/* ============================================================
 * 阶段4 场景化首屏 · 紫蓝品牌设计系统组件
 * 方案文档 §4：紫蓝 #4f46e5 基调 + 0.5px 细边框 + 8px 栅格 + 卡片化
 * 复用 :root 中的 --brand 系列变量（styles.css 已落地）
 * ============================================================ */

/* ---------- AI 主理人入口区（置顶，撮合对话 CTA） ---------- */
.stage4-ai-entry {
  margin: calc(var(--grid-unit) * 2) calc(var(--grid-unit) * 2) 0;
  padding: calc(var(--grid-unit) * 3);
  background: var(--gradient-brand);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-brand);
  color: #fff;
  position: relative;
  overflow: hidden;
}
.stage4-ai-entry::before {
  content: '';
  position: absolute;
  top: -40px; right: -40px;
  width: 160px; height: 160px;
  background: radial-gradient(circle, rgba(255,255,255,0.18) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}
.stage4-ai-entry-head {
  display: flex; align-items: center; gap: calc(var(--grid-unit) * 1.5);
  margin-bottom: calc(var(--grid-unit) * 1.5);
}
.stage4-ai-entry-logo {
  width: 44px; height: 44px;
  border-radius: 12px;
  background: rgba(255,255,255,0.22);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
  flex-shrink: 0;
}
.stage4-ai-entry-title { font-size: 17px; font-weight: 700; line-height: 1.3; }
.stage4-ai-entry-sub { font-size: 12.5px; opacity: 0.88; margin-top: 2px; }
.stage4-ai-entry-body {
  display: flex; align-items: center; gap: calc(var(--grid-unit) * 2);
  flex-wrap: wrap;
}
.stage4-ai-entry-input {
  flex: 1; min-width: 200px;
  display: flex; align-items: center; gap: var(--grid-unit);
  background: rgba(255,255,255,0.96);
  border-radius: var(--radius-brand);
  padding: 10px 14px;
}
.stage4-ai-entry-input input {
  flex: 1; border: none; background: transparent; outline: none;
  font-size: 14px; color: var(--text);
}
.stage4-ai-entry-input input::placeholder { color: #94a3b8; }
.stage4-ai-entry-cta {
  flex-shrink: 0;
  padding: 10px 22px;
  background: #fff;
  color: var(--brand);
  border: none; border-radius: var(--radius-brand);
  font-size: 14px; font-weight: 600;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
}
.stage4-ai-entry-cta:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(0,0,0,0.15); }
.stage4-ai-entry-features {
  display: flex; gap: calc(var(--grid-unit) * 2); margin-top: calc(var(--grid-unit) * 2);
  flex-wrap: wrap;
}
.stage4-ai-entry-feature {
  display: flex; align-items: center; gap: 5px;
  font-size: 12px; opacity: 0.92;
}

/* ---------- 活动专区（运营位） ---------- */
.stage4-activity {
  margin: calc(var(--grid-unit) * 2);
}
.stage4-section-head {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: calc(var(--grid-unit) * 1.5);
}
.stage4-section-title {
  font-size: 16px; font-weight: 700; color: var(--text);
  display: flex; align-items: center; gap: var(--grid-unit);
}
.stage4-section-title::before {
  content: ''; width: 4px; height: 18px;
  background: var(--gradient-brand); border-radius: 2px;
}
.stage4-section-more {
  font-size: 13px; color: var(--brand); cursor: pointer;
}
.stage4-activity-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: calc(var(--grid-unit) * 1.5);
}
.stage4-activity-card {
  border: var(--border-thin) solid var(--border);
  border-radius: var(--radius-brand);
  overflow: hidden;
  background: var(--surface);
  cursor: pointer;
  transition: box-shadow 0.2s, transform 0.2s;
}
.stage4-activity-card:hover { box-shadow: var(--shadow-brand); transform: translateY(-2px); }
.stage4-activity-card-img {
  width: 100%; height: 120px;
  background: var(--gradient-brand-soft);
  display: flex; align-items: center; justify-content: center;
  font-size: 36px;
}
.stage4-activity-card-body { padding: calc(var(--grid-unit) * 1.5); }
.stage4-activity-card-title { font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 4px; }
.stage4-activity-card-desc { font-size: 12px; color: var(--text-2); line-height: 1.5; }
.stage4-activity-card-tag {
  display: inline-block; margin-top: 6px;
  padding: 2px 8px; font-size: 11px;
  background: var(--brand-50); color: var(--brand);
  border-radius: 4px;
}

