/* ========================================
   SDPS 2026 Conference Website
   Refined Academic Design System
   ======================================== */

/* CSS Custom Properties */
:root {
    /* Primary Palette - Deep Academic Navy */
    --primary: #0c1829;
    --primary-light: #162544;
    --primary-medium: #1e3a5f;

    /* Accent - Warm Antique Gold */
    --accent: #c9a227;
    --accent-light: #ddb93d;
    --accent-dark: #a68520;
    --accent-muted: rgba(201, 162, 39, 0.15);

    /* Neutral Palette */
    --text: #2d3748;
    --text-light: #5a6a7e;
    --text-muted: #8b9cb3;

    /* Backgrounds */
    --bg: #fafbfc;
    --bg-warm: #f7f6f3;
    --bg-cream: #f3f1ec;
    --white: #ffffff;

    /* Borders & Shadows */
    --border: #e5e8ed;
    --border-light: #eef1f5;
    --shadow-sm: 0 2px 8px rgba(12, 24, 41, 0.04);
    --shadow-md: 0 8px 30px rgba(12, 24, 41, 0.08);
    --shadow-lg: 0 20px 50px rgba(12, 24, 41, 0.12);
    --shadow-gold: 0 8px 30px rgba(201, 162, 39, 0.2);

    /* Typography Scale */
    --font-display: 'Cormorant Garamond', Georgia, serif;
    --font-body: 'Outfit', system-ui, -apple-system, sans-serif;

    /* Spacing */
    --section-padding: clamp(80px, 12vw, 140px);
    --container-max: 1280px;

    /* Transitions */
    --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
    --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    font-weight: 400;
    font-size: 16px;
}

/* Typography */
h1,
h2,
h3,
h4 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
    color: var(--primary);
}

h1 {
    font-weight: 700;
}

h2 {
    font-weight: 600;
}

h3,
h4 {
    font-weight: 500;
}

p {
    font-size: 1.05rem;
    color: var(--text-light);
}

em {
    font-style: italic;
}

/* ========================================
   NAVIGATION
   ======================================== */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(229, 232, 237, 0.5);
    transition: all 0.4s var(--ease-smooth);
}

nav.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 clamp(20px, 4vw, 50px);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 85px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 14px;
    text-decoration: none;
    transition: transform 0.3s var(--ease-out);
}

.logo:hover {
    transform: translateY(-1px);
}

.logo img {
    height: 45px;
    width: auto;
}

.logo-text {
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--primary);
    letter-spacing: -0.02em;
}

.logo-year {
    color: var(--accent);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 38px;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: var(--text);
    font-size: 0.92rem;
    font-weight: 500;
    letter-spacing: 0.01em;
    position: relative;
    transition: color 0.3s ease;
    padding: 8px 0;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width 0.4s var(--ease-out);
}

.nav-links a:hover {
    color: var(--primary);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-cta {
    background: var(--primary) !important;
    color: var(--white) !important;
    padding: 12px 26px !important;
    border-radius: 6px;
    font-weight: 600 !important;
    font-size: 0.88rem !important;
    letter-spacing: 0.02em;
    transition: all 0.3s var(--ease-out) !important;
    box-shadow: 0 2px 8px rgba(12, 24, 41, 0.15);
}

.nav-cta:hover {
    background: var(--primary-light) !important;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(12, 24, 41, 0.2) !important;
}

.nav-cta::after {
    display: none !important;
}

/* Mobile Toggle */
.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 10px;
}

.mobile-toggle span {
    width: 24px;
    height: 2px;
    background: var(--primary);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* ========================================
   HERO SECTION
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 85px;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('../images/Arenberg_Castle.png');
    background-size: cover;
    background-position: center;
    z-index: -3;
}

.hero-bg-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg,
            rgba(12, 24, 41, 0.92) 0%,
            rgba(12, 24, 41, 0.85) 40%,
            rgba(30, 58, 95, 0.8) 100%);
    z-index: -2;
}

.hero-pattern {
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 20% 80%, rgba(201, 162, 39, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(201, 162, 39, 0.05) 0%, transparent 40%);
    z-index: -1;
}

.hero-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 60px clamp(20px, 4vw, 50px);
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: clamp(40px, 6vw, 100px);
    align-items: center;
}

/* Hero Content */
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.12);
    padding: 10px 20px;
    border-radius: 100px;
    font-family: var(--font-body);
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--accent-light);
    margin-bottom: 32px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    animation: fadeInUp 0.8s var(--ease-out);
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
        transform: scale(1);
    }

