/* CSS Variables & Reset */
:root {
    /* Colors - 究極のシンプルモノトーン */
    --bg-body: #050505;
    --bg-surface: #0a0a0a;
    --text-primary: #ffffff;
    --text-secondary: #a3a3a3;
    --accent: #ffffff;
    /* アクセントも白で統一してミニマルに */
    --border: #262626;
    /* Layout */
    --container-width: 1000px;
    --header-height: 80px;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html {
    scroll-behavior: smooth;
}
body {
    font-family: "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.8;
    letter-spacing: 0.05em;
    -webkit-font-smoothing: antialiased;
}
a {
    text-decoration: none;
    color: inherit;
    transition: 0.3s;
}
ul {
    list-style: none;
}
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 40px;
}
/* Typography */
h1,
h2,
h3,
h4,
h5 {
    font-weight: 500;
    letter-spacing: 0.1em;
    line-height: 1.4;
}
p {
    color: var(--text-secondary);
}
/* Buttons */
.btn {
    display: inline-block;
    padding: 14px 32px;
    border: 1px solid var(--border);
    color: var(--text-primary);
    font-size: 0.8rem;
    letter-spacing: 0.2em;
    cursor: pointer;
    transition: all 0.3s;
    background: transparent;
    text-align: center;
}
.btn:hover {
    border-color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}
.btn-primary {
    border-color: var(--text-primary);
    background: var(--text-primary);
    color: var(--bg-body);
}
.btn-primary:hover {
    background: transparent;
    color: var(--text-primary);
}
.btn-secondary {
    border-color: var(--border);
}
.btn-secondary:hover {
    border-color: var(--text-primary);
}
.btn-sm {
    padding: 8px 20px;
    font-size: 0.75rem;
}
.btn-block {
    display: block;
    width: 100%;
}
/* Header */
.header {
    height: var(--header-height);
    background: rgba(5, 5, 5, 0.9);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
}
.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}
.logo {
    font-size: 1.2rem;
    font-weight: 700;
}
.logo-accent {
    font-weight: 300;
}
.nav-list {
    display: flex;
    gap: 40px;
}
.nav-list a {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-transform: uppercase;
}
.nav-list a:hover {
    color: var(--text-primary);
}
/* Hero */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--header-height);
    border-bottom: 1px solid var(--border);
}
.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}
.hero-title {
    font-size: 3rem;
    margin-bottom: 30px;
    letter-spacing: 0.05em;
}
.hero-text-wrapper {
    border-left: 1px solid var(--border);
    padding-left: 30px;
    margin-bottom: 40px;
}
.hero-buttons {
    display: flex;
    gap: 20px;
}
.hero-image-placeholder {
    width: 100%;
    aspect-ratio: 1/1;
    border: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}
.placeholder-text {
    font-size: 0.8rem;
    letter-spacing: 0.3em;
    transform: rotate(-90deg);
    color: var(--text-secondary);
}
/* Sections */
.section {
    padding: 140px 0;
    border-bottom: 1px solid var(--border);
}
.section-header {
    margin-bottom: 80px;
}
.section-subtitle {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 15px;
    letter-spacing: 0.2em;
}
.section-title {
    font-size: 2rem;
}
/* Features */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    border-top: 1px solid var(--border);
    border-left: 1px solid var(--border);
}
.feature-card {
    padding: 60px 40px;
    border-right: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    background: transparent;
    transition: background 0.3s;
}
.feature-card:hover {
    background: var(--bg-surface);
}
.feature-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--border);
    margin-bottom: 20px;
    line-height: 1;
}
.feature-card h4 {
    font-size: 1.1rem;
    margin-bottom: 15px;
}
.feature-card p {
    font-size: 0.9rem;
    line-height: 2;
}
/* Plans */
.plans-table-container {
    margin-bottom: 80px;
    border: 1px solid var(--border);
}
.plans-table {
    width: 100%;
    border-collapse: collapse;
}
.plans-table th,
.plans-table td {
    padding: 25px;
    border: 1px solid var(--border);
    text-align: center;
    font-size: 0.9rem;
}
.plans-table th {
    font-weight: 400;
    color: var(--text-secondary);
    background: var(--bg-surface);
}
.plans-table td:first-child {
    text-align: left;
    color: var(--text-secondary);
}
.plan-header {
    padding: 40px 20px;
}
.plan-name {
    display: block;
    font-size: 0.8rem;
    letter-spacing: 0.2em;
    margin-bottom: 10px;
}
.plan-price {
    font-size: 1.2rem;
    display: block;
}
.plan-price small {
    font-size: 0.8rem;
    color: var(--text-secondary);
}
.recommended-badge {
    display: block;
    font-size: 0.6rem;
    color: var(--bg-body);
    background: var(--text-primary);
    width: fit-content;
    margin: 0 auto 10px;
    padding: 2px 8px;
    font-weight: 700;
}
.highlight-cell {
    color: var(--text-primary);
}
.plan-note {
    text-align: right;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 60px;
}
.plan-details-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}
.plan-detail-card {
    border: 1px solid var(--border);
    padding: 40px;
}
.plan-detail-card h4 {
    font-size: 1rem;
    margin-bottom: 10px;
}
.plan-lead {
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 0.9rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 15px;
    display: inline-block;
}
/* Rules */
.rules-wrapper {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 60px;
}
.rule-col h5 {
    font-size: 0.9rem;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border);
    display: inline-block;
}
/* Contact */
.contact-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
}
.contact-info p {
    margin-bottom: 30px;
    font-size: 1rem;
}
.contact-details {
    font-size: 1.2rem;
    color: var(--text-primary);
}
.form-group {
    margin-bottom: 40px;
}
.form-group label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
    letter-spacing: 0.1em;
}
.form-group input,
.form-group textarea {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--border);
    padding: 10px 0;
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: 0.3s;
}
.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-bottom-color: var(--text-primary);
}
/* Footer */
.footer {
    padding: 80px 0;
    border-top: 1px solid var(--border);
}
.footer-inner {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
}
.footer-logo h2 {
    font-size: 1rem;
    font-weight: 400;
}
.copyright {
    font-size: 0.75rem;
    color: var(--text-secondary);
}
/* Mobile */
@media (max-width: 768px) {
    .container {
        padding: 0 24px;
    }
    .hero-container,
    .features-grid,
    .plan-details-grid,
    .contact-layout,
    .rules-wrapper {
        grid-template-columns: 1fr;
    }
    .features-grid {
        border-left: none;
    }
    .feature-card {
        border-left: 1px solid var(--border);
    }
    .hero-title {
        font-size: 2.2rem;
    }
    .plans-table-container {
        overflow-x: auto;
    }
    .plans-table {
        min-width: 600px;
    }
    .nav-list {
        display: none;
    }
    /* Mobile Menu omitted for simplicity as per request */
    .header-btn {
        display: none;
    }
}