/* ==========================================================================
   DESIGN SYSTEM & VARIABLES
   ========================================================================== */

:root {
    /* Color Palette - Dark Mode (Default) */
    --bg-primary: #080710;
    --bg-secondary: #0f0e1d;
    --bg-navbar: rgba(8, 7, 16, 0.75);
    --bg-card: rgba(255, 255, 255, 0.03);
    --border-color: rgba(255, 255, 255, 0.08);
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --accent-glow: rgba(99, 102, 241, 0.15);
    
    /* Gradients */
    --gradient-hero: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
    --gradient-text: linear-gradient(90deg, #818cf8, #c084fc, #f472b6);
    
    /* Layout */
    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.4);
    
    /* Card Glows */
    --card-glow: rgba(255, 255, 255, 0.12);
}

[data-theme="light"] {
    /* Color Palette - Light Mode */
    --bg-primary: #f5f6fa;
    --bg-secondary: #ffffff;
    --bg-navbar: rgba(245, 246, 250, 0.8);
    --bg-card: rgba(0, 0, 0, 0.02);
    --border-color: rgba(0, 0, 0, 0.08);
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --accent-glow: rgba(99, 102, 241, 0.05);
    
    /* Gradients */
    --gradient-hero: linear-gradient(135deg, #4f46e5 0%, #9333ea 50%, #db2777 100%);
    --gradient-text: linear-gradient(90deg, #4f46e5, #7c3aed, #db2777);
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 16px 32px rgba(0, 0, 0, 0.1);
    
    /* Card Glows */
    --card-glow: rgba(99, 102, 241, 0.1);
}

/* ==========================================================================
   RESET & GLOBAL STYLES
   ========================================================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Outfit', 'Inter', 'Noto Sans JP', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* ==========================================================================
   BACKGROUND DECORATIVE GLOWS
   ========================================================================== */

.bg-glow {
    position: fixed;
    border-radius: var(--radius-full);
    filter: blur(120px);
    z-index: -1;
    opacity: 0.4;
    pointer-events: none;
    transition: opacity var(--transition-slow);
}

.bg-glow-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, #6366f1 0%, transparent 70%);
    top: -10%;
    left: -10%;
}

.bg-glow-2 {
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, #a855f7 0%, transparent 70%);
    bottom: -10%;
    right: -10%;
}

.bg-glow-3 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, #ec4899 0%, transparent 70%);
    top: 40%;
    left: 50%;
    transform: translate(-50%, -50%);
}

[data-theme="light"] .bg-glow {
    opacity: 0.15;
}

/* ==========================================================================
   TYPOGRAPHY UTILITIES
   ========================================================================== */

.gradient-text {
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: inline-block;
}

.badge {
    display: inline-block;
    padding: 6px 14px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-radius: var(--radius-full);
    background-color: var(--border-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    margin-bottom: 1rem;
}

/* ==========================================================================
   NAVIGATION BAR & ACTIONS
   ========================================================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background-color: var(--bg-navbar);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
    transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.25rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-logo {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
    border: 1.5px solid var(--text-primary);
}

.brand-name {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

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

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-fast);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Language Selector */
.lang-selector-container {
    display: flex;
    align-items: center;
    position: relative;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0 0.5rem;
    gap: 0.25rem;
    transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.lang-selector-container:hover {
    background-color: var(--border-color);
}

.lang-icon {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.lang-select {
    background: none;
    border: none;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    outline: none;
    padding: 0.5rem 1.8rem 0.5rem 0.25rem;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    transition: color var(--transition-fast);
}

.lang-select option {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.lang-selector-container::after {
    content: '\f0d7';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    position: absolute;
    right: 0.6rem;
    pointer-events: none;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Theme Toggle */
.theme-toggle {
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.theme-toggle:hover {
    background-color: var(--border-color);
}

/* ==========================================================================
   MAIN LAYOUT & SECTIONS
   ========================================================================== */

.main-content {
    max-width: 1200px;
    margin: 100px auto 40px;
    padding: 0 2rem;
}

section {
    padding: 60px 0;
}

/* ==========================================================================
   HERO / ABOUT SECTION
   ========================================================================== */

.hero-card {
    display: flex;
    align-items: center;
    gap: 4rem;
    padding: 3.5rem;
    background-color: var(--bg-card);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
}

.hero-left {
    flex-shrink: 0;
}

.avatar-container {
    position: relative;
    width: 200px;
    height: 200px;
}

.avatar-img {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    position: relative;
    z-index: 2;
    border: 4px solid var(--bg-secondary);
}

.avatar-ring {
    position: absolute;
    top: -5px;
    left: -5px;
    width: 210px;
    height: 210px;
    border-radius: 50%;
    background: var(--gradient-hero);
    z-index: 1;
    animation: rotate 10s linear infinite;
}

@keyframes rotate {
    100% {
        transform: rotate(360deg);
    }
}

.hero-right {
    flex-grow: 1;
}

.hero-badge {
    background: rgba(99, 102, 241, 0.1);
    color: #818cf8;
    border-color: rgba(99, 102, 241, 0.2);
}

.hero-title {
    font-size: 2.75rem;
    font-weight: 800;
    margin-bottom: 1.25rem;
    letter-spacing: -0.03em;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 700px;
}

