/* ============================================================
   戦国大戦術：ゲーム配布掲示板ヘッダー / V1.5
   - PC: 左ロゴ + 右説明の横長・省スペース構成
   - Mobile: 上下配置
   ============================================================ */

.sd-board-header {
    --sdbh-ink: #17191b;
    --sdbh-ink-soft: #2c2d2d;
    --sdbh-paper: #f6efe1;
    --sdbh-paper-2: #fffdf8;
    --sdbh-gold: #b88a36;
    --sdbh-gold-soft: #d5b66f;
    --sdbh-border: #92713a;
    --sdbh-muted: #68645d;

    position: relative;
    width: min(1000px, 100%);
    margin: 0 auto 24px;
    overflow: hidden;
    border: 1px solid var(--sdbh-border);
    border-radius: 8px;
    background: var(--sdbh-paper-2);
    box-shadow: 0 7px 22px rgba(20,20,18,.10);
    color: var(--sdbh-ink);
}

.sd-board-header::before {
    content: "";
    display: block;
    height: 4px;
    background: linear-gradient(90deg, var(--sdbh-ink) 0 18%, var(--sdbh-gold) 18% 82%, var(--sdbh-ink) 82% 100%);
}

.sd-board-header__main {
    display: grid;
    grid-template-columns: minmax(260px, 38%) minmax(0, 1fr);
    align-items: center;
    min-height: 170px;
    background:
        linear-gradient(120deg, rgba(255,255,255,.76), transparent 58%),
        var(--sdbh-paper);
}

.sd-board-header__visual {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    min-width: 0;
    padding: 24px 18px 24px 30px;
}

.sd-board-header__image {
    display: block;
    width: 100%;
    max-width: 340px;
    height: auto;
    object-fit: contain;
    object-position: left center;
}

.sd-board-header__body {
    min-width: 0;
    padding: 25px 34px 25px 28px;
    border-left: 1px solid rgba(146,113,58,.25);
}

.sd-board-header__eyebrow {
    margin: 0 0 10px;
    color: #4f3b1e;
    font-family: "Yu Mincho", "Hiragino Mincho ProN", "Hiragino Mincho Pro", serif;
    font-size: 1rem;
    font-weight: 700;
    line-height: 1.55;
    letter-spacing: .07em;
}

.sd-board-header__description {
    margin: 0;
    color: var(--sdbh-ink-soft);
    font-size: .92rem;
    line-height: 1.85;
}

.sd-board-header__guide {
    padding: 11px 24px 12px;
    border-top: 1px solid rgba(146,113,58,.28);
    background: rgba(255,253,248,.88);
}

.sd-board-header__note {
    margin: 0;
    color: var(--sdbh-muted);
    font-size: .76rem;
    line-height: 1.65;
}

.sd-board-header__sr-only {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0,0,0,0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

@media (max-width: 760px) {
    .sd-board-header { margin-bottom: 19px; border-radius: 6px; }
    .sd-board-header__main { grid-template-columns: minmax(210px, 34%) minmax(0,1fr); min-height: 145px; }
    .sd-board-header__visual { padding: 20px 14px 20px 20px; }
    .sd-board-header__image { max-width: 285px; }
    .sd-board-header__body { padding: 21px 21px 21px 20px; }
    .sd-board-header__eyebrow { margin-bottom: 7px; font-size: .91rem; }
    .sd-board-header__description { font-size: .84rem; line-height: 1.72; }
    .sd-board-header__guide { padding: 10px 17px 11px; }
}

@media (max-width: 560px) {
    .sd-board-header { margin-bottom: 16px; border-radius: 4px; }
    .sd-board-header::before { height: 3px; }
    .sd-board-header__main { display: block; min-height: 0; }
    .sd-board-header__visual { justify-content: center; padding: 16px 18px 10px; }
    .sd-board-header__image { width: min(92%, 330px); max-width: 330px; object-position: center; }
    .sd-board-header__body { padding: 12px 15px 15px; border-left: 0; border-top: 1px solid rgba(146,113,58,.22); text-align: left; }
    .sd-board-header__eyebrow { margin-bottom: 6px; font-size: .88rem; letter-spacing: .04em; }
    .sd-board-header__description { font-size: .8rem; line-height: 1.68; }
    .sd-board-header__guide { padding: 9px 14px 10px; }
    .sd-board-header__note { font-size: .72rem; line-height: 1.58; }
}