/**
 * ConcertOnly 品牌標誌系統 (Brand Identity System)
 * ===========================================
 * 版本：v8 (最終定案 — 極致精細化)
 * 特性：纖細比例、提前隱藏副標、頁尾已獨立為純 CSS 簽名
 */

:root {
    --logo-text: #2A2A2A;
    --logo-muted: #8A867F;
    --logo-ghost: #D2D0CA;
    --logo-accent: #c5a059;
    --logo-ease: cubic-bezier(0.19, 1, 0.22, 1);

    --logo-gap: 12px;
    --logo-en-size: 1.15rem;
    --logo-en-spacing: 5px;
    --logo-cn-size: 0.72rem;
    --logo-cn-spacing: 5px;
}

/* < 768px：隱藏中文副標，精簡間距 */
@media (max-width: 768px) {
    :root {
        --logo-gap: 10px;
        --logo-en-size: 1.15rem;
        --logo-en-spacing: 3px;
    }
    .co-brand-cn {
        display: none !important;
    }
    .co-brand-content {
        justify-content: center;
    }
}

/* ===== Logo 容器 ===== */
.co-brand {
    display: flex;
    align-items: center;
    gap: var(--logo-gap);
    text-decoration: none;
    color: var(--logo-text);
    padding: 6px 10px;
    border-radius: 4px;
    transition: transform 0.6s var(--logo-ease);
}

.co-brand:focus-visible {
    outline: 2px solid var(--logo-accent);
    outline-offset: 8px;
    background: rgba(197, 160, 89, 0.05);
}

/* ===== 音樂小節線標記 ===== */
.co-brand-mark {
    display: flex;
    align-items: center;
    gap: 6px;
    height: 28px;
}
@media (max-width: 768px) {
    .co-brand-mark { height: 28px; gap: 4px; }
}
.co-brand-mark .bar-thin {
    width: 1.5px;
    height: 100%;
    background: var(--logo-ghost);
}
.co-brand-mark .bar-thick {
    width: 2.5px;
    height: 100%;
    background: var(--logo-text);
    transition: background 0.6s var(--logo-ease);
}

/* ===== 文字內容區域 ===== */
.co-brand-content {
    display: flex;
    flex-direction: column;
    text-align: left;
}

/* 英文品牌名 (Playfair Display) */
.co-brand-en {
    font-family: 'Playfair Display', serif;
    font-size: var(--logo-en-size);
    letter-spacing: var(--logo-en-spacing);
    line-height: 1;
    display: flex;
    align-items: baseline;
}
.co-brand-en .concert { font-weight: 400; opacity: 0.7; }
.co-brand-en .only { font-weight: 900; }
.co-brand-en .dot { color: var(--logo-accent); margin-left: 2px; font-weight: 900; }

/* 中文副標題 (Noto Serif TC) */
.co-brand-cn {
    font-family: 'Noto Serif TC', serif;
    font-size: var(--logo-cn-size);
    letter-spacing: var(--logo-cn-spacing);
    color: var(--logo-muted);
    margin-top: 4px;
    font-weight: 400;
    line-height: 1;
}

/* ===== Hover 微位移 ===== */
.co-brand:hover {
    transform: translateX(2px);
}
.co-brand:hover .bar-thick {
    background: var(--logo-accent);
}

/* ===== prefers-reduced-motion ===== */
@media (prefers-reduced-motion: reduce) {
    .co-brand,
    .co-brand-mark .bar-thick {
        transition: none !important;
        transform: none !important;
    }
}