/* ============================================================
   科学计算器网 - 轻量 · 靓丽 · 时尚玻璃风（浅色）
   ============================================================ */
:root{
  --bg1:#eef2ff; --bg2:#faf5ff; --bg3:#ecfeff;
  --glass:rgba(255,255,255,.55);
  --glass-strong:rgba(255,255,255,.72);
  --border:rgba(15,23,42,.08);
  --border-strong:rgba(15,23,42,.14);
  --text:#0f172a; --muted:#64748b;
  --accent1:#06b6d4; --accent2:#6366f1; --accent3:#ec4899;
  --grad:linear-gradient(135deg,#22d3ee,#6366f1 55%,#a855f7);
  --grad-soft:linear-gradient(135deg,rgba(34,211,238,.16),rgba(168,85,247,.16));
  --glow:0 10px 30px rgba(99,102,241,.25);
  --radius:18px;
}
*{box-sizing:border-box;}
html,body{height:100%;}
body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",Segoe UI,Roboto,sans-serif;
  color:var(--text); line-height:1.65;
  background:
    radial-gradient(1000px 620px at 8% -10%, rgba(34,211,238,.20), transparent 60%),
    radial-gradient(1000px 620px at 100% 0%, rgba(168,85,247,.18), transparent 55%),
    radial-gradient(900px 600px at 50% 120%, rgba(99,102,241,.16), transparent 60%),
    linear-gradient(160deg,var(--bg1),var(--bg2) 55%,var(--bg3));
  background-attachment:fixed;
  min-height:100vh;
}
a{color:var(--accent2); text-decoration:none;}
a:hover{text-decoration:underline;}

/* ===== 顶部导航（玻璃） ===== */
.site-header{
  position:sticky; top:0; z-index:50;
  display:flex; align-items:center; gap:16px; flex-wrap:wrap; padding:14px 32px;
  background:rgba(255,255,255,.55); backdrop-filter:blur(16px); -webkit-backdrop-filter:blur(16px);
  border-bottom:1px solid var(--border);
}
.top-search{ flex:1 1 200px; max-width:460px; min-width:160px; }
.brand{display:flex; align-items:center; gap:12px;}
.brand:hover{text-decoration:none;}
.logo-mark{width:42px; height:42px; border-radius:12px; filter:drop-shadow(0 6px 14px rgba(99,102,241,.35)); flex:none;}
.logo-text{font-size:22px; font-weight:800; letter-spacing:.5px; background:var(--grad); -webkit-background-clip:text; background-clip:text; color:transparent;}
.logo-net{color:var(--accent1); -webkit-text-fill-color:var(--accent1);}
.top-nav{display:flex; gap:6px; flex-wrap:wrap;}
.top-nav a{
  padding:8px 16px; border-radius:999px; color:var(--text); font-size:14px; font-weight:600;
  border:1px solid transparent; transition:.15s;
}
.top-nav a:hover{background:var(--glass-strong); border-color:var(--border); text-decoration:none;}
.top-nav a.active{background:var(--grad); color:#fff; box-shadow:var(--glow);}
/* 汉堡按钮仅移动端显示 */
.menu-toggle{ display:none; }

/* ===== 布局（宽屏自适应） ===== */
.layout{
  max-width:1480px; margin:0 auto; display:flex; gap:24px;
  padding:24px; align-items:flex-start;
}
.sidebar{
  width:240px; flex:none; border-radius:var(--radius); padding:16px;
  position:sticky; top:86px;
  background:var(--glass); backdrop-filter:blur(14px); -webkit-backdrop-filter:blur(14px);
  border:1px solid var(--border); max-height:calc(100vh - 112px); overflow:auto;
}
.main-col{flex:1; min-width:0; display:flex; flex-direction:column;}

.nav-cat{font-size:12px; color:var(--muted); margin:16px 0 6px; font-weight:700; letter-spacing:.6px;}
.nav-cat:first-child{margin-top:0;}
.nav-sub{display:block; padding:7px 12px; color:var(--text); text-decoration:none; border-radius:8px; font-size:14px; transition:.15s; border:1px solid transparent;}
.nav-sub:hover{background:var(--glass-strong); border-color:var(--border); text-decoration:none;}
.nav-sub.active{background:var(--grad-soft); border-color:rgba(99,102,241,.30); color:var(--accent2); font-weight:700;}
.nav-item{display:block; padding:9px 12px; font-weight:700; text-decoration:none; color:var(--text); border-radius:8px; border:1px solid transparent;}
.nav-item:hover{background:var(--glass-strong); text-decoration:none;}

