/* ============================================================
 * 牙科朋友圈 AI 工具 - 主样式
 * 支持桌面 + 平板 + 手机响应式
 * ============================================================ */

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #eff6ff;
  --gradient: linear-gradient(135deg, #3b82f6 0%, #6366f1 100%);
  --gradient-soft: linear-gradient(135deg, #e0f2fe 0%, #f0f9ff 100%);
  --success: #10b981;
  --success-dark: #059669;
  --warning: #f59e0b;
  --danger: #ef4444;
  --danger-dark: #dc2626;
  --text-main: #0f172a;
  --text-body: #334155;
  --text-muted: #64748b;
  --text-faint: #94a3b8;
  --bg-page: #f5f7fb;
  --bg-card: #ffffff;
  --bg-soft: #f8fafc;
  --border: #e5e7eb;
  --border-soft: #f1f5f9;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.06), 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 10px 30px rgba(15, 23, 42, 0.08);
  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 14px;
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  background: var(--bg-page);
  color: var(--text-main);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

/* ============================================================
 * 顶部导航
 * ============================================================ */
.nav {
  background: #ffffff;
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  display: flex;
  align-items: center;
  min-height: 60px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}
.nav .brand {
  font-weight: 700;
  font-size: 17px;
  color: var(--text-main);
  margin-right: 32px;
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}
.nav .brand::before {
  content: "🦷";
  font-size: 22px;
}
.nav .brand .tag {
  font-size: 10px;
  color: #fff;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 10px;
  background: var(--gradient);
  letter-spacing: 0.5px;
}
.nav .links {
  display: flex;
  gap: 2px;
  flex: 1;
  align-items: center;
}
.nav .links a {
  padding: 9px 16px;
  color: var(--text-body);
  border-radius: var(--radius-sm);
  font-size: 14px;
  white-space: nowrap;
  transition: all 0.15s;
}
.nav .links a:hover {
  background: var(--bg-soft);
  text-decoration: none;
  color: var(--primary);
}
.nav .links a.active {
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 600;
}
.nav .user {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: var(--text-muted);
  white-space: nowrap;
}
.nav .user .provider {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 12px;
  font-size: 11px;
  color: var(--text-body);
  font-weight: 500;
}
.nav .user .provider.mock {
  background: #fef3c7;
  color: #92400e;
  border-color: #fcd34d;
}
.nav .user .user-name {
  max-width: 200px;
  overflow: hidden;
  text-overflow: ellipsis;
}
.nav .user .logout-btn {
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 13px;
}
.nav .user .logout-btn:hover {
  background: #fee2e2;
  color: var(--danger-dark);
  text-decoration: none;
}

/* 汉堡按钮（移动端显示） */
.nav-hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  margin-left: auto;
  border-radius: var(--radius-sm);
}
.nav-hamburger:hover { background: var(--bg-soft); }
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-body);
  border-radius: 2px;
  transition: all 0.25s;
}
.nav-hamburger span + span { margin-top: 5px; }
.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 移动端抽屉遮罩 */
.nav-backdrop {
  display: none;
  position: fixed;
  inset: 60px 0 0 0;
  background: rgba(15, 23, 42, 0.4);
  z-index: 90;
}
.nav-backdrop.open { display: block; }

/* ============================================================
 * 容器
 * ============================================================ */
.container {
  max-width: 1200px;
  margin: 24px auto;
  padding: 0 24px;
}
.container-narrow { max-width: 760px; }

/* ============================================================
 * 卡片
 * ============================================================ */
.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 22px 26px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-soft);
}
.card h2 {
  margin: 0 0 14px 0;
  font-size: 17px;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
}
.card h3 {
  margin: 18px 0 10px 0;
  font-size: 14px;
  color: var(--text-body);
  font-weight: 600;
}
.card h3:first-child { margin-top: 0; }

