/* ============ 全局重置 & 主题变量 ============ */
:root {
  --bg: #0f172a;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --primary: #4f46e5;
  --primary-dark: #4338ca;
  --danger: #dc2626;
  --success: #16a34a;
  --warning: #f59e0b;
  --border: #e2e8f0;
  --bg-soft: #f8fafc;
  --radius: 12px;
  --shadow: 0 10px 30px rgba(15, 23, 42, .15);
  --transition: all .2s ease;
}

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

/* 兜底:HTML hidden 属性优先于任何 display 声明,防止 .app{display:flex} 等覆盖导致隐藏失效 */
[hidden] { display: none !important; }

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #4f46e5 0%, #7c3aed 50%, #db2777 100%);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
}

/* ============ 容器 ============ */
.auth-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.auth-card {
  width: 100%;
  max-width: 420px;
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px 28px;
  animation: fadeUp .4s ease;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============ 头部 ============ */
.auth-header { text-align: center; margin-bottom: 24px; }

.logo {
  width: 56px; height: 56px;
  margin: 0 auto 12px;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
  font-size: 28px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 8px 20px rgba(79, 70, 229, .35);
}

.auth-title { font-size: 22px; font-weight: 700; }
.auth-subtitle { font-size: 13px; color: var(--muted); margin-top: 4px; }

/* ============ Tab 切换 ============ */
.tabs {
  display: flex;
  background: var(--bg-soft);
  border-radius: 10px;
  padding: 4px;
  margin-bottom: 20px;
}

.tab {
  flex: 1;
  padding: 10px;
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 14px;
  font-weight: 500;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition);
}
.tab.active {
  background: var(--card);
  color: var(--primary);
  box-shadow: 0 2px 8px rgba(0,0,0,.08);
}

/* ============ 表单 ============ */
.form { display: none; }
.form.active { display: block; }

.field { margin-bottom: 16px; }

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

.field input {
  width: 100%;
  padding: 11px 12px;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  background: var(--card);
  transition: var(--transition);
  outline: none;
}
.field input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, .15);
}
.field input.invalid {
  border-color: var(--danger);
  box-shadow: 0 0 0 3px rgba(220, 38, 38, .12);
}

.pwd-wrap { position: relative; }
.pwd-wrap input { padding-right: 42px; }
.toggle-pwd {
  position: absolute;
  right: 8px; top: 50%;
  transform: translateY(-50%);
  background: transparent;
  border: none;
  cursor: pointer;
  font-size: 18px;
  opacity: .6;
  transition: var(--transition);
}
.toggle-pwd:hover { opacity: 1; }

/* 验证码输入框 + 获取按钮(行业标准:横排布局) */
.code-wrap { display: flex; gap: 8px; }
.code-wrap input { flex: 1; min-width: 0; }
.btn-code {
  flex-shrink: 0;
  padding: 0 16px;
  height: 44px;
  border: 1px solid var(--primary);
  background: transparent;
  color: var(--primary);
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: var(--transition);
}
.btn-code:hover:not(:disabled) { background: var(--primary); color: #fff; }
.btn-code:disabled { opacity: .6; cursor: not-allowed; }

.error-msg {
  display: block;
  font-size: 12px;
  color: var(--danger);
  margin-top: 4px;
  min-height: 16px;
}

/* ============ 密码强度 ============ */
.strength { margin-top: 8px; }
.strength-track {
  display: block;
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}
.strength-fill {
  display: block;
  height: 100%;
  width: 0;
  border-radius: 3px;
  transition: width .3s, background .3s;
}
.strength-label {
  display: block;
  font-size: 11px;
  margin-top: 4px;
  color: var(--muted);
}

/* ============ 按钮 ============ */
.btn-primary {
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 8px;
  background: var(--primary);
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  margin-top: 4px;
}
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-primary:active { transform: translateY(0); }
.btn-primary:disabled { opacity: .6; cursor: not-allowed; transform: none; }
.btn-primary.danger { background: var(--danger); }
.btn-primary.danger:hover { background: #b91c1c; }