    50% {
        opacity: 0.6;
        transform: scale(1.1);
    }
}

.hero h1 {
    font-size: clamp(2.8rem, 5vw, 4.2rem);
    color: var(--white);
    margin-bottom: 28px;
    line-height: 1.08;
    letter-spacing: -0.02em;
    animation: fadeInUp 0.8s var(--ease-out) 0.1s both;
}

.hero h1 em {
    font-family: var(--font-display);
    font-style: italic;
    color: var(--accent-light);
    font-weight: 500;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: rgba(255, 255, 255, 0.75);
    max-width: 520px;
    margin-bottom: 44px;
    font-weight: 400;
    line-height: 1.75;
    animation: fadeInUp 0.8s var(--ease-out) 0.2s both;
}

/* Hero Meta */
.hero-meta {
    display: flex;
    gap: 36px;
    margin-bottom: 44px;
    animation: fadeInUp 0.8s var(--ease-out) 0.3s both;
}

.hero-meta-item {
    display: flex;
    align-items: center;
    gap: 14px;
}

.hero-meta-icon {
    width: 48px;
    height: 48px;
    background: rgba(201, 162, 39, 0.12);
    border: 1px solid rgba(201, 162, 39, 0.2);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s var(--ease-out);
}

.hero-meta-item:hover .hero-meta-icon {
    background: rgba(201, 162, 39, 0.2);
    transform: translateY(-2px);
}

.hero-meta-icon svg {
    width: 22px;
    height: 22px;
    color: var(--accent-light);
}

.hero-meta-text strong {
    display: block;
    color: var(--white);
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 2px;
}

.hero-meta-text span {
    color: rgba(255, 255, 255, 0.55);
    font-size: 0.82rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Hero Buttons */
.hero-buttons {
    display: flex;
    gap: 16px;
    animation: fadeInUp 0.8s var(--ease-out) 0.4s both;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 16px 32px;
    font-family: var(--font-body);
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s var(--ease-out);
    cursor: pointer;
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--accent);
    color: var(--primary);
    box-shadow: 0 4px 15px rgba(201, 162, 39, 0.3);
}

.btn-primary:hover {
    background: var(--accent-light);
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(201, 162, 39, 0.4);
}

.btn-primary svg {
    transition: transform 0.3s var(--ease-out);
}

.btn-primary:hover svg {
    transform: translateX(4px);
}

.btn-outline {
    background: transparent;
    color: var(--white);
    border-color: rgba(255, 255, 255, 0.25);
}

.btn-outline:hover {
    border-color: rgba(255, 255, 255, 0.5);
    background: rgba(255, 255, 255, 0.05);
}

.btn-secondary {
    background: var(--bg-cream);
    color: var(--primary);
    border: 2px solid var(--border);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
    border-color: var(--accent);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
}

/* Hero Visual / Card */
.hero-visual {
    animation: fadeIn 1s var(--ease-out) 0.5s both;
    display: flex;
    justify-content: center;
}

.hero-card {
    position: relative;
    max-width: 420px;
    width: 100%;
}

.hero-card-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120%;
    height: 120%;
    background: radial-gradient(circle, rgba(201, 162, 39, 0.15) 0%, transparent 70%);
    filter: blur(40px);
    z-index: -1;
}

.hero-card-inner {
    background: rgba(255, 255, 255, 0.97);
    backdrop-filter: blur(20px);
    border-radius: 16px;
    padding: 44px;
    box-shadow:
        0 30px 60px -15px rgba(0, 0, 0, 0.3),
        0 0 0 1px rgba(255, 255, 255, 0.1);
    position: relative;
    overflow: hidden;
}

.hero-card-inner::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 5px;
    background: linear-gradient(90deg, var(--accent), var(--accent-light), var(--accent));
}

.hero-card-header {
    text-align: center;
    margin-bottom: 32px;
}

.hero-card-logo {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
}

.hero-card-logo img {
    width: 65px;
    height: auto;
}

.hero-card h3 {
    font-size: 1.65rem;
    color: var(--primary);
    margin-bottom: 8px;
    letter-spacing: -0.01em;
}

.hero-card-subtitle {
    color: var(--text-light);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-weight: 500;
}

/* Countdown */
.countdown {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-bottom: 28px;
}

.countdown-item {
    text-align: center;
    background: var(--bg-cream);
    padding: 16px 8px;
    border-radius: 10px;
    border: 1px solid var(--border-light);
    transition: all 0.3s var(--ease-out);
}

