/* ============================================
   小悟学伴 - 挑战赛 & 上传页样式
   ============================================ */

/* === 挑战赛大厅 === */
.challenge-page {
    min-height: calc(100vh - 60px);
    background: #f8fafc;
    padding: 40px 24px;
}

.challenge-container {
    max-width: 960px;
    margin: 0 auto;
}

.challenge-page-header {
    text-align: center;
    margin-bottom: 36px;
}

.challenge-page-header h1 {
    font-size: 2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #f59e0b, #f97316, #ef4444);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
}

.challenge-page-header p {
    color: #64748b;
    font-size: 1rem;
}

/* 筛选按钮 */
.challenge-filters {
    display: flex;
    gap: 10px;
    margin-bottom: 24px;
    justify-content: center;
}

.filter-btn {
    padding: 8px 24px;
    border: 1px solid #e2e8f0;
    border-radius: 20px;
    background: #fff;
    color: #475569;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.filter-btn:hover { border-color: #f59e0b; color: #f59e0b; }

.filter-btn.active {
    background: linear-gradient(135deg, #f59e0b, #f97316);
    color: #fff;
    border-color: transparent;
}

/* 挑战赛卡片 */
.challenge-grid {
    display: grid;
    gap: 20px;
}

.challenge-card {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 16px;
    display: flex;
    gap: 28px;
    padding: 24px;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
    overflow: hidden;
}

.challenge-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #f59e0b, #f97316, #ef4444);
    transform: scaleX(0);
    transition: transform 0.3s;
}

.challenge-card:hover {
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    transform: translateY(-3px);
    border-color: #fcd34d;
}

.challenge-card:hover::before { transform: scaleX(1); }

/* 封面图 — 列表 4:3 裁切统一 */
.challenge-card-cover {
    width: 240px;
    aspect-ratio: 4 / 3;
    min-width: 240px;
    border-radius: 10px;
    overflow: hidden;
    flex-shrink: 0;
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
}
.challenge-card-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.challenge-card-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-width: 0;
}

.challenge-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 8px;
}

.challenge-card-header h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: #1e293b;
    flex: 1;
    margin-right: 12px;
}

.challenge-card-meta {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    font-size: 0.85rem;
    color: #64748b;
}

.challenge-card-meta span {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.challenge-card-footer {
    margin-top: auto;
    padding-top: 14px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.85rem;
}

/* === 挑战赛详情 === */
.challenge-detail {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 16px;
    padding: 32px;
    margin: 20px 0;
}

.challenge-detail-cover {
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 24px;
}
.challenge-detail-cover img {
    max-width: 100%;
    max-height: 400px;
    display: block;
    margin: 0 auto;
    border-radius: 12px;
    object-fit: scale-down;
}

.challenge-detail h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 16px;
}

.challenge-detail .challenge-meta-row {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    margin-bottom: 20px;
    padding-bottom: 20px;
    border-bottom: 1px solid #f1f5f9;
}

.challenge-detail .meta-item {
    display: flex;
    flex-direction: column;
}

.challenge-detail .meta-label {
    font-size: 0.8rem;
    color: #94a3b8;
    margin-bottom: 4px;
}

.challenge-detail .meta-value {
    font-size: 0.95rem;
    font-weight: 600;
    color: #1e293b;
}

.challenge-description {
    white-space: pre-wrap;
    font-size: 0.95rem;
    color: #475569;
    line-height: 1.8;
}

.challenge-detail-actions {
    margin-top: 24px;
    padding-top: 20px;
    border-top: 1px solid #f1f5f9;
    display: flex;
    gap: 12px;
}

/* === 作品展示区 === */
.submissions-section {
    margin-top: 32px;
}

.submissions-section h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 16px;
}

.submissions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.submission-card {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.2s;
}

.submission-card:hover {
    box-shadow: 0 4px 16px rgba(0,0,0,0.06);
    transform: translateY(-2px);
}

.submission-card-thumb {
    aspect-ratio: 3 / 2;
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    overflow: hidden;
}

.submission-card-thumb img,
.submission-card-thumb video {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.submission-card-thumb .thumb-placeholder {
    font-size: 2.5rem;
    opacity: 0.6;
}

.submission-card-body {
    padding: 12px 14px;
}

.submission-card-body h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: #1e293b;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.submission-card-featured {
    font-size: 0.7rem;
    color: #f59e0b;
    margin-top: 4px;
}

/* === 上传页 === */
.upload-page {
    min-height: calc(100vh - 60px);
    background: #f8fafc;
    padding: 40px 24px;
}

.upload-container {
    max-width: 680px;
    margin: 0 auto;
}

.upload-form {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 16px;
    padding: 32px;
}

/* 拖拽上传区 */
.upload-dropzone {
    border: 2px dashed #cbd5e1;
    border-radius: 14px;
    padding: 48px 24px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    background: #f8fafc;
}

.upload-dropzone:hover,
.upload-dropzone.drag-over {
    border-color: #f59e0b;
    background: #fffbeb;
}

