/* =============================================================================
 * top_course.css ― 半導体設計民主化シリーズ「扉ページ」専用スタイル
 *
 *   方針：4講座共通の style.css と同じ学術系トークン（配色・角丸・カード）を踏襲し、
 *         扉ページに必要な「ロードマップ図」「シリーズ内ナビ」「講座カード」を追加する。
 *         扉は site root（chip-makers.html）に置くため自己完結（style.css に依存しない）。
 *
 *   参考トークン（講座 style.css と一致させた値）：
 *     primary #1e293b / secondary #2563eb / accent #f1f5f9 / text #334155 / border #e2e8f0
 * ========================================================================== */

:root {
    --primary-color: #1e293b;
    --secondary-color: #2563eb;
    --accent-color: #f1f5f9;
    --text-color: #334155;
    --border-color: #e2e8f0;
    --muted: #64748b;
}

* { box-sizing: border-box; }

body {
    font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    margin: 0;
    padding: 0;
    background-color: #f8fafc;
}

/* ---- ヘッダ（講座と同じグラデーション） ---- */
header {
    background: linear-gradient(135deg, #0f172a, #1e3a8a);
    color: white;
    padding: 3rem 2rem 2.5rem;
    text-align: center;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
}
header h1 { margin: 0; font-size: 2.3rem; font-weight: 700; }
header .subtitle { margin: 0.6rem 0 0; font-size: 1.1rem; color: #93c5fd; }
header .eyebrow {
    display: inline-block; margin-bottom: 0.8rem; padding: 0.2rem 0.9rem;
    border: 1px solid rgba(147,197,253,0.5); border-radius: 9999px;
    font-size: 0.8rem; letter-spacing: 0.08em; color: #bfdbfe;
}

/* ---- シリーズ内ナビ（扉⇔tech-scout⇔各講座の横並びバー） ---- */
.series-nav {
    background: #0f172a;
    border-bottom: 1px solid #1e293b;
    padding: 0.6rem 1rem;
    position: sticky; top: 0; z-index: 50;
}
.series-nav ul {
    list-style: none; margin: 0 auto; padding: 0;
    max-width: 1200px; display: flex; flex-wrap: wrap; gap: 0.4rem 0.6rem; align-items: center;
}
.series-nav li { display: inline-flex; }
.series-nav a {
    display: inline-block; padding: 0.35rem 0.8rem; border-radius: 6px;
    color: #cbd5e1; text-decoration: none; font-size: 0.88rem; font-weight: 600;
    transition: all 0.2s ease;
}
.series-nav a:hover { background: #1e293b; color: #fff; }
.series-nav a.home { color: #93c5fd; }
.series-nav a.current { background: var(--secondary-color); color: #fff; }
.series-nav .sep { color: #334155; padding: 0 0.1rem; }

/* ---- メイン枠 ---- */
.wrap { max-width: 1200px; margin: 0 auto; padding: 2.5rem 2rem; }

.lead {
    font-size: 1.12rem; color: #475569; margin: 0 auto 2.5rem; max-width: 900px;
}
.lead strong { color: var(--primary-color); }

h2 {
    font-size: 1.7rem; color: var(--primary-color);
    border-left: 6px solid var(--secondary-color); padding-left: 1rem;
    margin: 3rem 0 1.5rem;
}
h2:first-of-type { margin-top: 0; }

/* ---- 思い・狙い（強調ボックス） ---- */
.mission {
    background: white; border: 1px solid var(--border-color); border-left: 5px solid var(--secondary-color);
    border-radius: 10px; padding: 1.75rem 2rem; margin: 1.5rem 0;
}
.mission p { margin: 0 0 1rem; }
.mission p:last-child { margin-bottom: 0; }
.mission .flag {
    font-weight: 700; color: var(--secondary-color);
}

/* ---- 5ステップ・ロードマップ ---- */
.roadmap {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
    gap: 1rem; margin: 1.5rem 0 0.5rem;
}
.step {
    position: relative; background: white; border: 1px solid var(--border-color);
    border-radius: 12px; padding: 1.4rem 1.25rem; display: flex; flex-direction: column;
}
.step .num {
    width: 2.2rem; height: 2.2rem; border-radius: 9999px;
    background: var(--secondary-color); color: #fff; font-weight: 700;
    display: flex; align-items: center; justify-content: center; margin-bottom: 0.8rem;
    font-size: 1.05rem;
}
.step h4 { margin: 0 0 0.5rem; font-size: 1.05rem; color: var(--primary-color); }
.step p { margin: 0; font-size: 0.9rem; color: var(--muted); }
.step .maps {
    margin-top: 0.9rem; padding-top: 0.7rem; border-top: 1px dashed var(--border-color);
    font-size: 0.82rem; color: var(--secondary-color); font-weight: 700;
}
.roadmap-note { font-size: 0.92rem; color: var(--muted); margin: 0.75rem 0 0; }

