/* ================================
   AISIVP 2027 - CSS Stylesheet
   Palette: deep indigo + electric cyan/violet/magenta (AI neural theme)
   ================================ */

/* CSS Variables / Color Palette */
:root {
    --primary: #0d0b2e;          /* deep indigo — navbar / footer */
    --navy: #241a5c;             /* indigo — headings, table header */
    --secondary: #6d28d9;        /* violet — links, icons */
    --accent: #22d3ee;           /* electric cyan — highlights */
    --accent-2: #9333ea;         /* violet — gradients, hover text */
    --light-bg: #f6f5fc;         /* violet-tinted light section */
    --white: #ffffff;
    --text-main: #1f2933;
    --text-muted: #64627b;
    --gradient-accent: linear-gradient(135deg, #0ea5e9 0%, #8b5cf6 55%, #d946ef 100%);
    --gradient-hero: linear-gradient(150deg, rgba(13, 11, 46, 0.94) 0%, rgba(46, 16, 101, 0.84) 55%, rgba(109, 40, 217, 0.72) 100%);
    --shadow-card: 0 4px 20px rgba(30, 20, 80, 0.08);
    --shadow-hover: 0 10px 32px rgba(30, 20, 80, 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', 'PingFang SC', 'Microsoft YaHei', 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-2);
}

img {
    max-width: 100%;
}

.container {
    width: 100%;
    max-width: 1180px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Inline SVG icon helper */
.icon {
    width: 1.25em;
    height: 1.25em;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
    vertical-align: -0.25em;
    flex-shrink: 0;
}

/* Anchor offset under sticky navbar */
section[id] {
    scroll-margin-top: 76px;
}

/* ================================
   Navigation
   ================================ */
.navbar {
    background-color: var(--primary);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-card);
    transition: var(--transition);
}

.navbar.scrolled {
    padding-top: 2px;
    padding-bottom: 2px;
    background-color: rgba(13, 11, 46, 0.96);
    backdrop-filter: blur(8px);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 0.9rem;
    padding-bottom: 0.9rem;
    gap: 20px;
}

.navbar-brand {
    display: flex;
    align-items: center;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--white);
    letter-spacing: 0.02em;
    white-space: nowrap;
}

.navbar-brand img {
    height: 40px;
    width: auto;
    margin-right: 10px;
}

.navbar-brand em {
    font-style: normal;
    color: var(--accent);
}

.nav-menu {
    display: flex;
    align-items: center;
    list-style: none;
    gap: 2px;
}

.nav-link {
    display: block;
    color: rgba(255, 255, 255, 0.88);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.6rem 0.75rem;
    border-radius: 8px;
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent);
    background: rgba(168, 85, 247, 0.15);
}

.nav-toggle {
    display: none;
    background: transparent;
    border: 1px solid rgba(168, 85, 247, 0.5);
    color: var(--accent);
    width: 44px;
    height: 40px;
    border-radius: 8px;
    cursor: pointer;
    align-items: center;
    justify-content: center;
}

.nav-toggle .icon { width: 22px; height: 22px; }
.nav-toggle .icon-close { display: none; }
.nav-toggle.open .icon-open { display: none; }
.nav-toggle.open .icon-close { display: block; }

/* ================================
   Hero Section
   ================================ */
.hero {
    background: var(--gradient-hero),
                url('../images/hero-bg.png') center center / cover no-repeat;
    color: var(--white);
    padding: 110px 0 90px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(ellipse at center, rgba(168, 85, 247, 0.1) 0%, transparent 70%);
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
    background: rgba(13, 11, 46, 0.38);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 60px 40px 50px;
    border: 1px solid rgba(168, 85, 247, 0.28);
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.25);
}

.hero h1 {
    font-size: clamp(3rem, 8vw, 4.6rem);
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 0 24px rgba(168, 85, 247, 0.3));
    margin-bottom: 1.2rem;
    letter-spacing: 0.05em;
    font-weight: 800;
}

/* Fallback for browsers without background-clip:text */
@supports not ((-webkit-background-clip: text) or (background-clip: text)) {
    .hero h1 { color: var(--accent); filter: none; }
}

.hero .subtitle {
    font-size: clamp(1.3rem, 3vw, 2rem);
    font-weight: 300;
    opacity: 0.95;
    margin-bottom: 2rem;
    line-height: 1.5;
    letter-spacing: 0.02em;
    text-shadow: 1px 1px 8px rgba(0, 0, 0, 0.5);
}