/* ============================================================
 * 表单
 * ============================================================ */
label {
  display: block;
  font-size: 13px;
  color: var(--text-body);
  margin-bottom: 6px;
  font-weight: 500;
}
input[type=text], input[type=password], input[type=email],
input[type=number], textarea, select {
  width: 100%;
  padding: 10px 13px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-family: inherit;
  background: #fff;
  color: var(--text-main);
  transition: border-color 0.15s, box-shadow 0.15s;
}
input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}
textarea { min-height: 100px; resize: vertical; }
.form-row { margin-bottom: 14px; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }

/* ============================================================
 * 按钮
 * ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
  background: #fff;
  color: var(--text-body);
  text-decoration: none;
  line-height: 1.2;
}
.btn:hover {
  background: var(--bg-soft);
  border-color: var(--text-faint);
  text-decoration: none;
}
.btn:active { transform: translateY(1px); }

.btn-primary {
  background: var(--gradient);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 1px 3px rgba(37, 99, 235, 0.3);
}
.btn-primary:hover {
  background: linear-gradient(135deg, #2563eb 0%, #5254e6 100%);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.35);
}
.btn-success {
  background: var(--success);
  color: #fff;
  border-color: transparent;
}
.btn-success:hover { background: var(--success-dark); color: #fff; }
.btn-danger {
  background: var(--danger);
  color: #fff;
  border-color: transparent;
}
.btn-danger:hover { background: var(--danger-dark); color: #fff; }
.btn-sm { padding: 6px 12px; font-size: 12px; gap: 4px; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn:disabled:hover { transform: none; }

/* ============================================================
 * 统计卡
 * ============================================================ */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 18px;
}
.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-lg);
  padding: 22px 20px;
  text-align: center;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.stat-card::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--gradient);
  opacity: 0.6;
}
.stat-card .n {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.1;
  letter-spacing: -0.5px;
}
.stat-card .l {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 6px;
}
.stat-card.pending .n { color: var(--warning); }
.stat-card.pending::before { background: linear-gradient(135deg, #fbbf24, #f59e0b); opacity: 0.8; }
.stat-card.approved .n { color: var(--success); }
.stat-card.approved::before { background: linear-gradient(135deg, #34d399, #10b981); opacity: 0.8; }
.stat-card.rejected .n { color: var(--danger); }
.stat-card.rejected::before { background: linear-gradient(135deg, #f87171, #ef4444); opacity: 0.8; }

/* ============================================================
 * 标签 chip / status
 * ============================================================ */
.chip {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11px;
  background: var(--bg-soft);
  color: var(--text-body);
  margin-right: 4px;
  border: 1px solid var(--border-soft);
  font-weight: 500;
}
.chip-sleep { background: #dbeafe; color: #1e40af; border-color: #bfdbfe; }
.chip-pain { background: #fee2e2; color: #991b1b; border-color: #fecaca; }
.chip-other { background: var(--bg-soft); color: var(--text-body); }

.status {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 600;
}
.status-draft { background: var(--bg-soft); color: var(--text-muted); }
.status-pending { background: #fef3c7; color: #92400e; }
.status-approved { background: #dcfce7; color: #166534; }
.status-rejected { background: #fee2e2; color: #991b1b; }

/* ============================================================
 * 复选按钮组（人群/痛点/产品）
 * ============================================================ */
.check-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.check-group label {
  display: inline-flex;
  align-items: center;
  padding: 8px 15px;
  border: 1.5px solid var(--border);
  border-radius: 20px;
  background: #fff;
  cursor: pointer;
  font-size: 13px;
  font-weight: normal;
  margin: 0;
  transition: all 0.15s;
  color: var(--text-body);
}
.check-group label:hover { border-color: var(--primary); color: var(--primary); }
.check-group input { display: none; }
.check-group input:checked + span {
  color: var(--primary);
  font-weight: 600;
}
.check-group label:has(input:checked) {
  border-color: var(--primary);
  background: var(--primary-light);
}
.check-group .cat-label {
  width: 100%;
  font-size: 12px;
  color: var(--text-muted);
  margin: 10px 0 4px 0;
  padding: 0;
  border: none;
  background: transparent;
  font-weight: 500;
}
.check-group .cat-label:first-child { margin-top: 0; }

