/* njfuer 校园邮箱 · 介绍页样式 */
:root{
  --brand:#0c3d31;
  --brand-2:#1c7a5f;
  --ink:#0d1b14;
  --ink-2:#2c3d34;
  --muted:#59675f;
  --line:#e2e8df;
  --line-2:#eaf0e8;
  --bg:#ffffff;
  --bg-soft:#f7f8f5;
  --radius:20px;
  --shadow-sm:0 1px 2px rgba(12,30,22,.05);
  --shadow:0 10px 30px -12px rgba(12,30,22,.18);
  --shadow-lg:0 30px 60px -30px rgba(12,30,22,.35);
  --max:1120px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  overflow-x:clip;
  font-family:-apple-system,BlinkMacSystemFont,"SF Pro Text","Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  color:var(--ink);
  background:var(--bg);
  -webkit-font-smoothing:antialiased;
  line-height:1.65;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
h1,h2,h3{margin:0;line-height:1.2;letter-spacing:-.02em;font-weight:700}
p{margin:0}
.wrap{width:100%;max-width:var(--max);margin:0 auto;padding:0 24px}
.voice{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:.5em;
  padding:13px 22px;border-radius:12px;font-size:15px;font-weight:600;
  border:1px solid transparent;cursor:pointer;transition:transform .18s ease,box-shadow .18s ease,background .18s ease,border-color .18s;
  white-space:nowrap;
}
.btn-sm{padding:9px 16px;font-size:14px;border-radius:10px}
.btn .arrow{transition:transform .18s ease}
.btn:hover .arrow{transform:translateX(3px)}
.btn-primary{background:linear-gradient(135deg,var(--brand),#145c49);color:#fff;box-shadow:0 10px 24px -10px rgba(12,61,49,.7)}
.btn-primary:hover{transform:translateY(-1px);box-shadow:0 16px 30px -12px rgba(12,61,49,.65)}
.btn-ghost{background:#fff;border-color:var(--line);color:var(--ink-2);box-shadow:var(--shadow-sm)}
.btn-ghost:hover{border-color:#c9d4ea;transform:translateY(-1px)}
.btn-light{background:#fff;color:var(--brand);box-shadow:0 14px 30px -14px rgba(0,0,0,.5)}
.btn-light:hover{transform:translateY(-1px)}

/* ---------- nav ---------- */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);backdrop-filter:saturate(180%) blur(14px);border-bottom:1px solid transparent}
.nav.scrolled{border-bottom-color:var(--line-2)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:68px;gap:24px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;letter-spacing:-.01em}
.brand-name{font-size:16px}
.brand-tag{font-size:12px;color:var(--muted);padding:2px 8px;border:1px solid var(--line);border-radius:999px;font-weight:500}
.nav-links{display:flex;gap:28px;font-size:14.5px;color:var(--ink-2)}
.nav-links a{position:relative;padding:4px 0;transition:color .16s}
.nav-links a:hover{color:var(--brand)}
.nav-links a::after{content:"";position:absolute;left:0;right:100%;bottom:-2px;height:2px;background:var(--brand);transition:right .2s ease;border-radius:2px}
.nav-links a:hover::after{right:0}