/* ===== 通用玻璃卡片 ===== */
.glass{
  background:var(--glass); backdrop-filter:blur(14px); -webkit-backdrop-filter:blur(14px);
  border:1px solid var(--border); border-radius:var(--radius);
}

/* ===== 首页 Hero / 搜索 ===== */
.hero{
  border-radius:var(--radius); padding:26px 32px; text-align:center; margin-bottom:22px;
  background:var(--glass); backdrop-filter:blur(16px); -webkit-backdrop-filter:blur(16px);
  border:1px solid var(--border); position:relative; overflow:hidden;
  box-shadow:0 12px 40px rgba(99,102,241,.10);
}
.hero::after{
  content:""; position:absolute; inset:0; pointer-events:none;
  background:radial-gradient(600px 220px at 50% -40%, rgba(34,211,238,.25), transparent 70%);
}
.hero h1{margin:0 0 10px; font-size:34px; background:var(--grad); -webkit-background-clip:text; background-clip:text; color:transparent; position:relative;}
.hero p{margin:0 0 18px; color:var(--muted); position:relative;}
.search{
  width:100%; max-width:480px; padding:10px 18px; border-radius:999px; font-size:15px; outline:none;
  background:rgba(255,255,255,.75); border:1px solid var(--border-strong); color:var(--text);
}
.search::placeholder{color:var(--muted);}
.search:focus{border-color:var(--accent2); box-shadow:var(--glow);}

/* ===== 首页：计算器全宽 + 热门推荐 ===== */
/* .featured 已在科学计算器区域统一定义（含光晕背景） */
.intro{
  border-radius:var(--radius); padding:22px 24px;
  background:var(--glass); backdrop-filter:blur(14px); -webkit-backdrop-filter:blur(14px);
  border:1px solid var(--border);
}
.intro h2{font-size:18px; margin:0 0 10px; color:var(--text);}
.intro p{margin:0; color:var(--muted); font-size:14px;}

/* ===== 分类 / 卡片（自适应列数） ===== */
.cat-sec{margin-bottom:26px;}
.cat-sec h2{font-size:18px; border-left:4px solid var(--accent2); padding-left:10px; margin:0 0 14px; color:var(--text);}
.cards{display:grid; grid-template-columns:repeat(auto-fill,minmax(220px,1fr)); gap:14px;}
.card{
  border-radius:12px; padding:16px; text-decoration:none; color:var(--text); transition:.18s;
  background:var(--glass); backdrop-filter:blur(10px); -webkit-backdrop-filter:blur(10px);
  border:1px solid var(--border);
}
.card:hover{transform:translateY(-3px); border-color:var(--accent2); box-shadow:0 12px 30px rgba(99,102,241,.18); text-decoration:none;}
.card-title{font-weight:700; margin-bottom:6px; color:var(--text);}
.card-desc{font-size:13px; color:var(--muted);}

