/* =========================================================
   Moreast — 首页专属布局文件（页眉 / 页脚 / 导航）
   ---------------------------------------------------------
   本文件【仅首页 index.html】使用，管理该页的页面框架样式：
     · 顶部导航（.site-header / .nav / .nav__*）
     · 移动端折叠菜单（.nav__toggle / .is-open）
     · 页脚（.site-footer / .footer__*）
   与各页内容样式 styles.css 完全分离。
   对应结构由 index-header.js 注入（<div id="site-header"> /
   <div id="site-footer">）。
   注意：本文件依赖 styles.css 中定义的 :root 设计变量。
   ========================================================= */

/* ---------- 5. 顶部导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

/* ===== Logo（品牌标识，非按钮） ===== */
.nav__logo {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  transition: opacity 0.25s ease;
}
.nav__logo:hover { opacity: 0.85; }

/* 标记图标 */
.nav__logo .mark {
  width: 38px; height: 38px; border-radius: 11px;
  background: linear-gradient(150deg, #1b3a6b 0%, #2b62b8 55%, #f5a623 120%);
  display: grid; place-items: center;
  color: #fff; font-weight: 900; font-size: 1.25rem;
  letter-spacing: -1px;
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.3), 0 4px 12px rgba(27,58,107,0.3);
}

/* 品牌文字（中文主标 + 英文辅标） */
.nav__brand-text { display: flex; flex-direction: column; line-height: 1.05; }
.nav__brand-cn {
  font-size: 1.2rem; font-weight: 800; color: var(--color-brand);
  letter-spacing: 0.04em;
}
.nav__brand-en {
  font-size: 0.62rem; font-weight: 700; letter-spacing: 0.32em;
  color: var(--color-accent-dark); text-transform: uppercase;
}

/* 右侧操作区：导航菜单 + CTA + 移动端按钮 */
.nav__right { display: flex; align-items: center; gap: var(--space-md); }
.nav__menu { display: flex; align-items: center; gap: 10px; }
.nav__menu a {
  font-size: var(--fs-sm); font-weight: 600; color: var(--color-text);
  padding: 8px 18px;
  border-radius: 8px;
  border: 1.5px solid #e5e7eb;
  background: #fff;
  transition: all 0.2s ease; position: relative;
}
.nav__menu a::after { display: none; }
.nav__menu a:hover,
.nav__menu a.is-active {
  color: #fff;
  background: linear-gradient(135deg, #1b3a6b, #2563eb);
  border-color: transparent;
}

.nav__lang {
  font-size: var(--fs-xs); font-weight: 700; padding: 0.4rem 0.9rem;
  border: 1px solid var(--color-border); border-radius: 20px; color: var(--color-text-muted);
}
.nav__toggle {
  display: none; background: none; border: none; font-size: 1.6rem;
  cursor: pointer; color: var(--color-brand); line-height: 1;
}

/* ---------- 12. 页脚 ---------- */
.site-footer { background: var(--color-bg-dark); color: #c7d4e6; padding: 2.2rem 0 1.5rem; }
.footer__grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 1.5rem; }
.footer__grid h4 { color: #fff; font-size: 0.95rem; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; margin-bottom: 0.6rem; }
.footer__grid a { color: #c7d4e6; font-size: 0.95rem; display: block; margin-bottom: 0.45rem; line-height: 1.5; }
.footer__grid a:hover { color: var(--color-accent); }
.footer__grid span { display: block; font-size: 0.95rem; color: #c7d4e6; margin-bottom: 0.45rem; line-height: 1.55; }
.footer__brand { color: #fff; font-weight: 800; font-size: 1.35rem; margin-bottom: 0.5rem; }
.footer__brand-col { grid-column: span 1; }
.footer__desc { font-size: 0.95rem; max-width: 380px; line-height: 1.65; margin-bottom: 0; color: #c7d4e6; }
.footer__contact-mini { display: flex; flex-direction: column; gap: 6px; }
.footer__contact-mini a { font-size: 0.95rem; color: #c7d4e6; margin-bottom: 0; }
.footer__contact-mini a:hover { color: var(--color-accent); }
.footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.12); margin-top: 1.25rem;
  padding-top: 0.8rem; font-size: 0.82rem; text-align: center; color: #8fa3c0;
}

/* ---------- 响应式：仅页眉 / 页脚布局 ---------- */
@media (max-width: 960px) {
  .footer__grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .nav__right { gap: 0.6rem; }
  .nav__menu {
    display: none;
    position: absolute; top: 72px; left: 0; right: 0;
    flex-direction: column; align-items: flex-start; gap: var(--space-sm);
    background: #fff; padding: var(--space-md);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
  }
  .nav__menu.is-open { display: flex; }
  .nav__menu a { font-size: 1rem; padding: 10px 20px; }
  .nav__toggle { display: block; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
  .footer__brand-col { grid-column: 1 / -1; }
}