}

/* ================================
   Registration Guidelines
   ================================ */
.fee-table-container {
    background: var(--white);
    border-radius: 15px;
    padding: 30px;
    box-shadow: var(--shadow-card);
    margin-bottom: 40px;
}

.fee-title {
    color: var(--primary);
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.table-responsive {
    overflow-x: auto;
}

.fee-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 600px;
}

.fee-table th,
.fee-table td {
    padding: 15px 20px;
    text-align: center;
    border: 1px solid #eee;
}

.fee-table th {
    background: var(--primary);
    color: var(--white);
    font-weight: 600;
}

.fee-table th small {
    font-weight: 400;
    opacity: 0.8;
}

.fee-table tbody tr:nth-child(even) {
    background: var(--light-bg);
}

.fee-table tbody tr:hover {
    background: rgba(21, 101, 192, 0.05);
}

.fee-table td:first-child {
    text-align: left;
    font-weight: 500;
}

.fee-table td i {
    color: var(--secondary);
}

/* Registration Steps - 优化版时间线样式 */
.reg-steps-container {
    margin-bottom: 40px;
}

.reg-title {
    color: var(--primary);
    margin-bottom: 25px;
    font-size: 1.3rem;
}

.reg-steps {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
    position: relative;
    max-width: 700px;
    margin: 0 auto;
}

/* 时间线主轴 */
.reg-steps::before {
    content: '';
    position: absolute;
    left: 32px;
    top: 45px;
    bottom: 45px;
    width: 3px;
    background: linear-gradient(to bottom, var(--secondary), var(--accent));
    border-radius: 2px;
}

.reg-step {
    display: flex;
    align-items: flex-start;
    gap: 25px;
    background: var(--white);
    padding: 25px 30px;
    border-radius: 16px;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
    width: 100%;
    margin-bottom: 20px;
    position: relative;
    border-left: 4px solid transparent;
}

.reg-step:last-child {
    margin-bottom: 0;
}

.reg-step:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-hover);
    border-left-color: var(--accent);
}

/* 步骤编号圆形 */
.reg-step-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    position: relative;
    z-index: 2;
    border: 3px solid var(--white);
    box-shadow: 0 4px 15px rgba(21, 101, 192, 0.3);
}

.reg-step-icon span {
    color: var(--white);
    font-weight: 700;
    font-size: 1.3rem;
}

/* 内容区域 */
.reg-step-content {
    flex: 1;
    padding-top: 3px;
}

.reg-step-content h4 {
    color: var(--primary);
    margin-bottom: 8px;
    font-size: 1.15rem;
    font-weight: 600;
    position: relative;
    display: inline-block;
}

.reg-step-content h4::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -4px;
    width: 40px;
    height: 3px;
    background: var(--accent);
    border-radius: 2px;
}

.reg-step-content p {
    color: var(--text-muted);
    margin: 12px 0 0;
    font-size: 0.95rem;
    line-height: 1.6;
}

/* 箭头指示器 */
.reg-step::after {
    content: '';
    position: absolute;
    right: 25px;
    top: 50%;
    transform: translateY(-50%);
    width: 0;
    height: 0;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    border-left: 10px solid var(--light-bg);
    opacity: 0;
    transition: var(--transition);
}

.reg-step:hover::after {
    border-left-color: var(--accent);
    opacity: 1;
}

/* What's Included */
.included-box {
    background: var(--white);
    border-radius: 15px;
    padding: 30px;
    box-shadow: var(--shadow-card);
    margin-bottom: 40px;
}

.included-title {
    color: var(--primary);
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.included-items {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.included-item {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 18px 15px;
    background: var(--light-bg);
    border-radius: 10px;
    color: var(--text-main);
    font-weight: 500;
    transition: var(--transition);
    text-align: center;
}

.included-item:hover {
    background: var(--secondary);
    color: var(--white);
}

.included-item i {
    font-size: 1.2rem;
    color: var(--accent);
}

.included-item:hover i {
    color: var(--white);
}

/* Registration CTA */
.registration-cta {
    text-align: center;
    padding: 20px 0;
}

/* ================================
   Publication / Indexing
   ================================ */
.publication-content {
    text-align: center;
}

.index-badges {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
    margin-top: 40px;
}

.index-badge {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 25px 35px;
    background: var(--white);
    border-radius: 15px;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
    min-width: 150px;
}

.index-badge:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.index-badge i {
    font-size: 2.5rem;
    color: var(--secondary);
    margin-bottom: 15px;
}

.index-badge span {
    font-weight: 600;
    color: var(--primary);
    font-size: 1rem;
}

.publication-note {
    margin-top: 40px;
    padding: 25px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    border-left: 4px solid var(--accent);
}

