html { margin: 0; padding: 0; width: 100%; }
body {
    margin: 0; padding: 0; width: 100%;
    background-color: #F8F7F3; color: #1A1A1A;
    overflow-x: hidden; overscroll-behavior: none;
}

.paper-texture {
    position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
    pointer-events: none; z-index: 50; opacity: 0.015; mix-blend-mode: multiply;
}

.blueprint-bg {
    position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
    pointer-events: none; z-index: 1; opacity: 0; 
    background-image: 
        linear-gradient(rgba(26, 26, 26, 0.1) 1px, transparent 1px),
        linear-gradient(90deg, rgba(26, 26, 26, 0.1) 1px, transparent 1px);
    background-size: 60px 60px; background-position: center center;
    will-change: opacity;
}
.bp-line-h { position: absolute; width: 100%; height: 1px; top: 50%; border-top: 1px dashed rgba(26, 26, 26, 0.2); }
.bp-line-v { position: absolute; height: 100%; width: 1px; left: 50%; border-left: 1px dashed rgba(26, 26, 26, 0.2); }

#canvas-container {
    position: fixed; top: 0; left: 0; width: 100%; height: 100vh;
    z-index: 5; pointer-events: none;
    display: flex; justify-content: center; align-items: center;
}

.content-layer { position: relative; z-index: 20; pointer-events: none; }
.scroll-section {
    height: 100vh; height: 100dvh; display: flex; flex-direction: column;
    justify-content: center; align-items: center;
    position: relative; pointer-events: auto; 
}
#canvas-container { height: 100vh; height: 100dvh; }

.museum-label { background-color: rgba(255, 255, 255, 0.92); backdrop-filter: blur(6px); }
.section-title { letter-spacing: -0.02em; line-height: 1.6 !important; }
.intro-fade { opacity: 0; transform: translateY(20px); }

#pedestal-fader {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(to bottom, transparent 60%, #F8F7F3 90%);
    z-index: 7; opacity: 0; pointer-events: none;
}

/* --- RESPONSIVE: trên điện thoại, chú thích nằm chồng lên cỗ máy nên cần nền mờ để đọc rõ --- */
@media (max-width: 767px) {
    .exhibit-caption {
        background: rgba(244, 247, 248, 0.82);
        backdrop-filter: blur(4px);
        -webkit-backdrop-filter: blur(4px);
        border-radius: 12px;
        padding: 18px 20px;
    }
    .exhibit-caption h2 { font-size: 2.25rem; }
}

/* --- Bài viết dài & module tương tác cờ quốc gia --- */
.article-figure { border: 1px solid #E0E8EA; border-radius: 10px; overflow: hidden; background: #fff; }
.article-figure img { display: block; width: 100%; height: auto; }
.article-figure.archival img { filter: grayscale(15%) sepia(12%) contrast(1.02); }
.article-figure figcaption {
    font-family: 'Inter', sans-serif; font-size: 11px; letter-spacing: .03em;
    color: #757575; padding: 10px 14px; border-top: 1px solid #EDEDED;
}
.stat-card { transition: transform .2s ease, border-color .2s ease; }
.stat-card:hover { transform: translateY(-2px); border-color: #111111; }

.flag-btn {
    display: flex; flex-direction: column; align-items: center; gap: 6px;
    padding: 14px 4px; border-radius: 8px; border: 1px solid #E0E8EA;
    background: #ffffff; cursor: pointer; transition: border-color .2s ease, background-color .2s ease, transform .2s ease;
}
.flag-btn:hover { border-color: #111111; transform: translateY(-2px); }
.flag-btn-active { border-color: #111111; background: #EFEFEF; }
.flag-img { display: block; width: 34px; height: 22px; border-radius: 3px; overflow: hidden; box-shadow: 0 1px 3px rgba(0,0,0,0.12); }
.flag-img svg { display: block; width: 100%; height: 100%; }
@media (max-width: 480px) {
    .flag-btn { padding: 10px 2px; }
    .flag-img { width: 26px; height: 17px; }
    .flag-label { font-size: 8.5px; letter-spacing: .02em; }
}
.flag-label {
    font-family: 'Inter', sans-serif; font-size: 10px; letter-spacing: .04em;
    text-transform: uppercase; color: #757575; text-align: center;
}
#flag-panel-text { transition: opacity .15s ease; }