.countdown-item:hover {
    border-color: var(--accent-muted);
    transform: translateY(-2px);
}

.countdown-number {
    font-family: var(--font-display);
    font-size: 1.9rem;
    font-weight: 700;
    color: var(--primary);
    display: block;
    line-height: 1;
    margin-bottom: 6px;
}

.countdown-label {
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    font-weight: 600;
}

.hero-card-footer {
    padding-top: 24px;
    border-top: 1px solid var(--border-light);
}

.deadline-badge {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 0.88rem;
    color: var(--text-light);
}

.deadline-badge svg {
    color: var(--accent);
}

.deadline-badge strong {
    color: var(--primary);
    font-weight: 600;
}

/* Scroll Indicator */
.hero-scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    animation: fadeIn 1s var(--ease-out) 1s both;
}

.hero-scroll-indicator span {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: rgba(255, 255, 255, 0.5);
    font-weight: 500;
}

.scroll-line {
    width: 1px;
    height: 50px;
    background: linear-gradient(to bottom, rgba(201, 162, 39, 0.8), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}

@keyframes scrollPulse {

    0%,
    100% {
        opacity: 0.5;
        transform: scaleY(1);
    }

    50% {
        opacity: 1;
        transform: scaleY(1.1);
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

/* ========================================
   SECTIONS - COMMON
   ======================================== */
section {
    padding: var(--section-padding) clamp(20px, 4vw, 50px);
}

.section-container {
    max-width: var(--container-max);
    margin: 0 auto;
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 70px;
}

.section-label {
    display: inline-block;
    font-family: var(--font-body);
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 18px;
    padding: 6px 14px;
    background: var(--accent-muted);
    border-radius: 4px;
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.8rem);
    color: var(--primary);
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

.section-description {
    color: var(--text-light);
    font-size: 1.1rem;
    line-height: 1.75;
}

/* ========================================
   ABOUT SECTION
   ======================================== */
#about {
    background: var(--white);
}

.about-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: clamp(50px, 8vw, 100px);
    align-items: center;
}

.about-content .section-label {
    margin-bottom: 16px;
}

.about-content h2 {
    font-size: clamp(1.8rem, 3vw, 2.2rem);
    color: var(--primary);
    margin-bottom: 28px;
    letter-spacing: -0.01em;
}

.about-content p {
    margin-bottom: 22px;
    color: var(--text-light);
    font-size: 1.02rem;
    line-height: 1.8;
}

.about-content p em {
    color: var(--primary);
    font-weight: 500;
}

/* About Stats */
.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
    padding-top: 40px;
    border-top: 1px solid var(--border);
}

.stat-item {
    text-align: left;
}

.stat-number {
    font-family: var(--font-display);
    font-size: clamp(2.2rem, 3.5vw, 2.8rem);
    font-weight: 700;
    color: var(--primary);
    display: block;
    margin-bottom: 6px;
    line-height: 1;
}

.stat-label {
    font-size: 0.78rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-weight: 600;
}

/* About Image */
.about-image {
    position: relative;
}

.about-image-wrapper {
    position: relative;
}

.about-image-main {
    width: 100%;
    height: 550px;
    background-image: url('../images/KU_Leuven_University_Library_02.jpg');
    background-size: cover;
    background-position: center;
    border-radius: 12px;
    position: relative;
    box-shadow: var(--shadow-lg);
}

.about-image-frame {
    position: absolute;
    top: 20px;
    left: 20px;
    right: -20px;
    bottom: -20px;
    border: 2px solid var(--accent);
    border-radius: 12px;
    z-index: -1;
    opacity: 0.4;
}

.about-badge {
    position: absolute;
    bottom: 35px;
    left: -30px;
    background: var(--white);
    padding: 28px 32px;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    min-width: 200px;
    border-left: 4px solid var(--accent);
}

.about-badge-icon {
    margin-bottom: 14px;
    color: var(--accent);
}

.about-badge-icon svg {
    width: 28px;
    height: 28px;
}

.about-badge strong {
    display: block;
    color: var(--primary);
    font-size: 1.2rem;
    font-family: var(--font-display);
    margin-bottom: 4px;
}

.about-badge span {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ========================================
   TOPICS SECTION
   ======================================== */
#topics {
    background: var(--bg-warm);
}

/* Knowledge Graph Layout */
.topics-grid {
    position: relative;
    max-width: 1100px;
    margin: 40px auto 0;
    padding: 160px 0 40px;
    /* Space for the Top Hub */
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
}

