.cover {
    position: absolute;
    inset: 0;
    overflow: hidden;
    background: #000;
}

.cover[hidden] {
    display: none;
}

.cover-image {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.cover-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    padding: clamp(24px, 6vw, 72px);
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.55) 0%, rgba(0, 0, 0, 0.15) 40%, rgba(0, 0, 0, 0.55) 100%);
    color: #fff;
}

.cover-titles {
    max-width: 640px;
}

.cover-title {
    margin: 0;
    font-family: var(--theme-font-serif);
    font-size: clamp(28px, 5vw, 56px);
    line-height: 1.1;
    text-shadow: 0 2px 18px rgba(0, 0, 0, 0.6);
}

.cover-subtitle {
    margin: 16px 0 0;
    font-family: var(--theme-font-sans);
    font-size: clamp(15px, 2vw, 21px);
    font-weight: 400;
    opacity: 0.92;
    text-shadow: 0 1px 10px rgba(0, 0, 0, 0.6);
}

.cover-author {
    margin: 20px 0 0;
    font-family: var(--theme-font-sans);
    font-size: clamp(14px, 1.6vw, 18px);
    opacity: 0.85;
}

.cover-open {
    margin-top: 28px;
    padding: 12px 26px;
    font-family: var(--theme-font-sans);
    font-size: var(--theme-font-md);
    font-weight: 600;
    color: #111;
    background: #fff;
    border: none;
    border-radius: var(--theme-radius-full);
    cursor: pointer;
    box-shadow: var(--theme-shadow-md);
    transition: transform 150ms ease;
}

.cover-open:hover {
    transform: translateY(-1px);
}

.cover-foot {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: clamp(20px, 4vw, 40px);
}

.cover-logo {
    height: clamp(34px, 5vw, 56px);
    width: auto;
    filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.5));
}