/* ===================================
   CSS Variables (Design Tokens)
   =================================== */
:root {
    /* Colors */
    --color-bg-primary: #0a0a0f;
    --color-bg-secondary: #12121a;
    --color-bg-tertiary: #1a1a25;
    --color-bg-card: rgba(26, 26, 37, 0.8);

    --color-text-primary: #ffffff;
    --color-text-secondary: #a0a0b0;
    --color-text-muted: #6b6b7a;

    --color-accent-primary: #6366f1;
    --color-accent-secondary: #8b5cf6;
    --color-accent-tertiary: #a855f7;
    --color-accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);

    --color-glow: rgba(99, 102, 241, 0.4);
    --color-glow-strong: rgba(139, 92, 246, 0.6);

    /* Typography */
    --font-primary: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Consolas', monospace;

    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3.5rem;
    --font-size-6xl: 4.5rem;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px var(--color-glow);

    /* Z-index */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal: 400;
    --z-tooltip: 500;
    --z-loading: 9999;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    cursor: none;
}

a {
    text-decoration: none;
    color: inherit;
    cursor: none;
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul,
ol {
    list-style: none;
}

/* Selection */
::selection {
    background-color: var(--color-accent-primary);
    color: var(--color-text-primary);
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-accent-primary);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-accent-secondary);
}

/* ===================================
   Custom Cursor
   =================================== */
.cursor {
    position: fixed;
    width: 8px;
    height: 8px;
    background: var(--color-text-primary);
    border-radius: 50%;
    pointer-events: none;
    z-index: var(--z-tooltip);
    transform: translate(-50%, -50%);
    transition: transform 0.1s ease, background 0.2s ease;
}

.cursor-follower {
    position: fixed;
    width: 40px;
    height: 40px;
    border: 1px solid var(--color-accent-primary);
    border-radius: 50%;
    pointer-events: none;
    z-index: var(--z-tooltip);
    transform: translate(-50%, -50%);
    transition: transform 0.15s ease, width 0.3s ease, height 0.3s ease, border-color 0.3s ease;
}

.cursor.hover {
    transform: translate(-50%, -50%) scale(1.5);
    background: var(--color-accent-primary);
}

.cursor-follower.hover {
    width: 60px;
    height: 60px;
    border-color: var(--color-accent-secondary);
}

@media (max-width: 768px) {

    .cursor,
    .cursor-follower {
        display: none;
    }

    body {
        cursor: auto;
    }

    a,
    button {
        cursor: pointer;
    }
}

/* ===================================
   Loading Screen
   =================================== */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--color-bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: var(--z-loading);
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid var(--color-bg-tertiary);
    border-top-color: var(--color-accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-text {
    margin-top: var(--spacing-lg);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    letter-spacing: 2px;
    text-transform: uppercase;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* ===================================
   Container
   =================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
}

/* ===================================
   Navigation
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    padding: var(--spacing-lg) 0;
    transition: background var(--transition-base), padding var(--transition-base), backdrop-filter var(--transition-base);
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(20px);
    padding: var(--spacing-md) 0;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-text {
    font-size: var(--font-size-2xl);
    font-weight: 800;
    background: var(--color-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-2xl);
}

.nav-link {
    position: relative;
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: color var(--transition-base);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent-gradient);
    transition: width var(--transition-base);
}

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

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    width: 30px;
    height: 24px;
    justify-content: center;
}

.hamburger {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--color-text-primary);
    transition: transform var(--transition-base), opacity var(--transition-base);
}

.hamburger::before,
.hamburger::after {
    content: '';
    display: block;
    width: 100%;
    height: 2px;
    background: var(--color-text-primary);
    transition: transform var(--transition-base);
}

.hamburger::before {
    transform: translateY(-8px);
}

.hamburger::after {
    transform: translateY(6px);
}

.nav-toggle.active .hamburger {
    background: transparent;
}

.nav-toggle.active .hamburger::before {
    transform: translateY(0) rotate(45deg);
}

.nav-toggle.active .hamburger::after {
    transform: translateY(-2px) rotate(-45deg);
}