/* Central Hub Styles */
.topic-hub {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
    width: 280px;
    height: 280px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--white);
    box-shadow:
        0 0 0 8px rgba(255, 255, 255, 0.5),
        0 0 0 20px rgba(201, 162, 39, 0.05),
        var(--shadow-xl);
    border: 1px solid var(--accent-muted);
}

.topic-hub::before {
    content: '';
    position: absolute;
    inset: -2px;
    border-radius: 50%;
    background: conic-gradient(from 180deg, transparent, var(--accent), transparent);
    opacity: 0.3;
    animation: rotate 10s linear infinite;
}

@keyframes rotate {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

.hub-inner {
    text-align: center;
    background: var(--white);
    border-radius: 50%;
    width: 96%;
    height: 96%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 2;
}

.hub-label {
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-size: 0.65rem;
    color: var(--accent);
    font-weight: 700;
    margin-bottom: 8px;
}

.hub-inner h3 {
    font-size: 1.5rem;
    line-height: 1.1;
    margin-bottom: 12px;
    color: var(--primary);
}

.hub-icon {
    color: var(--accent);
    width: 32px;
    height: 32px;
}

/* Spine/Central Axis for Connections */
.topics-grid::before {
    content: '';
    position: absolute;
    top: 140px;
    /* Center of hub */
    bottom: 40px;
    left: 50%;
    width: 2px;
    background: linear-gradient(to bottom, var(--accent), var(--border-light));
    transform: translateX(-50%);
    opacity: 0.3;
}

/* Cards positioned as Leaves */
.topic-card {
    background: var(--white);
    border-radius: 16px;
    border: 1px solid var(--border);
    transition: all 0.4s var(--ease-out);
    position: relative;
    width: 42%;
    margin-bottom: 60px;
    z-index: 5;
}

.topic-card:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-md);
    border-color: var(--accent-muted);
}

/* Positioning */
.topic-card:nth-child(even) {
    /* Odd in CSS count (2,4,6...) because Hub is 1 */
    margin-right: auto;
    margin-left: 0;
    text-align: right;
}

.topic-card:nth-child(odd) {
    /* Even in CSS count (3,5,7...) */
    margin-left: auto;
    margin-right: 0;
    text-align: left;
}

/* Connection Arms */
.topic-card::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 60px;
    height: 1px;
    background: var(--accent-light);
    opacity: 0.4;
}

.topic-card:nth-child(even)::after {
    right: -60px;
}

.topic-card:nth-child(odd)::after {
    left: -60px;
}

/* Connection Nodes (Circles on Spine) */
.topic-card::before {
    content: '';
    position: absolute;
    top: 50%;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--white);
    border: 2px solid var(--accent);
    z-index: 10;
    margin-top: -6px;
    transition: all 0.3s ease;
}

.topic-card:nth-child(even)::before {
    right: -19.5%;
}

.topic-card:nth-child(odd)::before {
    left: -19.5%;
}

.topic-card:hover::before {
    background: var(--accent);
    box-shadow: 0 0 10px var(--accent);
    transform: scale(1.2);
}

/* Content Alignment adjustments for "Leaves" look */
.topic-card:nth-child(even) .topic-number {
    left: 24px;
    right: auto;
}

.topic-card:nth-child(even) h4 {
    padding-left: 50px;
    padding-right: 0;
}

.topic-card-inner {
    padding: 36px;
    position: relative;
}

.topic-number {
    font-family: var(--font-display);
    font-size: 3.5rem;
    font-weight: 500;
    color: var(--accent-muted);
    position: absolute;
    top: 20px;
    right: 24px;
    line-height: 1;
    opacity: 0.8;
}

.topic-card h4 {
    font-size: 1.15rem;
    color: var(--primary);
    margin-bottom: 14px;
    padding-right: 50px;
    line-height: 1.4;
}

.topic-card p {
    font-size: 0.92rem;
    color: var(--text-light);
    line-height: 1.7;
}

/* ========================================
   SUBMISSION SECTION
   ======================================== */
#submission {
    background: var(--white);
}

.submission-layout {
    display: grid;
    grid-template-columns: 1fr 1.1fr;
    gap: clamp(40px, 6vw, 80px);
    align-items: start;
}

.submission-types h3 {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 32px;
}

.submission-type-grid {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.submission-type {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 22px 0;
    border-bottom: 1px solid var(--border-light);
    transition: all 0.3s var(--ease-out);
}

