/* ── 预览区 ── */
.fs-preview {
    text-align: center;
    padding: 2.5rem 1rem;
    border-radius: 10px;
    background: #fafafa;
    border: 1px solid #e8eaf0;
    transition: background 0.3s, color 0.3s;
}

.fs-preview.dark {
    background: #1a1a2e;
    border-color: #2a2a4a;
}

.fs-date {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 0.6rem;
}

.fs-preview.dark .fs-date { color: #aaa; }

.fs-time {
    font-family: 'Fira Code', monospace;
    font-size: 4.5rem;
    font-weight: 700;
    color: #1a1a1a;
    letter-spacing: 2px;
    line-height: 1.2;
}

.fs-preview.dark .fs-time { color: #fff; }

.fs-zone {
    font-size: 0.9rem;
    color: #999;
    margin-top: 0.5rem;
}

.fs-preview.dark .fs-zone { color: #888; }

/* ── 全屏覆盖层 ── */
.fs-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 9999;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: #fff;
    transition: background 0.3s;
    cursor: pointer;
}

.fs-overlay.active {
    display: flex;
}

.fs-overlay.dark {
    background: #0a0a1a;
}

.fs-overlay-date {
    font-size: 2vw;
    color: #666;
    margin-bottom: 1vh;
}

.fs-overlay.dark .fs-overlay-date { color: #aaa; }

.fs-overlay-time {
    font-family: 'Fira Code', monospace;
    font-size: 15vw;
    font-weight: 700;
    color: #1a1a1a;
    letter-spacing: 0.5vw;
    line-height: 1.2;
}

.fs-overlay.dark .fs-overlay-time { color: #fff; }

.fs-overlay-zone {
    font-size: 1.5vw;
    color: #999;
    margin-top: 1vh;
}

.fs-overlay.dark .fs-overlay-zone { color: #888; }

.fs-overlay-hint {
    position: absolute;
    bottom: 3vh;
    font-size: 1vw;
    color: #ccc;
    opacity: 0.6;
}

.fs-overlay.dark .fs-overlay-hint { color: #555; }

/* ── Mobile ── */
@media (max-width: 640px) {
    .fs-time {
        font-size: 3rem;
    }
    .fs-overlay-time {
        font-size: 18vw;
    }
    .fs-overlay-date {
        font-size: 4vw;
    }
    .fs-overlay-zone {
        font-size: 3vw;
    }
    .fs-overlay-hint {
        font-size: 3vw;
    }
}