/* ==========================================================================
   CSS Variables & Reset (McKinsey Inspired Theme)
   ========================================================================== */

:root {
    /* Colors - Corporate, Trustworthy, Intellectual */
    --clr-primary: #051c2c;
    /* Deep Navy - Trust & Authority */
    --clr-secondary: #0056b3;
    /* Sharp Blue - Action & Modernity */
    --clr-accent: #f4c20d;
    /* Subtle Gold/Yellow - Insight & Excellence (Optional touch) */

    --clr-text-main: #333333;
    --clr-text-light: #666666;
    --clr-text-inverse: #ffffff;

    --clr-bg-main: #ffffff;
    --clr-bg-alt: #f5f5f5;
    /* Soft gray for alternating sections */
    --clr-bg-dark: #0f2027;

    --clr-border: #e0e0e0;

    /* Typography */
    --font-heading: 'Inter', 'Noto Sans JP', sans-serif;
    --font-body: 'Inter', 'Noto Sans JP', sans-serif;

    /* Spacing & Layout */
    --space-xs: 0.5rem;
    /* 8px */
    --space-sm: 1rem;
    /* 16px */
    --space-md: 2rem;
    /* 32px */
    --space-lg: 4rem;
    /* 64px */
    --space-xl: 8rem;
    /* 128px */

    --container-max: 1200px;
    --container-padding: 2rem;

    /* Transitions */
    --trans-fast: 0.2s ease;
    --trans-smooth: 0.4s cubic-bezier(0.25, 1, 0.5, 1);
}

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

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

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

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

ul {
    list-style: none;
}

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

/* ==========================================================================
   Typography
   ========================================================================== */

h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.2;
    color: var(--clr-primary);
    margin-bottom: var(--space-sm);
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4.5rem);
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    letter-spacing: -0.01em;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
}

p {
    margin-bottom: var(--space-sm);
}

/* ==========================================================================
   Layout & Components
   ========================================================================== */

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    font-size: 0.875rem;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all var(--trans-fast);
}

.btn-primary {
    background-color: var(--clr-secondary);
    color: var(--clr-text-inverse);
}

.btn-primary:hover {
    background-color: #004494;
    /* Darker blue */
}

.btn-outline {
    background-color: transparent;
    color: var(--clr-text-inverse);
    border-color: var(--clr-text-inverse);
}

.btn-outline:hover {
    background-color: var(--clr-text-inverse);
    color: var(--clr-primary);
}

/* ==========================================================================
   Header / Navigation
   ========================================================================== */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--clr-border);
    transition: transform var(--trans-fast), background-color var(--trans-fast);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--clr-primary);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

/* Nav Links */
.main-nav ul {
    display: flex;
    gap: var(--space-md);
}

.main-nav a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--clr-text-light);
    position: relative;
    padding-bottom: 0.25rem;
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--clr-primary);
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0%;
    height: 2px;
    background-color: var(--clr-secondary);
    transition: width var(--trans-smooth);
}

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

/* Mobile Toggle */
.menu-toggle {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001;
}

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--clr-primary);
    position: relative;
    transition: background-color var(--trans-fast);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: inherit;
    left: 0;
    transition: transform var(--trans-fast);
}

.hamburger::before {
    top: -6px;
}

.hamburger::after {
    bottom: -6px;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    background-color: var(--clr-primary);
    /* 高品質な建築・ビジネスイメージ（Unsplash提供のフリー素材）を追加 */
    background-image: url('https://images.unsplash.com/photo-1486406146926-c627a92ad1ab?q=80&w=2070&auto=format&fit=crop');
    background-size: cover;
    background-position: center;
    color: var(--clr-text-inverse);
    padding-top: 80px;
    /* Header offset */
}

/* オーバーレイで文字を読みやすくしつつ、ネイビーの世界観を付与 */
.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to right, rgba(5, 28, 44, 0.95) 0%, rgba(5, 28, 44, 0.6) 100%);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    animation: fadeInUp 1s cubic-bezier(0.25, 1, 0.5, 1) forwards;
}

.hero-subtitle {
    font-size: 0.875rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--clr-accent);
    margin-bottom: var(--space-sm);
    display: block;
}

.hero-title {
    color: var(--clr-text-inverse);
    margin-bottom: var(--space-md);
}

.hero-description {
    font-size: 1.25rem;
    font-weight: 300;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--space-lg);
    max-width: 600px;
}

.hero-actions {
    display: flex;
    gap: var(--space-sm);
}

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

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

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

.site-footer {
    background-color: var(--clr-primary);
    color: var(--clr-text-inverse);
    padding: var(--space-xl) 0 var(--space-md);
}

.footer-container {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-lg);
    margin-bottom: var(--space-lg);
}