.hero-meta {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.hero-meta-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.05rem;
    background: rgba(255, 255, 255, 0.08);
    padding: 8px 18px;
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.14);
}

.hero-meta-item .icon {
    color: var(--accent);
    width: 1.2em;
    height: 1.2em;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

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

.btn-primary {
    background: var(--gradient-accent);
    color: var(--white);
    box-shadow: 0 6px 20px rgba(139, 92, 246, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(217, 70, 239, 0.5);
    color: var(--white);
}

.btn-ghost {
    background: transparent;
    color: var(--white);
    border: 2px solid rgba(255, 255, 255, 0.85);
    padding: 12px 30px;
}

.btn-ghost:hover {
    background: var(--white);
    color: var(--navy);
    transform: translateY(-3px);
}

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

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

.section-title {
    font-size: clamp(1.6rem, 3vw, 2.1rem);
    font-weight: 700;
    color: var(--navy);
    text-align: center;
    margin-bottom: 1rem;
    position: relative;
}

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

.section-subtitle {
    text-align: center;
    color: var(--text-muted);
    max-width: 760px;
    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 .icon {
    color: var(--accent);
    width: 1.5em;
    height: 1.5em;
    margin-top: 3px;
}

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

.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 transparent;
    border-image: var(--gradient-accent) 1;
    border-image-slice: 1 0 0 0;
}

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

.topic-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, rgba(34, 211, 238, 0.12), rgba(168, 85, 247, 0.14));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.topic-icon .icon {
    width: 28px;
    height: 28px;
    color: var(--secondary);
}

.topic-card h3 {
    color: var(--navy);
    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 #ece9f9;
    color: var(--text-muted);
    font-size: 0.95rem;
    display: flex;
    align-items: flex-start;
    gap: 8px;
}

.topic-card li::before {
    content: '';
    flex-shrink: 0;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--gradient-accent);
    margin-top: 9px;
}

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

/* ================================
   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(--gradient-accent);
    border-radius: 2px;
}

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

.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;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

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

/* ================================
   Submission Guidelines
   ================================ */
.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 .icon {
    width: 28px;
    height: 28px;
    color: var(--secondary);
}

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

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

.guidelines-list li {
    padding: 10px 0;
    border-bottom: 1px solid #f0edf9;
    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 .icon {
    color: var(--accent);
    margin-top: 3px;
}

.step-badge {
    background: var(--gradient-accent);
    color: var(--white);
    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;
    margin-top: 1px;
}

.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(--navy);
    font-weight: 500;
    transition: var(--transition);
}

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

.download-btn .icon {
    width: 22px;
    height: 22px;
    color: var(--secondary);
}

.download-btn:hover .icon {
    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,
.included-title,
.reg-title {
    color: var(--navy);
    margin-bottom: 20px;
    font-size: 1.3rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.fee-title .icon,
.included-title .icon,
.reg-title .icon {
    color: var(--accent);
}

.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 #eae6f6;
}

.fee-table th {
    background: var(--navy);
    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(168, 85, 247, 0.07);
}

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

.fee-table td:first-child .icon {
    color: var(--secondary);
    margin-right: 8px;
}

/* Registration Steps */
.reg-steps-container {
    margin-bottom: 0;
}

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

/* Timeline axis */
.reg-steps::before {
    content: '';
    position: absolute;
    left: 32px;
    top: 45px;
    bottom: 45px;
    width: 3px;
    background: linear-gradient(to bottom, var(--accent), var(--accent-2));
    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);
}

.reg-step-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 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(139, 92, 246, 0.35);
}

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

.reg-step-content {
    flex: 1;
    padding-top: 3px;
}

.reg-step-content h4 {
    color: var(--navy);
    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(--gradient-accent);
    border-radius: 2px;
}

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

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

.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 .icon {
    color: var(--accent);
}

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

/* ================================
   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 .icon {
    width: 40px;
    height: 40px;
    color: var(--secondary);
    margin-bottom: 15px;
}

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

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

.publication-note p {
    margin: 0;
    font-size: 1rem;
    color: var(--text-main);
}

.publication-note .icon {
    color: var(--accent);
    margin-right: 6px;
}

/* ================================
   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);
    transition: var(--transition);
}

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

.committee-section h4 {
    color: var(--navy);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid transparent;
    border-image: var(--gradient-accent) 1;
    border-image-slice: 0 0 1 0;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.committee-section h4 .icon {
    color: var(--accent);
}

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

.committee-list li {
    padding: 15px 0;
    border-bottom: 1px solid #f0edf9;
}