.nav-close {
    display: none;
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: var(--color-bg-secondary);
        flex-direction: column;
        justify-content: center;
        gap: var(--spacing-2xl);
        padding: var(--spacing-3xl);
        transition: right var(--transition-base);
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-close {
        position: absolute;
        top: var(--spacing-xl);
        right: var(--spacing-xl);
        width: 40px;
        height: 40px;
        display: flex;
        align-items: center;
        justify-content: center;
        background: transparent;
        border: 1px solid var(--color-border);
        border-radius: 50%;
        color: var(--color-text-primary);
        font-size: var(--font-size-lg);
        cursor: pointer;
        transition: all var(--transition-base);
    }

    .nav-close:hover {
        background: var(--color-accent-primary);
        border-color: var(--color-accent-primary);
        color: var(--color-bg-primary);
        transform: rotate(90deg);
    }

    .nav-link {
        font-size: var(--font-size-xl);
    }
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    position: relative;
    min-height: 100vh;
    /* 100vhを確保 */
    height: 100vh;
    /* 高さ固定 */
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: 0;
    /* パディング削除 */
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.hero-gradient {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(ellipse at 20% 20%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(139, 92, 246, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(168, 85, 247, 0.1) 0%, transparent 70%);
}

.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--color-accent-primary);
    border-radius: 50%;
    opacity: 0.5;
    animation: float 20s infinite ease-in-out;
}

@keyframes float {

    0%,
    100% {
        transform: translateY(0) translateX(0);
        opacity: 0.5;
    }

    25% {
        transform: translateY(-30px) translateX(15px);
        opacity: 0.8;
    }

    50% {
        transform: translateY(-60px) translateX(-10px);
        opacity: 0.3;
    }

    75% {
        transform: translateY(-30px) translateX(-20px);
        opacity: 0.7;
    }
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--spacing-2xl);
    padding: var(--spacing-4xl) var(--spacing-xl);
}

.hero-image-wrapper {
    position: relative;
}

.hero-image-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 200px;
    height: 200px;
    background: var(--color-accent-gradient);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    filter: blur(40px);
    opacity: 0.6;
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        transform: translate(-50%, -50%) scale(1);
        opacity: 0.6;
    }

    50% {
        transform: translate(-50%, -50%) scale(1.1);
        opacity: 0.8;
    }
}

.hero-image {
    position: relative;
    width: 180px;
    height: 180px;
    border-radius: 50%;
    border: 4px solid var(--color-accent-primary);
    object-fit: cover;
    z-index: 1;
    animation: fadeInUp 1s ease forwards;
}

.hero-text {
    max-width: 700px;
}

.hero-greeting {
    font-size: var(--font-size-lg);
    color: var(--color-accent-primary);
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.2s forwards;
}

.hero-name {
    font-size: var(--font-size-5xl);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.4s forwards;
}

.name-highlight {
    background: var(--color-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-title {
    font-size: var(--font-size-2xl);
    font-weight: 400;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    height: 40px;
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.6s forwards;
}

.typing-text {
    color: var(--color-text-primary);
}

.typing-cursor {
    color: var(--color-accent-primary);
    animation: blink 0.8s infinite;
}

@keyframes blink {

    0%,
    50% {
        opacity: 1;
    }

    51%,
    100% {
        opacity: 0;
    }
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-2xl);
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.8s forwards;
}

.hero-cta {
    display: flex;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    justify-content: center;
    opacity: 0;
    animation: fadeInUp 0.8s ease 1s forwards;
}

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

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

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-base);
    font-weight: 600;
    transition: all var(--transition-base);
}

.btn-primary {
    background: var(--color-accent-gradient);
    color: var(--color-text-primary);
    box-shadow: 0 4px 20px var(--color-glow);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px var(--color-glow-strong);
}

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

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

.btn-outline {
    background: transparent;
    border: 1px solid var(--color-text-muted);
    color: var(--color-text-secondary);
}

.btn-outline:hover {
    border-color: var(--color-accent-primary);
    color: var(--color-accent-primary);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 0;
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    /* 横方向中央揃え */
    gap: var(--spacing-sm);
    color: var(--color-text-muted);
    font-size: var(--font-size-xs);
    text-transform: uppercase;
    letter-spacing: 2px;
    animation: fadeInUp 0.8s ease 1.2s forwards;
    opacity: 0;
    z-index: 10;
}

