/* ================================
   Swiss Style with Japanese Ma
   Design System
   ================================ */

:root {
    /* Color Palette - Warm & Intentional */
    --color-navy: #2c2420;
    --color-navy-light: #3d3530;
    --color-text: #3d3530;
    --color-text-secondary: #7c6f64;
    --color-accent: #e07a2f;
    --color-background: #faf8f5;
    --color-white: #fffef9;
    --color-border: #e8e3db;
    
    /* Typography Scale - Mathematical Progression */
    --font-display: 'Albert Sans', -apple-system, sans-serif;
    --font-body: 'Albert Sans', -apple-system, sans-serif;
    --font-accent: 'Instrument Serif', Georgia, serif;
    
    /* Spacing - 8px Baseline Grid */
    --space-xs: 8px;
    --space-sm: 16px;
    --space-md: 24px;
    --space-lg: 32px;
    --space-xl: 48px;
    --space-2xl: 64px;
    --space-3xl: 96px;
    --space-4xl: 128px;
    
    /* Shadows - Subtle Elevation */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.08);
    
    /* Border Radius - Minimal */
    --radius-sm: 2px;
    --radius-md: 4px;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ================================
   Reset & Base Styles
   ================================ */

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    font-weight: 400;
    line-height: 1.6;
    color: var(--color-text);
    background: radial-gradient(ellipse at top, #fffcf5 0%, var(--color-background) 50%);
    background-attachment: fixed;
}

/* ================================
   Typography - Strong Hierarchy
   ================================ */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: -0.02em;
    color: var(--color-navy);
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-lg);
}

.hero-title-accent {
    color: var(--color-accent);
    display: inline-block;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--space-md);
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    max-width: 600px;
}

/* ================================
   Layout Containers
   ================================ */

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.section {
    padding: var(--space-4xl) 0;
}

.section-alt {
    background-color: var(--color-white);
}

/* ================================
   Navigation - Clean & Minimal
   ================================ */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-weight: 700;
    font-size: 1.125rem;
    color: var(--color-navy);
    text-decoration: none;
}

.brand-initial {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background-color: var(--color-navy);
    color: var(--color-white);
    font-weight: 800;
    font-size: 1.25rem;
    border-radius: var(--radius-sm);
}

.brand-text {
    letter-spacing: -0.01em;
}

.nav-menu {
    display: flex;
    gap: var(--space-xl);
    list-style: none;
}

.nav-link {
    position: relative;
    font-weight: 500;
    font-size: 0.938rem;
    color: var(--color-text);
    text-decoration: none;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    transition: color var(--transition-fast);
}

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

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

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background-color: var(--color-navy);
    transition: all var(--transition-base);
}

/* ================================
   Hero Section - Asymmetric Layout
   ================================ */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 72px;
    background-color: var(--color-white);
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.hero-label {
    display: inline-block;
    font-size: 0.813rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
}

.hero-description {
    font-size: 1.25rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
    max-width: 480px;
}

.hero-visual {
    position: relative;
    height: 400px;
}

.visual-block {
    position: absolute;
    background: linear-gradient(135deg, #2c2420 0%, #4a3f35 100%);
    box-shadow: var(--shadow-lg);
}

.visual-block-1 {
    top: 0;
    right: 80px;
    width: 280px;
    height: 280px;
    border-radius: var(--radius-md);
}

.visual-block-2 {
    bottom: 0;
    right: 0;
    width: 200px;
    height: 200px;
    background: linear-gradient(135deg, #e07a2f 0%, #d4692a 100%);
    border-radius: var(--radius-md);
}

/* ================================
   Section Headers
   ================================ */

.section-header {
    margin-bottom: var(--space-3xl);
}

/* ================================
   Class Cards - Asymmetric Grid
   ================================ */

.class-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--space-lg);
}

.class-card {
    position: relative;
    background-color: var(--color-white);
    padding: var(--space-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    overflow: hidden;
}

.class-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 0;
    background-color: var(--color-accent);
    transition: height var(--transition-base);
}

.class-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.class-card:hover::before {
    height: 100%;
}

.class-number {
    position: absolute;
    top: var(--space-md);
    right: var(--space-md);
    font-size: 5rem;
    font-weight: 800;
    line-height: 1;
    color: var(--color-background);
    opacity: 0.5;
    pointer-events: none;
}