/* ===== 计算器页面容器 ===== */
.calc{border-radius:var(--radius); padding:24px; background:var(--glass); backdrop-filter:blur(14px); -webkit-backdrop-filter:blur(14px); border:1px solid var(--border); box-shadow:0 12px 40px rgba(99,102,241,.08);}
.calc h2{margin-top:0; color:var(--text);}
.desc{color:var(--muted); margin-bottom:16px; font-size:14px;}
.row{display:flex; align-items:center; gap:10px; margin-bottom:12px; flex-wrap:wrap;}
.row label{width:128px; flex:none; font-size:14px; color:var(--muted);}
.row input,.row select{
  padding:9px 11px; border-radius:8px; font-size:14px; flex:1; min-width:120px;
  background:rgba(255,255,255,.8); border:1px solid var(--border-strong); color:var(--text); outline:none;
}
.row input:focus,.row select:focus{border-color:var(--accent2); box-shadow:var(--glow);}
.row input[type="datetime-local"]{color-scheme:light;}
button{
  padding:9px 16px; border:none; border-radius:8px; cursor:pointer; font-size:14px; transition:.15s;
  background:var(--grad); color:#fff; font-weight:600;
}
button:hover{filter:brightness(1.05); box-shadow:var(--glow);}
.swap{background:rgba(99,102,241,.12); color:var(--accent2); border:1px solid rgba(99,102,241,.25);}
.result{
  margin-top:16px; padding:16px; border-radius:10px; font-size:16px; line-height:1.9;
  background:var(--grad-soft); border:1px solid rgba(99,102,241,.25);
}
.result strong{color:var(--accent2);}
.disp{
  width:100%; padding:14px; font-size:22px; text-align:right; border-radius:10px; margin-bottom:12px;
  background:rgba(255,255,255,.8); border:1px solid var(--border-strong); color:var(--text);
}
.pad,.sci-pad{display:grid; grid-template-columns:repeat(4,1fr); gap:8px;}
.pad button,.sci-pad button{padding:14px; font-size:18px; color:#fff;}
.pad button{background:var(--grad);}
.pad button:hover{filter:brightness(1.08);}
.conv-table{width:100%; margin-top:16px; border-collapse:collapse; overflow:hidden; border-radius:10px;}
.conv-table th,.conv-table td{border:1px solid var(--border); padding:8px; text-align:right; font-size:14px;}
.conv-table th{background:rgba(99,102,241,.10); color:var(--muted);}
.hint{font-size:12px; color:var(--muted); margin-top:8px;}
.frac-row{display:flex; align-items:center; gap:8px; flex-wrap:wrap; margin-bottom:14px;}
.frac-row input{width:80px; padding:8px; border-radius:8px; text-align:center; background:rgba(255,255,255,.8); border:1px solid var(--border-strong); color:var(--text);}
.frac-row span{font-size:18px; color:var(--text);}

/* ===== 文章页（介绍 / 免责） ===== */
.doc{border-radius:var(--radius); padding:28px 30px; background:var(--glass); backdrop-filter:blur(14px); -webkit-backdrop-filter:blur(14px); border:1px solid var(--border);}
.doc h1{margin:0 0 14px; font-size:26px; color:var(--text);}
.doc h2{margin:22px 0 8px; font-size:18px; color:var(--text); border-left:4px solid var(--accent2); padding-left:10px;}
.doc p,.doc li{color:var(--muted); font-size:14.5px;}
.doc ul{padding-left:22px;}
.doc strong{color:var(--text);}

/* ===== 科学计算器 ===== */
.sci{ border-radius:18px; padding:16px; background:var(--glass-strong); backdrop-filter:blur(12px); -webkit-backdrop-filter:blur(12px); border:1px solid var(--border-strong); outline:none; }
.sci-display{ background:linear-gradient(160deg,#312e81,#1e1b4b); color:#fff; border-radius:12px; padding:14px 16px; text-align:right; margin-bottom:12px; border:1px solid rgba(255,255,255,.12); box-shadow:inset 0 0 24px rgba(34,211,238,.10); }
.sci-expr{ font-size:15px; color:#a5b4fc; line-height:20px; min-height:20px; white-space:nowrap; overflow-x:auto; }
.sci-out{ font-size:30px; font-weight:600; margin-top:2px; line-height:40px; min-height:40px; white-space:nowrap; overflow-x:auto; color:#eaf2ff; }
.sci-bar{ display:flex; justify-content:space-between; align-items:center; font-size:13px; color:var(--muted); margin-bottom:10px; }
.sci-deg label{ margin-left:8px; cursor:pointer; color:var(--text); }
.sci-mem{ font-variant-numeric:tabular-nums; color:var(--accent2); }
.sci-grid{ display:grid; grid-template-columns:repeat(5,1fr); gap:8px; margin-bottom:7px; }
.sci-grid button{ padding:16px 6px; font-size:17px; color:var(--text); border:1px solid var(--border); border-radius:12px; cursor:pointer; transition:.12s; background:rgba(255,255,255,.7); }
.sci-grid button:hover{ background:#fff; border-color:rgba(99,102,241,.5); }
/* 函数键区（sin/cos/tan 等）：缩小以降低整体高度 */
.sci-fn{ gap:5px; margin-bottom:4px; }
.sci-fn button{ padding:9px 4px; font-size:13px; border-radius:8px; }
.sci-fn button:hover{ background:rgba(99,102,241,.26); }
.sci-ac{ background:rgba(244,63,94,.16) !important; color:#be123c !important; border-color:rgba(244,63,94,.35) !important; font-weight:700; }
.sci-ac:hover{ background:rgba(244,63,94,.28) !important; }
.sci-eq{ background:var(--grad) !important; color:#fff !important; font-weight:700; border-color:transparent !important; }
.sci-eq:hover{ filter:brightness(1.08); box-shadow:var(--glow); }
.sci-hist{ margin-top:12px; border-top:1px dashed var(--border-strong); padding-top:10px; font-size:13px; color:var(--muted); }
.sci-hist div{ padding:2px 0; font-variant-numeric:tabular-nums; }

