:root {
    /* Colors */
    --bg-color: #f5f5f5;
    /* Dull white / Off-white */
    --text-color: #333333;
    /* Dark Gray */
    --text-light: #666666;
    --accent-color: #555555;
    --link-color: #000000;
    --border-color: #e0e0e0;

    /* Typography */
    --font-main: 'Inter', 'Noto Sans JP', sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 0.875rem;
    --font-size-lg: 1.25rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;
    --font-size-3xl: 3rem;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 32px;
    --spacing-xl: 64px;
    --spacing-2xl: 128px;

    /* Layout */
    --container-width: 1200px;
    --header-height: 80px;
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.8;
    font-size: var(--font-size-base);
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

a {
    text-decoration: none;
    color: var(--link-color);
    transition: opacity 0.3s ease;
}

a:hover {
    opacity: 0.7;
}

/* Header */
.site-header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    background-color: rgba(245, 245, 245, 0.95);
    backdrop-filter: blur(10px);
    z-index: 100;
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s ease;
}

.site-header.scrolled {
    border-bottom-color: var(--border-color);
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text-color);
}

.logo img {
    height: 48px;
    width: auto;
    transition: transform 0.3s ease;
}

.logo-text {
    font-weight: 600;
    font-size: 1.2rem;
    letter-spacing: 0.05em;
}

.logo:hover img {
    transform: scale(1.05);
}

.site-header nav ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.nav-link .en {
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    transition: transform 0.3s ease;
}

.nav-link .ja {
    font-size: 0.6rem;
    color: var(--text-light);
    margin-top: 2px;
    opacity: 0.8;
    transition: color 0.3s ease;
}

.nav-link:hover .en {
    transform: translateY(-2px);
}

.nav-link:hover .ja {
    color: var(--text-color);
}

/* Hero */
.hero-section {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding-top: var(--header-height);
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: 800px;
    padding: 0 var(--spacing-md);
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 1s ease forwards 0.5s;
}

.hero-section h1 {
    font-size: clamp(2.5rem, 5vw, 5rem);
    font-weight: 300;
    margin-bottom: var(--spacing-lg);
    line-height: 1.1;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--text-light);
    font-weight: 300;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-xl);
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    opacity: 0;
    animation: fadeIn 1s ease forwards 1.5s;
}

.scroll-line {
    width: 1px;
    height: 60px;
    background-color: var(--accent-color);
    display: block;
    margin: 0 auto;
    position: relative;
    overflow: hidden;
}

.scroll-line::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--bg-color);
    animation: scrollLine 2s cubic-bezier(0.77, 0, 0.175, 1) infinite;
}

/* Animations */
@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

@keyframes scrollLine {
    0% {
        transform: translateY(-100%);
    }

    100% {
        transform: translateY(100%);
    }
}

/* Footer */
.site-footer {
    padding: var(--spacing-lg) 0;
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-light);
    border-top: 1px solid var(--border-color);
}

/* Sections General */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-header {
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: var(--font-size-2xl);
    font-weight: 300;
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font-size: var(--font-size-sm);
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

/* About Section */
.about-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.about-intro {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: start;
}

.about-intro-text p {
    font-size: 1.1rem;
    line-height: 2;
    color: var(--text-color);
}

.about-details {
    width: 100%;
}

.about-text p {
    margin-bottom: var(--spacing-md);
    color: var(--text-light);
}

.skills-list {
    margin-top: var(--spacing-lg);
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.skills-list span {
    font-size: var(--font-size-sm);
    padding: 4px 12px;
    border: 1px solid var(--border-color);
    border-radius: 100px;
    color: var(--text-color);
}

.profile-img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.profile-img:hover {
    transform: scale(1.02);
}

@media (max-width: 768px) {
    .about-intro {
        grid-template-columns: 1fr;
    }
}

/* Services Section */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.service-card {
    padding: var(--spacing-lg);
    background-color: #ffffff;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

.service-card h3 {
    font-size: var(--font-size-lg);
    font-weight: 400;
    margin-bottom: var(--spacing-md);
}

.service-card p {
    color: var(--text-light);
    font-size: var(--font-size-sm);
}

/* Contact Section */
.contact-section {
    text-align: center;
    padding-bottom: var(--spacing-2xl);
}

.contact-text {
    max-width: 600px;
    margin: 0 auto var(--spacing-lg);
    color: var(--text-light);
}

.btn {
    display: inline-block;
    padding: 12px 32px;
    border-radius: 100px;
    font-size: var(--font-size-sm);
    font-weight: 500;
    letter-spacing: 0.05em;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: var(--text-color);
    color: #ffffff;
}

.btn-primary:hover {
    background-color: var(--accent-color);
    transform: translateY(-2px);
    opacity: 1;
}

.social-links {
    margin-top: var(--spacing-xl);
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
}

.social-links a {
    color: var(--text-light);
    position: relative;
    transition: color 0.3s ease, transform 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.social-links a svg {
    width: 24px;
    height: 24px;
}

.social-links a:hover {
    color: var(--text-color);
    transform: translateY(-2px);
    opacity: 1;
}

/* Scroll Animation Classes */
.fade-in-section {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

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

.service-card {
    /* Override transition for hover effect to not conflict */
    transition: transform 0.3s ease, box-shadow 0.3s ease, opacity 0.8s ease-out;
}

/* Biography */
.bio-list {
    margin-top: var(--spacing-md);
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--spacing-sm) var(--spacing-lg);
    align-items: baseline;
}

.bio-year {
    font-weight: 500;
    color: var(--text-color);
    font-feature-settings: "tnum";
    white-space: nowrap;
}

.bio-desc {
    color: var(--text-light);
    margin-bottom: var(--spacing-sm);
}

/* Business Activities */
.business-list {
    margin-top: var(--spacing-md);
    list-style: none;
}

.business-list li {
    margin-bottom: var(--spacing-xs);
    color: var(--text-light);
    position: relative;
    padding-left: 1.5em;
}

.business-list li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--accent-color);
}

/* Subsections in About */
.about-subsection {
    margin-top: var(--spacing-xl);
}

.about-subtitle {
    font-size: var(--font-size-lg);
    font-weight: 400;
    margin-bottom: var(--spacing-md);
    color: var(--text-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: var(--spacing-xs);
}

@media (max-width: 600px) {
    .bio-list {
        grid-template-columns: 1fr;
        gap: 4px;
    }

    .bio-year {
        margin-top: var(--spacing-sm);
    }
}

/* Responsive Navigation */
@media (max-width: 768px) {
    .site-header {
        height: 60px;
    }

    .logo img {
        height: 36px;
    }

    .logo {
        gap: 8px;
    }

    .logo-text {
        font-size: 1rem;
    }

    .site-header nav ul {
        gap: var(--spacing-md);
    }

    .nav-link .en {
        font-size: 0.75rem;
    }

    .nav-link .ja {
        font-size: 0.5rem;
    }
}

@media (max-width: 480px) {
    .site-header {
        height: 60px;
    }

    .logo img {
        height: 32px;
    }

    .logo-text {
        font-size: 0.9rem;
    }

    .site-header nav ul {
        gap: var(--spacing-sm);
    }

    .nav-link .en {
        font-size: 0.7rem;
    }

    .nav-link .ja {
        font-size: 0.45rem;
        margin-top: 1px;
    }

    .hero-section {
        padding-top: 60px;
    }
}