.footer-brand {
    flex: 1;
    min-width: 300px;
}

.footer-brand h2 {
    color: var(--clr-text-inverse);
    font-size: 1.5rem;
    margin-bottom: var(--space-sm);
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    gap: var(--space-lg);
    flex-wrap: wrap;
}

.footer-column h3 {
    color: var(--clr-text-inverse);
    font-size: 1rem;
    margin-bottom: var(--space-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: 0.5rem;
}

.footer-column a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.9rem;
    text-decoration: none;
    transition: color var(--trans-fast);
}

.footer-column a:hover {
    color: var(--clr-text-inverse);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--space-sm);
    text-align: center;
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.5);
}

/* ==========================================================================
   Responsive Design (Mobile)
   ========================================================================== */

@media (max-width: 768px) {
    .header-btn {
        display: none;
    }

    .menu-toggle {
        display: block;
    }

    .main-nav {
        display: none;
        /* JSでトグル制御する予定 */
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: white;
        padding: var(--space-md) var(--container-padding);
        box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    }

    .main-nav ul {
        flex-direction: column;
        gap: var(--space-sm);
    }

    .hero-actions {
        flex-direction: column;
    }

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

    .footer-container {
        flex-direction: column;
    }
}

/* ==========================================================================
   Sections General
   ========================================================================== */

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

.section-dark {
    background-color: var(--clr-primary);
    color: var(--clr-text-inverse);
}

.bg-light {
    background-color: var(--clr-bg-alt);
}

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

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

.text-white {
    color: var(--clr-text-inverse);
}

.text-light {
    color: rgba(255, 255, 255, 0.7);
}

.text-white-opacity {
    color: rgba(255, 255, 255, 0.85);
}

.mt-4 {
    margin-top: var(--space-md);
}

.section-subtitle {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--clr-secondary);
    margin-bottom: var(--space-xs);
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    margin-bottom: var(--space-sm);
}

.section-divider {
    width: 60px;
    height: 3px;
    background-color: var(--clr-secondary);
    margin: 0 auto var(--space-md);
}

/* ==========================================================================
   Services Section
   ========================================================================== */

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
}

.service-card {
    background: #fff;
    padding: var(--space-md);
    border: 1px solid var(--clr-border);
    transition: transform var(--trans-smooth), box-shadow var(--trans-smooth);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.05);
    border-color: transparent;
}

.service-icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-sm);
    color: var(--clr-primary);
}

.service-title {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
}

.service-desc {
    color: var(--clr-text-light);
    margin-bottom: var(--space-md);
    flex-grow: 1;
}

.link-arrow {
    display: inline-flex;
    align-items: center;
    font-weight: 600;
    color: var(--clr-secondary);
    font-size: 0.9rem;
}

.link-arrow .arrow {
    transition: transform var(--trans-fast);
    margin-left: 0.5rem;
}

.link-arrow:hover .arrow {
    transform: translateX(5px);
}

/* ==========================================================================
   About Overview Section
   ========================================================================== */

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

.about-text {
    padding-right: var(--space-md);
}

.about-image-placeholder {
    aspect-ratio: 4 / 3;
    background-color: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: rgba(255, 255, 255, 0.3);
    font-size: 1.5rem;
    font-weight: 300;
    letter-spacing: 0.1em;
    border: 1px dashed rgba(255, 255, 255, 0.2);
}

@media (max-width: 900px) {
    .about-overview {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }

    .about-text {
        padding-right: 0;
    }
}

/* ==========================================================================
   Insight / Blog Section
   ========================================================================== */

.insight-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    align-items: center;
}

.blog-preview-card {
    background: #fff;
    border-radius: 4px;
    overflow: hidden;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.08);
    border: 1px solid var(--clr-border);
    transition: transform var(--trans-smooth);
}

.blog-preview-card:hover {
    transform: translateY(-5px);
}

.blog-header {
    background-color: #f8f9fa;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--clr-border);
    display: flex;
    align-items: center;
}

.blog-header::before {
    content: '';
    display: inline-block;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: #ff5f56;
    box-shadow: 16px 0 0 #ffbd2e, 32px 0 0 #27c93f;
    margin-right: 1.5rem;
}

.blog-domain {
    font-family: monospace;
    font-size: 0.8rem;
    color: var(--clr-text-light);
    background: #e9ecef;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
}

.blog-body {
    padding: var(--space-md);
}

.blog-body h4 {
    margin-bottom: var(--space-xs);
    color: var(--clr-primary);
}

.blog-body p {
    font-size: 0.9rem;
    color: var(--clr-text-light);
    margin-bottom: 0;
}

@media (max-width: 900px) {
    .insight-container {
        grid-template-columns: 1fr;
        gap: var(--space-lg);
    }

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