@media (max-height: 700px) {
    .scroll-indicator {
        bottom: 15px;
        /* 縦幅が狭い時は詰める */
        transform: scale(0.9);
        /* translateXを除去 */
    }
}

.scroll-mouse {
    width: 26px;
    height: 40px;
    border: 2px solid var(--color-text-muted);
    border-radius: 15px;
    position: relative;
}

.scroll-wheel {
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--color-accent-primary);
    border-radius: 2px;
    animation: scroll 2s infinite;
}

@keyframes scroll {
    0% {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }

    100% {
        transform: translateX(-50%) translateY(18px);
        opacity: 0;
    }
}

@media (max-width: 768px) {
    .hero-content {
        margin-top: -40px;
        /* 少し上にずらして下部のスペースを確保 */
    }

    .hero-name {
        font-size: 2.5rem;
        margin-bottom: var(--spacing-xs);
    }

    .hero-title {
        font-size: var(--font-size-lg);
        margin-bottom: var(--spacing-md);
        height: auto;
    }

    .hero-description {
        font-size: var(--font-size-base);
        margin-bottom: var(--spacing-lg);
    }

    .hero-image {
        width: 130px;
        /* 少し小さく */
        height: 130px;
    }

    .hero-image-glow {
        width: 140px;
        height: 140px;
    }

    /* 縦幅が狭い端末向けの追加調整 */
    @media (max-height: 667px) {
        .hero-image {
            width: 100px;
            height: 100px;
        }

        .hero-image-glow {
            width: 110px;
            height: 110px;
        }

        .hero-description {
            margin-bottom: var(--spacing-md);
        }
    }
}

/* ===================================
   Section Styles
   =================================== */
.section {
    padding: var(--spacing-4xl) 0;
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    margin-bottom: var(--spacing-3xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.section-number {
    font-family: var(--font-mono);
    font-size: var(--font-size-xl);
    color: var(--color-accent-primary);
    font-weight: 400;
}

/* ===================================
   About Section
   =================================== */
.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}

.about-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.stat-card {
    background: var(--color-bg-card);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    transition: all var(--transition-base);
}

.stat-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-primary);
    box-shadow: var(--shadow-glow);
}

.stat-icon {
    font-size: var(--font-size-2xl);
    color: var(--color-accent-primary);
    margin-bottom: var(--spacing-md);
}

.stat-number {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    background: var(--color-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-top: var(--spacing-sm);
}

@media (max-width: 992px) {
    .about-content {
        grid-template-columns: 1fr;
    }

    .about-stats {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 576px) {
    .about-stats {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   Experience Section
   =================================== */
.timeline {
    position: relative;
    padding-left: var(--spacing-3xl);
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--color-accent-primary), var(--color-accent-tertiary));
}

.timeline-item {
    position: relative;
    padding-bottom: var(--spacing-3xl);
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: calc(-1 * var(--spacing-3xl) - 5px);
    width: 12px;
    height: 12px;
    background: var(--color-accent-primary);
    border-radius: 50%;
    box-shadow: 0 0 20px var(--color-glow);
}

.timeline-dot.education {
    background: var(--color-accent-tertiary);
}

.timeline-content {
    background: var(--color-bg-card);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    transition: all var(--transition-base);
}

.timeline-content:hover {
    transform: translateX(10px);
    border-color: var(--color-accent-primary);
}

.timeline-date {
    font-family: var(--font-mono);
    font-size: var(--font-size-sm);
    color: var(--color-accent-primary);
    margin-bottom: var(--spacing-sm);
}

.timeline-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.timeline-role {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.timeline-description {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    line-height: 1.7;
}

@media (max-width: 576px) {
    .timeline {
        padding-left: var(--spacing-xl);
    }

    .timeline-dot {
        left: calc(-1 * var(--spacing-xl) - 5px);
    }
}

/* ===================================
   Skills Section
   =================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.skill-card {
    background: var(--color-bg-card);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    text-align: center;
    transition: all var(--transition-base);
}

.skill-card:hover {
    transform: translateY(-10px);
    border-color: var(--color-accent-primary);
    box-shadow: var(--shadow-glow);
}

.skill-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: center;
}

.skill-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    filter: drop-shadow(0 0 10px var(--color-glow));
}