/* 科学计算器：主体 + 右侧"计算记录"面板 —— 宽屏自适应 */
.sci-wrap{
  display:grid;
  grid-template-columns: minmax(360px, 1fr) 260px;
  gap:20px; align-items:stretch;
  max-width:1140px; margin:0 auto; width:100%;
}
.sci-side{
  background:var(--glass); border:1px solid var(--border); border-radius:18px;
  padding:16px; overflow:auto; position:sticky; top:96px;
  align-self:stretch;   /* 与计算器等高 */
  display:flex; flex-direction:column;
}
.sci-side h3{ margin:0 0 10px; font-size:14px; color:var(--text); }
.sci-side .sci-hist{ border-top:none; padding-top:0; margin-top:0; }

/* 首页科学计算器区域：轻量化，不套双层框 */
.featured{
  padding:20px 16px 8px; text-align:center;
  /* 仅保留极淡的底部光晕，无边框无卡片感 */
  background:
    radial-gradient(800px 300px at 50% 0%, rgba(34,211,238,.10), transparent 70%);
}

/* ===== 广告位（预留） ===== */
.ad-slot{
  display:flex; align-items:center; justify-content:center; text-align:center;
  border:1.5px dashed var(--border-strong); border-radius:14px; color:var(--muted);
  background:rgba(255,255,255,.35); font-size:13px; letter-spacing:1px; margin:16px 0;
  /* 在此处粘贴广告联盟代码（如 Google AdSense / 百度联盟） */
}
.ad-banner{ height:90px; }
.ad-leaderboard{ height:120px; margin-top:26px; }
/* 未投放广告（内容为空）时自动隐藏广告位 */
.ad-slot:empty{ display:none; }

/* ===== 页脚 ===== */
.site-footer{
  text-align:center; padding:26px 20px; margin-top:24px; color:var(--muted); font-size:13px;
  background:rgba(255,255,255,.55); backdrop-filter:blur(14px); -webkit-backdrop-filter:blur(14px);
  border-top:1px solid var(--border);
}
.site-footer p{margin:6px 0;}
.site-footer a{color:var(--accent2);}

/* ===== 响应式（多端适应） ===== */
@media(max-width:860px){
  .layout{flex-direction:column; padding:14px;}
  .sidebar{width:100%; position:static; max-height:none; top:auto;}
  .row label{width:100px;}
}
/* 中等屏幕：计算记录面板移至计算器下方 */
@media(max-width:960px){
  .sci-wrap{ grid-template-columns:1fr; max-width:680px; }
  .sci-side{ max-height:none; position:static; }
}
@media(max-width:760px){
  /* ===== 移动端顶部导航（两排：Logo+搜索 / 汉堡） ===== */
  .site-header{
    padding:10px 14px; gap:8px; align-items:center;
  }
  /* 第一排：Logo + 搜索 */
  .brand{ flex:none; }
  .top-search{ flex:1; min-width:0; max-width:none; }
  /* 汉堡按钮 */
  .menu-toggle{
    display:flex; align-items:center; justify-content:center;
    width:40px; height:38px; border-radius:10px; font-size:20px;
    background:var(--grad); color:#fff; border:none; cursor:pointer;
    box-shadow:var(--glow); flex:none;
  }
  .menu-toggle:active{ transform:scale(.92); }