.check-group label.custom-tag {
  background: #fffbeb;
  border-color: #fcd34d;
  padding-right: 32px;
  position: relative;
}
.check-group label.custom-tag:hover { border-color: #f59e0b; }
.check-group label.custom-tag:has(input:checked) {
  background: #fef3c7;
  border-color: #f59e0b;
}
.check-group label.custom-tag .tag-x {
  position: absolute;
  right: 6px;
  top: 50%;
  transform: translateY(-50%);
  border: none;
  background: transparent;
  color: #b45309;
  cursor: pointer;
  font-size: 16px;
  width: 20px;
  height: 20px;
  line-height: 1;
  padding: 0;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.6;
  transition: all 0.15s;
}
.check-group label.custom-tag:hover .tag-x { opacity: 1; }
.check-group label.custom-tag .tag-x:hover {
  background: #f59e0b;
  color: #fff;
}

/* ============================================================
 * 生成结果卡片
 * ============================================================ */
.variant {
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 14px;
  background: #fff;
  transition: all 0.2s;
}
.variant:hover { box-shadow: var(--shadow); }
.variant.selected {
  border-color: var(--primary);
  background: var(--primary-light);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}
.variant .head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  gap: 8px;
  flex-wrap: wrap;
}
.variant .style-tag {
  background: #e0e7ff;
  color: #3730a3;
  padding: 4px 12px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 600;
}
.variant .text {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-body);
  white-space: pre-wrap;
  word-break: break-word;
}
.variant .ops {
  display: flex;
  gap: 8px;
  margin-top: 14px;
  flex-wrap: wrap;
}

mark.flag-high {
  background: #fecaca;
  color: #991b1b;
  padding: 1px 4px;
  border-radius: 3px;
  font-weight: 600;
}
mark.flag-medium {
  background: #fed7aa;
  color: #9a3412;
  padding: 1px 4px;
  border-radius: 3px;
}

/* ============================================================
 * 表格
 * ============================================================ */
.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
table {
  width: 100%;
  border-collapse: collapse;
  min-width: 500px;
}
th, td {
  text-align: left;
  padding: 11px 14px;
  border-bottom: 1px solid var(--border-soft);
  font-size: 13px;
}
th {
  background: var(--bg-soft);
  font-weight: 600;
  color: var(--text-body);
  font-size: 12px;
  letter-spacing: 0.03em;
}
tbody tr:hover { background: var(--bg-soft); }

/* ============================================================
 * Flash 消息
 * ============================================================ */
.flash {
  padding: 12px 18px;
  border-radius: var(--radius-sm);
  margin-bottom: 14px;
  font-size: 14px;
  border: 1px solid;
}
.flash-success { background: #dcfce7; color: #166534; border-color: #86efac; }
.flash-error { background: #fee2e2; color: #991b1b; border-color: #fca5a5; }

/* ============================================================
 * 登录页
 * ============================================================ */
.login-wrap {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #dbeafe 0%, #ede9fe 50%, #f0f9ff 100%);
  padding: 20px;
}
.login-box {
  background: #fff;
  padding: 40px 36px;
  border-radius: 18px;
  box-shadow: 0 20px 50px rgba(15, 23, 42, 0.12);
  width: 100%;
  max-width: 380px;
}
.login-box h1 {
  margin: 0 0 6px 0;
  font-size: 22px;
  color: var(--text-main);
  font-weight: 700;
}
.login-box .sub {
  color: var(--text-muted);
  font-size: 13px;
  margin-bottom: 26px;
}
.login-box .btn { width: 100%; margin-top: 8px; padding: 12px; font-size: 15px; }
.login-hint {
  margin-top: 20px;
  padding: 14px;
  background: var(--bg-soft);
  border-radius: var(--radius-sm);
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.7;
  border: 1px solid var(--border-soft);
}

/* 分隔线 "或" */
.or-divider {
  display: flex;
  align-items: center;
  text-align: center;
  margin: 20px 0 14px 0;
  color: var(--text-faint);
  font-size: 12px;
}
.or-divider::before,
.or-divider::after {
  content: "";
  flex: 1;
  border-bottom: 1px solid var(--border);
}
.or-divider span { padding: 0 12px; }

