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

:root {
    --bg-primary: #F8FAFB;
    --bg-secondary: #FFFFFF;
    --accent-1: #3B82F6;
    --accent-2: #1E40AF;
    --accent-3: #8B5CF6;
    --accent-4: #06B6D4;
    --text-primary: #1E293B;
    --text-secondary: #475569;
    --border-light: #E2E8F0;
    --shadow-color: rgba(59, 130, 246, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, #EEF2FF 100%);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Navigation */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.92);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-light);
    z-index: 1000;
    padding: 0.8rem 2rem;
}

.nav-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.nav-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-2);
    letter-spacing: -0.02em;
}

.nav-title a {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-title a:hover {
    color: var(--accent-1);
}

.nav-links {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    list-style: none;
}

.nav-links li {
    display: inline-block;
}

.nav-links a {
    display: block;
    padding: 0.6rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    border-radius: 8px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-links a:hover {
    background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
    color: white;
    transform: translateY(-2px);
}

/* Hero Section */
.hero {
    margin-top: 80px;
    padding: 4rem 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.05) 0%, transparent 70%);
    animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {

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

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

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: 4.5rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--accent-2), var(--accent-3));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-svg {
    width: 350px;
    height: 350px;
    margin: 2rem auto;
}

.hero-description {
    max-width: 800px;
    margin: 2rem auto;
    font-size: 1.2rem;
    color: var(--text-secondary);
    line-height: 1.8;
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow-color);
}

/* Main Content */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
}

/* Section Headers */
.section-header {
    margin: 4rem 0 2rem;
    padding-left: 1.5rem;
    border-left: 5px solid var(--accent-1);
    position: relative;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-2);
    letter-spacing: -0.02em;
}

.section-header::before {
    content: '';
    position: absolute;
    left: -5px;
    top: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(180deg, var(--accent-1), var(--accent-3));
    border-radius: 3px;
}

/* Bento Grid Layout */
.bento-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.bento-card {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-light);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.bento-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-1), var(--accent-3));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s ease;
}

.bento-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px var(--shadow-color);
    border-color: var(--accent-1);
}

.bento-card:hover::before {
    transform: scaleX(1);
}

.card-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    animation: morph 6s ease-in-out infinite;
}

@keyframes morph {

    0%,
    100% {
        border-radius: 50% 40% 45% 55%;
    }

    25% {
        border-radius: 40% 50% 55% 45%;
    }

    50% {
        border-radius: 45% 55% 50% 40%;
    }

    75% {
        border-radius: 55% 45% 40% 50%;
    }
}

.card-icon::after {
    content: '';
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    animation: pulse-icon 3s ease-in-out infinite;
}

@keyframes pulse-icon {

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

    50% {
        transform: scale(1.2);
        opacity: 0.8;
    }
}

.bento-card h3 {
    font-size: 1.6rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--accent-2);
    letter-spacing: -0.01em;
}

.bento-card p,
.bento-card li {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.7;
}

/* Current Position Special Card */
.featured-card {
    grid-column: span 2;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.05), rgba(139, 92, 246, 0.05));
    border: 2px solid var(--accent-1);
}

.position-photo {
    float: right;
    width: 200px;
    margin: 0 0 1rem 1.5rem;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

/* Lists */
.content-list {
    list-style: none;
    padding: 0;
}

.content-list li {
    padding: 0.8rem 0;
    border-bottom: 1px solid var(--border-light);
}

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

.year-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 6px;
    font-weight: 600;
    font-size: 0.9rem;
    margin-right: 0.8rem;
}

/* TOC */
.toc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.toc-item {
    background: var(--bg-secondary);
    padding: 1.2rem;
    border-radius: 12px;
    border: 1px solid var(--border-light);
    transition: all 0.3s ease;
}

.toc-item:hover {
    transform: translateX(8px);
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.08), rgba(139, 92, 246, 0.08));
    border-color: var(--accent-1);
}

.toc-item a {
    color: var(--accent-2);
    text-decoration: none;
    font-weight: 600;
    font-size: 1.05rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.toc-item a::before {
    content: '→';
    font-size: 1.2rem;
    transition: transform 0.3s ease;
}

.toc-item:hover a::before {
    transform: translateX(4px);
}

/* Links */
a {
    color: var(--accent-1);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--accent-3);
}

/* Footer Language Selector */
.language-footer {
    background: linear-gradient(135deg, var(--accent-2), var(--accent-3));
    padding: 3rem 2rem;
    margin-top: 5rem;
    text-align: center;
    color: white;
}

.language-footer h3 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    font-weight: 700;
}

.language-list {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    list-style: none;
    margin-bottom: 2rem;
}

.language-list li {
    background: rgba(255, 255, 255, 0.15);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    padding: 0.8rem 1.5rem;
    border-radius: 10px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.language-list li:hover,
.language-list li.active {
    background: white;
    border-color: white;
    transform: translateY(-3px);
}

.language-list li a {
    color: white;
    text-decoration: none;
    font-weight: 600;
}

.language-list li:hover a,
.language-list li.active a {
    color: var(--accent-2);
}

.copyright {
    margin-top: 2rem;
    font-size: 0.95rem;
    opacity: 0.9;
}

.copyright a {
    color: white;
    text-decoration: underline;
}

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-decoration: none;
    font-size: 1.5rem;
    box-shadow: 0 4px 12px var(--shadow-color);
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px var(--shadow-color);
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }

    .hero-svg {
        width: 250px;
        height: 250px;
    }

    .section-header h2 {
        font-size: 1.8rem;
    }

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

    .featured-card {
        grid-column: span 1;
    }

    .position-photo {
        float: none;
        display: block;
        margin: 0 auto 1rem;
    }

    .nav-content {
        flex-direction: column;
        gap: 0.5rem;
    }

    .nav-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }

    .nav-links a {
        padding: 0.5rem 0.7rem;
        font-size: 0.9rem;
    }

    .bento-card {
        padding: 1.5rem;
    }
}