  /* 浮窗菜单（默认隐藏）——遮罩极淡，不干扰菜单可读性 */
  .menu-overlay{
    position:fixed; inset:0; z-index:90;
    background:rgba(0,0,0,.18);
    opacity:0; visibility:hidden;
    transition:opacity .2s ease, visibility .2s ease;
  }
  .menu-overlay.show{ opacity:1; visibility:visible; }
  .top-nav{
    display:block;   /* 始终存在但定位到屏幕外 */
    position:fixed; top:0; right:0; z-index:100;
    width:min(280px, 80vw); height:100vh;
    padding:60px 18px 24px;
    background:#ffffff;   /* 纯白不透明，杜绝任何透叠 */
    border-left:1px solid var(--border-strong);
    box-shadow:-8px 0 32px rgba(99,102,241,.16);
    transform:translateX(100%);
    transition:transform .28s cubic-bezier(.22,.61,.36,1);
    overflow-y:auto; -webkit-overflow-scrolling:touch;
    flex-direction:column; gap:6px;
    /* 强制不继承任何滤镜/透明 */
    opacity:1 !important; filter:none !important; backdrop-filter:none !important; -webkit-backdrop-filter:none !important;
  }
  .top-nav.open{ transform:translateX(0); }
  .top-nav a{
    display:flex; align-items:center; gap:10px;
    white-space:normal; padding:15px 16px; font-size:16px; font-weight:600;
    border-radius:12px; border:1px solid transparent;
    transition:.15s;
  }
  .top-nav a:hover{ background:var(--glass-strong); border-color:var(--border); text-decoration:none; }
  .top-nav a.active{ background:var(--grad-soft); border-color:rgba(99,102,241,.30); color:var(--accent2); font-weight:700; }

  .hero{padding:28px 18px;}
  .hero h1{font-size:26px;}
  .cards{grid-template-columns:repeat(auto-fill,minmax(150px,1fr));}
  .sci-grid button{font-size:15px; padding:13px 4px;}
  .sci-fn button{ font-size:12px; padding:8px 3px; }
  .sci-out{font-size:24px;}

  /* 移动端：计算器绝对置顶，全宽优先呈现 */
  .sci-wrap{ grid-template-columns:1fr; max-width:none; width:100%; }
  .sci-side{ max-height:none; position:static; order:2; }
  .featured{ padding:12px 8px 4px; }

  /* 首页布局：计算器在最上方，其他内容依次下排 */
  .home{ display:flex; flex-direction:column; gap:0; }
  .home .featured{ order:-1; margin-top:0; margin-bottom:20px; }

  /* 移动端隐藏左侧边栏，让计算器直接占据首屏 */
  .sidebar{ display:none; }

  /* 移动端让分类标题更紧凑 */
  .cat-sec{ margin-bottom:18px; }
  .cat-sec h2{ font-size:16px; }
}

/* ============================================================
   视觉/体验微调：滚动渐显 · 按压反馈 · 返回顶部 · 轻动效
   ============================================================ */
html{ scroll-behavior:smooth; }

/* 滚动渐显（默认隐藏，进入视口后上浮淡入） */
.reveal{
  opacity:0; transform:translateY(18px);
  transition:opacity .55s cubic-bezier(.22,.61,.36,1), transform .55s cubic-bezier(.22,.61,.36,1);
}
.reveal.in{ opacity:1; transform:none; }

/* 按钮按压反馈 */
.sci-grid button:active,.pad button:active{ transform:scale(.94); }
button:active{ transform:translateY(1px); }

/* 返回顶部悬浮按钮 */
.to-top{
  position:fixed; right:20px; bottom:22px; z-index:60;
  width:46px; height:46px; border-radius:50%; padding:0; font-size:20px; line-height:1;
  display:flex; align-items:center; justify-content:center;
  background:var(--grad); color:#fff; border:none; cursor:pointer;
  box-shadow:var(--glow);
  opacity:0; visibility:hidden; transform:translateY(10px);
  transition:opacity .25s ease, transform .25s ease, visibility .25s ease;
}
.to-top.show{ opacity:1; visibility:visible; transform:none; }
.to-top:hover{ filter:brightness(1.08); box-shadow:var(--glow); }
.to-top:active{ transform:scale(.92); }

/* Logo 轻浮动（科技感点缀） */
.logo-mark{ animation:logoFloat 5s ease-in-out infinite; }
@keyframes logoFloat{ 0%,100%{ transform:translateY(0); } 50%{ transform:translateY(-3px); } }

/* 无障碍：尊重系统「减少动态效果」设置 */
@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  .reveal{ opacity:1 !important; transform:none !important; transition:none; }
  .logo-mark{ animation:none; }
}
@media(max-width:760px){
  .to-top{ right:14px; bottom:16px; width:42px; height:42px; font-size:18px; }
}