/* ============================================
   校园论坛 - 全局公共样式
   ============================================ */

/* CSS 变量 */
:root {
  --primary: #6366f1;
  --primary-light: #818cf8;
  --primary-dark: #4f46e5;
  --secondary: #8b5cf6;
  --bg: #f3f4f6;
  --bg-white: #ffffff;
  --text: #1f2937;
  --text-light: #6b7280;
  --text-lighter: #9ca3af;
  --border: #e5e7eb;
  --danger: #ef4444;
  --success: #10b981;
  --warning: #f59e0b;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --max-width: 640px;
}

/* 重置 */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  color: var(--primary-dark);
}

img {
  max-width: 100%;
  height: auto;
}

/* ============================================
   导航栏
   ============================================ */
.navbar {
  background: var(--bg-white);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.navbar-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 16px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-logo {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}

.navbar-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}

/* ============================================
   按钮
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 16px;
  border: none;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
  line-height: 1.4;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--primary-dark);
  color: #fff;
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border: 1px solid var(--primary);
}

.btn-outline:hover {
  background: var(--primary);
  color: #fff;
}

.btn-danger {
  background: var(--danger);
  color: #fff;
}

.btn-ghost {
  background: transparent;
  color: var(--text-light);
}

.btn-ghost:hover {
  background: var(--bg);
}

.btn-sm {
  padding: 4px 12px;
  font-size: 13px;
}

.btn-block {
  width: 100%;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ============================================
   表单
   ============================================ */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--text);
  background: var(--bg-white);
  transition: border-color 0.2s;
  outline: none;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.form-textarea {
  resize: vertical;
  min-height: 100px;
}

.form-hint {
  font-size: 12px;
  color: var(--text-lighter);
  margin-top: 4px;
}

.form-error {
  font-size: 12px;
  color: var(--danger);
  margin-top: 4px;
}

/* ============================================
   卡片
   ============================================ */
.card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 16px;
  box-shadow: var(--shadow);
}

/* ============================================
   帖子卡片
   ============================================ */
.post-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 16px;
  margin-bottom: 12px;
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: box-shadow 0.2s;
}

.post-card:hover {
  box-shadow: var(--shadow-md);
}

.post-card-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-card-content {
  font-size: 14px;
  color: var(--text-light);
  margin-bottom: 12px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  line-height: 1.5;
}

.post-card-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 12px;
  color: var(--text-lighter);
}

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

.post-card-image {
  width: 100%;
  border-radius: var(--radius);
  margin-bottom: 12px;
  max-height: 200px;
  object-fit: cover;
}

/* ============================================
   板块标签
   ============================================ */
.category-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 600;
  background: rgba(99, 102, 241, 0.1);
  color: var(--primary);
}

/* ============================================
   板块导航
   ============================================ */
.categories-nav {
  display: flex;
  gap: 8px;
  padding: 12px 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.categories-nav::-webkit-scrollbar {
  display: none;
}

.category-chip {
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  border: 1px solid var(--border);
  background: var(--bg-white);
  color: var(--text-light);
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
}

.category-chip:hover,
.category-chip.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* ============================================
   评论
   ============================================ */
.comment-item {
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}

.comment-item:last-child {
  border-bottom: none;
}

.comment-author {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}

.comment-content {
  font-size: 14px;
  color: var(--text);
  margin-bottom: 4px;
}

.comment-time {
  font-size: 12px;
  color: var(--text-lighter);
}

/* ============================================
   Toast 通知
   ============================================ */
.toast-container {
  position: fixed;
  top: 70px;
  right: 16px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  padding: 12px 16px;
  border-radius: var(--radius);
  font-size: 14px;
  color: #fff;
  box-shadow: var(--shadow-md);
  animation: slideIn 0.3s ease;
  max-width: 320px;
}

.toast-success { background: var(--success); }
.toast-error { background: var(--danger); }
.toast-warning { background: var(--warning); }

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

/* ============================================
   模态框
   ============================================ */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.modal {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 24px;
  width: 100%;
  max-width: 400px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}

.modal-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
}

.modal-actions {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
  margin-top: 20px;
}

/* ============================================
   空状态
   ============================================ */
.empty-state {
  text-align: center;
  padding: 48px 16px;
  color: var(--text-lighter);
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: 12px;
}

.empty-state-text {
  font-size: 15px;
}

/* ============================================
   加载状态
   ============================================ */
.loading {
  text-align: center;
  padding: 24px;
  color: var(--text-lighter);
  font-size: 14px;
}

.spinner {
  display: inline-block;
  width: 24px;
  height: 24px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ============================================
   布局容器
   ============================================ */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px;
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.page-title {
  font-size: 20px;
  font-weight: 700;
}

/* ============================================
   底部栏（发帖浮动按钮）
   ============================================ */
.fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-size: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
  cursor: pointer;
  border: none;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
}

.fab:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 16px rgba(99, 102, 241, 0.5);
  color: #fff;
}

/* ============================================
   帖子详情页
   ============================================ */
.post-detail {
  margin-bottom: 24px;
}

.post-detail-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
}

.post-detail-content {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
  margin-bottom: 16px;
  white-space: pre-wrap;
  word-break: break-word;
}

.post-detail-image {
  width: 100%;
  border-radius: var(--radius);
  margin-bottom: 16px;
}

.post-detail-actions {
  display: flex;
  gap: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

/* ============================================
   响应式
   ============================================ */
@media (max-width: 480px) {
  .container {
    padding: 12px;
  }

  .navbar-inner {
    padding: 0 12px;
  }

  .post-detail-title {
    font-size: 18px;
  }

  .modal {
    padding: 20px;
  }
}