/* ============ 表单提示 ============ */
.form-tip {
  text-align: center;
  font-size: 13px;
  color: var(--muted);
  margin-top: 16px;
}
.form-tip a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}
.form-tip a:hover { text-decoration: underline; }

/* ============ 已登录用户信息 ============ */
.user-info {
  background: var(--bg-soft);
  border-radius: 10px;
  padding: 16px;
  margin: 16px 0 20px;
}
.info-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
}
.info-row:last-child { border-bottom: none; }
.info-row span { color: var(--muted); }
.info-row code {
  font-family: "SF Mono", Consolas, monospace;
  color: var(--text);
  max-width: 60%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
/* 数字 ID 突出显示(QQ 式,个人资料页) */
.uid-code {
  font-family: "SF Mono", Consolas, monospace;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.5px;
  color: var(--primary);
}

/* 用户行内数字 ID 标签(社交列表/搜索结果) */
.user-uid {
  margin-left: 8px;
  font-size: 12px;
  font-weight: 400;
  color: var(--muted);
  font-family: "SF Mono", Consolas, monospace;
}

/* ============ Toast ============ */
.toast {
  position: fixed;
  top: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(-20px);
  padding: 12px 24px;
  border-radius: 8px;
  background: var(--text);
  color: #fff;
  font-size: 14px;
  box-shadow: var(--shadow);
  opacity: 0;
  transition: var(--transition);
  z-index: 1000;
  max-width: 90%;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }

/* ============ 响应式 ============ */
@media (max-width: 480px) {
  .auth-card { padding: 24px 18px; }
  .auth-title { font-size: 20px; }
}

/* ============ 登录后应用布局 ============ */
.app {
  position: fixed; inset: 0; z-index: 10;
  display: flex; flex-direction: column;
  background: var(--bg-soft);
  overflow-y: auto;
}
.app-header {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 24px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}
.app-brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 15px; color: var(--text); }
.app-brand .logo { width: 30px; height: 30px; border-radius: 8px; font-size: 15px; margin: 0; }
.app-user { display: flex; align-items: center; gap: 10px; }
.app-avatar {
  width: 30px; height: 30px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-size: 13px; font-weight: 600;
}
.app-username { font-size: 14px; font-weight: 500; color: var(--text); }
.btn-logout {
  padding: 6px 14px; border: 1px solid var(--border); border-radius: 8px;
  background: var(--card); color: var(--danger); font-size: 13px; cursor: pointer;
  transition: var(--transition);
}
.btn-logout:hover { background: var(--danger); color: #fff; border-color: var(--danger); }

/* 二级导航 */
.app-nav {
  display: flex; gap: 2px; padding: 0 24px;
  background: var(--card); border-bottom: 1px solid var(--border);
}
.app-tab {
  padding: 12px 18px; border: none; background: transparent;
  color: var(--muted); font-size: 14px; font-weight: 500; cursor: pointer;
  border-bottom: 2px solid transparent; transition: var(--transition);
}
.app-tab.active { color: var(--primary); border-bottom-color: var(--primary); }
.app-tab:hover { color: var(--text); }

/* 内容区 */
.app-content { flex: 1; width: 100%; max-width: 960px; margin: 24px auto; padding: 0 24px; }
.view { display: none; animation: fadeUp .3s ease; }
.view.active { display: block; }
.card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 24px; }
.card-title { font-size: 18px; font-weight: 700; color: var(--text); margin: 0; }
.card-subtitle { font-size: 13px; color: var(--muted); margin: 4px 0 20px; }

/* ============ 我的文件 ============ */
.files-bar { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin: 0 0 20px; }
.files-head { display: flex; align-items: baseline; gap: 10px; }
.files-count {
  font-size: 13px; color: var(--muted); font-weight: 500;
  background: var(--bg-soft); padding: 3px 10px; border-radius: 20px;
}
.btn-upload {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 9px 18px; border-radius: 8px;
  background: var(--primary); color: #fff;
  font-size: 14px; font-weight: 500; cursor: pointer;
  transition: var(--transition); white-space: nowrap;
}
.btn-upload:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-upload.disabled { opacity: .6; cursor: not-allowed; transform: none; }