.skill-name {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.skill-bar {
    height: 6px;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: var(--color-accent-gradient);
    border-radius: var(--radius-full);
    width: 0;
    transition: width 1.5s ease;
}

@media (max-width: 992px) {
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 576px) {
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   Certifications Section
   =================================== */
.certifications-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.cert-card {
    background: var(--color-bg-card);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    text-align: center;
    transition: all var(--transition-base);
}

.cert-card:hover {
    transform: translateY(-10px);
    border-color: var(--color-accent-primary);
    box-shadow: var(--shadow-glow);
}

.cert-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-accent-gradient);
    border-radius: 50%;
    font-size: var(--font-size-3xl);
    color: var(--color-text-primary);
}

.cert-icon.oracle {
    background: linear-gradient(135deg, #f80000 0%, #c00000 100%);
}

.cert-icon.boki {
    background: linear-gradient(135deg, #50C878 0%, #228B22 100%);
}

.cert-name {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

.cert-org {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

@media (max-width: 992px) {
    .certifications-grid {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   Articles Section
   =================================== */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-3xl);
}

.article-card {
    background: var(--color-bg-card);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
}

.article-card:hover {
    transform: translateY(-10px);
    border-color: var(--color-accent-primary);
    box-shadow: var(--shadow-glow);
}

.article-emoji {
    font-size: var(--font-size-5xl);
    padding: var(--spacing-xl);
    background: var(--color-bg-tertiary);
    text-align: center;
}

.article-content {
    padding: var(--spacing-xl);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.article-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    margin-top: auto;
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.article-meta span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.article-skeleton {
    background: var(--color-bg-card);
    border: 1px solid rgba(99, 102, 241, 0.1);
    border-radius: var(--radius-lg);
    height: 280px;
    position: relative;
    overflow: hidden;
}

.article-skeleton::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.05), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%);
    }

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

.articles-cta {
    text-align: center;
}

@media (max-width: 992px) {
    .articles-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 576px) {
    .articles-grid {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   Output Section
   =================================== */
.output-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.output-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-3xl);
    line-height: 1.8;
}

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

.social-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg);
    background: var(--color-bg-card);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-lg);
    min-width: 100px;
    transition: all var(--transition-base);
}

.social-link:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent-primary);
    box-shadow: var(--shadow-glow);
}

.social-icon {
    font-size: var(--font-size-2xl);
    color: var(--color-text-secondary);
    transition: color var(--transition-base);
    width: 32px;
    height: 32px;
}

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

.zenn-icon,
.qiita-icon,
.connpass-icon {
    fill: currentColor;
}

.social-link span {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

/* ===================================
   Footer
   =================================== */
.footer {
    padding: var(--spacing-3xl) 0;
    border-top: 1px solid rgba(99, 102, 241, 0.2);
}

.footer-content {
    text-align: center;
}

.footer-text {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.footer-name {
    color: var(--color-accent-primary);
    font-weight: 600;
}

.footer-copyright {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

/* ===================================
   Back to Top Button
   =================================== */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    width: 50px;
    height: 50px;
    background: var(--color-accent-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-primary);
    font-size: var(--font-size-lg);
    box-shadow: var(--shadow-glow);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-base);
    z-index: var(--z-sticky);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px var(--color-glow-strong);
}

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

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

/* Stagger animation for children */
.stagger-children>* {
    opacity: 0;
    transform: translateY(20px);
}

.stagger-children.visible>*:nth-child(1) {
    animation: fadeInUp 0.5s ease 0.1s forwards;
}

.stagger-children.visible>*:nth-child(2) {
    animation: fadeInUp 0.5s ease 0.2s forwards;
}

.stagger-children.visible>*:nth-child(3) {
    animation: fadeInUp 0.5s ease 0.3s forwards;
}

.stagger-children.visible>*:nth-child(4) {
    animation: fadeInUp 0.5s ease 0.4s forwards;
}

.stagger-children.visible>*:nth-child(5) {
    animation: fadeInUp 0.5s ease 0.5s forwards;
}

.stagger-children.visible>*:nth-child(6) {
    animation: fadeInUp 0.5s ease 0.6s forwards;
}

.stagger-children.visible>*:nth-child(7) {
    animation: fadeInUp 0.5s ease 0.6s forwards;
}