.class-content {
    position: relative;
    z-index: 1;
}

.class-meta {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
}

.class-grade,
.class-name {
    font-size: 0.813rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
}

.class-grade {
    background-color: var(--color-navy);
    color: var(--color-white);
}

.class-name {
    background-color: var(--color-background);
    color: var(--color-text);
}

.class-unit {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    color: var(--color-navy);
}

.class-description {
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

.class-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    font-size: 0.938rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-navy);
    text-decoration: none;
    transition: all var(--transition-fast);
}

.class-link svg {
    transition: transform var(--transition-fast);
}

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

.class-link:hover svg {
    transform: translateX(4px);
}

/* ================================
   Info Section - Asymmetric Layout
   ================================ */

.info-layout {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--space-3xl);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-xl);
}

.info-item {
    padding: var(--space-lg) 0;
    border-top: 2px solid var(--color-navy);
}

.info-number {
    font-size: 0.813rem;
    font-weight: 700;
    color: var(--color-accent);
    margin-bottom: var(--space-sm);
}

.info-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    color: var(--color-navy);
}

.info-text {
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
}

/* ================================
   Updates Section
   ================================ */

.updates-layout {
    max-width: 800px;
}

.updates-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
    margin-top: var(--space-2xl);
}

.update-card {
    padding: var(--space-lg) 0;
    border-bottom: 1px solid var(--color-border);
}

.update-card:last-child {
    border-bottom: none;
}

.update-date {
    display: block;
    font-size: 0.813rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-sm);
}

.update-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
    color: var(--color-navy);
}

.update-description {
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-md);
}

.update-link {
    display: inline-flex;
    align-items: center;
    font-size: 0.938rem;
    font-weight: 600;
    color: var(--color-navy);
    text-decoration: none;
    border-bottom: 2px solid var(--color-accent);
    transition: all var(--transition-fast);
}

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

/* ================================
   Contact Section
   ================================ */

.section-contact {
    background-color: var(--color-white);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--space-3xl);
}

.contact-intro {
    font-size: 1.125rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
    margin-top: var(--space-md);
}

.contact-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-xl);
}

.contact-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.contact-label {
    font-size: 0.813rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
}

.contact-value {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--color-navy);
    text-decoration: none;
    line-height: 1.6;
}

.contact-value[href]:hover {
    color: var(--color-accent);
}

/* ================================
   Footer
   ================================ */

.footer {
    background: linear-gradient(to bottom, #2c2420 0%, #1f1b17 100%);
    color: var(--color-white);
    padding: var(--space-xl) 0;
}

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

.footer-text {
    font-size: 0.938rem;
    color: rgba(255, 255, 255, 0.8);
}

/* ================================
   Responsive Design
   ================================ */

@media (max-width: 968px) {
    :root {
        --space-3xl: 64px;
        --space-4xl: 96px;
    }
    
    .hero-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
    
    .hero-visual {
        height: 300px;
    }
    
    .visual-block-1 {
        width: 200px;
        height: 200px;
        right: 60px;
    }
    
    .visual-block-2 {
        width: 150px;
        height: 150px;
    }
    
    .info-layout {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
    
    .info-grid {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        flex-direction: column;
        gap: 0;
        background-color: var(--color-white);
        border-bottom: 1px solid var(--color-border);
        padding: var(--space-md) var(--space-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
        box-shadow: var(--shadow-md);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        padding: var(--space-md) 0;
        border-bottom: 1px solid var(--color-border);
    }
    
    .nav-link:last-child {
        border-bottom: none;
    }
    
    .nav-link::after {
        display: none;
    }
    
    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(6px, 6px);
    }
    
    .nav-toggle.active span:nth-child(2) {
        transform: rotate(-45deg) translate(1px, -1px);
    }
    
    .class-grid {
        grid-template-columns: 1fr;
    }
    
    .hero {
        min-height: auto;
        padding: var(--space-3xl) 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--space-md);
    }
    
    .nav-container {
        padding: 0 var(--space-md);
    }
    
    .hero-grid {
        padding: 0 var(--space-md);
    }
    
    .section {
        padding: var(--space-3xl) 0;
    }
    
    .class-number {
        font-size: 3.5rem;
    }
    
    .visual-block-1 {
        width: 160px;
        height: 160px;
        right: 40px;
    }
    
    .visual-block-2 {
        width: 120px;
        height: 120px;
    }
}