.sub-tabs { display: flex; gap: 2px; margin: 0 0 18px; border-bottom: 1px solid var(--border); }
.sub-tab {
  padding: 8px 18px; border: none; background: transparent;
  color: var(--muted); font-size: 13px; font-weight: 500; cursor: pointer;
  border-bottom: 2px solid transparent; transition: var(--transition);
}
.sub-tab.active { color: var(--primary); border-bottom-color: var(--primary); }
.sub-tab:hover { color: var(--text); }

.files-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; }
.files-empty {
  grid-column: 1 / -1;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 56px 20px; text-align: center;
}
.files-empty[hidden] { display: none; }
.empty-icon { color: var(--border); margin-bottom: 16px; }
.empty-text { font-size: 16px; font-weight: 600; color: var(--text); margin-bottom: 6px; }
.empty-sub { font-size: 13px; color: var(--muted); }

.file-card {
  position: relative; border-radius: 12px; overflow: hidden;
  background: var(--bg-soft); aspect-ratio: 1; box-shadow: var(--shadow);
  cursor: pointer; transition: transform .2s ease, box-shadow .2s ease;
}
.file-card:hover { transform: translateY(-2px); box-shadow: 0 14px 36px rgba(15, 23, 42, .2); }
.file-card img, .file-card video { width: 100%; height: 100%; object-fit: cover; display: block; }
.file-del {
  position: absolute; top: 8px; right: 8px; width: 28px; height: 28px; border-radius: 50%;
  border: none; background: rgba(0,0,0,.6); color: #fff; font-size: 14px; cursor: pointer;
  display: flex; align-items: center; justify-content: center; opacity: 0; transition: opacity .2s; z-index: 3;
}
.file-del:hover { background: var(--danger); }
.file-card:hover .file-del { opacity: 1; }
.file-meta {
  position: absolute; left: 0; right: 0; bottom: 0;
  display: flex; justify-content: space-between; align-items: center; gap: 8px;
  padding: 8px 10px; font-size: 11px; color: #fff;
  background: linear-gradient(to top, rgba(0,0,0,.7), transparent);
  opacity: 0; transition: opacity .2s; z-index: 2;
}
.file-card:hover .file-meta { opacity: 1; }
.file-meta .name { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; flex: 1; }
.file-meta .date { opacity: .85; flex-shrink: 0; }

/* 视频播放覆盖层 */
.play-overlay {
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  background: rgba(0,0,0,.18); opacity: 0; transition: opacity .2s; z-index: 1;
}
.file-card:hover .play-overlay { opacity: 1; }
.play-overlay::before {
  content: '▶'; width: 50px; height: 50px; border-radius: 50%;
  background: rgba(255,255,255,.92); color: var(--text); font-size: 18px;
  display: flex; align-items: center; justify-content: center; padding-left: 3px;
  box-shadow: 0 4px 16px rgba(0,0,0,.3);
}

/* 音频卡 */
.audio-card {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 18px 12px; gap: 6px; aspect-ratio: 1;
}
.audio-icon { font-size: 44px; margin-bottom: 4px; }
.audio-name {
  font-size: 12px; color: var(--text); text-align: center; word-break: break-all;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
  max-width: 100%; line-height: 1.4;
}
.audio-size { font-size: 11px; color: var(--muted); }
.audio-card audio { width: 100%; max-width: 180px; margin-top: 6px; }
.audio-card .file-del { top: 8px; right: 8px; opacity: 1; background: rgba(0,0,0,.08); color: var(--muted); }
.audio-card .file-del:hover { background: var(--danger); color: #fff; }

