/* ============================================================
   チュートリアル（初回説明）オーバーレイ
   ============================================================ */
#intro-overlay,
#monster-house-intro-overlay {
    z-index: 200;
    background: rgba(5, 10, 30, 0.97);
    align-items: stretch;
    justify-content: flex-start;
}

#app.portrait-mode .intro-content {
    display: flex;
    flex-direction: column;
    height: 100%;
    width: 100%;
    padding: 70px 50px 50px;
    box-sizing: border-box;
}

#app.portrait-mode .intro-scroll-area {
    flex: 1;
    overflow-y: auto;
    padding-right: 10px;
    display: flex;
    flex-direction: column;
    gap: 40px;
}

#app.portrait-mode .intro-title {
    font-family: var(--font-pixel);
    font-size: 48px;
    color: var(--accent-color);
    text-align: center;
    line-height: 1.6;
    margin: 0;
    padding-bottom: 10px;
    border-bottom: 2px solid rgba(80, 110, 210, 0.4);
}

#app.portrait-mode .intro-text {
    font-family: var(--font-pixel);
    font-size: 36px;
    color: #d8e4ff;
    line-height: 1.9;
    margin: 0;
}

#app.portrait-mode .intro-difficulty-list {
    background: rgba(80, 110, 210, 0.1);
    border: 1px solid rgba(80, 110, 210, 0.35);
    border-radius: 12px;
    padding: 30px 36px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

#app.portrait-mode .intro-difficulty-list .intro-text {
    color: #ffe97a;
}

#app.portrait-mode .intro-text-hint {
    color: #ffaaaa;
}

#app.portrait-mode .intro-text-last {
    color: #ffe97a;
    text-align: center;
    font-size: 50px;
}

#app.portrait-mode .intro-start-btn {
    width: 100%;
    font-size: 44px;
    padding: 30px;
    margin-top: 40px;
    flex-shrink: 0;
    background: linear-gradient(180deg, #4facfe 0%, #3399f5 50%, #1580e8 100%);
    border: 2px solid rgba(79, 172, 254, 0.5);
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.1);
    color: #fff;
}

#app.portrait-mode .intro-start-btn:hover {
    filter: brightness(1.1);
    transform: translateY(-2px);
}

#app.portrait-mode .intro-start-btn:active {
    filter: brightness(0.9);
    transform: translateY(2px);
}