/* ---------- hero ---------- */
.hero{position:relative;padding:72px 0 0;overflow:hidden}
.hero-bg{
  position:absolute;inset:0;pointer-events:none;
  background:
    radial-gradient(760px 460px at 18% -12%,rgba(28,122,95,.16),transparent 62%),
    radial-gradient(680px 460px at 86% 2%,rgba(12,61,49,.10),transparent 64%),
    radial-gradient(900px 520px at 50% 118%,rgba(230,243,235,.9),transparent 60%),
    linear-gradient(180deg,#f7f8f5,#ffffff 58%);
}
.hero-bg::after{
  content:"";position:absolute;inset:0;
  background-image:linear-gradient(rgba(12,30,22,.045) 1px,transparent 1px),linear-gradient(90deg,rgba(12,30,22,.045) 1px,transparent 1px);
  background-size:56px 56px;
  mask-image:radial-gradient(700px 420px at 50% 0%,#000 20%,transparent 78%);
  -webkit-mask-image:radial-gradient(700px 420px at 50% 0%,#000 20%,transparent 78%);
}
.hero-inner{position:relative;display:grid;grid-template-columns:1.05fr .95fr;gap:56px;align-items:center;padding-bottom:56px}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:12.5px;letter-spacing:.14em;color:var(--brand);font-weight:600;margin-bottom:22px}
.eyebrow .dot{width:7px;height:7px;border-radius:50%;background:var(--brand);box-shadow:0 0 0 4px rgba(12,61,49,.14)}
.hero h1{font-size:clamp(2.2rem,4.6vw,3.7rem);letter-spacing:-.045em;font-weight:800}
.grad{background:linear-gradient(115deg,var(--brand) 10%,#145c49 45%,var(--brand-2));-webkit-background-clip:text;background-clip:text;color:transparent}
.lede{margin-top:22px;font-size:16.5px;color:var(--muted);max-width:31em}
.lede strong{color:var(--ink-2)}
.hero-actions{display:flex;gap:12px;margin-top:32px;flex-wrap:wrap}
.hero-meta{list-style:none;display:flex;flex-wrap:wrap;gap:18px;margin:26px 0 0;padding:0;font-size:13.5px;color:var(--muted)}
.hero-meta li{position:relative;padding-left:18px}
.hero-meta li::before{content:"";position:absolute;left:0;top:.55em;width:8px;height:8px;border-radius:3px;background:linear-gradient(135deg,var(--brand),var(--brand-2));opacity:.55}

/* mail preview card */
.hero-visual{position:relative}
.mailcard{background:#fff;border:1px solid var(--line);border-radius:20px;box-shadow:var(--shadow-lg);overflow:hidden;transform:rotate(.4deg)}
.mailcard-top{display:flex;align-items:center;gap:10px;padding:16px 18px;border-bottom:1px solid var(--line-2)}
.mc-title{font-weight:700;font-size:14px}
.mc-badge{background:var(--brand);color:#fff;font-size:11.5px;font-weight:700;padding:1px 7px;border-radius:999px}
.mc-dots{margin-left:auto;display:flex;gap:5px}
.mc-dots i{width:7px;height:7px;border-radius:50%;background:#d8dfee}
.mc-list{list-style:none;margin:0;padding:6px}
.mc-list li{display:flex;align-items:center;gap:12px;padding:12px;border-radius:12px}
.mc-list li + li{margin-top:2px}
.mc-list li.unread{background:linear-gradient(90deg,rgba(12,61,49,.06),rgba(12,61,49,0))}
.av{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;font-size:13px;font-weight:700;color:#fff;flex:none}
.av-blue{background:linear-gradient(135deg,#1c7a5f,#0c3d31)}
.av-teal{background:linear-gradient(135deg,#22c3d6,#1c7a5f)}
.av-indigo{background:linear-gradient(135deg,#6f8f5f,#3f5f3f)}
.mc-main{display:flex;flex-direction:column;min-width:0}
.mc-main b{font-size:13.5px;font-weight:600}
.mc-main em{font-style:normal;font-size:12.5px;color:var(--muted);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.mc-time{margin-left:auto;font-size:11.5px;color:#8a978e;flex:none}
.mailcard-foot{display:flex;align-items:center;gap:6px;padding:12px 18px;border-top:1px solid var(--line-2);background:#fbfcf9}
.ok{font-size:10.5px;font-weight:700;letter-spacing:.04em;color:#0d7a56;background:#e8f7f0;border:1px solid #c9ecdd;padding:2px 7px;border-radius:6px}
.mc-foot-text{margin-left:auto;font-size:11.5px;color:#8a978e}
.float-badge{
  position:absolute;right:-12px;top:-16px;display:flex;align-items:center;gap:8px;
  background:#fff;border:1px solid var(--line);border-radius:999px;padding:9px 16px;font-size:12.5px;color:var(--ink-2);
  box-shadow:var(--shadow);font-weight:500;
}
.pulse{width:8px;height:8px;border-radius:50%;background:#12b76a;box-shadow:0 0 0 0 rgba(18,183,106,.6);animation:pulse 2.2s infinite}
@keyframes pulse{0%{box-shadow:0 0 0 0 rgba(18,183,106,.45)}70%{box-shadow:0 0 0 10px rgba(18,183,106,0)}100%{box-shadow:0 0 0 0 rgba(18,183,106,0)}}