/* ---------- 成长榜单区（Top 店铺 + 成长分） ---------- */
.stage4-ranking {
  margin: calc(var(--grid-unit) * 2);
}
.stage4-ranking-list {
  display: flex; flex-direction: column; gap: var(--grid-unit);
}
.stage4-ranking-item {
  display: flex; align-items: center; gap: calc(var(--grid-unit) * 1.5);
  padding: calc(var(--grid-unit) * 1.5);
  border: var(--border-thin) solid var(--border);
  border-radius: var(--radius-brand);
  background: var(--surface);
  cursor: pointer;
  transition: box-shadow 0.2s;
}
.stage4-ranking-item:hover { box-shadow: var(--shadow-brand); }
.stage4-ranking-num {
  width: 28px; height: 28px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: 700; flex-shrink: 0;
  color: #fff;
}
.stage4-ranking-num.top1 { background: linear-gradient(135deg, #f59e0b, #fbbf24); }
.stage4-ranking-num.top2 { background: linear-gradient(135deg, #94a3b8, #cbd5e1); color: var(--text); }
.stage4-ranking-num.top3 { background: linear-gradient(135deg, #d97706, #f59e0b); }
.stage4-ranking-num.normal { background: var(--brand-100); color: var(--brand); }
.stage4-ranking-logo {
  width: 48px; height: 48px; border-radius: 10px;
  object-fit: cover; flex-shrink: 0;
  border: var(--border-thin) solid var(--border);
}
.stage4-ranking-info { flex: 1; min-width: 0; }
.stage4-ranking-name { font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 4px; }
.stage4-ranking-meta { font-size: 12px; color: var(--text-2); display: flex; gap: calc(var(--grid-unit)); flex-wrap: wrap; }
.stage4-ranking-score {
  text-align: right; flex-shrink: 0;
}
.stage4-ranking-score-val {
  font-size: 20px; font-weight: 800; color: var(--brand);
  line-height: 1;
}
.stage4-ranking-score-label { font-size: 11px; color: var(--text-2); margin-top: 2px; }

/* 成长分四维进度条 */
.stage4-growth-bars {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--grid-unit);
  margin-top: calc(var(--grid-unit));
  padding-top: calc(var(--grid-unit));
  border-top: var(--border-thin) dashed var(--border);
}
.stage4-growth-bar-item { text-align: center; }
.stage4-growth-bar-label { font-size: 11px; color: var(--text-2); margin-bottom: 4px; }
.stage4-growth-bar-track {
  height: 6px; background: var(--brand-50); border-radius: 3px; overflow: hidden;
}
.stage4-growth-bar-fill { height: 100%; background: var(--gradient-brand); border-radius: 3px; transition: width 0.4s; }
.stage4-growth-bar-val { font-size: 11px; font-weight: 600; color: var(--brand); margin-top: 3px; }

/* ---------- 店铺卡片成长徽章 ---------- */
.stage4-store-badge {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 2px 8px;
  background: var(--gradient-brand-soft);
  border: var(--border-thin) solid var(--brand-200);
  border-radius: 10px;
  font-size: 11px; font-weight: 600; color: var(--brand);
}
.stage4-store-badge-icon { font-size: 10px; }

/* ---------- 响应式适配（PC + 移动同步） ---------- */
@media (max-width: 768px) {
  .stage4-ai-entry { margin: calc(var(--grid-unit)) calc(var(--grid-unit)) 0; padding: calc(var(--grid-unit) * 2); }
  .stage4-ai-entry-title { font-size: 15px; }
  .stage4-ai-entry-sub { font-size: 11.5px; }
  .stage4-ai-entry-input { min-width: 100%; }
  .stage4-ai-entry-cta { width: 100%; padding: 11px; }
  .stage4-ai-entry-features { gap: var(--grid-unit); }
  .stage4-ai-entry-feature { font-size: 11px; }

  .stage4-activity, .stage4-ranking { margin: calc(var(--grid-unit)); }
  .stage4-activity-grid { grid-template-columns: repeat(2, 1fr); gap: var(--grid-unit); }
  .stage4-activity-card-img { height: 100px; font-size: 28px; }

  .stage4-ranking-item { padding: var(--grid-unit); gap: var(--grid-unit); }
  .stage4-ranking-logo { width: 40px; height: 40px; }
  .stage4-ranking-name { font-size: 13px; }
  .stage4-ranking-meta { font-size: 11px; gap: 6px; }
  .stage4-ranking-score-val { font-size: 17px; }
  .stage4-growth-bars { grid-template-columns: repeat(2, 1fr); gap: 6px; }
}

