/* ============================================
   ICCSC 2026 — Clean Conference Website
   ============================================ */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    color: #1a202c;
    background: #ffffff;
    line-height: 1.7;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

a {
    color: #2b6cb0;
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #1a365d;
}

img {
    max-width: 100%;
    display: block;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    line-height: 1.3;
    color: #1a202c;
    margin-bottom: 0.5em;
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 1.75rem;
}

h3 {
    font-size: 1.35rem;
}

h4 {
    font-size: 1.1rem;
}

p {
    margin-bottom: 1rem;
    color: #4a5568;
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 20px;
}

/* --- Top Bar (IEEE badge) --- */
.top-bar {
    background: #1a365d;
    color: #fff;
    font-size: 13px;
    padding: 6px 0;
    text-align: center;
    letter-spacing: 0.5px;
}

/* --- Navigation --- */
.site-nav {
    background: #fff;
    border-bottom: 1px solid #e2e8f0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo img {
    height: 50px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
    list-style: none;
}

.nav-links a {
    display: block;
    padding: 8px 14px;
    font-size: 14px;
    font-weight: 500;
    color: #4a5568;
    border-radius: 6px;
    transition: background 0.2s, color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    background: #ebf4ff;
    color: #2b6cb0;
}

.nav-cta {
    background: #2b6cb0 !important;
    color: #fff !important;
    font-weight: 600 !important;
}

.nav-cta:hover {
    background: #1a365d !important;
}

/* Mobile nav toggle */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #1a202c;
    padding: 8px;
}

/* Dropdown */
.nav-dropdown {
    position: relative;
}

.nav-dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
    min-width: 180px;
    padding: 8px 0;
    z-index: 100;
}

.nav-dropdown:hover .nav-dropdown-menu {
    display: block;
}

.nav-dropdown-menu a {
    display: block;
    padding: 8px 16px;
    font-size: 14px;
    color: #4a5568;
    border-radius: 0;
}

.nav-dropdown-menu a:hover {
    background: #f7fafc;
    color: #2b6cb0;
}

/* --- Hero Section --- */
.hero {
    background: linear-gradient(135deg, #1a365d 0%, #2b6cb0 60%, #3182ce 100%);
    color: #fff;
    padding: 100px 0 80px;
    text-align: center;
}

.hero h1 {
    font-size: 2.6rem;
    color: #fff;
    margin-bottom: 16px;
    font-weight: 800;
}

.hero .subtitle {
    font-size: 1.3rem;
    font-weight: 500;
    color: #fff;
    opacity: 1;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
    margin-bottom: 40px;
}

.hero .badge-line {
    display: inline-block;
    background: rgba(255, 255, 255, 0.15);
    padding: 6px 20px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: 20px;
}

/* Countdown */
.countdown {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.countdown-item {
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 16px 20px;
    min-width: 80px;
    text-align: center;
}

.countdown-item .num {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    line-height: 1;
}

.countdown-item .unit {
    display: block;
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 1px;
    opacity: 0.7;
    margin-top: 4px;
}

.hero-btns {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

/* --- Buttons --- */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    text-align: center;
    transition: all 0.2s;
    border: 2px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background: #fff;
    color: #1a365d;
}

.btn-primary:hover {
    background: #ebf4ff;
    color: #1a365d;
}

.btn-outline {
    background: transparent;
    color: #fff;
    border-color: rgba(255, 255, 255, 0.4);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    border-color: #fff;
}

.btn-blue {
    background: #2b6cb0;
    color: #fff;
}

.btn-blue:hover {
    background: #1a365d;
    color: #fff;
}

/* --- Sections --- */
.section {
    padding: 70px 0;
}

.section-gray {
    background: #f7fafc;
}

.section-title {
    text-align: center;
    margin-bottom: 50px;
}

.section-title .overline {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: #2b6cb0;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 8px;
}

/* --- Page Header (internal pages) --- */
.page-header {
    background: #f7fafc;
    border-bottom: 1px solid #e2e8f0;
    padding: 50px 0 40px;
    text-align: center;
}

.page-header .overline {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: #2b6cb0;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 8px;
}

.page-header h1 {
    font-size: 2.2rem;
    margin: 0;
}

/* --- Grid --- */
.grid {
    display: grid;
    gap: 24px;
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

.grid-sidebar {
    grid-template-columns: 2fr 1fr;
}

/* --- Cards --- */
.card {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 28px;
    transition: box-shadow 0.2s;
}

.card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

.card-accent {
    border-top: 3px solid #2b6cb0;
}

.card-dark {
    background: #1a365d;
    color: #fff;
    border-color: #1a365d;
}

.card-dark p,
.card-dark li {
    color: rgba(255, 255, 255, 0.8);
}

.card-dark h4 {
    color: #fff;
}

.card-blue {
    background: #2b6cb0;
    color: #fff;
    border-color: #2b6cb0;
}

.card-blue p {
    color: rgba(255, 255, 255, 0.85);
}

.card-blue h4 {
    color: #fff;
}

/* --- Deadline List --- */
.deadline-list {
    list-style: none;
}

.deadline-list li {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid #edf2f7;
    font-size: 15px;
}

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

.deadline-label {
    color: #718096;
}

.deadline-date {
    font-weight: 600;
    color: #2b6cb0;
}

/* --- Committee List --- */
.committee-list {
    list-style: none;
}

.committee-list li {
    padding: 10px 0;
    border-bottom: 1px solid #edf2f7;
    font-size: 15px;
    color: #4a5568;
}