/* stats */
.stats{position:relative;z-index:1;display:grid;grid-template-columns:repeat(4,1fr);gap:0;border-top:1px solid var(--line-2);padding-top:30px;padding-bottom:38px}
.stat{text-align:center;border-right:1px solid var(--line-2)}
.stat:last-child{border-right:0}
.stat b{display:block;font-size:26px;letter-spacing:-.02em;background:linear-gradient(135deg,var(--brand),var(--brand-2));-webkit-background-clip:text;background-clip:text;color:transparent}
.stat span{font-size:13px;color:var(--muted)}

/* ---------- sections ---------- */
.section{padding:76px 0}
.section-alt{background:var(--bg-soft);border-top:1px solid var(--line-2);border-bottom:1px solid var(--line-2)}
.sec-head{max-width:640px;margin-bottom:42px}
.eyebrow2{font-size:12px;letter-spacing:.16em;color:#8a978e;font-weight:700;margin-bottom:12px}
.sec-head h2{font-size:clamp(1.6rem,2.8vw,2.25rem)}
.sec-sub{margin-top:14px;color:var(--muted);font-size:15.5px}
.narrow{max-width:820px}

/* cards */
.grid{display:grid;gap:20px}
.grid-3{grid-template-columns:repeat(3,1fr)}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px;transition:transform .2s ease,box-shadow .2s ease,border-color .2s}
.card:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:#d7e0f0}
.card h3{font-size:16.5px;margin:16px 0 8px}
.card p{font-size:14.5px;color:var(--muted)}
.ico{width:42px;height:42px;border-radius:12px;display:grid;place-items:center;background:linear-gradient(135deg,rgba(12,61,49,.10),rgba(28,122,95,.10));color:var(--brand);border:1px solid rgba(12,61,49,.12)}
.ico svg{width:21px;height:21px}

/* steps */
.steps{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(3,1fr);gap:28px;counter-reset:step}
.steps li{position:relative;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px 26px 26px;box-shadow:var(--shadow-sm)}
.steps li::before{content:"";position:absolute;left:0;right:0;top:0;height:3px;border-radius:14px 14px 0 0;background:linear-gradient(90deg,var(--brand),var(--brand-2))}
.step-no{font-size:12.5px;font-weight:800;letter-spacing:.1em;color:var(--brand);opacity:.75}
.steps h3{font-size:17px;margin:10px 0 8px}
.steps p{font-size:14.5px;color:var(--muted)}
.steps a{color:var(--brand);text-decoration:underline;text-underline-offset:3px}