/* 游客体验按钮 */
.btn-guest {
  width: 100%;
  padding: 12px;
  font-size: 14px;
  background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
  color: #92400e;
  border: 1px solid #fcd34d;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-weight: 600;
  transition: all 0.15s;
}
.btn-guest:hover {
  background: linear-gradient(135deg, #fde68a 0%, #fcd34d 100%);
  box-shadow: 0 4px 12px rgba(245, 158, 11, 0.25);
  color: #78350f;
}

/* ============================================================
 * 游客顶部 banner（粘顶 + 滚动时 compact）
 * ============================================================ */
.guest-banner {
  position: sticky;
  top: 60px;  /* nav 高度 */
  z-index: 80;
  background: linear-gradient(135deg, #fef3c7 0%, #fed7aa 100%);
  border-bottom: 1px solid #fcd34d;
  color: #92400e;
  padding: 10px 24px;
  font-size: 13px;
  transition: padding 0.25s ease, font-size 0.25s ease;
  box-shadow: 0 1px 0 rgba(0,0,0,0.03);
}
.guest-banner-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.guest-banner .gb-icon { font-size: 15px; }
.guest-banner strong { color: #78350f; }
.guest-banner .gb-label { font-weight: 700; color: #78350f; }
.guest-banner .gb-desc { color: #b45309; }
.guest-banner .quota {
  display: inline-block;
  background: #fff;
  padding: 3px 12px;
  border-radius: 12px;
  font-weight: 700;
  color: #78350f;
  border: 1.5px solid #fcd34d;
  min-width: 58px;
  text-align: center;
  transition: all 0.2s;
}
.guest-banner .quota.low {
  background: #fee2e2;
  color: #991b1b;
  border-color: #fca5a5;
}
/* 次数变化时的脉冲动画 */
@keyframes quotaPulse {
  0%   { transform: scale(1); box-shadow: 0 0 0 0 rgba(245, 158, 11, 0.6); }
  40%  { transform: scale(1.18); box-shadow: 0 0 0 10px rgba(245, 158, 11, 0); }
  100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(245, 158, 11, 0); }
}
.guest-banner .quota.pulse {
  animation: quotaPulse 0.7s ease-out;
}
.guest-banner .upgrade-link {
  margin-left: auto;
  color: #78350f;
  font-weight: 600;
  text-decoration: underline;
  white-space: nowrap;
}

/* ---------- Compact 模式（滚动时）---------- */
.guest-banner.compact {
  padding: 6px 24px;
  font-size: 12px;
}
.guest-banner.compact .gb-desc { display: none; }
.guest-banner.compact .gb-label { display: none; }
.guest-banner.compact .gb-exit { display: none; }
.guest-banner.compact .quota {
  padding: 2px 10px;
  min-width: 50px;
}
.guest-banner.compact .gb-quota-wrap::before {
  content: "剩 ";
}
.guest-banner.compact .gb-quota-wrap {
  font-size: 11px;
  color: #92400e;
}
/* compact 模式下隐藏 "今日剩余" 文字，只保留 "剩" 前缀 */
.guest-banner.compact .gb-quota-wrap {
  font-size: 0;  /* 隐藏文本节点 */
}
.guest-banner.compact .gb-quota-wrap::before {
  font-size: 12px;
}
.guest-banner.compact .gb-quota-wrap .quota {
  font-size: 12px;
}

/* 手机：banner 顶部对齐 mobile nav 56px */
@media (max-width: 768px) {
  .guest-banner {
    top: 56px;
    padding: 9px 16px;
  }
  .guest-banner.compact { padding: 6px 16px; }
  .guest-banner .gb-desc { display: none; }  /* 手机默认就隐藏长描述 */
  .guest-banner.compact .upgrade-link,
  .guest-banner.compact .gb-icon { display: none; }
}