.submission-type:hover {
    padding-left: 12px;
}

.submission-type:last-child {
    border-bottom: none;
}

.submission-type-icon {
    width: 50px;
    height: 50px;
    background: var(--bg-cream);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    flex-shrink: 0;
    transition: all 0.3s var(--ease-out);
}

.submission-type:hover .submission-type-icon {
    background: var(--accent-muted);
    color: var(--accent-dark);
}

.submission-type-icon svg {
    width: 22px;
    height: 22px;
}

.submission-type span {
    font-size: 1.02rem;
    color: var(--text);
    font-weight: 500;
}

.template-download {
    margin-top: 36px;
    display: flex;
    gap: 16px;
}

.template-download .btn {
    flex: 1;
    justify-content: center;
    white-space: nowrap;
}

/* Dates Container */
.dates-container {
    background: var(--primary);
    padding: clamp(40px, 5vw, 60px);
    border-radius: 16px;
    color: var(--white);
    position: relative;
    overflow: hidden;
}

.dates-container::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: radial-gradient(circle at top right, rgba(201, 162, 39, 0.1) 0%, transparent 60%);
}

.dates-header {
    margin-bottom: 36px;
    position: relative;
}

.dates-header h3 {
    font-size: 1.8rem;
    color: var(--white);
    margin-bottom: 0;
}

.dates-decoration {
    width: 60px;
    height: 3px;
    background: var(--accent);
    margin-top: 16px;
    border-radius: 2px;
}

.dates-list {
    position: relative;
}

.date-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.date-item:last-child {
    border-bottom: none;
}

.date-item.highlight {
    background: rgba(201, 162, 39, 0.1);
    margin: 0 -20px;
    padding: 20px;
    border-radius: 8px;
    border-bottom: none;
}

.date-label {
    font-size: 0.95rem;
    font-weight: 400;
    color: rgba(255, 255, 255, 0.7);
}

.date-value {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--accent-light);
}

.date-highlight {
    background: var(--accent);
    color: var(--primary) !important;
    padding: 8px 18px;
    border-radius: 100px;
    font-size: 0.9rem;
    font-weight: 700;
}

/* ========================================
   PHD SYMPOSIUM SECTION
   ======================================== */
#phd {
    background: var(--bg-cream);
}

.phd-content {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: clamp(40px, 6vw, 80px);
    align-items: start;
}

.phd-info h3 {
    font-size: 1.6rem;
    margin-bottom: 24px;
    color: var(--primary);
}

.phd-info>p {
    margin-bottom: 20px;
    color: var(--text-light);
    font-size: 1.02rem;
    line-height: 1.8;
}

/* PhD Features */
.phd-features {
    margin-top: 40px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.phd-feature {
    display: flex;
    align-items: flex-start;
    gap: 18px;
    padding: 24px;
    background: var(--white);
    border-radius: 12px;
    border: 1px solid var(--border);
    transition: all 0.3s var(--ease-out);
}

.phd-feature:hover {
    border-color: var(--accent-muted);
    box-shadow: var(--shadow-sm);
}

.phd-feature-icon {
    width: 48px;
    height: 48px;
    background: var(--accent-muted);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-dark);
    flex-shrink: 0;
}

.phd-feature-icon svg {
    width: 24px;
    height: 24px;
}

.phd-feature h4 {
    font-size: 1.05rem;
    color: var(--primary);
    margin-bottom: 6px;
    font-family: var(--font-body);
    font-weight: 600;
}

.phd-feature p {
    font-size: 0.9rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* PhD Card */
.phd-card {
    background: var(--white);
    padding: clamp(36px, 4vw, 50px);
    border-radius: 16px;
    border: 1px solid var(--border);
    text-align: center;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 120px;
}

.phd-card-icon {
    width: 72px;
    height: 72px;
    background: var(--bg-cream);
    border-radius: 50%;
    margin: 0 auto 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
}

.phd-card-icon svg {
    width: 36px;
    height: 36px;
}

.phd-card h4 {
    font-size: 1.4rem;
    color: var(--primary);
    margin-bottom: 14px;
}

.phd-card>p {
    margin-bottom: 28px;
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

.phd-organizer {
    margin-top: 36px;
    padding-top: 28px;
    border-top: 1px solid var(--border);
}

.phd-organizer-label {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--text-muted);
    margin-bottom: 10px !important;
    font-weight: 600;
}

.phd-organizer-name {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 6px !important;
}

