/* 模块四：活动模块
   ========================================
   学术交流平台 - 活动模块样式
   设计风格：与首页一致的典雅质朴
   ======================================== */

/* ===== 筛选栏 ===== */
.activity-filter-section {
    background: var(--color-white);
    padding: 0 0 20px;
    border-bottom: 1px solid var(--color-border);
}

/* ===== 活动列表区域 ===== */
.activity-list-section {
    padding: 30px 0 60px;
    background: var(--color-primary-light);
}

.activity-list-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
    padding: 0 4px;
}

.activity-list-count {
    font-size: 14px;
    color: var(--color-text-light);
}

.activity-list-count strong {
    color: var(--color-accent-red);
    font-size: 16px;
}

/* ===== 活动卡片 ===== */
.activity-card {
    display: flex;
    background: var(--color-white);
    border-radius: 6px;
    border: 1px solid var(--color-border);
    margin-bottom: 20px;
    overflow: hidden;
    transition: all 0.3s ease;
}

.activity-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(61, 52, 39, 0.12);
    border-color: var(--color-primary-dark);
}

.activity-card-img {
    width: 280px;
    flex-shrink: 0;
    position: relative;
    overflow: hidden;
}

.activity-card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.activity-card:hover .activity-card-img img {
    transform: scale(1.08);
}

/* 活动状态标识 */
.activity-status {
    position: absolute;
    top: 12px;
    left: 12px;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    padding: 3px 12px;
    border-radius: 2px;
    font-weight: 600;
    letter-spacing: 1px;
}

.activity-status--ongoing {
    background: #27AE60;
    color: #FFFFFF;
}

.activity-status--upcoming {
    background: #F39C12;
    color: #FFFFFF;
}

.activity-status--ended {
    background: rgba(61, 52, 39, 0.6);
    color: #FFFFFF;
}

.activity-card-body {
    flex: 1;
    padding: 20px 24px;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.activity-card-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
}

.activity-card-date {
    font-size: 12px;
    color: var(--color-text-light);
}

.activity-card-date i {
    margin-right: 4px;
}

/* 活动类型标签 */
.activity-tag {
    display: inline-block;
    font-size: 11px;
    padding: 2px 10px;
    border-radius: 2px;
    font-weight: 600;
    letter-spacing: 1px;
}

.activity-tag--conference {
    background-color: var(--color-primary);
    color: var(--color-dark);
}

.activity-tag--lecture {
    background-color: #5B8C5A;
    color: #FFFFFF;
}

.activity-tag--exchange {
    background-color: #7B6BA5;
    color: #FFFFFF;
}

.activity-tag--competition {
    background-color: var(--color-accent-red);
    color: #FFFFFF;
}

.activity-tag--fieldwork {
    background-color: var(--color-brown-medium);
    color: #FFFFFF;
}

.activity-card-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-dark);
    line-height: 1.5;
    margin: 0 0 10px;
    letter-spacing: 0.5px;
}

.activity-card-title a {
    color: inherit;
    transition: color 0.3s ease;
}

.activity-card-title a:hover {
    color: var(--color-primary-dark);
}

.activity-card-info {
    display: flex;
    align-items: center;
    gap: 18px;
    font-size: 13px;
    color: var(--color-text-light);
    margin-bottom: 10px;
}

.activity-card-info i {
    margin-right: 4px;
    color: var(--color-primary-dark);
}

.activity-card-desc {
    font-size: 13px;
    color: var(--color-text-light);
    line-height: 1.8;
    flex: 1;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin: 0 0 14px;
}

.activity-card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 14px;
    border-top: 1px solid var(--color-border);
    flex-wrap: wrap;
    gap: 10px;
}

.activity-card-stats {
    display: flex;
    gap: 16px;
    font-size: 12px;
    color: var(--color-text-light);
}

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

.activity-card-stats i {
    font-size: 11px;
}

.activity-card-stats strong {
    color: var(--color-primary-dark);
}

.activity-card-deadline {
    font-size: 12px;
    color: var(--color-accent-red);
}

.activity-card-deadline i {
    margin-right: 4px;
}

/* 活动卡片操作按钮 */
.activity-card-btn {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: 13px;
    font-weight: 600;
    padding: 6px 20px;
    border-radius: 4px;
    transition: all 0.3s ease;
    letter-spacing: 0.5px;
}