/* split / clients */
.split{display:grid;grid-template-columns:.95fr 1.05fr;gap:48px;align-items:start}
.snippet{margin-top:26px;border:1px solid var(--line);border-radius:14px;overflow:hidden;background:#0d1526;box-shadow:var(--shadow)}
.snippet-head{display:flex;align-items:center;justify-content:space-between;padding:11px 16px;background:#111b30;color:#c8d3e8;font-size:12.5px;border-bottom:1px solid rgba(255,255,255,.06)}
.copy{background:rgba(255,255,255,.08);color:#dbe4f3;border:1px solid rgba(255,255,255,.12);border-radius:8px;padding:5px 10px;font-size:12px;cursor:pointer;transition:background .16s}
.copy:hover{background:rgba(255,255,255,.15)}
.snippet pre{margin:0;padding:18px 16px;overflow-x:auto}
.snippet code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;font-size:13px;color:#a9c4ff;line-height:1.9;white-space:pre}
.table-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow-sm);overflow:hidden}
.table-card>table{min-width:520px}
.table-scroll{overflow-x:auto}
table{width:100%;border-collapse:collapse;font-size:14px}
thead th{text-align:left;font-size:12px;letter-spacing:.08em;color:#8a978e;font-weight:700;padding:14px 22px;background:#fbfcf9;border-bottom:1px solid var(--line-2)}
tbody td{padding:14px 22px;border-bottom:1px solid var(--line-2);color:var(--ink-2)}
tbody tr:last-child td{border-bottom:0}
tbody tr:hover td{background:#fafbff}
.pill{display:inline-block;font-size:11.5px;font-weight:700;color:#0d7a56;background:#e8f7f0;border:1px solid #c9ecdd;border-radius:6px;padding:1px 8px}
.pill-ghost{color:#4a5b7a;background:#f2f5fb;border-color:#e1e7f2}
.table-note{margin:0;padding:14px 22px;border-top:1px solid var(--line-2);font-size:12.5px;color:var(--muted);background:#fbfcf9;word-break:break-all}
.table-note code{font-size:12px;color:var(--brand)}

/* faq */
.qa{background:#fff;border:1px solid var(--line);border-radius:14px;padding:0 22px;margin-bottom:12px;transition:border-color .2s,box-shadow .2s}
.qa[open]{border-color:#d5dfef;box-shadow:var(--shadow-sm)}
.qa summary{cursor:pointer;list-style:none;padding:19px 0;font-weight:600;font-size:15.5px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.qa summary::-webkit-details-marker{display:none}
.qa summary::after{content:"+";font-size:20px;color:#9aa6bd;font-weight:400;transition:transform .2s}
.qa[open] summary::after{content:"−";color:var(--brand)}
.qa p{padding:0 0 20px;color:var(--muted);font-size:14.5px;margin:0}
.qa code{background:#f3f6fc;padding:1px 6px;border-radius:5px;font-size:13px;color:var(--ink-2)}
.qa a{color:var(--brand);text-decoration:underline;text-underline-offset:3px}

/* cta */
.cta{background:linear-gradient(120deg,#082a22,#0c3d31 45%,#1c7a5f);color:#fff;padding:64px 0}
.cta-inner{display:flex;align-items:center;justify-content:space-between;gap:28px;flex-wrap:wrap}
.cta h2{font-size:clamp(1.5rem,2.6vw,2rem)}
.cta p{color:rgba(255,255,255,.82);margin-top:8px;font-size:15px}

/* footer */
.foot{padding:44px 0 54px;background:#fff}
.foot-inner{display:grid;grid-template-columns:1fr auto;gap:18px;align-items:center}
.foot-brand{display:flex;align-items:center;gap:9px;font-weight:700;font-size:14.5px}
.foot-links{display:flex;gap:22px;font-size:13.5px;color:var(--muted)}
.foot-links a:hover{color:var(--brand)}
.foot-copy{grid-column:1/-1;font-size:12.5px;color:#8a978e;border-top:1px solid var(--line-2);padding-top:20px}

/* motion */
@media (prefers-reduced-motion:no-preference){
  .hero-copy>*{animation:rise .7s cubic-bezier(.22,.7,.3,1) both}
  .hero-copy>*:nth-child(2){animation-delay:.06s}
  .hero-copy>*:nth-child(3){animation-delay:.12s}
  .hero-copy>*:nth-child(4){animation-delay:.18s}
  .hero-copy>*:nth-child(5){animation-delay:.24s}
  .hero-visual{animation:rise .9s cubic-bezier(.22,.7,.3,1) .12s both}
  @keyframes rise{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
}