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

.committee-list strong {
    color: #1a202c;
}

/* --- Speaker Card --- */
.speaker-card {
    display: flex;
    gap: 30px;
    align-items: flex-start;
}

.speaker-img {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
    border: 4px solid #edf2f7;
}

.speaker-info h3 {
    color: #2b6cb0;
    margin-bottom: 4px;
}

.speaker-info h5 {
    color: #718096;
    font-weight: 500;
    margin-bottom: 12px;
    font-size: 0.95rem;
}

.speaker-info p {
    font-size: 0.95rem;
}

/* --- Table --- */
.clean-table {
    width: 100%;
    border-collapse: collapse;
}

.clean-table th {
    background: #f7fafc;
    padding: 14px 20px;
    text-align: left;
    font-weight: 600;
    font-size: 14px;
    color: #718096;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-bottom: 2px solid #e2e8f0;
}

.clean-table td {
    padding: 16px 20px;
    border-bottom: 1px solid #edf2f7;
    color: #4a5568;
}

.clean-table .fee {
    font-weight: 700;
    color: #2b6cb0;
    text-align: right;
}

.clean-table th:last-child {
    text-align: right;
}

/* --- Registration Table --- */
.reg-table {
    width: 100%;
    border-collapse: collapse;
}

.reg-table th {
    background: #2b6cb0;
    color: #fff;
    padding: 14px 20px;
    text-align: left;
    font-weight: 600;
    font-size: 14px;
}

.reg-table th:first-child {
    border-radius: 8px 0 0 0;
}

.reg-table th:last-child {
    border-radius: 0 8px 0 0;
}

.reg-table th em {
    color: #bee3f8;
}

.reg-table td {
    padding: 14px 20px;
    border-bottom: 1px solid #edf2f7;
    color: #4a5568;
    font-size: 15px;
}

.reg-table td:first-child {
    font-weight: 600;
    color: #2d3748;
}

.reg-table tbody tr:hover {
    background: #f7fafc;
}

.section-row td {
    font-weight: 700;
    color: #fff !important;
    padding: 12px 20px !important;
    font-size: 15px;
    border-bottom: none !important;
}



.section-paper td {
    background: #0085c3 !important;
}

.section-abstract td {
    background: #f4a460 !important;
}

.section-audience td {
    background: #f0c75e !important;
}

/* --- Info Box --- */
.info-box {
    background: #ebf8ff;
    border-left: 4px solid #2b6cb0;
    padding: 20px 24px;
    border-radius: 0 8px 8px 0;
    margin: 20px 0;
}

.info-box ul {
    list-style: none;
}

.info-box li {
    padding: 8px 0;
    display: flex;
    gap: 12px;
    align-items: baseline;
    color: #2d3748;
}

.info-box li::before {
    content: "→";
    color: #2b6cb0;
    font-weight: 700;
    flex-shrink: 0;
}

/* --- Track List --- */
.track-card h4 {
    color: #2b6cb0;
    margin-bottom: 12px;
}

.track-card ul {
    list-style: disc;
    padding-left: 20px;
    color: #718096;
}

.track-card ul li {
    padding: 4px 0;
    font-size: 15px;
}

/* --- Footer --- */
.site-footer {
    background: #1a202c;
    color: #a0aec0;
    padding: 60px 0 0;
}

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

.site-footer h4 {
    color: #fff;
    font-size: 1rem;
    margin-bottom: 16px;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 8px;
}

.footer-links a {
    color: #a0aec0;
    font-size: 14px;
}

.footer-links a:hover {
    color: #fff;
}

.footer-bottom {
    margin-top: 40px;
    padding: 20px 0;
    border-top: 1px solid #2d3748;
    font-size: 13px;
    text-align: center;
    color: #718096;
}

/* --- Utilities --- */
.text-center {
    text-align: center;
}

.text-muted {
    color: #718096 !important;
}

.mb-0 {
    margin-bottom: 0;
}

.mb-1 {
    margin-bottom: 8px;
}

.mb-2 {
    margin-bottom: 16px;
}

.mb-3 {
    margin-bottom: 24px;
}

.mb-4 {
    margin-bottom: 32px;
}

.mb-5 {
    margin-bottom: 48px;
}

.mt-4 {
    margin-top: 32px;
}

.mt-5 {
    margin-top: 48px;
}

.sticky {
    position: sticky;
    top: 90px;
}

/* --- Award Icon --- */
.award-icon {
    font-size: 36px;
    margin-bottom: 16px;
}

/* --- Responsive --- */
@media (max-width: 900px) {

    .grid-2,
    .grid-3,
    .grid-4,
    .grid-sidebar {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 16px;
        border-bottom: 1px solid #e2e8f0;
        box-shadow: 0 8px 16px rgba(0, 0, 0, 0.06);
    }

    .nav-links.open {
        display: flex;
    }

    .nav-toggle {
        display: block;
    }

    .hero h1 {
        font-size: 1.8rem;
    }

    .speaker-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .speaker-img {
        width: 120px;
        height: 120px;
    }
}

@media (max-width: 600px) {
    .hero {
        padding: 60px 0 50px;
    }

    h1 {
        font-size: 1.6rem;
    }

    .section {
        padding: 50px 0;
    }

    .countdown-item {
        min-width: 65px;
        padding: 12px;
    }

    .countdown-item .num {
        font-size: 1.5rem;
    }
}