html {
    font-family: Arial, Helvetica, sans-serif;
    color: #1f2933;
    background: #f6f8fa;
}

body {
    margin: 0;
}

.site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem 1.5rem;
    background: #ffffff;
    border-bottom: 1px solid #d8dee4;
}

.brand {
    color: #0f3a5f;
    font-weight: 700;
    text-decoration: none;
}

.site-header nav {
    display: flex;
    align-items: center;
    gap: .75rem;
}

.site-header a {
    color: #0f3a5f;
}

.site-header form {
    margin: 0;
}

.page {
    max-width: 1120px;
    margin: 0 auto;
    padding: 2rem 1.25rem;
}

button,
.button {
    min-height: 44px;
    padding: .65rem 1rem;
    border: 0;
    border-radius: 6px;
    background: #0f6b5f;
    color: #fff;
    font-weight: 700;
    cursor: pointer;
}

button.danger {
    background: #a83232;
}

input,
select,
textarea {
    width: 100%;
    max-width: 36rem;
    min-height: 42px;
    padding: .5rem .65rem;
    border: 1px solid #b7c0ca;
    border-radius: 6px;
    font: inherit;
}

textarea {
    min-height: 8rem;
}

.form-panel {
    display: grid;
    gap: .65rem;
    max-width: 42rem;
}

.library-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}

.library-cards a,
.content-card {
    display: grid;
    gap: .4rem;
    min-height: 96px;
    padding: 1rem;
    border: 1px solid #d8dee4;
    border-radius: 8px;
    background: #fff;
    color: #1f2933;
    text-decoration: none;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1rem;
}

.admin-table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
}

.admin-table th,
.admin-table td {
    padding: .75rem;
    border-bottom: 1px solid #d8dee4;
    text-align: left;
}

.viewer-shell {
    position: relative;
    min-height: 70vh;
    border: 1px solid #d8dee4;
    background: #fff;
}

.viewer-shell iframe,
.viewer-shell video {
    width: 100%;
    min-height: 70vh;
    display: block;
}

.watermark {
    position: absolute;
    z-index: 2;
    top: 1rem;
    right: 1rem;
    padding: .4rem .6rem;
    background: rgba(255, 255, 255, .78);
    color: #3f4652;
    font-size: .9rem;
    pointer-events: none;
}