/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
    /* Colors */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F8F9FB;
    --text-primary: #1A1A1A;
    --text-secondary: #949EA9;
    --text-muted: #C4CBD5;
    --accent-gradient: linear-gradient(135deg, #FF6B9D 0%, #FF8A5B 50%, #FFB347 100%);
    --glow-blue: rgba(100, 180, 255, 0.15);
    --glow-purple: rgba(180, 120, 255, 0.1);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 40px;
    --spacing-xl: 64px;
    --spacing-2xl: 100px;

    /* Border Radius */
    --radius-sm: 12px;
    --radius-md: 20px;
    --radius-lg: 32px;
    --radius-xl: 40px;
    --radius-pill: 100px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Reset */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ===========================
   Ambient Glow Effects
   =========================== */
.glow {
    position: fixed;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    pointer-events: none;
    z-index: 0;
    filter: blur(120px);
}

.glow-top-left {
    top: -200px;
    left: -200px;
    background: var(--glow-blue);
}

.glow-top-right {
    top: 100px;
    right: -300px;
    background: var(--glow-purple);
}

.glow-bottom-left {
    bottom: 200px;
    left: -200px;
    background: rgba(120, 200, 255, 0.1);
}

/* ===========================
   Header & Navigation
   =========================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: var(--spacing-md) var(--spacing-lg);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

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

.nav-left,
.nav-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.nav-link {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

.logo {
    font-size: 24px;
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

/* ===========================
   Hero Section
   =========================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-2xl) var(--spacing-lg);
    max-width: 1400px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-title {
    font-size: clamp(48px, 8vw, 96px);
    font-weight: 800;
    line-height: 1.05;
    letter-spacing: -3px;
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 400px;
    line-height: 1.6;
}

/* Card Stack */
.card-stack {
    position: relative;
    width: 400px;
    height: 500px;
    perspective: 1000px;
}

.stack-card {
    position: absolute;
    width: 100%;
    height: 400px;
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-md);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
    transition: transform var(--transition-slow), box-shadow var(--transition-normal);
    overflow: hidden;
}

.card-1 {
    z-index: 3;
    transform: translateY(0) rotate(0deg);
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
}

.card-2 {
    z-index: 2;
    transform: translateY(20px) translateX(10px) rotate(3deg);
    background: linear-gradient(135deg, #2d4a3e 0%, #1d3a2e 100%);
}

.card-3 {
    z-index: 1;
    transform: translateY(40px) translateX(20px) rotate(6deg);
    background: linear-gradient(135deg, #4a2d3e 0%, #3a1d2e 100%);
}

.card-stack:hover .card-1 {
    transform: translateY(-10px) rotate(-2deg);
}

.card-stack:hover .card-2 {
    transform: translateY(10px) translateX(20px) rotate(5deg);
}

.card-stack:hover .card-3 {
    transform: translateY(30px) translateX(40px) rotate(10deg);
}

.card-tag {
    display: inline-block;
    background: rgba(255, 255, 255, 0.15);
    color: white;
    padding: 8px 16px;
    border-radius: var(--radius-pill);
    font-size: 13px;
    font-weight: 500;
    backdrop-filter: blur(10px);
}

.card-preview {
    width: 100%;
    height: 280px;
    margin-top: var(--spacing-sm);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-preview::after {
    content: '';
    width: 60%;
    height: 70%;
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md);
}

/* ===========================
   Work Section
   =========================== */
.work {
    padding: var(--spacing-2xl) var(--spacing-lg);
    max-width: 1400px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.work-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.section-title {
    font-size: clamp(48px, 6vw, 80px);
    font-weight: 800;
    letter-spacing: -2px;
}

.filters {
    display: flex;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 20px;
    border-radius: var(--radius-pill);
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    background: transparent;
}

.filter-btn:hover {
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--text-primary);
    color: white;
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    cursor: pointer;
    opacity: 1;
    transform: translateY(0);
    animation: fadeInUp 0.6s ease forwards;
}

.project-card.hidden {
    display: none;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.12);
}

/* Metadata Badges */
.meta-badges {
    display: flex;
    gap: 8px;
    margin-top: 8px;
    flex-wrap: wrap;
}