/* ---- 4講座カード ---- */
.course-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(420px, 1fr));
    gap: 1.75rem; margin-top: 1.5rem;
}
.course-card {
    background: white; border: 1px solid var(--border-color); border-radius: 14px;
    padding: 1.9rem; display: flex; flex-direction: column; align-items: flex-start;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.02);
    transition: transform 0.2s ease, box-shadow 0.2s ease; position: relative;
}
.course-card:hover { transform: translateY(-3px); box-shadow: 0 12px 20px -6px rgba(0,0,0,0.08); }
.course-card .layer {
    font-size: 0.78rem; font-weight: 700; letter-spacing: 0.05em;
    color: var(--secondary-color); margin-bottom: 0.5rem;
}
.course-card h3 { margin: 0 0 0.6rem; font-size: 1.3rem; color: var(--primary-color); line-height: 1.4; }
.course-card p { margin: 0 0 1.2rem; color: var(--muted); font-size: 0.95rem; flex-grow: 1; }
.course-card .tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1.3rem; }
.course-card .tag {
    background: var(--accent-color); color: #475569; border-radius: 9999px;
    padding: 0.2rem 0.7rem; font-size: 0.78rem; font-weight: 600;
}
.course-card .actions { display: flex; align-items: center; gap: 0.8rem; flex-wrap: wrap; }

/* バッジ（講座 style.css と同一） */
.badge {
    display: inline-block; padding: 0.25rem 0.75rem; border-radius: 9999px;
    font-size: 0.8rem; font-weight: bold;
}
.badge-info { background-color: #e0f2fe; color: #0369a1; }
.badge-success { background-color: #dcfce7; color: #15803d; }
.badge-warning { background-color: #fef9c3; color: #a16207; }
.badge-danger { background-color: #fee2e2; color: #b91c1c; }
.badge-secondary { background-color: #f1f5f9; color: #475569; }

.btn-enter {
    background-color: var(--secondary-color); color: white; text-decoration: none;
    padding: 0.7rem 1.4rem; border-radius: 6px; font-weight: bold; font-size: 0.92rem;
    transition: background-color 0.2s ease;
}
.btn-enter:hover { background-color: #1d4ed8; }

/* 並び順を示す通し番号 */
.course-card .order {
    position: absolute; top: 1.2rem; right: 1.4rem;
    font-size: 0.8rem; color: #cbd5e1; font-weight: 700;
}

footer {
    text-align: center; padding: 2rem; background-color: var(--primary-color);
    color: #94a3b8; font-size: 0.9rem; margin-top: 3rem;
}
footer a { color: #93c5fd; text-decoration: none; }
footer a:hover { text-decoration: underline; }

@media (max-width: 900px) {
    .course-grid { grid-template-columns: 1fr; }
    .course-grid { gap: 1.25rem; }
}

/* ---- 読み物コーナーへの誘導（扉トップの「まず世界を読む」ブロック） ---- */
.read-first {
    background: linear-gradient(135deg, #0f172a, #1e3a8a);
    color: #fff; border-radius: 14px; padding: 1.9rem 2rem; margin: 0 0 2.5rem;
    display: flex; gap: 1.5rem; align-items: center; flex-wrap: wrap;
    box-shadow: 0 8px 20px -8px rgba(15,23,42,0.35);
}
.read-first .rf-body { flex: 1 1 380px; }
.read-first .rf-eyebrow {
    display: inline-block; margin-bottom: 0.6rem; padding: 0.2rem 0.85rem;
    border: 1px solid rgba(147,197,253,0.5); border-radius: 9999px;
    font-size: 0.78rem; letter-spacing: 0.06em; color: #bfdbfe;
}
.read-first h3 { margin: 0.2rem 0 0.5rem; font-size: 1.4rem; color: #fff; line-height: 1.4; }
.read-first p { margin: 0; color: #cbd5e1; font-size: 0.97rem; }
.read-first .rf-action { flex: 0 0 auto; }
.read-first .rf-btn {
    display: inline-block; background: #fff; color: #1e3a8a !important; font-weight: 700;
    padding: 0.8rem 1.6rem; border-radius: 8px; text-decoration: none; white-space: nowrap;
    transition: transform 0.2s ease;
}
.read-first .rf-btn:hover { transform: translateY(-2px); }

@media (max-width: 640px) {
    .read-first { padding: 1.5rem; }
    .read-first .rf-action { flex-basis: 100%; }
    .read-first .rf-btn { display: block; text-align: center; }
}