/* ============ Lightbox(图片 / 视频)============ */
.lightbox {
  position: fixed; inset: 0; z-index: 100;
  display: flex; align-items: center; justify-content: center;
  background: rgba(15, 23, 42, .92); padding: 40px;
  animation: fadeUp .2s ease;
}
.lightbox[hidden] { display: none; }
.lb-media { max-width: 90vw; max-height: 80vh; border-radius: 8px; box-shadow: 0 20px 60px rgba(0,0,0,.5); }
.lb-img { object-fit: contain; }
.lb-video { background: #000; }
.lb-close {
  position: absolute; top: 20px; right: 24px; width: 40px; height: 40px; border-radius: 50%;
  border: none; background: rgba(255,255,255,.15); color: #fff; font-size: 18px; cursor: pointer;
  transition: var(--transition);
}
.lb-close:hover { background: rgba(255,255,255,.28); }
.lb-info { position: absolute; bottom: 28px; left: 0; right: 0; text-align: center; color: rgba(255,255,255,.85); font-size: 13px; }

@media (max-width: 600px) {
  .app-content { padding: 0 14px; margin-top: 16px; }
  .app-header, .app-nav { padding-left: 14px; padding-right: 14px; }
  .files-grid { grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
  .lightbox { padding: 20px; }
}

/* ============ 社交页 ============ */
.social-card { padding: 24px; }

/* 社交子 Tab 切换面板 */
.stab-pane { display: none; animation: fadeUp .25s ease; }
.stab-pane.active { display: block; }

/* 区块标题 */
.section-title {
  font-size: 13px; font-weight: 600; color: var(--muted);
  margin: 20px 0 10px; display: flex; align-items: center; gap: 8px;
  text-transform: uppercase; letter-spacing: .5px;
}
.section-title:first-child { margin-top: 0; }
.count-badge {
  font-size: 11px; font-weight: 600; color: var(--primary);
  background: rgba(79, 70, 229, .12); padding: 2px 8px; border-radius: 10px;
}

/* 搜索栏 */
.search-bar { display: flex; gap: 8px; margin-bottom: 12px; }
.search-bar input {
  flex: 1; padding: 10px 12px;
  border: 1.5px solid var(--border); border-radius: 8px;
  font-size: 14px; background: var(--card); outline: none;
  transition: var(--transition);
}
.search-bar input:focus {
  border-color: var(--primary); box-shadow: 0 0 0 3px rgba(79, 70, 229, .15);
}
.search-bar button {
  padding: 0 16px; border: none; border-radius: 8px;
  background: var(--primary); color: #fff; font-size: 14px; font-weight: 500;
  cursor: pointer; transition: var(--transition); white-space: nowrap;
}
.search-bar button:hover { background: var(--primary-dark); }
.search-bar button:disabled { opacity: .6; cursor: not-allowed; }

/* 搜索结果 */
.search-results {
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--card); overflow: hidden; margin-bottom: 4px;
}
.search-results[hidden] { display: none; }
.search-results-empty { padding: 18px; text-align: center; color: var(--muted); font-size: 13px; }

/* 用户行(搜索结果 / 好友 / 群成员) */
.user-list { display: flex; flex-direction: column; gap: 4px; }
.user-row {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 12px; border-radius: 10px;
  background: var(--bg-soft); transition: var(--transition);
}
.user-row:hover { background: #eef2ff; }
.user-avatar {
  width: 38px; height: 38px; border-radius: 50%; flex-shrink: 0;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff; font-size: 15px; font-weight: 600;
  display: flex; align-items: center; justify-content: center;
}
.user-main { flex: 1; min-width: 0; }
.user-name { font-size: 14px; font-weight: 500; color: var(--text); }
.user-sub { font-size: 12px; color: var(--muted); margin-top: 2px; }
.user-actions { display: flex; gap: 6px; flex-shrink: 0; }

.btn-mini {
  padding: 6px 14px; border: none; border-radius: 7px;
  font-size: 12px; font-weight: 500; cursor: pointer;
  transition: var(--transition);
}
.btn-mini.primary { background: var(--primary); color: #fff; }
.btn-mini.primary:hover { background: var(--primary-dark); }
.btn-mini.ghost { background: transparent; color: var(--muted); border: 1px solid var(--border); }
.btn-mini.ghost:hover { color: var(--danger); border-color: var(--danger); }
.btn-mini.danger { background: transparent; color: var(--danger); border: 1px solid var(--border); }
.btn-mini.danger:hover { background: var(--danger); color: #fff; border-color: var(--danger); }
.btn-mini:disabled { opacity: .6; cursor: not-allowed; }