.hero-stats {
    display: flex;
    gap: 3rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-num {
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* ==========================================================================
   PROJECTS SECTION
   ========================================================================== */

.section-title {
    font-size: 2.25rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 0.5rem;
    letter-spacing: -0.02em;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 3.5rem;
    font-size: 1.05rem;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2.5rem;
}

/* Project Card */
.project-card {
    position: relative;
    background-color: var(--bg-card);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    padding: 2.5rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: transform 0.1s ease, box-shadow var(--transition-fast), border-color var(--transition-fast);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.project-card:hover {
    box-shadow: var(--shadow-lg);
    border-color: rgba(255, 255, 255, 0.18);
}

[data-theme="light"] .project-card:hover {
    border-color: rgba(0, 0, 0, 0.15);
}

/* 3D dynamic border glow wrapper */
.card-border-glow {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 3;
    transition: background var(--transition-fast);
}

.project-header {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    margin-bottom: 1.5rem;
}

.project-icon-wrapper {
    width: 50px;
    height: 50px;
    border-radius: var(--radius-sm);
    background-color: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--accent-color);
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.02);
}

[data-theme="light"] .project-icon-wrapper {
    background-color: rgba(0, 0, 0, 0.03);
}

.project-meta {
    display: flex;
    flex-direction: column;
}

.project-name {
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.project-tagline {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.project-body {
    flex-grow: 1;
    margin-bottom: 2rem;
}

.project-desc {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
}

.project-features {
    list-style: none;
}

.project-features li {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.project-features li i {
    font-size: 0.8rem;
    color: var(--text-primary);
    opacity: 0.7;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
}

.tech-badge {
    font-size: 0.75rem;
    font-weight: 500;
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
}

[data-theme="light"] .tech-badge {
    background-color: rgba(0, 0, 0, 0.03);
}

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

/* Buttons */
.action-btn {
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 600;
    padding: 0.65rem 1.1rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    cursor: pointer;
    transition: background-color var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast), opacity var(--transition-fast);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    text-decoration: none;
}

.action-btn:hover {
    background-color: var(--border-color);
    border-color: var(--text-secondary);
}

.link-btn {
    flex-grow: 1;
}

.copy-btn {
    width: 42px;
    flex-shrink: 0;
    padding: 0;
}

.visit-btn {
    background: var(--gradient-hero);
    color: #ffffff;
    border: none;
    flex-grow: 1;
}

.visit-btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.disabled-btn {
    background-color: rgba(255, 255, 255, 0.02);
    border: 1px dashed var(--border-color);
    color: var(--text-muted);
    cursor: not-allowed;
    flex-grow: 1;
}

[data-theme="light"] .disabled-btn {
    background-color: rgba(0, 0, 0, 0.02);
}

/* ==========================================================================
   CONTACT SECTION
   ========================================================================== */

.contact-section {
    margin-top: 40px;
    margin-bottom: 60px;
}

.contact-card {
    background: var(--gradient-hero);
    border-radius: var(--radius-lg);
    padding: 4rem 2.5rem;
    text-align: center;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.contact-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.25);
    z-index: 1;
}

.contact-title, .contact-text, .contact-grid {
    position: relative;
    z-index: 2;
}

.contact-title {
    font-size: 2.25rem;
    font-weight: 800;
    color: #ffffff;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.contact-text {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.1rem;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    max-width: 900px;
    margin: 0 auto;
}

.contact-item {
    background-color: rgba(0, 0, 0, 0.4);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: 2rem 1.5rem;
    color: #ffffff;
    text-decoration: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
}

a.contact-item:hover {
    transform: translateY(-5px);
    background-color: rgba(0, 0, 0, 0.55);
    border-color: rgba(255, 255, 255, 0.3);
}

.contact-item i {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #ffffff 0%, rgba(255, 255, 255, 0.7) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.contact-label {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: rgba(255, 255, 255, 0.6);
    font-weight: 600;
}

.contact-value {
    font-size: 1.05rem;
    font-weight: 500;
    word-break: break-all;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */

.footer {
    text-align: center;
    padding: 3rem 0;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ==========================================================================
   TOAST NOTIFICATION
   ========================================================================== */

.toast {
    position: fixed;
    bottom: -80px;
    left: 50%;
    transform: translateX(-50%);
    background-color: #10b981;
    color: #ffffff;
    padding: 1rem 2rem;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    box-shadow: 0 10px 25px rgba(16, 185, 129, 0.3);
    font-weight: 600;
    font-size: 0.95rem;
    z-index: 1000;
    transition: bottom 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.toast.show {
    bottom: 40px;
}

/* ==========================================================================
   RESPONSIVE DESIGN (MEDIA QUERIES)
   ========================================================================== */

@media (max-width: 1024px) {
    .hero-card {
        gap: 3rem;
        padding: 2.5rem;
    }
    .hero-title {
        font-size: 2.25rem;
    }
}

@media (max-width: 768px) {
    .navbar {
        position: relative;
    }
    .main-content {
        margin-top: 20px;
    }
    .hero-card {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
    }
    .hero-stats {
        justify-content: center;
        gap: 2rem;
    }
    .projects-grid {
        grid-template-columns: 1fr;
    }
    .contact-card {
        padding: 3rem 1.5rem;
    }
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    .contact-item {
        padding: 1.5rem 1rem;
    }
}