/* ========================================
   CSS Variables
======================================== */
:root {
    /* Colors */
    --primary-color: #4A90E2;
    --secondary-color: #7ED321;
    --accent-color: #F5A623;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-light: #999999;
    --background: #FAFBFC;
    --white: #FFFFFF;
    --border-color: #E8E8E8;
    
    /* Typography */
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-japanese: 'Noto Sans JP', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 4rem;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.12);
    --shadow-lg: 0 8px 16px rgba(0,0,0,0.16);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

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

body {
    font-family: var(--font-main);
    color: var(--text-primary);
    background-color: var(--background);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
    color: #3a7bc8;
}

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

/* ========================================
   Layout Components
======================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-xl);
    color: var(--text-primary);
}

/* ========================================
   Header
======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: all var(--transition-normal);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) 0;
}

.logo-link {
    display: inline-flex;
    align-items: center;
    transition: transform var(--transition-fast);
}

.logo-link:hover {
    transform: translateY(-2px);
}

.logo-img {
    height: 45px;
    width: auto;
    display: block;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-link {
    font-weight: 500;
    color: var(--text-primary);
    transition: color var(--transition-fast);
}

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

/* ========================================
   Hero Section
======================================== */
.hero {
    padding: calc(100px + var(--spacing-xxl)) 0 var(--spacing-xxl);
    text-align: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--primary-color), #667eea);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    font-family: var(--font-japanese);
}

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: 8px;
    font-weight: 600;
    transition: all var(--transition-normal);
    cursor: pointer;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    box-shadow: 0 4px 14px rgba(74, 144, 226, 0.3);
}

.btn-primary:hover {
    background: #3a7bc8;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.4);
}

/* ========================================
   Works Section
======================================== */
.works {
    padding: var(--spacing-xxl) 0;
}

.works-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-lg);
}

.work-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

.work-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.work-image {
    position: relative;
    overflow: hidden;
    height: 250px;
    background: #f0f0f0;
}

/* Project specific backgrounds */
.work-card:nth-child(1) .work-image {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.work-card:nth-child(2) .work-image {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.work-card:nth-child(3) .work-image {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

/* Work placeholder styling */
.work-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: white;
    text-align: center;
    padding: var(--spacing-lg);
}

.work-placeholder h3 {
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0 0 var(--spacing-sm) 0;
    font-family: var(--font-japanese);
}

.work-placeholder p {
    font-size: 1rem;
    opacity: 0.9;
    margin: 0;
    font-family: var(--font-japanese);
}

.work-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center top;
    transition: transform var(--transition-normal);
}

.work-card:hover .work-image img {
    transform: scale(1.05);
}

.work-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.work-card:hover .work-overlay {
    opacity: 1;
}

.work-link {
    color: white;
    font-weight: 600;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid white;
    border-radius: 4px;
    transition: all var(--transition-fast);
}

.work-link:hover {
    background: white;
    color: var(--text-primary);
}

.work-content {
    padding: var(--spacing-lg);
}

.work-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    font-family: var(--font-japanese);
}

.work-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
    font-family: var(--font-japanese);
}

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

.tag {
    padding: 4px 12px;
    background: var(--background);
    color: var(--text-secondary);
    font-size: 0.875rem;
    border-radius: 20px;
    font-weight: 500;
}

/* ========================================
   About Section
======================================== */
.about {
    padding: var(--spacing-xxl) 0;
    background: var(--white);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-text {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-secondary);
    font-family: var(--font-japanese);
}

.about-text p {
    margin-bottom: var(--spacing-md);
}

/* ========================================
   Contact Section
======================================== */
.contact {
    padding: var(--spacing-xxl) 0;
}

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

.contact-content p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    font-family: var(--font-japanese);
}

.contact-info {
    font-size: 1.125rem;
    color: var(--text-primary);
}

/* ========================================
   Footer
======================================== */
.footer {
    padding: var(--spacing-lg) 0;
    background: var(--text-primary);
    color: white;
    text-align: center;
}

.copyright {
    font-size: 0.875rem;
    opacity: 0.8;
}