body {
    background: linear-gradient(90deg, rgba(54, 188, 221, 0.583) 0%, rgba(98, 135, 202, 0.46) 50%, rgba(26, 72, 158, 0.647) 100%), url('../img/home/bgt.png');
    background-size: 100%;
    background-repeat: repeat;
    background-position: top center;
    background-attachment: fixed;
    color: #000;
}

.collaboration-upload-panel {
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: 18px;
    padding: 1.5rem;
    box-shadow: 0 12px 30px rgba(15, 70, 120, 0.08);
    margin-bottom: 2rem;
}

.collaboration-upload-panel h2 {
    margin-bottom: 1rem;
    font-size: clamp(1.2rem, 2vw, 1.7rem);
}

.collaboration-upload-panel label {
    display: block;
    margin-bottom: 0.45rem;
    font-weight: 600;
    color: #194d8a;
}

.collaboration-upload-panel input,
.collaboration-upload-panel textarea {
    width: 100%;
    border: 1px solid #c5d9f0;
    border-radius: 10px;
    padding: 0.7rem 0.8rem;
    background: #f9fbff;
}

.collaboration-upload-hint {
    display: block;
    margin-top: 0.4rem;
    color: #496787;
}

.collaboration-upload-panel textarea {
    resize: vertical;
    min-height: 125px;
}

.collaboration-form-actions {
    margin-top: 1rem;
    display: flex;
    justify-content: flex-end;
}

.primary-button,
.secondary-button,
.collaboration-comment-form button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.6rem 1.1rem;
    border-radius: 999px;
    text-decoration: none;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.primary-button,
.collaboration-comment-form button {
    border: none;
    background: linear-gradient(135deg, #1a5eaf, #2a7ad6);
    color: white;
    box-shadow: 0 10px 20px rgba(30, 95, 172, 0.18);
}

.secondary-button {
    border: 1px solid rgba(26, 94, 175, 0.2);
    background: linear-gradient(135deg, #edf6ff, #dfeeff);
    color: #173d70;
}

.primary-button:hover,
.secondary-button:hover,
.collaboration-comment-form button:hover {
    transform: translateY(-1px);
}

.collaboration-status {
    min-height: 1.5rem;
    margin-top: 1rem;
    color: #1a4d89;
    font-weight: 600;
}

.collaboration-status.error {
    color: #a52d2d;
}

.collaboration-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.collaboration-card {
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: 18px;
    padding: 1rem;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
}

.collaboration-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    margin-bottom: 0.85rem;
}

.collaboration-header h3 {
    margin: 0;
    font-size: 1.15rem;
}

.collaboration-type {
    display: inline-flex;
    padding: 0.28rem 0.6rem;
    border-radius: 999px;
    background: #e8f1ff;
    color: #1d4d87;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
}

.collaboration-preview {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-height: 220px;
    border-radius: 12px;
    background: linear-gradient(135deg, #f4f9ff, #edf4ff);
    border: 1px solid rgba(26, 94, 175, 0.1);
    margin-bottom: 1rem;
    overflow: hidden;
}

.collaboration-preview img,
.collaboration-preview video,
.collaboration-preview audio {
    display: block;
    max-width: 100%;
    max-height: 350px;
}

.collaboration-preview img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.collaboration-document-icon {
    font-size: 3rem;
    margin-bottom: 0.25rem;
}

.collaboration-document-label {
    text-align: center;
    font-weight: 600;
    color: #1d4d87;
}

.collaboration-description {
    margin: 0.5rem 0 0.75rem;
    color: #2a3a4e;
    line-height: 1.5;
}

.collaboration-meta {
    color: #496787;
    font-size: 0.85rem;
    margin-bottom: 0.85rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem 0.75rem;
}

.collaboration-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.collaboration-comments {
    border-top: 1px solid #dfeaf8;
    padding-top: 0.85rem;
}

.collaboration-comments summary {
    cursor: pointer;
    list-style: none;
    font-weight: 700;
    color: #1a4b8d;
}

.collaboration-comments summary::-webkit-details-marker {
    display: none;
}

.collaboration-comments-body {
    margin-top: 0.75rem;
}

.collaboration-comment-list {
    list-style: none;
    padding: 0;
    margin: 0 0 0.75rem;
}

.collaboration-comment-list li {
    background: #f4f8fd;
    border-radius: 10px;
    padding: 0.7rem 0.8rem;
    margin-bottom: 0.5rem;
    color: #1f2c3d;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.collaboration-comment-date {
    color: #5e738d;
    font-size: 0.75rem;
}

.collaboration-empty-comments {
    margin: 0 0 0.75rem;
    color: #5e738d;
}

.collaboration-comment-form {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.collaboration-comment-form textarea {
    width: 100%;
    min-height: 90px;
    resize: vertical;
    border: 1px solid #bfd7ef;
    border-radius: 10px;
    padding: 0.65rem;
}

.collaboration-empty-state {
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: 18px;
    padding: 2rem;
    text-align: center;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.06);
}

.collaboration-empty-state.error-state {
    border-color: rgba(165, 45, 45, 0.25);
}

@media (max-width: 640px) {
    .collaboration-upload-panel {
        padding: 1rem;
    }

    .collaboration-actions {
        flex-direction: column;
    }

    .collaboration-header {
        align-items: flex-start;
        flex-direction: column;
    }

    .primary-button,
    .secondary-button,
    .collaboration-comment-form button {
        width: 100%;
    }
}