.publication-note p {
    margin: 0;
    font-size: 1rem;
    opacity: 0.95;
}

/* ================================
   Speakers
   ================================ */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.speaker-card {
    background: var(--white);
    border-radius: 15px;
    padding: 25px;
    text-align: center;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
    cursor: pointer;
}

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

.speaker-photo {
    position: relative;
    width: 120px;
    height: 120px;
    margin: 0 auto 20px;
    border-radius: 50%;
    overflow: hidden;
}

.speaker-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    clip-path: inset(0 0 6% 0);
}

.speaker-card h4 {
    color: var(--primary);
    margin-bottom: 8px;
    font-size: 1rem;
}

.speaker-title {
    color: var(--secondary);
    font-size: 0.85rem;
    margin-bottom: 5px;
}

.speaker-topic {
    color: var(--text-muted);
    font-size: 0.8rem;
    line-height: 1.4;
}

/* Speaker Modal */
.speaker-modal .modal-content {
    border-radius: 15px;
    border: none;
    overflow: hidden;
}

.speaker-modal .modal-header {
    background: var(--primary);
    color: var(--white);
    border-bottom: none;
}

.speaker-modal .modal-header .btn-close {
    filter: invert(1);
}

.speaker-modal .modal-body {
    padding: 30px;
}

.speaker-modal-photo {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    overflow: hidden;
    margin: 0 auto 20px;
    border: 4px solid var(--accent);
}

.speaker-modal-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    clip-path: inset(0 0 6% 0);
}

.speaker-modal-name {
    text-align: center;
    color: var(--primary);
    font-size: 1.4rem;
    margin-bottom: 5px;
}

.speaker-modal-affiliation {
    text-align: center;
    color: var(--secondary);
    font-size: 1rem;
    margin-bottom: 20px;
}

.speaker-modal-bio {
    color: var(--text-main);
    line-height: 1.7;
    margin-bottom: 20px;
    text-align: justify;
}

.speaker-modal-topic {
    background: var(--light-bg);
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid var(--accent);
}

.speaker-modal-topic h5 {
    color: var(--primary);
    font-size: 1rem;
    margin-bottom: 10px;
}

.speaker-modal-topic h5 i {
    color: var(--accent);
    margin-right: 8px;
}

.speaker-modal-topic p {
    color: var(--text-main);
    margin: 0;
    font-weight: 500;
}

/* ================================
   Committee
   ================================ */
.committee-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.committee-section {
    background: var(--white);
    padding: 25px;
    border-radius: 15px;
    box-shadow: var(--shadow-card);
}

.committee-section h4 {
    color: var(--primary);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--accent);
    font-size: 1rem;
}

.committee-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.committee-list li {
    padding: 15px 0;
    border-bottom: 1px solid #f0f0f0;
}

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

.committee-name {
    display: block;
    color: var(--text-main);
    font-weight: 600;
    font-size: 0.95rem;
    margin-bottom: 5px;
}

.committee-affiliation {
    display: block;
    color: var(--text-muted);
    font-size: 0.85rem;
    line-height: 1.4;
}

/* ================================
   Venue
   ================================ */
.venue-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.venue-info h3 {
    color: var(--primary);
    margin-bottom: 20px;
}

.venue-info p {
    color: var(--text-muted);
    margin-bottom: 15px;
    font-size: 1.05rem;
}

.venue-info i {
    color: var(--accent);
    margin-right: 10px;
    width: 20px;
}

.venue-map {
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow-card);
}

.venue-image {
    width: 100%;
    height: 400px;
    object-fit: cover;
    display: block;
    clip-path: inset(0 0 6% 0);
}

/* ================================
   Contact
   ================================ */
.contact-wrapper {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-item-inline {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 25px;
    background: var(--white);
    border-radius: 15px;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
}

.contact-item-inline:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.contact-item-inline .contact-icon {
    width: 50px;
    height: 50px;
    background: var(--light-bg);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-item-inline .contact-icon i {
    font-size: 1.3rem;
    color: var(--secondary);
}

.contact-item-inline h4 {
    color: var(--primary);
    margin-bottom: 5px;
    font-size: 1rem;
}

.contact-item-inline p {
    color: var(--text-muted);
    margin: 0;
    font-size: 0.9rem;
}

.contact-item-inline a {
    color: var(--secondary);
}

/* ================================
   Footer
   ================================ */
.footer {
    background: var(--primary);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 50px;
    margin-bottom: 40px;
}

.footer-about h3 {
    margin-bottom: 20px;
}

.footer-about h3 span {
    color: var(--accent);
}

.footer-about p {
    opacity: 0.8;
    font-size: 0.95rem;
    line-height: 1.8;
}

.footer-links h4,
.footer-contact h4 {
    color: var(--accent);
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.footer-links ul {
    list-style: none;
    padding: 0;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--accent);
    padding-left: 5px;
}

.footer-contact p {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    opacity: 0.8;
}