/* responsive */
@media (max-width:1000px){
  .hero-inner{grid-template-columns:1fr;gap:44px}
  .hero-visual{max-width:520px}
  .grid-3{grid-template-columns:repeat(2,1fr)}
  .split{grid-template-columns:1fr;gap:32px}
  .steps{grid-template-columns:1fr}
  .nav-links{display:none}
}
@media (max-width:720px){
  .section{padding:64px 0}
  .hero{padding-top:44px}
  .stats{grid-template-columns:repeat(2,1fr);gap:22px 0}
  .stat:nth-child(2){border-right:0}
  .stat:nth-child(1),.stat:nth-child(2){padding-bottom:4px}
  .grid-3{grid-template-columns:1fr}
  .foot-inner{grid-template-columns:1fr}
  .brand-tag{display:none}
  .hero-meta{gap:12px}
}
@media (max-width:480px){
  .wrap{padding:0 18px}
  .hero-actions .btn{width:100%;justify-content:center}
  .btn-sm{width:auto}
  .mc-time{display:none}
}

/* anchor offset for sticky nav */
section[id], main section[id]{scroll-margin-top:84px}
/* keep the mock card footer text clear of the floating badge */
.mailcard-foot{padding-right:18px}
@media (max-width:520px){
  .float-badge{position:static;margin:-6px 0 0;display:inline-flex;transform:none}
}


@media (max-width:720px){
  .mailcard{transform:none}
  .hero-inner{gap:36px}
  .stats{border-top:1px solid var(--line-2)}
  .table-card{border-radius:14px}
  .table-card>table{min-width:480px}
  .qa{padding:0 18px}
}


/* ---------- 界面预览 ---------- */
.sec-center{max-width:720px;margin-left:auto;margin-right:auto;text-align:center}
.browser{
  margin:0;
  border:1px solid var(--line);
  border-radius:18px;
  overflow:hidden;
  background:#0d1526;
  box-shadow:0 40px 80px -40px rgba(12,30,22,.45);
}
.browser-bar{
  display:flex;align-items:center;gap:12px;
  padding:11px 16px;
  background:linear-gradient(180deg,#f7f8f5,#eaeff8);
  border-bottom:1px solid var(--line);
}
.browser-bar .dots{display:flex;gap:6px}
.browser-bar .dots i{width:9px;height:9px;border-radius:50%;background:#cdd6e6}
.browser-bar .dots i:nth-child(1){background:#f2a5a0}
.browser-bar .dots i:nth-child(2){background:#f3ce8e}
.browser-bar .dots i:nth-child(3){background:#a9d8b0}
.browser-bar .addr{
  flex:1;text-align:center;
  font-size:12px;color:#59675f;
  background:#fff;border:1px solid var(--line);border-radius:999px;
  padding:4px 14px;
}
.browser-bar .lock{font-size:11px;opacity:.55}
.browser img{display:block;width:100%;height:auto}
.preview-notes{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin-top:22px}
.note{background:#fff;border:1px solid var(--line);border-radius:12px;padding:14px 18px;display:flex;flex-direction:column;gap:2px}
.note b{font-size:14px}
.note span{font-size:12.5px;color:var(--muted)}
@media (max-width:720px){
  .preview-notes{grid-template-columns:1fr}
  .browser{border-radius:14px}
  .browser-bar .addr{font-size:11px}
}


/* 移动端客户端参数表：隐藏服务器列 */
.table-hint{display:none;margin:0;padding:0 22px 12px;font-size:12.5px;color:var(--muted)}
@media (max-width:560px){
  .hide-sm{display:none !important}
  .table-hint{display:block;padding-top:12px}
  .table-card>table{min-width:0}
  thead th, tbody td{padding:12px 14px}
}