/* 好友请求卡 */
.requests-list { display: flex; flex-direction: column; gap: 6px; }
.requests-list:empty { display: none; }

/* 空状态块 */
.empty-block {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 40px 20px; text-align: center;
}
.empty-block[hidden] { display: none; }

/* 群聊卡列表 */
.group-list { display: flex; flex-direction: column; gap: 8px; }
.group-list[hidden] { display: none; }
.group-row {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 14px; border-radius: 10px; cursor: pointer;
  background: var(--bg-soft); transition: var(--transition);
}
.group-row:hover { background: #eef2ff; transform: translateX(2px); }
.group-avatar {
  width: 42px; height: 42px; border-radius: 12px; flex-shrink: 0;
  background: linear-gradient(135deg, #0ea5e9, #4f46e5);
  color: #fff; font-size: 18px; font-weight: 600;
  display: flex; align-items: center; justify-content: center;
}
.group-main { flex: 1; min-width: 0; }
.group-name { font-size: 14px; font-weight: 500; color: var(--text); }
.group-sub { font-size: 12px; color: var(--muted); margin-top: 2px; }
.role-tag {
  display: inline-block; font-size: 11px; font-weight: 600;
  padding: 2px 8px; border-radius: 10px; margin-left: 6px;
}
.role-tag.owner { background: rgba(245, 158, 11, .15); color: #b45309; }
.role-tag.admin { background: rgba(79, 70, 229, .12); color: var(--primary); }
.role-tag.member { background: rgba(100, 116, 139, .12); color: var(--muted); }

/* 弹层 Modal */
.modal { position: fixed; inset: 0; z-index: 200; display: flex; align-items: center; justify-content: center; padding: 20px; }
.modal[hidden] { display: none; }
.modal-mask {
  position: absolute; inset: 0;
  background: rgba(15, 23, 42, .55); backdrop-filter: blur(2px);
  animation: fadeIn .2s ease;
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.modal-card {
  position: relative; z-index: 1;
  width: 100%; max-width: 460px;
  background: var(--card); border-radius: var(--radius);
  box-shadow: 0 24px 64px rgba(15, 23, 42, .3);
  display: flex; flex-direction: column; max-height: 88vh;
  animation: fadeUp .25s ease;
}
.modal-card.lg { max-width: 560px; }
.modal-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 20px; border-bottom: 1px solid var(--border);
}
.modal-header h3 { font-size: 16px; font-weight: 700; color: var(--text); }
.modal-close {
  width: 28px; height: 28px; border: none; border-radius: 50%;
  background: var(--bg-soft); color: var(--muted); font-size: 14px; cursor: pointer;
  transition: var(--transition);
}
.modal-close:hover { background: var(--danger); color: #fff; }
.modal-body { flex: 1; overflow-y: auto; padding: 20px; }
.modal-footer {
  display: flex; justify-content: flex-end; gap: 10px;
  padding: 14px 20px; border-top: 1px solid var(--border);
}
.modal-footer .btn-primary { width: auto; padding: 10px 22px; margin-top: 0; }
.btn-secondary {
  padding: 10px 22px; border: 1px solid var(--border); border-radius: 8px;
  background: var(--card); color: var(--muted); font-size: 14px; font-weight: 500;
  cursor: pointer; transition: var(--transition);
}
.btn-secondary:hover { color: var(--text); border-color: var(--muted); }

/* 群信息区 */
.group-info {
  background: var(--bg-soft); border-radius: 10px; padding: 12px 16px;
  margin-bottom: 16px;
}
.group-info .info-row { padding: 6px 0; }

/* 群成员列表(比搜索结果更紧凑) */
.group-members { margin-top: 4px; }