.phd-organizer-email {
    font-size: 0.9rem;
    color: var(--accent);
}

.phd-actions {
    display: flex;
    gap: 16px;
}

.phd-actions .btn {
    flex: 1;
    justify-content: center;
    white-space: nowrap;
}

/* ========================================
   CONTACT SECTION
   ======================================== */
#contact {
    background: var(--white);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.contact-card {
    background: var(--bg);
    border-radius: 12px;
    border: 1px solid var(--border);
    transition: all 0.4s var(--ease-out);
    overflow: hidden;
}

.contact-card:hover {
    border-color: var(--accent);
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.contact-card-inner {
    padding: 32px;
    text-align: center;
}

.contact-role {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--accent);
    margin-bottom: 14px;
    font-weight: 700;
}

.contact-name {
    font-size: 1.15rem;
    color: var(--primary);
    margin-bottom: 10px;
}

.contact-email {
    font-size: 0.9rem;
    color: var(--text-light);
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact-email:hover {
    color: var(--accent);
}

/* ========================================
   FOOTER
   ======================================== */
footer {
    background: var(--primary);
    color: var(--white);
    padding: 80px 0 40px;
    position: relative;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent), var(--accent-light), var(--accent));
}

.footer-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 clamp(20px, 4vw, 50px);
}

.footer-top {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: clamp(40px, 6vw, 80px);
    margin-bottom: 60px;
}

.footer-brand h3 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: var(--white);
}

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

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
    max-width: 360px;
    font-size: 1rem;
    line-height: 1.7;
}

.footer-links h4 {
    font-family: var(--font-body);
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 24px;
    color: var(--white);
}

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

.footer-links ul li {
    margin-bottom: 14px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    display: inline-block;
}

.footer-links a:hover {
    color: var(--accent);
    transform: translateX(4px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.88rem;
    color: rgba(255, 255, 255, 0.4);
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */
@media (max-width: 1100px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 50px;
    }

    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-meta {
        justify-content: center;
    }

    .hero-buttons {
        justify-content: center;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 50px;
    }

    .about-image {
        order: -1;
    }

    .submission-layout {
        grid-template-columns: 1fr;
    }

    .phd-content {
        grid-template-columns: 1fr;
    }

    .phd-card {
        position: static;
        max-width: 450px;
        margin: 0 auto;
    }

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

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 20px;
        gap: 0;
        box-shadow: var(--shadow-md);
        border-top: 1px solid var(--border);
    }

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

    .nav-links li {
        width: 100%;
    }

    .nav-links a {
        display: block;
        padding: 16px 0;
        border-bottom: 1px solid var(--border-light);
    }

    .nav-links a::after {
        display: none;
    }

    .nav-cta {
        margin-top: 10px;
        text-align: center;
    }

    .mobile-toggle {
        display: flex;
    }

    .hero h1 {
        font-size: 2.4rem;
    }

    .hero-meta {
        flex-direction: column;
        gap: 20px;
        align-items: center;
    }

    .hero-buttons {
        flex-direction: column;
        width: 100%;
        max-width: 300px;
        margin: 0 auto;
    }

    .btn {
        width: 100%;
    }

    .hero-scroll-indicator {
        display: none;
    }

    .about-stats {
        grid-template-columns: repeat(3, 1fr);
        gap: 20px;
    }

    .topics-grid {
        padding-top: 20px;
    }

    .topic-hub {
        display: none;
        /* Hide complex hub on mobile */
    }

    .topics-grid::before {
        display: none;
        /* Hide spine */
    }

    .topic-card {
        width: 100%;
        margin: 0 0 20px 0 !important;
        text-align: left !important;
    }

    .topic-card::before,
    .topic-card::after {
        display: none;
        /* Hide connectors */
    }

    /* Reset text alignment content */
    .topic-card:nth-child(even) .topic-number {
        left: auto;
        right: 24px;
    }

    .topic-card:nth-child(even) h4 {
        padding-left: 0;
        padding-right: 50px;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }

    .template-download,
    .phd-actions {
        flex-direction: column;
    }

    .template-download .btn,
    .phd-actions .btn {
        white-space: normal;
    }
}

@media (max-width: 480px) {
    .countdown {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-stats {
        grid-template-columns: 1fr;
        text-align: center;
    }

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

    .about-badge {
        left: 20px;
        right: 20px;
        bottom: -40px;
    }

    .about-image-main {
        height: 350px;
    }

    .about-image-wrapper {
        margin-bottom: 80px;
    }
}