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

:root {
    --primary-color: #000000;
    --accent-color: #2563eb;
    --bg-white: #ffffff;
    --bg-light: #f8f9fa;
    --text-gray: #6b7280;
    --border-light: #e5e7eb;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--primary-color);
    background: var(--bg-white);
    overflow-x: hidden;
}

/* ナビゲーション */
nav {
    position: fixed;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

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

.nav-links a {
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 500;
    position: relative;
    transition: color 0.3s ease;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: width 0.3s ease;
}

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

/* ヒーローセクション */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-white);
    position: relative;
}

.hero-content {
    text-align: center;
    max-width: 800px;
    padding: 0 2rem;
    animation: fadeInUp 1s ease;
}

.hero h1 {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.hero .subtitle {
    font-size: 1.5rem;
    color: var(--text-gray);
    margin-bottom: 2rem;
    font-weight: 300;
}

.cta-button {
    display: inline-block;
    padding: 1rem 3rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

/* セクション共通スタイル */
section {
    padding: 5rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    scroll-margin-top: 100px; /* ナビゲーションバーの高さ分のマージン */
    opacity: 0;
    transform: translateY(30px);
}

section.visible {
    animation: fadeInUp 1s ease forwards;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
}

/* Aboutセクション */
.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 4rem;
    align-items: center;
}

.profile-image {
    width: 300px;
    height: 300px;
    background: var(--bg-light);
    border-radius: 20px;
    position: relative;
    overflow: hidden;
}

.profile-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.about-text h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
}

.about-text p {
    color: var(--text-gray);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

/* スキルセクション */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-card {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    transition: all 0.3s ease;
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.skill-icon {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    border-radius: 15px;
    margin: 0 auto 1rem;
}

.skill-card h4 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.skill-card p {
    color: var(--text-gray);
    font-size: 0.9rem;
}

/* ワークセクション */
.works-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.work-card {
    background: var(--bg-white);
    border: 1px solid var(--border-light);
    border-radius: 15px;
    overflow: hidden;
    transition: all 0.3s ease;
    cursor: pointer;
}

.work-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
}

.work-image {
    height: 250px;
    background: var(--bg-light);
    position: relative;
}

.work-image::before {
    content: 'Project Image';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--text-gray);
}

.work-info {
    padding: 2rem;
}

.work-info h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.work-info p {
    color: var(--text-gray);
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

.work-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tag {
    background: var(--bg-light);
    padding: 0.3rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--text-gray);
}

/* コンタクトセクション */
.contact {
    background: var(--bg-light);
    border-radius: 30px;
    text-align: center;
}

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

.contact p {
    color: var(--text-gray);
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

.social-links {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    margin-top: 2rem;
}

.social-link {
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-decoration: none;
    transition: all 0.3s ease;
}

.social-link:hover {
    transform: translateY(-3px);
    background: var(--accent-color);
}

/* フッター */
footer {
    text-align: center;
    padding: 3rem 2rem;
    color: var(--text-gray);
    border-top: 1px solid var(--border-light);
}

/* アニメーション */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* レスポンシブ */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

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

    .profile-image {
        width: 250px;
        height: 250px;
        margin: 0 auto;
    }

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