@media (min-width: 1024px) {
  .stage4-ai-entry { margin: calc(var(--grid-unit) * 3) auto 0; max-width: 960px; }
  .stage4-activity, .stage4-ranking, .stage4-external { margin: calc(var(--grid-unit) * 3) auto; max-width: 960px; }
}

/* ============================================================
 * 阶段6-② 公域联盟区块 + 内页付款弹窗
 * ============================================================ */
.stage4-external { padding: 0 16px; }
.stage4-external-note { font-size: 12px; color: var(--brand); font-weight: 600; }
.stage4-external-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}
.stage4-external-card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px;
  border: var(--border-thin) solid var(--brand-200);
  border-radius: var(--radius-brand);
  background: #fff;
  box-shadow: var(--shadow-brand);
  cursor: pointer;
  transition: all 0.2s ease;
  position: relative;
}
.stage4-external-card:hover {
  border-color: var(--brand);
  box-shadow: var(--shadow-brand-lg);
  transform: translateY(-2px);
}
.stage4-external-card-icon {
  width: 48px; height: 48px;
  display: flex; align-items: center; justify-content: center;
  font-size: 26px;
  background: var(--gradient-brand-soft);
  border-radius: 10px;
  flex-shrink: 0;
}
.stage4-external-card-body { flex: 1; min-width: 0; }
.stage4-external-card-title { font-size: 14px; font-weight: 700; color: var(--text-1, #1e293b); margin-bottom: 2px; }
.stage4-external-card-desc { font-size: 11.5px; color: var(--text-2, #64748b); line-height: 1.4; }
.stage4-external-card-price { font-size: 15px; font-weight: 700; color: #ef4444; margin-top: 4px; }
.stage4-external-card-rebate { font-size: 11px; color: #10b981; font-weight: 400; margin-left: 6px; }
.stage4-external-card-tag {
  position: absolute; top: 8px; right: 8px;
  font-size: 10px; padding: 2px 6px;
  background: var(--gradient-brand);
  color: #fff; border-radius: 4px; font-weight: 600;
}

/* 付款弹窗 */
.stage4-external-overlay {
  position: fixed; top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(15, 23, 42, 0.55);
  display: flex; align-items: center; justify-content: center;
  z-index: 10000;
  animation: stage4FadeIn 0.2s ease;
}
@keyframes stage4FadeIn { from { opacity: 0; } to { opacity: 1; } }
.stage4-external-modal {
  width: 90%; max-width: 520px;
  background: #fff;
  border-radius: var(--radius-card);
  box-shadow: 0 20px 60px rgba(0,0,0,0.25);
  overflow: hidden;
  animation: stage4SlideUp 0.25s ease;
}
@keyframes stage4SlideUp { from { transform: translateY(20px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }
.stage4-external-modal-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 20px;
  background: var(--gradient-brand);
  color: #fff;
}
.stage4-external-modal-title { font-size: 15px; font-weight: 700; }
.stage4-external-modal-close {
  background: rgba(255,255,255,0.2);
  border: none; color: #fff;
  width: 28px; height: 28px; border-radius: 50%;
  cursor: pointer; font-size: 14px;
  display: flex; align-items: center; justify-content: center;
}
.stage4-external-modal-close:hover { background: rgba(255,255,255,0.35); }
.stage4-external-modal-body { padding: 0; max-height: 60vh; overflow-y: auto; }
.stage4-external-order-info {
  display: flex; flex-wrap: wrap; gap: 12px;
  padding: 12px 20px;
  background: #f8fafc;
  font-size: 12px; color: #475569;
  border-bottom: 1px solid #e2e8f0;
}
.stage4-external-iframe {
  width: 100%; height: 320px;
  border: none;
  display: block;
}
.stage4-external-pay-done {
  background: var(--gradient-brand);
  color: #fff; border: none;
  padding: 10px 24px;
  border-radius: var(--radius-brand);
  font-size: 14px; font-weight: 700;
  cursor: pointer;
  transition: all 0.2s ease;
}
.stage4-external-pay-done:hover { box-shadow: var(--shadow-brand-lg); transform: translateY(-1px); }
.stage4-external-modal-foot {
  padding: 10px 20px;
  background: #f8fafc;
  border-top: 1px solid #e2e8f0;
  text-align: center;
}

@media (max-width: 640px) {
  .stage4-external-grid { grid-template-columns: 1fr; }
  .stage4-external-modal { width: 95%; }
  .stage4-external-iframe { height: 280px; }
}