/* CSS Custom Properties - ダークモード対応 */
:root {
    /* ダークモード（デフォルト） */
    --bg-primary: #0a0a0a;
    --bg-secondary: #1a1a1a;
    --bg-card: #1f1f1f;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --accent: #6366f1;
    --accent-hover: #818cf8;
    --border: #2a2a2a;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-hover: rgba(99, 102, 241, 0.2);
}

[data-theme="light"] {
    /* ライトモード */
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-card: #ffffff;
    --text-primary: #0a0a0a;
    --text-secondary: #4a4a4a;
    --text-muted: #999999;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --border: #e5e5e5;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-hover: rgba(99, 102, 241, 0.15);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans JP', 'Inter', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Navigation */
.nav {
    position: sticky;
    top: 0;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    z-index: 100;
    backdrop-filter: blur(10px);
    background-color: rgba(26, 26, 26, 0.8);
}

[data-theme="light"] .nav {
    background-color: rgba(245, 245, 245, 0.8);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

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

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

.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    padding: 0.5rem;
    transition: transform 0.3s ease;
}

.theme-toggle:hover {
    transform: scale(1.1);
}

/* Hero Section */
.hero {
    min-height: 80vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 4rem 0;
    animation: fadeIn 0.8s ease;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 700;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--accent);
    color: white;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px var(--shadow-hover);
}

.btn-secondary {
    background-color: transparent;
    color: var(--accent);
    border: 2px solid var(--accent);
}

.btn-secondary:hover {
    background-color: var(--accent);
    color: white;
}

/* Section Titles */
.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: 3rem;
    text-align: center;
}

.page-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    margin-bottom: 3rem;
    text-align: center;
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.project-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 1.5rem;
    transition: all 0.3s ease;
    color: inherit;
    display: block;
    animation: fadeIn 0.6s ease;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px var(--shadow-hover);
    border-color: var(--accent);
}

.project-card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    background-color: var(--bg-secondary);
}

.project-card-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 0.75rem;
}

.project-card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.project-card-status {
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.project-card-status.released {
    background-color: rgba(34, 197, 94, 0.2);
    color: #22c55e;
}

.project-card-status.wip {
    background-color: rgba(251, 191, 36, 0.2);
    color: #fbbf24;
}

.project-card-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.6;
}

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

.project-card-tag {
    padding: 0.25rem 0.75rem;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.project-card-links {
    display: flex;
    gap: 0.75rem;
    margin-top: 1rem;
}

.project-card-link {
    padding: 0.5rem 1.25rem;
    background-color: var(--accent);
    color: white;
    text-decoration: none;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.project-card-link:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
}

/* Filter Buttons */
.filter-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
}

.filter-btn {
    padding: 0.625rem 1.5rem;
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 2rem;
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn:hover,
.filter-btn.active {
    background-color: var(--accent);
    color: white;
    border-color: var(--accent);
}

/* Skills Section */
.skills {
    padding: 6rem 0;
    background-color: var(--bg-secondary);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.skill-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 1rem;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
}

.skill-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px var(--shadow);
}

.skill-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.skill-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.skill-card p {
    color: var(--text-secondary);
}

/* Contact Section */
.contact {
    padding: 6rem 0;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 2rem;
    background-color: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.3s ease;
}

.contact-link:hover {
    transform: translateY(-2px);
    border-color: var(--accent);
    box-shadow: 0 8px 20px var(--shadow);
}

.contact-icon {
    font-size: 1.5rem;
}

/* Project Detail Page */
.project-detail {
    padding: 4rem 0;
    max-width: 900px;
    margin: 0 auto;
}

.back-link {
    display: inline-block;
    margin-bottom: 2rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.back-link:hover {
    color: var(--accent);
}

.project-detail-header {
    margin-bottom: 3rem;
}

.project-detail-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: 1rem;
}

.project-detail-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

.project-detail-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.project-detail-link {
    padding: 0.625rem 1.5rem;
    background-color: var(--accent);
    color: white;
    text-decoration: none;
    border-radius: 0.5rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.project-detail-link:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
}

.project-detail-section {
    margin-bottom: 3rem;
}

.project-detail-section h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--accent);
}

.project-detail-section h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    margin-top: 1.5rem;
}

.project-detail-section p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.project-detail-section ul {
    list-style: none;
    padding-left: 0;
}

.project-detail-section li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
}

.project-detail-section li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--accent);
}

.project-detail-screenshot {
    width: 100%;
    border-radius: 0.5rem;
    margin: 1.5rem 0;
    border: 1px solid var(--border);
}

/* Footer */
.footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    text-align: center;
    color: var(--text-secondary);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }

    .nav-container {
        padding: 1rem 1.5rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .nav-links a {
        font-size: 0.875rem;
    }

    .projects-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

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

    .contact-links {
        flex-direction: column;
        align-items: stretch;
    }

    .filter-buttons {
        justify-content: flex-start;
    }
}

@media (max-width: 480px) {
    .nav-links {
        gap: 0.5rem;
    }

    .nav-links a:not(.nav-logo) {
        display: none;
    }
}