:root {
    --main-bg: #ffffff;
    --black: #1a1a1a;
    --accent: #666666;
    --white: #ffffff;
    --transition: 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

/* 基本設定 */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: "Helvetica Neue", Arial, sans-serif; background: var(--main-bg); color: var(--black); line-height: 1.8; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 5%; }
.flex-between { display: flex; justify-content: space-between; align-items: center; }

/* ヘッダー */
.header { width: 100%; padding: 15px 0; position: sticky; top: 0; background: #fff; z-index: 1000; border-bottom: 1px solid #eee; }
.header-logo { height: 70px; mix-blend-mode: multiply; filter: brightness(1.05) contrast(1.1); }
.nav-list { display: flex; list-style: none; gap: 40px; }
.nav-list a { text-decoration: none; color: var(--black); font-weight: 600; font-size: 0.95rem; position: relative; padding-bottom: 5px; transition: 0.3s; }
.nav-list a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--black); transition: 0.3s; }
.nav-list a:hover::after { width: 100%; }

/* ヒーローエリア */
.hero { min-height: 20vh; display: flex; justify-content: center; align-items: center; padding: 60px 0 30px 0; text-align: center; }
.hero-title { font-family: serif; font-size: clamp(1.3rem, 2vw, 2.5rem); margin-bottom: 20px; letter-spacing: 0.05em; }
.hero-sub { font-family: serif; font-size: 1.2rem; color: var(--accent); letter-spacing: 0.1em; text-transform: uppercase; }

/* 理念・セクション共通 */
.section { padding: 80px 0; }
.bg-black { background: var(--black); color: #fff; }
.section-title { text-align: center; margin-bottom: 60px; font-family: serif; }

.philosophy-content { max-width: 700px; margin: 0 auto; text-align: center; }
.philosophy-text { font-size: 1.1rem; color: var(--accent); line-height: 2.2; }

/* カード・FAQ */
.product-list-vertical { display: flex; flex-direction: column; gap: 30px; max-width: 900px; margin: 0 auto; }
.item-vertical { padding: 80px 60px; border: 1px solid #333; position: relative; z-index: 1; transition: var(--transition); }
.item-vertical::after { position: absolute; right: 40px; bottom: -10px; font-size: 8rem; font-weight: 900; color: rgba(255, 255, 255, 0.15); z-index: 0; line-height: 1; }
.card-a::after { content: "01"; }
.card-b::after { content: "02"; }
.card-c::after { content: "03"; }
.card-text { z-index: 1; position: relative; }

.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { margin-bottom: 30px; border-bottom: 1px solid #eee; padding-bottom: 20px; }
.faq-link { color: var(--black); text-decoration: underline; font-weight: bold; }
.faq-link:hover { color: var(--accent); text-decoration: none; }
.faq-note { font-size: 0.9rem; margin-top: 10px; color: var(--accent); font-style: italic; }

/* ボタン・CTA */
.cta-area { text-align: center; margin: 60px 0; }
.btn-primary { display: inline-block; padding: 18px 40px; background-color: var(--black); color: #fff; text-decoration: none; font-weight: 600; border-radius: 5px; transition: var(--transition); }
.btn-primary:hover { background-color: var(--accent); transform: translateY(-2px); box-shadow: 0 5px 15px rgba(0,0,0,0.2); }
.nav-back-group { display: flex; justify-content: center; margin: 40px 0; }
.btn-back { display: inline-flex; align-items: center; text-decoration: none; padding: 12px 24px; border-radius: 5px; border: 1px solid var(--black); background: var(--black); color: #fff; transition: all 0.3s ease; }
.btn-back:hover { transform: translateY(-3px); box-shadow: 0 5px 10px rgba(0,0,0,0.1); }

.footer { padding: 60px 0; background: var(--black); color: var(--white); text-align: center; }

.price-list {
    list-style: none;
    margin: 20px 0;
    padding: 0;
}

.price-list li {
    margin-bottom: 10px; /* 余白を少し詰める */
    padding: 20px;       /* 内側に余白を作る */
    border: 1px solid #eee; /* 境界線で囲む */
    border-radius: 8px;   /* 角を少し丸くして柔らかく */
}

.plan-header {
    font-weight: bold;
    font-size: 1.1rem;
    margin-bottom: 8px; /* 見出しと説明の距離を適切に */
    color: var(--black);
    line-height: 1.4;
}

.price-list p {
    color: var(--accent);
    margin: 0;
    font-size: 0.95rem;
}

/* レスポンシブ */
@media (max-width: 768px) {
    .nav-list { gap: 15px; }
    .item-vertical { padding: 45px 15px; }
}