.activity-card-btn--ongoing,
.activity-card-btn--upcoming {
    background: linear-gradient(135deg, var(--color-brown), var(--color-primary-dark));
    color: #FFFFFF;
}

.activity-card-btn--ongoing:hover,
.activity-card-btn--upcoming:hover {
    background: linear-gradient(135deg, var(--color-dark), var(--color-brown));
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(61, 52, 39, 0.3);
}

.activity-card-btn--ended {
    background: var(--color-primary-light);
    color: var(--color-brown);
    border: 1px solid var(--color-border);
}

.activity-card-btn--ended:hover {
    background: var(--color-primary);
    color: var(--color-dark);
    border-color: var(--color-primary-dark);
}

/* ===== 详情页样式 ===== */

/* 详情页 Banner */
.activity-detail-banner {
    position: relative;
    height: 240px;
    margin-top: 60px;
    overflow: hidden;
}

.activity-detail-banner > img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.activity-detail-banner-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        135deg,
        rgba(61, 52, 39, 0.8) 0%,
        rgba(91, 74, 63, 0.65) 50%,
        rgba(139, 115, 85, 0.4) 100%
    );
}

.activity-detail-banner-content {
    position: relative;
    z-index: 2;
    padding: 60px 0 0;
}

.activity-detail-banner-content .activity-status {
    position: static;
    margin-bottom: 14px;
}

.activity-detail-banner-content h1 {
    font-size: 30px;
    font-weight: 700;
    color: #FFFFFF;
    letter-spacing: 2px;
    margin: 0;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

/* 详情内容区域 */
.activity-detail-section {
    padding: 24px 0 60px;
    background: var(--color-primary-light);
}

/* 活动信息卡片 */
.activity-detail-card {
    background: var(--color-white);
    border-radius: 6px;
    border: 1px solid var(--color-border);
    padding: 24px 28px;
    margin-bottom: 20px;
}

.activity-info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.info-value--highlight {
    color: var(--color-accent-red);
}


/* Tab 导航 */
.activity-detail-tabs {
    background: var(--color-white);
    border-radius: 6px 6px 0 0;
    border: 1px solid var(--color-border);
    border-bottom: none;
    margin-bottom: 0;
}

.activity-detail-tabs .nav-tabs {
    border-bottom: none;
    padding: 0 10px;
}

.activity-detail-tabs .nav-tabs > li > a {
    color: var(--color-text-light);
    font-size: 14px;
    font-weight: 500;
    padding: 16px 22px;
    border: none;
    border-bottom: 2px solid transparent;
    transition: all 0.3s ease;
    letter-spacing: 0.5px;
}

.activity-detail-tabs .nav-tabs > li > a:hover {
    color: var(--color-dark);
    background: var(--color-primary-light);
    border-bottom-color: var(--color-primary-dark);
}

.activity-detail-tabs .nav-tabs > li > a i {
    margin-right: 6px;
}

.activity-detail-tabs .nav-tabs > li.active > a,
.activity-detail-tabs .nav-tabs > li.active > a:hover,
.activity-detail-tabs .nav-tabs > li.active > a:focus {
    color: var(--color-dark);
    background: none;
    border: none;
    border-bottom: 2px solid var(--color-primary-dark);
    font-weight: 600;
}

/* Tab 内容 */
.activity-tab-content {
    background: var(--color-white);
    border-radius: 0 0 6px 6px;
    border: 1px solid var(--color-border);
    border-top: none;
    padding: 30px 36px;
    margin-bottom: 20px;
}

/* 活动介绍 - 富文本内容 */
.rich-text-content h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-dark);
    margin: 28px 0 14px;
    padding-left: 14px;
    border-left: 3px solid var(--color-primary-dark);
}

.rich-text-content h3:first-child {
    margin-top: 0;
}

.rich-text-content p {
    font-size: 14px;
    line-height: 2;
    color: var(--color-text);
    margin-bottom: 14px;
}

.rich-text-content ul,
.rich-text-content ol {
    padding-left: 3em;
    margin-bottom: 14px;
}

.rich-text-content li {
    font-size: 14px;
    line-height: 2;
    color: var(--color-text);
}

/* ===== 报名表单 ===== */
.signup-notice {
    display: flex;
    gap: 12px;
    padding: 16px 20px;
    background: var(--color-primary-light);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    margin-bottom: 28px;
    font-size: 13px;
    color: var(--color-text);
    line-height: 1.7;
}