.meta-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    background: rgba(0, 0, 0, 0.05);
    color: var(--text-secondary);
}

.meta-badge.status-active .status-dot {
    background-color: #10b981;
    box-shadow: 0 0 0 2px rgba(16, 185, 129, 0.2);
}

.meta-badge.status-beta .status-dot {
    background-color: #f59e0b;
    box-shadow: 0 0 0 2px rgba(245, 158, 11, 0.2);
}

.meta-badge.status-archive .status-dot {
    background-color: #9ca3af;
}

.status-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
}

.project-image {
    height: 220px;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: var(--spacing-md);
}

.project-image-energy {
    background: linear-gradient(135deg, #FF6B9D 0%, #FF8A5B 100%);
}

.project-image-finance {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
}

.project-image-viz {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

/* Project Thumbnail Images */
.project-thumb {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 1;
    transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.project-card:hover .project-thumb {
    transform: scale(1.05);
}

/* Detail Page Thumbnail */
.detail-thumb {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
}

.project-tag {
    position: relative;
    /* Ensure tag stays on top of image */
    z-index: 2;
    align-self: flex-start;
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 6px 14px;
    border-radius: var(--radius-pill);
    font-size: 12px;
    font-weight: 500;
    backdrop-filter: blur(10px);
}

.project-info {
    padding: var(--spacing-md);
    background: var(--bg-primary);
}

.project-title {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 4px;
}

.project-desc {
    font-size: 14px;
    color: var(--text-secondary);
}

/* ===========================
   Footer
   =========================== */
.footer {
    padding: var(--spacing-2xl) var(--spacing-lg);
    position: relative;
    overflow: hidden;
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    text-align: center;
    position: relative;
    z-index: 1;
    padding: var(--spacing-2xl) 0;
}

.footer-title {
    font-size: clamp(48px, 8vw, 100px);
    font-weight: 800;
    letter-spacing: -3px;
    margin-bottom: var(--spacing-sm);
}

.footer-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

.cta-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--text-primary);
    color: white;
    padding: 16px 32px;
    border-radius: var(--radius-pill);
    font-size: 16px;
    font-weight: 600;
    transition: all var(--transition-normal);
}

.cta-button:hover {
    transform: scale(1.05);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
}

.arrow-icon {
    width: 20px;
    height: 20px;
    transition: transform var(--transition-fast);
}

.cta-button:hover .arrow-icon {
    transform: translateX(4px);
}

.footer-bottom {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-xl);
    border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    font-size: 14px;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.social-link:hover {
    color: var(--text-primary);
}

.back-to-top {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 14px;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.back-to-top:hover {
    color: var(--text-primary);
}

.arrow-up {
    width: 16px;
    height: 16px;
}

.footer-glow {
    position: absolute;
    bottom: -200px;
    left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 400px;
    background: radial-gradient(ellipse, var(--glow-blue) 0%, transparent 70%);
    pointer-events: none;
}

/* ===========================
   Animations
   =========================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ===========================
   Responsive Design
   =========================== */
/* タブレット (1024px以下): 2列 */
@media (max-width: 1024px) {
    .hero {
        flex-direction: column;
        text-align: center;
        padding-top: 150px;
    }

    .hero-content {
        margin-bottom: var(--spacing-xl);
    }

    .hero-subtitle {
        margin: 0 auto;
    }

    .card-stack {
        width: 320px;
        height: 420px;
    }

    .stack-card {
        height: 340px;
    }

    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .project-image {
        height: 180px;
    }
}

/* スマホ横向き (768px以下): 2列維持だがカード小さく */
@media (max-width: 768px) {
    .header {
        padding: var(--spacing-sm);
    }

    .nav-left {
        display: none;
    }

    .work-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .filters {
        width: 100%;
        overflow-x: auto;
        padding-bottom: var(--spacing-sm);
        -webkit-overflow-scrolling: touch;
    }

    .filter-btn {
        white-space: nowrap;
    }

    .footer-bottom {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }

    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-md);
    }

    .project-image {
        height: 150px;
    }

    .project-title {
        font-size: 16px;
    }

    .project-desc {
        font-size: 12px;
    }

    .card-stack {
        width: 280px;
        height: 380px;
    }

    .stack-card {
        height: 300px;
    }
}

/* スマホ縦向き (480px以下): 1列 */
@media (max-width: 480px) {
    .hero-title {
        letter-spacing: -1px;
    }