/* ============================================================
 * Tabs（内页导航）
 * ============================================================ */
.tabs {
  display: flex;
  gap: 4px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 18px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.tabs a {
  padding: 11px 18px;
  color: var(--text-muted);
  border-bottom: 2px solid transparent;
  font-size: 14px;
  white-space: nowrap;
  flex-shrink: 0;
}
.tabs a.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 600;
}
.tabs a:hover { text-decoration: none; color: var(--primary); }

/* ============================================================
 * 工具类
 * ============================================================ */
.muted { color: var(--text-muted); font-size: 13px; }
.text-right { text-align: right; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.flex { display: flex; }
.flex-between { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px; }
.gap-8 { gap: 8px; }

/* ============================================================
 * 响应式：平板 ≤ 960px
 * ============================================================ */
@media (max-width: 960px) {
  .stats { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .form-grid { grid-template-columns: 1fr; }
  .container { padding: 0 16px; margin: 16px auto; }
  .card { padding: 20px; }
}

/* ============================================================
 * 响应式：手机 ≤ 768px —— 汉堡菜单 + 单列布局
 * ============================================================ */
@media (max-width: 768px) {
  body { font-size: 14px; }

  /* 导航：brand + hamburger 一行，links 变成下拉抽屉 */
  .nav {
    padding: 0 16px;
    min-height: 56px;
  }
  .nav .brand { font-size: 15px; margin-right: 0; flex: 1; }
  .nav .brand .tag { font-size: 9px; padding: 1px 6px; }

  .nav-hamburger { display: block; }

  .nav .links {
    position: fixed;
    top: 56px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    gap: 0;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 8px 20px rgba(15, 23, 42, 0.1);
    transform: translateY(-150%);
    transition: transform 0.28s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 95;
    max-height: calc(100vh - 56px);
    overflow-y: auto;
  }
  .nav .links.open { transform: translateY(0); }
  .nav .links a {
    padding: 14px 20px;
    border-radius: 0;
    font-size: 15px;
    border-left: 3px solid transparent;
  }
  .nav .links a.active {
    background: var(--primary-light);
    border-left-color: var(--primary);
  }

  .nav .user {
    order: 99;
    width: 100%;
    padding: 14px 20px;
    border-top: 1px solid var(--border-soft);
    justify-content: space-between;
    gap: 8px;
    flex-wrap: wrap;
  }
  .nav .user .user-name { max-width: none; flex: 1; min-width: 0; font-size: 13px; }
  .nav .user .provider { font-size: 10px; padding: 3px 8px; }
  .nav .user .logout-btn { padding: 6px 10px; }

  /* 容器：更紧凑 */
  .container { padding: 0 14px; margin: 12px auto; }

  /* 卡片：减少 padding */
  .card { padding: 18px; border-radius: 12px; margin-bottom: 14px; }
  .card h2 { font-size: 16px; }

  /* 统计卡：2 列 */
  .stats { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .stat-card { padding: 18px 12px; border-radius: 12px; }
  .stat-card .n { font-size: 26px; }
  .stat-card .l { font-size: 12px; }

  /* 按钮在小屏略大以便点击 */
  .btn { padding: 11px 18px; font-size: 14px; }
  .btn-sm { padding: 6px 12px; font-size: 12px; }

  /* 表格左右滚动 */
  .card table { min-width: 500px; }

  /* 生成结果卡片 */
  .variant { padding: 16px; }
  .variant .text { font-size: 14px; }

  /* 登录页 */
  .login-box { padding: 32px 24px; }
  .login-box h1 { font-size: 19px; }

  /* form-row 里的 input + button 组合，改为上下排列 */
  .form-row[style*="display:flex"] { flex-direction: column; }
  .form-row[style*="display:flex"] .btn { width: 100%; }
}

/* ============================================================
 * 响应式：小屏手机 ≤ 420px
 * ============================================================ */
@media (max-width: 420px) {
  .stats { grid-template-columns: 1fr; }
  .stat-card { padding: 16px; }
  .stat-card .n { font-size: 28px; }

  .card { padding: 16px; }
  .nav .brand { font-size: 14px; }
  .nav .brand::before { font-size: 18px; }
}