/* --- CSS Variables --- */
:root {
    --bg-color: #ffffff;
    --text-color: #1a1a1a;
    --primary-color: #0055ff;
    --secondary-color: #f0f4f9;
    --border-color: #e0e0e0;
    --font-family-sans: 'Inter', 'Noto Sans JP', sans-serif;
    --transition-speed: 0.3s;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #f0f4f9;
    --primary-color: #337aff;
    --secondary-color: #2a2a2a;
    --border-color: #444444;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-sans);
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color var(--transition-speed), color var(--transition-speed);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.section {
    padding: 100px 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 60px;
}

/* --- Header --- */
.header {
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    z-index: 100;
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    transition: background-color var(--transition-speed), border-color var(--transition-speed);
}
[data-theme="dark"] .header {
    background-color: rgba(26, 26, 26, 0.8);
}
.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}
.header-logo {
    font-weight: 700;
    font-size: 1.5rem;
    text-decoration: none;
    color: var(--text-color);
}
.gnav ul {
    display: flex;
    list-style: none;
    gap: 30px;
}
.gnav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color var(--transition-speed);
}
.gnav a:hover {
    color: var(--primary-color);
}
.theme-switcher {
    cursor: pointer;
}
.theme-icon {
    display: none;
}
html:not([data-theme="dark"]) #theme-toggle-light-icon {
    display: block;
}
[data-theme="dark"] #theme-toggle-dark-icon {
    display: block;
}
.mobile-menu-button { display: none; }


/* --- Hero Section --- */
.hero {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    min-height: 80vh;
    padding-top: 70px;
}
.hero-title {
    font-size: 4rem;
    line-height: 1.2;
    margin-bottom: 20px;
}
.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-color);
    opacity: 0.8;
}

/* --- Service Section --- */
.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}
.service-card {
    background-color: var(--secondary-color);
    padding: 40px;
    border-radius: 12px;
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}
.service-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
}
[data-theme="dark"] .service-card:hover {
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}
.service-card-title {
    font-size: 1.5rem;
    margin-bottom: 15px;
}

/* --- Works Section --- */
.works-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 30px;
}
.work-item {
    position: relative;
    overflow: hidden;
    border-radius: 12px;
    display: block;
}
.work-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform var(--transition-speed) ease;
}
.work-item:hover img {
    transform: scale(1.05);
}
.work-info {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 20px;
    background: linear-gradient(to top, rgba(0,0,0,0.7), transparent);
    color: white;
    transform: translateY(100%);
    opacity: 0;
    transition: transform var(--transition-speed), opacity var(--transition-speed);
}
.work-item:hover .work-info {
    transform: translateY(0);
    opacity: 1;
}
.work-info h3 {
    font-size: 1.5rem;
}

/* --- Contact Section --- */
.contact {
    text-align: center;
    background-color: var(--secondary-color);
}
.cta-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 15px 40px;
    text-decoration: none;
    font-weight: 700;
    border-radius: 50px;
    margin-top: 30px;
    transition: transform var(--transition-speed), background-color var(--transition-speed);
}
.cta-button:hover {
    transform: scale(1.05);
    background-color: #0044cc;
}
[data-theme="dark"] .cta-button:hover {
    background-color: #559bff;
}


/* --- Footer --- */
.footer {
    padding: 40px 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

/* --- Animation --- */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}
.animate-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
    .section-title { font-size: 2rem; }
    .hero-title { font-size: 2.5rem; }
    
    .gnav { display: none; } /* Hide for now. JS will handle it. */
    .mobile-menu-button {
        display: block;
        background: none;
        border: none;
        cursor: pointer;
        z-index: 101;
    }
    .mobile-menu-button span {
        display: block;
        width: 25px;
        height: 2px;
        background-color: var(--text-color);
        margin: 5px 0;
    }
}