/* Reset and Global */
:root {
    --bg-color: #0d0d0d;
    --text-color: #e0e0e0;
    --accent-color: #d4af37; /* Gold */
    --accent-hover: #b5952f;
    --surface-color: #1a1a1a;
    --border-color: #333;
    --font-primary: 'Noto Serif JP', serif;
    --font-secondary: 'Noto Sans JP', sans-serif;
    --transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-secondary);
    line-height: 1.8;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-primary);
    font-weight: 400;
    line-height: 1.4;
}

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

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

/* Animations */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: all 1s ease-out;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

.reveal-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: all 1s ease-out;
}

.reveal-left.active {
    opacity: 1;
    transform: translateX(0);
}

.reveal-right {
    opacity: 0;
    transform: translateX(50px);
    transition: all 1s ease-out;
}

.reveal-right.active {
    opacity: 1;
    transform: translateX(0);
}

/* Typography Helpers */
.title-jp-vertical {
    writing-mode: vertical-rl;
    text-orientation: upright;
    letter-spacing: 0.3em;
    font-size: 2rem;
    color: var(--accent-color);
}

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

/* Sidebar Navigation (Unique Structure) */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 250px;
    height: 100vh;
    background-color: var(--surface-color);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 40px 20px;
    z-index: 100;
    transform: translateX(0);
    transition: transform 0.5s ease;
}

.logo-container {
    margin-bottom: 60px;
    text-align: center;
}

.logo-text {
    font-family: var(--font-primary);
    font-size: 24px;
    color: var(--accent-color);
    letter-spacing: 2px;
}

.nav-menu {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.nav-link {
    font-size: 16px;
    letter-spacing: 1px;
    position: relative;
    display: inline-block;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

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

.main-content {
    margin-left: 250px;
    min-height: 100vh;
}

/* Split Hero (Unique Design) */
.hero-split {
    display: flex;
    min-height: 100vh;
    border-bottom: 1px solid var(--border-color);
}

.hero-text-box {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 60px;
    position: relative;
}

.hero-image-box {
    flex: 1;
    background-size: cover;
    background-position: center;
    position: relative;
}

.hero-image-box::before {
    content: '';
    position: absolute;
    top:0; left:0; width:100%; height:100%;
    background: linear-gradient(90deg, var(--bg-color) 0%, transparent 50%);
}

.lead-title {
    font-size: 3.5rem;
    color: #fff;
    margin-bottom: 30px;
}

.gold-text {
    color: var(--accent-color);
}

.lead-desc {
    font-size: 1.1rem;
    color: #aaa;
    max-width: 500px;
    margin-bottom: 40px;
}

.btn-gold {
    display: inline-block;
    padding: 15px 40px;
    background-color: transparent;
    border: 1px solid var(--accent-color);
    color: var(--accent-color);
    font-family: var(--font-primary);
    letter-spacing: 2px;
    position: relative;
    overflow: hidden;
}

.btn-gold::before {
    content: '';
    position: absolute;
    top: 0; left: -100%; width: 100%; height: 100%;
    background-color: var(--accent-color);
    transition: var(--transition);
    z-index: -1;
}

.btn-gold:hover {
    color: #000;
}

.btn-gold:hover::before {
    left: 0;
}

/* Sections */
.section {
    padding: 100px 0;
    border-bottom: 1px solid var(--border-color);
}

.section-head {
    display: flex;
    align-items: flex-start;
    margin-bottom: 60px;
    gap: 30px;
}

.section-bg {
    background-color: var(--surface-color);
}

/* Grids */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }

/* Cards */
.dark-card {
    background: #111;
    border: 1px solid var(--border-color);
    padding: 40px;
    transition: var(--transition);
}

.dark-card:hover {
    border-color: var(--accent-color);
    transform: translateY(-10px);
}

.card-num {
    font-family: var(--font-primary);
    font-size: 3rem;
    color: rgba(212, 175, 55, 0.2);
    margin-bottom: 20px;
    line-height: 1;
}

/* Contact Footer */
.footer-contact {
    background: #000;
    padding: 80px 20px;
    text-align: center;
}

.footer-nav {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin: 40px 0;
    flex-wrap: wrap;
}

.legal-text {
    font-size: 12px;
    color: #666;
}

/* Mobile */
.mobile-toggle {
    display: none;
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    background: var(--accent-color);
    color: #000;
    border: none;
    padding: 10px 15px;
    font-family: var(--font-primary);
    cursor: pointer;
}

@media (max-width: 900px) {
    .sidebar {
        transform: translateX(-100%);
    }
    .sidebar.open {
        transform: translateX(0);
    }
    .main-content {
        margin-left: 0;
    }
    .hero-split {
        flex-direction: column-reverse;
    }
    .grid-2, .grid-3 {
        grid-template-columns: 1fr;
    }
    .mobile-toggle {
        display: block;
    }
    .title-jp-vertical {
        writing-mode: horizontal-tb;
        text-orientation: mixed;
        letter-spacing: 0.1em;
        font-size: 1.5rem;
    }
    .section-head {
        flex-direction: column;
    }
}