    .section-title {
        letter-spacing: -1px;
    }

    .footer-title {
        letter-spacing: -1px;
    }

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

    .project-image {
        height: 200px;
    }

    .project-title {
        font-size: 18px;
    }

    .project-desc {
        font-size: 14px;
    }

    .project-info {
        padding: var(--spacing-sm);
    }
}

/* ===========================
   Project Detail Page Styles
   =========================== */
.project-hero {
    min-height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 150px var(--spacing-lg) var(--spacing-xl);
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.project-hero-content {
    max-width: 700px;
}

.project-category-tag {
    display: inline-block;
    background: var(--accent-gradient);
    color: white;
    padding: 10px 24px;
    border-radius: var(--radius-pill);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.project-main-title {
    font-size: clamp(40px, 6vw, 72px);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -2px;
    margin-bottom: var(--spacing-md);
}

.project-main-desc {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

.demo-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--text-primary);
    color: white;
    padding: 16px 32px;
    border-radius: var(--radius-pill);
    font-size: 16px;
    font-weight: 600;
    transition: all var(--transition-normal);
}

.demo-button:hover {
    transform: scale(1.05);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
}

.demo-button .arrow-icon {
    width: 18px;
    height: 18px;
}

.demo-button:hover .arrow-icon {
    transform: translate(3px, -3px);
}

/* Project Visual */
.project-visual {
    padding: 0 var(--spacing-lg) var(--spacing-xl);
    max-width: 1200px;
    margin: 0 auto;
}

.project-mockup {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    aspect-ratio: 16 / 9;
}

.mockup-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 18px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: rgba(255, 255, 255, 0.5);
}

/* Project Details */
.project-details {
    padding: var(--spacing-xl) var(--spacing-lg);
    max-width: 1000px;
    margin: 0 auto;
}

.details-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
}

.details-section {
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
}

.details-title {
    font-size: 14px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.details-text {
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-primary);
}

.feature-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.feature-list li {
    font-size: 15px;
    color: var(--text-primary);
    padding-left: 24px;
    position: relative;
}

.feature-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #38ef7d;
    font-weight: 600;
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tech-tag {
    display: inline-block;
    background: var(--text-primary);
    color: white;
    padding: 8px 16px;
    border-radius: var(--radius-pill);
    font-size: 13px;
    font-weight: 500;
}

/* Project CTA */
.project-cta {
    padding: var(--spacing-2xl) var(--spacing-lg);
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.cta-title {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 800;
    letter-spacing: -1px;
    margin-bottom: var(--spacing-lg);
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.demo-button.large {
    padding: 20px 40px;
    font-size: 18px;
}

.github-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: transparent;
    color: var(--text-primary);
    padding: 20px 40px;
    border-radius: var(--radius-pill);
    font-size: 18px;
    font-weight: 600;
    border: 2px solid var(--text-primary);
    transition: all var(--transition-normal);
}

.github-button:hover {
    background: var(--text-primary);
    color: white;
}

.github-button .arrow-icon {
    width: 18px;
    height: 18px;
}

/* Project Footer */
.project-footer {
    padding: var(--spacing-xl) var(--spacing-lg);
}

.project-footer .footer-content {
    padding: var(--spacing-lg) 0;
}

.back-link {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

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

/* Responsive for Detail Page */
@media (max-width: 768px) {
    .project-hero {
        padding-top: 120px;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

    .demo-button.large,
    .github-button {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
}

/* ===========================
   Hero Reveal Animation
   =========================== */
/* The h1 is intentionally not animated so it paints immediately (LCP). */
.hero-subtitle,
.card-stack {
    animation: hero-reveal 0.8s ease both;
}

.hero-subtitle {
    animation-delay: 0.15s;
}

.card-stack {
    animation-delay: 0.3s;
}

@keyframes hero-reveal {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (prefers-reduced-motion: reduce) {
    .hero-subtitle,
    .card-stack {
        animation: none;
    }
}