/* ベースの変数定義 */
:root {
    --primary-color: #3498db;
    --primary-hover: #2980b9;
    --text-main: #1e293b;
    --text-light: #64748b;
    --bg-main: #ffffff;
    --bg-alt: #f8fafc;
}

body { margin: 0; font-family: 'Noto Sans JP', sans-serif; color: var(--text-main); line-height: 1.6; background-color: var(--bg-alt); }
.container { max-width: 1000px; margin: 0 auto; padding: 0 20px; }

/* Header */
.header { padding: 20px 0; background: var(--bg-main); border-bottom: 1px solid #e2e8f0; }
.logo { font-size: 20px; font-weight: 700; margin: 0; }

/* Hero Section */
.hero { padding: 70px 0 60px; text-align: center; background: var(--bg-main); border-bottom: 1px solid #e2e8f0; }
.hero-title { font-size: clamp(28px, 5vw, 42px); font-weight: 900; line-height: 1.3; margin-bottom: 20px; color: #0f172a; }
.hero-subtitle { font-size: 16px; color: var(--text-light); margin-bottom: 35px; max-width: 650px; margin-left: auto; margin-right: auto; }
.hero-cta { display: flex; gap: 15px; justify-content: center; }

/* Buttons */
.btn { display: inline-block; padding: 14px 28px; border-radius: 8px; font-weight: 700; text-decoration: none; transition: all 0.2s ease; }
.btn-primary { background-color: var(--primary-color); color: #ffffff; box-shadow: 0 4px 6px rgba(52, 152, 219, 0.2); }
.btn-primary:hover { background-color: var(--primary-hover); transform: translateY(-2px); }

/* Docs Section (New) */
.docs-section { padding: 60px 0; background: var(--bg-alt); }
.section-title { text-align: center; font-size: 28px; font-weight: 900; margin-bottom: 20px; margin-top: 0;}
.docs-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 20px; }
.doc-card { display: block; background: var(--bg-main); padding: 25px; border-radius: 12px; border: 1px solid #e2e8f0; text-decoration: none; color: var(--text-main); transition: transform 0.2s, box-shadow 0.2s; }
.doc-card:hover { transform: translateY(-3px); box-shadow: 0 8px 20px rgba(0,0,0,0.06); border-color: #cbd5e1; }
.doc-icon { font-size: 32px; margin-bottom: 10px; }
.doc-card h4 { margin: 0 0 10px 0; font-size: 18px; color: #0f172a; border-bottom: 1px dashed #e2e8f0; padding-bottom: 8px; }
.doc-card p { margin: 0; font-size: 14px; color: var(--text-light); }

/* Features Section */
.features { padding: 60px 0; background: var(--bg-main); border-top: 1px solid #e2e8f0; }
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 25px; }
.feature-card { padding: 20px; text-align: center; }
.feature-icon { font-size: 36px; margin-bottom: 15px; }
.feature-card h4 { font-size: 18px; margin: 0 0 10px 0; }
.feature-card p { color: var(--text-light); margin: 0; font-size: 14px; text-align: left; }

/* Footer */
.footer { padding: 30px 0; background: #0f172a; color: #94a3b8; font-size: 14px; }
.footer-content { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 15px; }
.footer-links a { color: #94a3b8; text-decoration: none; margin-left: 20px; }
.footer-links a:hover { color: #ffffff; }

@media (max-width: 768px) {
    .footer-content { flex-direction: column; text-align: center; }
    .footer-links a { margin: 0 10px; }
}