:root {
    --bg-color: #020604;
    --text-main: #f0f8f4;
    --text-muted: #88b092;
    --accent-blue: #00ffaa;
    --accent-blue-dark: #00aa66;
    --accent-silver: #c0d0c8;
    --card-bg: #07120a;
    --border-color: rgba(255, 255, 255, 0.1);
    --font-serif: 'Noto Serif JP', serif;
    --font-sans: 'Outfit', sans-serif;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: var(--font-serif);
    line-height: 1.8;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(0, 255, 170, 0.03), transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(255, 255, 255, 0.02), transparent 25%);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 2rem 4rem;
    z-index: 100;
    background: rgba(3, 5, 10, 0.5);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}

.logo {
    font-family: var(--font-sans);
    font-size: 1.5rem;
    letter-spacing: 0.2rem;
    font-weight: 400;
    color: var(--text-main);
    text-shadow: 0 0 10px rgba(0, 255, 170, 0.3);
}

.nav ul {
    display: flex;
    gap: 3rem;
    list-style: none;
}

.nav a {
    color: var(--text-main);
    text-decoration: none;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    letter-spacing: 0.1rem;
    font-weight: 300;
    transition: color 0.3s, text-shadow 0.3s;
}

.nav a:hover {
    color: var(--accent-blue);
    text-shadow: 0 0 8px rgba(0, 255, 170, 0.6);
}

/* Main Layout */
.section {
    padding: 8rem 4rem;
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    font-family: var(--font-sans);
    font-size: 3rem;
    font-weight: 300;
    letter-spacing: 0.1rem;
    margin-bottom: 4rem;
    color: var(--text-main);
    text-align: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
}

.section-title .sub {
    display: block;
    font-family: var(--font-serif);
    font-size: 0.9rem;
    font-weight: 300;
    color: var(--accent-blue);
    margin-top: 0.5rem;
    letter-spacing: 0.2em;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    padding: 0;
    text-align: center;
}

.hero::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(to bottom, transparent 0%, rgba(2, 6, 4, 0.6) 60%, var(--bg-color) 100%);
    z-index: 1;
}

.hero-image {
    position: absolute;
    top: 0; left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 0;
    opacity: 0.85;
    filter: brightness(1.0) contrast(1.1);
}

.hero-content {
    z-index: 2;
    max-width: 800px;
    padding: 0 2rem;
}

.hero-title .en {
    display: block;
    font-family: var(--font-sans);
    font-size: clamp(3rem, 6vw, 5rem);
    font-weight: 200;
    letter-spacing: 0.2em;
    color: var(--text-main);
    text-shadow: 0 4px 15px rgba(0, 0, 0, 0.8), 0 0 20px rgba(0, 255, 170, 0.5);
    line-height: 1.1;
    margin-bottom: 1rem;
}

.hero-title .ja {
    display: block;
    font-family: var(--font-serif);
    font-size: clamp(1.2rem, 2.5vw, 1.8rem);
    font-weight: 300;
    line-height: 1.8;
    color: var(--accent-silver);
    letter-spacing: 0.1em;
    text-shadow: 0 2px 8px rgba(0, 0, 0, 0.9);
}

/* Note-style Card UI */
.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 3rem;
}

.card {
    display: flex;
    flex-direction: column;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    height: 100%;
    position: relative;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5), 0 0 15px rgba(0, 255, 170, 0.1);
    border-color: rgba(0, 255, 170, 0.3);
}

.card-img-placeholder {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background-color: #111;
}

.card-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
    opacity: 0.8;
}

.card:hover .card-img {
    transform: scale(1.05);
    opacity: 1;
}

.card-content {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.card-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
    font-family: var(--font-sans);
    font-size: 0.75rem;
}

.category-chip {
    padding: 0.2em 0.8em;
    border: 1px solid var(--accent-blue-dark);
    color: var(--accent-blue);
    border-radius: 4px;
    background: rgba(0, 255, 170, 0.05);
}

.date {
    color: var(--text-muted);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: 1rem;
    line-height: 1.6;
    color: var(--text-main);
    transition: color 0.3s ease;
}

.card:hover .card-title {
    color: var(--accent-blue);
}

.card-excerpt {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.read-more {
    font-family: var(--font-sans);
    font-size: 0.8rem;
    color: var(--accent-silver);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.read-more::after {
    content: '→';
    transition: transform 0.3s;
}

.card:hover .read-more::after {
    transform: translateX(5px);
    color: var(--accent-blue);
}

/* Profile Section */
.profile-content {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 3rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.profile-bio {
    font-size: 1.1rem;
    color: var(--text-main);
    margin-bottom: 2rem;
    text-align: center;
}

.profile-themes {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 4px;
}

.profile-themes h3 {
    font-size: 1rem;
    color: var(--accent-blue);
    margin-bottom: 1rem;
    font-family: var(--font-sans);
}

.profile-themes ul {
    list-style: none;
    padding-left: 0;
}

.profile-themes li {
    color: var(--text-muted);
    margin-bottom: 0.8rem;
    font-size: 0.95rem;
    position: relative;
    padding-left: 1.5rem;
}

.profile-themes li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.6rem;
    width: 6px;
    height: 6px;
    background-color: var(--accent-blue-dark);
    border-radius: 50%;
}

.profile-career {
    font-size: 0.95rem;
    color: var(--text-muted);
    text-align: center;
}

.substack-btn {
    display: inline-block;
    padding: 1rem 2rem;
    background-color: transparent;
    color: var(--accent-blue);
    border: 1px solid var(--accent-blue);
    border-radius: 4px;
    text-decoration: none;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.substack-btn span {
    font-weight: 600;
}

.substack-btn:hover {
    background-color: var(--accent-blue);
    color: #000;
    box-shadow: 0 0 15px rgba(0, 255, 170, 0.4);
}

/* Newsletter Section */
.newsletter-section {
    background: linear-gradient(135deg, #050a15 0%, #020408 100%);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    padding: 6rem 2rem;
    text-align: center;
}

.newsletter-content {
    max-width: 600px;
    margin: 0 auto;
}

.newsletter-title {
    font-size: 2rem;
    font-weight: 300;
    margin-bottom: 1rem;
    color: var(--text-main);
}

.newsletter-desc {
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    font-size: 0.95rem;
}

.newsletter-form {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.newsletter-input {
    flex-grow: 1;
    padding: 1rem 1.5rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-main);
    font-family: var(--font-sans);
    outline: none;
    transition: border-color 0.3s, background 0.3s;
}

.newsletter-input:focus {
    border-color: var(--accent-blue);
    background: rgba(0, 255, 170, 0.02);
}

.newsletter-btn {
    padding: 1rem 2.5rem;
    background-color: var(--accent-blue);
    color: #000;
    border: none;
    border-radius: 4px;
    font-family: var(--font-sans);
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    letter-spacing: 0.05em;
}

.newsletter-btn:hover {
    background-color: #33eeff;
    transform: translateY(-2px);
}

/* Footer */
.footer {
    text-align: center;
    padding: 3rem;
    font-family: var(--font-sans);
    font-size: 0.8rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 1s cubic-bezier(0.16, 1, 0.3, 1), transform 1s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .header {
        padding: 1rem 1.5rem;
    }
    
    .nav {
        display: none;
    }

    .section {
        padding: 5rem 1.5rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .newsletter-form {
        flex-direction: column;
    }

    .newsletter-btn {
        width: 100%;
    }
}