.footer-contact i {
    color: var(--accent);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    text-align: center;
    opacity: 0.7;
    font-size: 0.9rem;
}

/* ================================
   Back to Top Button
   ================================ */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--accent);
    color: var(--primary);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
    z-index: 1000;
}

.back-to-top:hover {
    background: #e6970c;
    transform: translateY(-5px);
}

.back-to-top.show {
    display: flex;
}

/* ================================
   Countdown Timer
   ================================ */
.countdown-container {
    background: rgba(249, 168, 37, 0.12);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 35px 40px;
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-top: 30px;
    border: 1px solid rgba(249, 168, 37, 0.2);
}

.countdown-number {
    display: block;
    font-size: 3rem;
    font-weight: 800;
    color: var(--accent);
    text-shadow: 0 0 20px rgba(249, 168, 37, 0.35);
}

.countdown-label {
    font-size: 0.95rem;
    opacity: 0.9;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

/* ================================
   Sponsors & Partners
   ================================ */
.sponsor-tier {
    margin-bottom: 2.5rem;
}

.sponsor-tier:last-child {
    margin-bottom: 0;
}

.sponsor-tier-label {
    text-align: center;
    font-size: 1.1rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    margin-bottom: 1.5rem;
    padding: 6px 24px;
    border-radius: 4px;
    display: inline-block;
}

.sponsor-tier-label.gold {
    background: linear-gradient(135deg, #f9a825, #fbc02d);
    color: #5d4037;
}.sponsor-logos {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.5rem;
}

.sponsor-logo-box {
    background: var(--white);
    border-radius: 12px;
    padding: 1.8rem 1.5rem;
    text-align: center;
    min-width: 180px;
    flex: 1 1 200px;
    max-width: 260px;
    transition: var(--transition);
    box-shadow: var(--shadow-card);
    border: 2px solid transparent;
}

.sponsor-logo-box:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--accent);
}

.sponsor-logo-box i {
    font-size: 2.5rem;
    margin-bottom: 0.8rem;
    display: block;
}

.sponsor-logo-box span {
    display: block;
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--primary);
    margin-bottom: 0.3rem;
}

.sponsor-logo-box small {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ================================
   Responsive Design
   ================================ */
@media (max-width: 992px) {
    .about-content,
    .venue-content,
    .contact-content,
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .hero {
        padding: 100px 0 80px;
    }
    
    .section {
        padding: 60px 0;
    }
}

@media (max-width: 768px) {
    .navbar-collapse {
        background: var(--primary);
        padding: 20px;
        border-radius: 10px;
        margin-top: 10px;
    }
    
    .hero-meta {
        flex-direction: column;
        gap: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn-primary-custom,
    .btn-secondary-custom {
        width: 100%;
        justify-content: center;
    }
    
    .stats-bar {
        padding: 30px 0;
    }
    
    .stats-item {
        padding: 10px;
    }
    
    .stats-number {
        font-size: 2rem;
    }
    
    .countdown-container {
        gap: 15px;
        padding: 20px;
    }
    
    .countdown-number {
        font-size: 1.8rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .topics-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .topic-card,
    .speaker-card,
    .step-card {
        padding: 25px;
    }
    
    .timeline {
        padding-left: 30px;
    }
    
    .guidelines-container {
        grid-template-columns: 1fr;
    }
    
    .guidelines-box {
        min-height: auto;
    }
    
    .included-items {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .fee-table {
        font-size: 0.9rem;
    }
    
    .speakers-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .committee-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-wrapper {
        grid-template-columns: 1fr;
    }
    
    .venue-content {
        grid-template-columns: 1fr;
    }
    
    .venue-image {
        height: 250px;
    }
    
    /* Registration Steps 移动端优化 */
    .reg-steps::before {
        left: 24px;
    }
    
    .reg-step {
        padding: 20px;
        gap: 20px;
    }
    
    .reg-step-icon {
        width: 42px;
        height: 42px;
    }
    
    .reg-step-icon span {
        font-size: 1.1rem;
    }
    
    .reg-step-content h4 {
        font-size: 1.05rem;
    }
    
    .reg-step-content p {
        font-size: 0.9rem;
    }
    
    .reg-step::after {
        display: none;
    }
}

@media (max-width: 576px) {
    .index-badges {
        gap: 15px;
    }
    
    .index-badge {
        padding: 20px 25px;
        min-width: 130px;
    }
    
    .footer-content {
        gap: 30px;
    }
    
    .included-items {
        grid-template-columns: 1fr;
    }
    
    .topics-grid {
        grid-template-columns: 1fr;
    }
    
    .speakers-grid {
        grid-template-columns: 1fr;
    }
    
    .committee-grid {
        grid-template-columns: 1fr;
    }
    
    .sponsor-logo-box {
        min-width: 140px;
        flex: 1 1 140px;
    }
}