.jumbotron{
    cursor: pointer;
    width: 10rem; /* 设置宽度为300px */
    height: 10rem; /* 设置高度为300px，与宽度相等，确保为正方形 */
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0; /* 取消默认的内边距 */
}
#recentlyLearning { display: none; }

.continue-learning-card {
    display: block;
    padding: 14px 16px;
    background: #fff;
    border: 1px solid #e9ecef;
    border-radius: 10px;
    text-decoration: none;
    color: inherit;
    transition: transform 0.2s, box-shadow 0.2s;
}
.continue-learning-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    text-decoration: none;
    color: inherit;
}

.continue-learning-header {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    color: #6c757d;
    margin-bottom: 8px;
}

.continue-learning-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.continue-learning-progress {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 6px;
}
.progress-bar-bg {
    flex: 1;
    height: 4px;
    background: #e9ecef;
    border-radius: 2px;
    overflow: hidden;
}
.progress-bar-fill {
    height: 100%;
    background: #4a90d9;
    border-radius: 2px;
    transition: width 0.3s;
}
.progress-bar-fill.completed { background: #28a745; }
.progress-text {
    font-size: 0.75rem;
    color: #6c757d;
    min-width: 32px;
    text-align: right;
}

.continue-learning-time {
    font-size: 0.75rem;
    color: #adb5bd;
}
.jumbotron {
    transition: transform 0.2s, box-shadow 0.2s;
    min-width: 140px;
    max-width: 170px;
}
.jumbotron:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}
#card-container {
    flex-wrap: wrap;
    gap: 20px;
}

/* 学习时长排行榜 */
.leaderboard-card {
    padding: 14px 16px;
    background: #fff;
    border: 1px solid #e9ecef;
    border-radius: 10px;
}
.leaderboard-header {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    color: #6c757d;
    margin-bottom: 10px;
}
.leaderboard-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.leaderboard-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 0;
}
.leaderboard-rank {
    width: 18px;
    font-size: 0.8rem;
    font-weight: 700;
    text-align: center;
    flex-shrink: 0;
}
.leaderboard-rank.rank-1 { color: #f5a623; }
.leaderboard-rank.rank-2 { color: #a0a0a0; }
.leaderboard-rank.rank-3 { color: #cd7f32; }
.leaderboard-avatar {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    object-fit: cover;
    flex-shrink: 0;
    background: #e9ecef;
}
.leaderboard-name {
    flex: 1;
    font-size: 0.8rem;
    color: #333;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.leaderboard-duration {
    font-size: 0.75rem;
    color: #6c757d;
    flex-shrink: 0;
}
.leaderboard-empty {
    font-size: 0.8rem;
    color: #adb5bd;
    text-align: center;
    padding: 8px 0;
}

/* 每日签到卡片（渐变色调） */
.signin-card {
    padding: 14px 16px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 10px;
    color: #fff;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.25);
}
.signin-header {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 10px;
}
.signin-header svg { color: #ffeaa0; }
.signin-days {
    font-size: 0.8rem;
    opacity: 0.95;
    margin-bottom: 10px;
}
.signin-days strong {
    font-size: 1.1rem;
    font-weight: 700;
    color: #ffeaa0;
    margin: 0 2px;
}
.signin-btn {
    width: 100%;
    padding: 5px 10px;
    font-size: 0.78rem;
    font-weight: 700;
    color: #5a3a8f;
    background: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: transform 0.1s, background 0.2s;
}
.signin-btn:hover { background: #f8f5ff; }
.signin-btn:active { transform: translateY(1px); }
.signin-btn:disabled { cursor: not-allowed; transform: none; }
.signin-btn.signed {
    background: rgba(255,255,255,0.2);
    color: rgba(255,255,255,0.8);
    cursor: default;
}
.signin-btn.signed:hover { background: rgba(255,255,255,0.2); }
.signin-hint {
    margin-top: 8px;
    font-size: 0.7rem;
    color: rgba(255,255,255,0.85);
    text-align: center;
    min-height: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 767px) {
    #recentlyLearning { margin-top: 1rem !important; }
    #signInWidget { margin-top: 1rem !important; }
}