.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;
}

.committee-note {
    margin-top: 35px;
    text-align: center;
    color: var(--text-muted);
    font-size: 1.02rem;
}

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

.venue-info h3 {
    color: var(--navy);
    margin-bottom: 20px;
    font-size: 1.35rem;
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.venue-info h3 .icon {
    color: var(--accent);
    margin-top: 5px;
}

.venue-info p {
    color: var(--text-muted);
    margin-bottom: 15px;
    font-size: 1.02rem;
}

.venue-info > p > .icon {
    color: var(--accent);
    margin-right: 8px;
}

.venue-info h4 {
    color: var(--navy);
}

.venue-highlights {
    list-style: none;
    padding: 0;
    margin-bottom: 10px;
}

.venue-highlights li {
    padding: 6px 0 6px 22px;
    position: relative;
    color: var(--text-muted);
}

.venue-highlights li::before {
    content: '';
    position: absolute;
    left: 4px;
    top: 14px;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--gradient-accent);
}

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

.venue-image {
    width: 100%;
    height: 420px;
    object-fit: cover;
    display: block;
    transition: transform 0.5s ease;
}

.venue-map:hover .venue-image {
    transform: scale(1.04);
}

.mt-4 { margin-top: 1.5rem; }
.mb-3 { margin-bottom: 1rem; }

/* ================================
   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-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, rgba(34, 211, 238, 0.12), rgba(168, 85, 247, 0.14));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-icon .icon {
    color: var(--secondary);
}

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

.contact-item-inline p {
    color: var(--text-muted);
    margin: 0 0 4px;
    font-size: 0.9rem;
    word-break: break-all;
}

.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;
    display: flex;
    align-items: center;
    gap: 10px;
}

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

.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;
    word-break: break-all;
}

.footer-contact .icon {
    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;
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.8);
}

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

/* ================================
   Back to Top Button
   ================================ */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-accent);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 6px 20px rgba(139, 92, 246, 0.45);
    transition: var(--transition);
    z-index: 1000;
}

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

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

/* ================================
   Countdown Timer
   ================================ */
.countdown-container {
    background: rgba(139, 92, 246, 0.12);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 30px 40px;
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-top: 30px;
    border: 1px solid rgba(168, 85, 247, 0.3);
}

.countdown-number {
    display: block;
    font-size: 2.8rem;
    font-weight: 800;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-variant-numeric: tabular-nums;
}

@supports not ((-webkit-background-clip: text) or (background-clip: text)) {
    .countdown-number { color: var(--accent); }
}

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

/* ================================
   Scroll Reveal Animation
   ================================ */
.reveal {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
    opacity: 1;
    transform: none;
}

/* No-JS / reduced-motion fallback */
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    .reveal { opacity: 1; transform: none; transition: none; }
}

/* ================================
   Responsive Design
   ================================ */
@media (max-width: 992px) {
    .about-content,
    .venue-content,
    .footer-content {
        grid-template-columns: 1fr;
    }

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

    .hero {
        padding: 90px 0 70px;
    }

    .section {
        padding: 60px 0;
    }

    .nav-link {
        padding: 0.5rem 0.55rem;
        font-size: 0.88rem;
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--primary);
        flex-direction: column;
        align-items: stretch;
        padding: 15px 20px 20px;
        gap: 4px;
        border-top: 1px solid rgba(168, 85, 247, 0.25);
        box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3);
    }

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

    .nav-link {
        padding: 0.8rem 1rem;
        font-size: 1rem;
    }

    .hero-meta {
        flex-direction: column;
        align-items: center;
        gap: 0.8rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .countdown-container {
        gap: 14px;
        padding: 20px;
    }

    .countdown-number {
        font-size: 1.9rem;
    }

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

    .topic-card,
    .guidelines-box {
        padding: 25px;
    }

    .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;
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
    }

    .venue-image {
        height: 260px;
    }

    .reg-steps::before {
        left: 24px;
    }

    .reg-step {
        padding: 20px;
        gap: 18px;
    }

    .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;
    }

    .timeline {
        padding-left: 30px;
    }
}

@media (max-width: 576px) {
    .topics-grid {
        grid-template-columns: 1fr;
    }

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

    .included-items {
        grid-template-columns: 1fr;
    }

    .index-badges {
        gap: 15px;
    }

    .index-badge {
        padding: 20px 25px;
        min-width: 130px;
    }

    .footer-content {
        gap: 30px;
    }

    .hero-content {
        padding: 40px 20px 35px;
    }

    .navbar-brand span {
        font-size: 1.15rem;
    }
}