/* 默认使用浅色主题变量，适配更多用户的系统风格 */
:root {
  color-scheme: light dark;
  --bg: #f8fafc;
  --bg-grad-a: #f9fafb;
  --bg-grad-b: #f3f4f6;
  --bg-grad-c: #eef2f7;
  --card: #ffffff;
  --card-glow: rgba(34, 197, 94, 0.08);
  --text: #111827;
  --muted: #6b7280;
  --accent: #22c55e;
  --accent-2: #34d399;
  --warn: #f59e0b;
  --info: #3b82f6;
  /* 高亮项（浅色主题） */
  --hl-bg: #fff5f5;          /* 淡红背景，保证对比度 */
  --hl-border: #ef4444;      /* 红色边框 */
  --hl-text: #b91c1c;        /* 深红文字，浅色背景可读 */
}

/* 深色主题覆盖：跟随系统深色模式 */
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --bg-grad-a: #0b1220;
    --bg-grad-b: #0d1b2a;
    --bg-grad-c: #102038;
    --card: #111827;
    --card-glow: rgba(34, 197, 94, 0.14);
    --text: #e5e7eb;
    --muted: #9ca3af;
    --info: #60a5fa;
    /* 高亮项（深色主题） */
    --hl-bg: rgba(239,68,68,0.16);
    --hl-border: #ef4444;
    --hl-text: #ffffff;
  }
}

* { box-sizing: border-box; }
html, body { height: 100%; font-size: 18px; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #ffffff; /* 纯白背景，去除渐变与光效 */
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

.app {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 30px;
}

.card {
  width: 100%;
  max-width: 760px;
  background: transparent;
  border: 0;
  border-radius: 0;
  box-shadow: none;
  padding: 20px 22px;
  position: relative;
}
.card::after { content: none; }

@keyframes glow {
  from { opacity: 0.4; }
  to   { opacity: 0.9; }
}

.title { font-size: 26px; font-weight: 900; margin-bottom: 12px; letter-spacing: 0.3px; }
.desc { color: var(--muted); margin-bottom: 20px; line-height: 1.7; }

.callout {
  background: rgba(34,197,94,0.18);
  border: 1px solid rgba(34,197,94,0.35);
  color: #eafff2;
  border-radius: 14px;
  padding: 14px 16px;
  font-weight: 800;
  margin-bottom: 16px;
}

.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand .logo { width: 28px; height: 28px; border-radius: 8px; background: linear-gradient(135deg, var(--accent), var(--accent-2)); box-shadow: 0 6px 20px rgba(52, 211, 153, 0.35); }
.brand .name { font-weight: 800; }
.mode-switch { color: var(--muted); font-size: 14px; }
.mode-switch a { color: var(--info); text-decoration: none; }
.mode-switch a:hover { text-decoration: underline; }

.steps { margin: 16px 0; }
.step {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  border-radius: 14px;
  background: rgba(255,255,255,0.03);
  border: 1px dashed #374151;
  margin-bottom: 10px;
}
.step .no {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px; height: 28px;
  border-radius: 999px;
  background: #374151;
  font-size: 14px; font-weight: 900;
}
.step .ico { width: 22px; height: 22px; opacity: 0.95; }
.step .txt { line-height: 1.8; font-size: 18px; }

.actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 12px; }
.btn {
  appearance: none;
  border: none;
  padding: 10px 14px;
  border-radius: 10px;
  color: #0b0f17;
  font-weight: 700;
  cursor: pointer;
}
.btn-primary { background: var(--accent); }
.btn-secondary { background: #60a5fa; }
.btn-warning { background: var(--warn); color: #101418; }
.btn:hover { filter: brightness(1.05); box-shadow: 0 8px 24px rgba(0,0,0,0.25); transform: translateY(-1px); transition: all .18s ease; }
.btn:active { transform: translateY(0); }

.note { margin-top: 16px; color: var(--muted); font-size: 16px; }

.iframe-wrap { width: 100%; height: 74vh; border-radius: 14px; overflow: hidden; border: 1px solid #1f2937; position: relative; }
.iframe { width: 100%; height: 100%; border: 0; background: #0b0f17; }
.skeleton {
  position: absolute; inset: 0; display: grid; place-items: center;
  background: repeating-linear-gradient(90deg, rgba(255,255,255,0.04), rgba(255,255,255,0.04) 10px, rgba(255,255,255,0.02) 10px, rgba(255,255,255,0.02) 20px);
}
.loader { width: 44px; height: 44px; border-radius: 50%; border: 3px solid rgba(255,255,255,0.18); border-top-color: #60a5fa; animation: spin 1s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.badge { display: block; text-align: center; font-size: 22px; font-weight: 600; color: #4b5563; margin: 8px 0 6px; }
.badge .ico { display: none; }

/* 居中大字提示与盾牌图标样式 */
.card.center { text-align: center; }
.hero { margin: 6px 0 12px; }
.hero-line { font-size: 26px; font-weight: 900; letter-spacing: 0; }
.hero-line.sub { font-size: 24px; margin-top: 8px; opacity: 1; }
.shield { display: grid; place-items: center; margin: 18px 0 14px; }
.shield .ico { width: 96px; height: 96px; }

.grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; margin: 24px 0 6px; }
.grid-item { display: flex; flex-direction: column; align-items: center; gap: 6px; color: var(--muted); }
.grid-item .ico { width: 30px; height: 30px; }
.grid-item .label { font-size: 12px; line-height: 1.25; letter-spacing: 0; font-weight: 500; }
.grid-item.highlight { border: 1px solid var(--hl-border); border-radius: 12px; padding: 8px; background: var(--hl-bg); color: var(--hl-text); }
.grid-item.highlight .label { font-weight: 500; color: var(--hl-text); }

/* 系统浏览器内全屏嵌入内容，仅显示目标页面，无任何文案 */
.embed-full { position: fixed; inset: 0; padding: 0; margin: 0; background: var(--bg); }
.embed-full .iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.embed-full .skeleton { position: absolute; inset: 0; display: grid; place-items: center; }
/* 响应式微调：更小屏幕降低字号与间距，避免变形 */
/* 统一风格：移除小屏特化，保持各设备一致显示 */

/* 较宽屏幕下，底部菜单采用 5 列布局更贴近参考样式 */
/* 移除宽屏5列布局，始终保持4列以贴合参考图 */

/* 在社交应用内（in-app）适当收紧行距以提升可读性 */
/* 统一风格：移除环境差异样式 */
/* 底部小图标（QQ / QQ空间） */
.mini { display: flex; gap: 24px; align-items: flex-start; margin-top: 8px; }
.mini-item { display: flex; flex-direction: column; align-items: center; color: var(--muted); }
.mini-item .ico { width: 24px; height: 24px; }
.mini-label { font-size: 12px; line-height: 1.25; margin-top: 6px; }