/* ============================================================
   footer.css — 底部页脚样式（所有页面共用）
   结构：订阅区 → 链接区 → 版权栏
   ============================================================ */

.site-footer {
  margin-top: 4rem;
  border-top: 1px solid var(--border);
  background: var(--surface);
}

/* ---------- 订阅区 ---------- */
.footer-news {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1.2rem;
  padding-block: 2.2rem;
  border-bottom: 1px solid var(--border);
}

.footer-news h3 {
  font-size: 1.2rem;
}

.footer-news p {
  color: var(--text-2);
  font-size: 0.9rem;
  margin-top: 0.25rem;
}

.footer-news-form {
  display: flex;
  gap: 0.6rem;
}

.news-input {
  padding: 0.7rem 1.15rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 0.9rem;
  min-width: 280px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.news-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-soft);
}

.news-input::placeholder {
  color: var(--text-2);
}

/* ---------- 链接区 ---------- */
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr 1fr;
  gap: 2rem;
  padding-block: 2.8rem 2.2rem;
}

.footer-brand .brand {
  margin-bottom: 0.6rem;
}

.footer-brand p {
  color: var(--text-2);
  font-size: 0.92rem;
  max-width: 300px;
}

.footer-social {
  display: flex;
  gap: 0.55rem;
  margin-top: 1rem;
}

.footer-social a {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg);
  display: grid;
  place-items: center;
  color: var(--text-2);
  transition: all 0.2s ease;
}

.footer-social a:hover {
  color: var(--primary);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.footer-col h4 {
  font-size: 0.95rem;
  margin-bottom: 0.9rem;
}

.footer-col a {
  display: block;
  color: var(--text-2);
  font-size: 0.9rem;
  padding: 0.22rem 0;
  transition: color 0.2s ease;
}

.footer-col a:hover {
  color: var(--primary);
}

/* ---------- 版权栏 ---------- */
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding-block: 1.3rem;
  border-top: 1px solid var(--border);
  color: var(--text-2);
  font-size: 0.85rem;
}

.back-top {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  color: var(--primary);
  font-weight: 600;
}

.back-top:hover {
  text-decoration: underline;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1100px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr 1fr;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 720px) {
  .footer-news {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-news-form {
    width: 100%;
    flex-direction: column;
  }

  .news-input {
    width: 100%;
    min-width: 0;
  }
}

@media (max-width: 560px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-brand {
    grid-column: auto;
  }

  .footer-bottom {
    justify-content: center;
    text-align: center;
  }
}

/* 移动端：品牌/关于信息 + 各栏目整列居中 */
@media (max-width: 720px) {
  .footer-brand {
    text-align: center;
  }

  .footer-brand .brand {
    justify-content: center;
  }

  .footer-brand p {
    margin-inline: auto;
  }

  .footer-social {
    justify-content: center;
  }

  /* 导航 / 文档分类 / 资源 / 支持 / 关于 各列整体居中 */
  .footer-col {
    text-align: center;
  }

  .footer-col h4 {
    text-align: center;
  }
}