:root {
    /* Colors */
    --color-primary: #003366;
    /* Navy Blue - Trust */
    --color-primary-light: #004d99;
    --color-accent: #FF9900;
    /* Warm Orange - Smile */
    --color-accent-light: #ffb84d;
    --color-text-main: #333333;
    --color-text-light: #666666;
    --color-bg-light: #f4f7fa;
    --color-white: #ffffff;

    /* Fonts */
    --font-main: 'Noto Sans JP', sans-serif;
    --font-heading: 'Inter', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;

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

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    color: var(--color-text-main);
    line-height: 1.6;
    background-color: var(--color-white);
}

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

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

ul {
    list-style: none;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-heading);
    line-height: 1.3;
    font-weight: 700;
    color: var(--color-primary);
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: var(--spacing-lg);
    position: relative;
    display: inline-block;
    left: 50%;
    transform: translateX(-50%);
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--color-accent);
    margin: var(--spacing-sm) auto 0;
    border-radius: 2px;
}

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

.grid {
    display: grid;
    gap: var(--spacing-md);
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.flex {
    display: flex;
    align-items: center;
}

.flex-between {
    justify-content: space-between;
}

.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    background-color: var(--color-accent);
    color: var(--color-white);
    font-weight: bold;
    border-radius: 50px;
    transition: transform var(--transition-fast), background-color var(--transition-fast);
}

.btn:hover {
    background-color: var(--color-accent-light);
    transform: translateY(-2px);
}

.btn-primary {
    background-color: var(--color-primary);
}

.btn-primary:hover {
    background-color: var(--color-primary-light);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    z-index: 1000;
    padding: var(--spacing-sm) 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.nav-links a {
    font-weight: 600;
    color: var(--color-primary);
}

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

.mobile-menu-btn {
    display: none;
    font-size: 1.5rem;
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-primary);
}

/* Hero Section */
.hero {
    height: 100vh;
    min-height: 600px;
    background-image: linear-gradient(rgba(0, 51, 102, 0.7), rgba(0, 51, 102, 0.7)), url('../images/hero_office.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    display: flex;
    align-items: center;
    text-align: center;
    color: var(--color-white);
    padding-top: 80px;
    /* Header height */
}

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

.hero h1 {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-white);
    text-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

/* Services */
.services {
    padding: var(--spacing-xl) 0;
    background-color: var(--color-bg-light);
}

.service-card {
    background: var(--color-white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    transition: transform var(--transition-normal);
    height: 100%;
}

.service-card:hover {
    transform: translateY(-10px);
}

.service-img {
    height: 200px;
    width: 100%;
    object-fit: cover;
}

.service-content {
    padding: var(--spacing-md);
}

.service-content h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--color-primary);
}

/* About */
.about {
    padding: var(--spacing-xl) 0;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
}

.about-text h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

/* Contact */
.contact {
    padding: var(--spacing-xl) 0;
    background-color: var(--color-primary);
    color: var(--color-white);
    text-align: center;
}

.contact h2 {
    color: var(--color-white);
    margin-bottom: var(--spacing-md);
}

.contact-info {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
}

/* Footer */
.footer {
    background-color: #002244;
    color: rgba(255, 255, 255, 0.7);
    padding: var(--spacing-lg) 0;
    text-align: center;
}

/* Responsive */
@media (max-width: 768px) {
    .header .container {
        justify-content: space-between;
    }

    .nav-links {
        position: fixed;
        top: 70px;
        right: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--color-white);
        flex-direction: column;
        align-items: center;
        justify-content: center;
        transition: right var(--transition-normal);
    }

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

    .mobile-menu-btn {
        display: block;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

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