/* ============================================
   AI论文助手 — 公共样式
   兼容 百度APP WebKit 537.36 / Chrome 97
   ============================================ */

*,*::before,*::after{margin:0;padding:0;-webkit-box-sizing:border-box;box-sizing:border-box}
html{font-size:16px;-webkit-text-size-adjust:100%;-ms-text-size-adjust:100%;scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","微软雅黑",Arial,sans-serif;background:#06061a;color:#e2e8f0;-webkit-font-smoothing:antialiased;overflow-x:hidden}

/* ---- 通用渐变文字 ---- */
.gradient-text{background:-webkit-linear-gradient(135deg,#a78bfa,#60a5fa);background:linear-gradient(135deg,#a78bfa,#60a5fa);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}

/* ============ 导航栏 ============ */
.nav{position:fixed;top:0;left:0;right:0;z-index:500;-webkit-transition:background .3s,box-shadow .3s;transition:background .3s,box-shadow .3s}
.nav.scrolled{background:rgba(6,6,26,.92);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);box-shadow:0 1px 0 rgba(255,255,255,.06)}
.nav-inner{max-width:1200px;margin:0 auto;padding:0 24px;height:68px;display:-webkit-box;display:-webkit-flex;display:flex;-webkit-box-align:center;-webkit-align-items:center;align-items:center;-webkit-box-pack:justify;-webkit-justify-content:space-between;justify-content:space-between}

/* 品牌 */
.brand{display:-webkit-box;display:-webkit-flex;display:flex;-webkit-box-align:center;-webkit-align-items:center;align-items:center;gap:10px;text-decoration:none}
.brand-logo{width:36px;height:36px;-webkit-flex-shrink:0;flex-shrink:0}
.brand-logo svg{width:100%;height:100%;display:block}.brand-logo-img{width:36px;height:36px;display:block;object-fit:contain;-webkit-border-radius:6px;border-radius:6px}
.brand-name{font-size:18px;font-weight:700;color:#fff;letter-spacing:.3px}

/* 导航链接 */
.nav-links{display:-webkit-box;display:-webkit-flex;display:flex;gap:4px}
.nav-link{padding:8px 16px;border-radius:8px;color:rgba(255,255,255,.6);text-decoration:none;font-size:14px;font-weight:500;-webkit-transition:all .2s;transition:all .2s}
.nav-link:hover{color:#fff;background:rgba(255,255,255,.08)}
.nav-link.active{color:#fff;background:rgba(124,58,237,.2)}

/* 导航按钮 */
.btn-nav{padding:8px 20px;border-radius:8px;background:-webkit-linear-gradient(135deg,#7C3AED,#2563EB);background:linear-gradient(135deg,#7C3AED,#2563EB);color:#fff;text-decoration:none;font-size:14px;font-weight:600;-webkit-transition:opacity .2s;transition:opacity .2s}
.btn-nav:hover{opacity:.85}

/* 移动端汉堡 */
.nav-toggle{display:none;-webkit-box-orient:vertical;-webkit-box-direction:normal;-webkit-flex-direction:column;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:4px}
.nav-toggle span{display:block;width:22px;height:2px;background:rgba(255,255,255,.8);border-radius:2px;-webkit-transition:all .3s;transition:all .3s}

/* 移动端菜单 */
.nav-mobile{display:none;-webkit-box-orient:vertical;-webkit-box-direction:normal;-webkit-flex-direction:column;flex-direction:column;padding:12px 24px 16px;background:rgba(6,6,26,.96);border-top:1px solid rgba(255,255,255,.06)}
.nav-mobile.open{display:-webkit-box;display:-webkit-flex;display:flex}
.nm-link{padding:12px 0;color:rgba(255,255,255,.7);text-decoration:none;font-size:15px;border-bottom:1px solid rgba(255,255,255,.06)}
.nm-link:last-child{border-bottom:none}

/* ============ Toast ============ */
.toast{position:fixed;bottom:32px;left:50%;-webkit-transform:translateX(-50%);transform:translateX(-50%);background:rgba(15,15,40,.95);border:1px solid rgba(255,255,255,.12);color:#fff;padding:12px 28px;border-radius:40px;font-size:14px;z-index:9999;white-space:nowrap;box-shadow:0 8px 32px rgba(0,0,0,.4);-webkit-transition:opacity .3s;transition:opacity .3s}
.toast.hidden{display:none}
.toast.show{opacity:1}

/* ============ 响应式 ============ */
@media(max-width:768px){
  .nav-links,.nav-actions{display:none}
  .nav-toggle{display:-webkit-box;display:-webkit-flex;display:flex}
}