.signup-notice > i {
    font-size: 18px;
    color: var(--color-primary-dark);
    flex-shrink: 0;
    margin-top: 2px;
}

.signup-notice strong {
    color: var(--color-accent-red);
}

.form-section-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-dark);
    margin: 28px 0 18px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--color-border);
    letter-spacing: 1px;
}

.form-section-title:first-child {
    margin-top: 0;
}

.form-section-title i {
    margin-right: 8px;
    color: var(--color-primary-dark);
}

.form-label {
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 6px;
    display: block;
}

.required {
    color: var(--color-accent-red);
    margin-right: 2px;
}

.signup-form .form-control {
    height: 40px;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    padding: 0 14px;
    font-size: 14px;
    color: var(--color-text);
    background: var(--color-white);
    transition: border-color 0.3s ease;
    box-shadow: none;
}

.signup-form .form-control:focus {
    border-color: var(--color-primary-dark);
    box-shadow: 0 0 0 3px rgba(196, 167, 108, 0.15);
}

.signup-form textarea.form-control {
    height: auto;
    padding: 10px 14px;
    resize: vertical;
}

.signup-form select.form-control {
    appearance: auto;
}

.radio-group {
    display: flex;
    align-items: center;
    gap: 20px;
    padding-top: 8px;
}

.radio-inline {
    font-size: 14px;
    color: var(--color-text);
    cursor: pointer;
}

.radio-inline input[type="radio"] {
    margin-right: 4px;
}

.form-actions {
    display: flex;
    gap: 12px;
    padding-top: 24px;
    border-top: 1px solid var(--color-border);
    margin-top: 28px;
}

.btn-submit {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 36px;
    background: linear-gradient(135deg, var(--color-brown), var(--color-primary-dark));
    color: #FFFFFF;
    border: none;
    border-radius: 4px;
    font-size: 15px;
    font-weight: 600;
    letter-spacing: 1px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-submit:hover {
    background: linear-gradient(135deg, var(--color-dark), var(--color-brown));
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(61, 52, 39, 0.3);
}

.btn-submit:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
}

.btn-reset {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 24px;
    background: var(--color-primary-light);
    color: var(--color-text-light);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-reset:hover {
    background: var(--color-primary);
    color: var(--color-dark);
    border-color: var(--color-primary-dark);
}

.status-dot--ongoing {
    background: #27AE60;
}

.status-dot--upcoming {
    background: #F0AD4E;
}

.status-dot--ended {
    background: #999;
}

/* 活动卡片占位图 */
.activity-card-img-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #F5EFE0, #E6D9B8);
    color: #C4A76C;
    font-size: 36px;
}

/* 活动统计简报 */
.activity-stats-brief {
    display: flex;
    gap: 16px;
    font-size: 13px;
    color: var(--color-text-light);
}

.activity-stats-brief strong {
    color: var(--color-accent-gold);
    font-size: 15px;
}

/* ===== 响应式 ===== */
@media (max-width: 991px) {
    .activity-card {
        flex-direction: column;
    }

    .activity-card-img {
        width: 100%;
        height: 200px;
    }

    .activity-detail-banner {
        height: 180px;
    }

    .activity-detail-banner-content h1 {
        font-size: 22px;
    }

    .activity-info-grid {
        grid-template-columns: 1fr;
    }

    .activity-tab-content {
        padding: 24px 20px;
    }

    .signup-form .col-sm-6 {
        margin-bottom: 0;
    }

}

@media (max-width: 767px) {
    .activity-detail-banner {
        height: 150px;
    }

    .activity-detail-banner-content {
        padding: 40px 0 0;
    }

    .activity-detail-banner-content h1 {
        font-size: 18px;
    }

    .activity-card-body {
        padding: 16px 18px;
    }

    .activity-card-title {
        font-size: 15px;
    }

    .activity-card-info {
        flex-direction: column;
        gap: 4px;
    }

    .activity-card-footer {
        flex-direction: column;
        align-items: flex-start;
    }

    .activity-detail-tabs .nav-tabs > li > a {
        padding: 12px 14px;
        font-size: 13px;
    }

    .activity-intro-content h3 {
        font-size: 15px;
    }

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

    .btn-submit,
    .btn-reset {
        width: 100%;
        justify-content: center;
    }

    .activity-list-section {
        padding: 20px 0 40px;
    }
}