.upload-dropzone-content {
    pointer-events: none;
}

.upload-icon {
    font-size: 3rem;
    margin-bottom: 12px;
}

.upload-dropzone-content p {
    font-size: 1rem;
    color: #475569;
    margin-bottom: 8px;
}

.upload-hint {
    font-size: 0.8rem;
    color: #94a3b8;
}

/* 文件预览 */
.file-preview {
    margin-top: 16px;
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 16px;
}

.file-preview-item {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 10px;
}

.file-preview-name {
    font-size: 0.9rem;
    font-weight: 500;
    color: #1e293b;
    flex: 1;
}

.file-preview-size {
    font-size: 0.8rem;
    color: #94a3b8;
}

.file-preview-thumb {
    padding: 10px;
    background: #fff;
    border-radius: 8px;
    text-align: center;
}

.file-preview-thumb img,
.file-preview-thumb video {
    max-width: 100%;
    max-height: 200px;
    border-radius: 4px;
}

/* 上传进度条 */
.upload-progress {
    margin-top: 16px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.progress-bar {
    flex: 1;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #f59e0b, #f97316);
    border-radius: 4px;
    transition: width 0.3s;
    width: 0%;
}

.progress-text {
    font-size: 0.85rem;
    font-weight: 600;
    color: #f59e0b;
    min-width: 40px;
    text-align: right;
}

/* === 精选轮播 === */
.featured-carousel-wrap {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    user-select: none;
    -webkit-user-select: none;
}
.featured-carousel-wrap::-webkit-scrollbar { display: none; }
.featured-carousel-wrap img { pointer-events: none; }
.featured-carousel {
    display: flex;
    gap: 16px;
    width: max-content;
    padding-bottom: 4px;
    align-items: stretch;
}
.featured-carousel .submission-wall-card {
    flex: 0 0 280px;
    display: flex;
    flex-direction: column;
    scroll-snap-align: start;
}
.featured-carousel .submission-wall-thumb { flex-shrink: 0; }
.featured-carousel .submission-wall-body { flex: 1; display: flex; flex-direction: column; }
.featured-carousel .submission-wall-meta { margin-top: auto; }

/* === 作品墙 === */
.submissions-wall {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.submission-wall-card {
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.2s;
}

.submission-wall-card:hover {
    box-shadow: 0 4px 16px rgba(0,0,0,0.06);
    transform: translateY(-2px);
}

.submission-wall-thumb {
    aspect-ratio: 3 / 2;
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    cursor: pointer;
}

.submission-wall-thumb img,
.submission-wall-thumb video {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.submission-wall-thumb .thumb-placeholder {
    font-size: 2.5rem;
    opacity: 0.6;
}

.submission-wall-body {
    padding: 12px 14px;
}

.submission-wall-body h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: #1e293b;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-bottom: 8px;
}

.submission-user-row {
    display: flex;
    align-items: center;
    gap: 6px;
    text-decoration: none;
    margin-bottom: 8px;
    cursor: pointer;
    width: fit-content;
}
.submission-user-row:hover .submission-user-name {
    color: #0ea5e9;
}
.submission-user-avatar {
    width: 22px;
    height: 22px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
}
.submission-user-name {
    font-size: 0.75rem;
    color: #64748b;
    transition: color 0.15s;
}

.submission-wall-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.submission-wall-badge {
    font-size: 0.7rem;
    color: #f59e0b;
    font-weight: 600;
    white-space: nowrap;
}

.submission-like-btn {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border: 1px solid #e2e8f0;
    border-radius: 16px;
    background: #fff;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.8rem;
    color: #94a3b8;
    transition: all 0.15s;
    white-space: nowrap;
    margin-left: auto;
}

.submission-like-btn:hover {
    border-color: #fca5a5;
    color: #ef4444;
    background: #fef2f2;
}

.submission-like-btn.liked {
    border-color: #fecaca;
    color: #ef4444;
    background: #fef2f2;
}

.submission-like-btn .like-icon {
    font-size: 0.85rem;
}

.submission-like-btn .like-count {
    font-weight: 600;
}

/* 响应式 */
@media (max-width: 768px) {
    .featured-carousel .submission-wall-card { flex: 0 0 240px; }
    .submissions-wall { grid-template-columns: 1fr; }
    .submission-like-btn { padding: 8px 14px; font-size: 0.85rem; }
    .submission-user-name { font-size: 0.8rem; }
    .submission-wall-body { padding: 10px 12px; }
    .submission-wall-body h4 { font-size: 0.85rem; }
    .featured-carousel-wrap { overflow-x: auto; }
}
@media (max-width: 768px) {
    .challenge-card {
        flex-direction: column;
        gap: 16px;
        padding: 16px;
    }
    .challenge-card-cover {
        width: 100%;
        min-width: 0;
        aspect-ratio: 4 / 3;
    }
    .challenge-card-meta { flex-direction: column; gap: 8px; }
    .challenge-detail .challenge-meta-row { flex-direction: column; gap: 12px; }
    .submissions-grid { grid-template-columns: 1fr; }
    .upload-form { padding: 20px; }
}