:root{
  --ink:#0B0B0B;
  --ink-soft:#3A3A3A;
  --grey:#8E8E8E;
  --grey-2:#C9C9C9;
  --paper:#FFFFFF;
  --bg:#1a1a1a;
  --bg-2:#242424;
  --card:#2a2a2a;
  --card-2:#323232;
  --line:rgba(255,255,255,.12);
  --line-soft:rgba(255,255,255,.08);
  --text:#FFFFFF;
  --muted:#8E8E8E;
  --primary:#FFFFFF;
  --primary-ink:#0B0B0B;
  --danger:#e85d5d;
  --unread:#FFFFFF;
  --radius:12px;
  --safe-b:env(safe-area-inset-bottom);
  --safe-t:env(safe-area-inset-top);
  --font:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
  --ease:cubic-bezier(.22,.61,.36,1);
}
*{box-sizing:border-box}
html,body{margin:0;height:100%;background:var(--bg);color:var(--text);font:15px/1.5 var(--font);-webkit-font-smoothing:antialiased}
[hidden]{display:none!important}
button{font:inherit;color:inherit}
input,select,textarea{font:inherit;color:inherit}
.muted{color:var(--muted)}.small{font-size:12px}
.error{color:var(--danger);min-height:1.5em;margin:8px 0 0;font-size:14px}
.spacer{flex:1}

/* logo: white dot + SYNTH MOBILITY */
.logo,.brand-logo{font-weight:800;letter-spacing:-.02em;font-size:15px;text-transform:uppercase;display:flex;align-items:center;gap:9px;color:var(--paper)}
.logo i,.brand-logo i{display:block;width:9px;height:9px;background:currentColor;border-radius:50%;flex:none}

.btn{border:0;border-radius:10px;padding:10px 16px;background:var(--card-2);cursor:pointer;font-weight:500;display:inline-flex;align-items:center;justify-content:center;gap:6px;white-space:nowrap;transition:background .25s var(--ease),color .25s var(--ease),border-color .25s var(--ease)}
.btn:active{transform:scale(.98)}
.btn.primary{background:var(--paper);color:var(--primary-ink)}
.btn.primary:hover{background:var(--grey-2)}
.btn.primary:disabled{opacity:.55}
.btn.ghost{background:transparent;border:1px solid var(--line);color:var(--text)}
.btn.ghost:hover{border-color:rgba(255,255,255,.28);background:rgba(255,255,255,.04)}
.btn.danger{background:rgba(232,93,93,.15);color:var(--danger);border:1px solid rgba(232,93,93,.35)}
.btn.small{padding:5px 10px;font-size:13px;border-radius:8px}
.btn.block{width:100%}
.link{border:0;background:none;color:var(--grey-2);cursor:pointer;font-size:13px;padding:0 4px;white-space:nowrap}
.link:hover{color:var(--paper)}
.icon-btn{border:0;background:transparent;width:40px;height:40px;border-radius:10px;font-size:20px;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;flex:none;color:var(--grey-2)}
.icon-btn:hover{background:rgba(255,255,255,.08);color:var(--paper)}

/* login — smooth black/grey gradient, no noise/brush */
.login{
  min-height:100%;
  display:flex;align-items:center;justify-content:center;padding:24px;
  /* single soft radial: lighter centre, darker edges — no noise/brush/banding layers */
  background-color:#0c0c0c;
  background-image:radial-gradient(ellipse 85% 65% at 50% 42%, #2f2f2f 0%, #1c1c1c 45%, #101010 78%, #070707 100%);
}
.login-card{
  width:100%;max-width:380px;
  background:rgba(20,20,20,.92);
  border:1px solid var(--line);
  border-radius:16px;
  padding:40px 28px 32px;
  text-align:center;
  backdrop-filter:blur(8px);
  box-shadow:0 24px 60px rgba(0,0,0,.45);
}
.login-card .brand-logo{justify-content:center;font-size:16px;margin-bottom:28px}
.login-card input#pw,
.user-field{
  width:100%;margin:0 0 12px;padding:0;
  border:1px solid var(--line);border-radius:10px;
  background:rgba(255,255,255,.04);color:var(--paper);
  display:flex;align-items:center;overflow:hidden;
}
.login-card input#pw{
  display:block;padding:13px 14px;font-size:16px;outline:none;
}
.login-card input#pw::placeholder,
.user-field input::placeholder{color:var(--grey)}
.login-card input#pw:focus,
.user-field:focus-within{border-color:rgba(255,255,255,.4);background:rgba(255,255,255,.07)}
.user-field input{
  flex:1;min-width:0;border:0;outline:none;background:transparent;
  padding:13px 10px 13px 14px;font-size:16px;color:var(--paper);
}
.user-suffix{
  flex:none;padding:0 12px 0 0;font-size:13px;color:var(--grey);
  white-space:nowrap;user-select:none;
}
.login-card .btn.primary{margin-top:8px;padding:13px 16px;font-weight:600;letter-spacing:.02em}

/* mailbox — plain dark charcoal (pre-v3) */
.app{display:flex;height:100%;height:100dvh;overflow:hidden;background:var(--bg)}
.sidebar{
  width:248px;flex:none;background:var(--bg-2);border-right:1px solid var(--line-soft);
  display:flex;flex-direction:column;padding:calc(14px + var(--safe-t)) 12px calc(14px + var(--safe-b));gap:6px;overflow-y:auto
}
.brand{padding:2px 6px 12px;display:flex;flex-direction:column;gap:4px}
.brand .brand-logo{font-size:13px;letter-spacing:-.01em}
.brand-user{font-size:12px;color:var(--muted);padding-left:18px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.compose-btn{margin-bottom:8px}
.folders a,.mailboxes a{display:flex;align-items:center;gap:10px;padding:9px 10px;border-radius:10px;color:var(--grey-2);text-decoration:none;font-size:15px}
.mailboxes a{font-size:14px;padding:7px 10px}
.folders a:hover,.mailboxes a:hover{background:rgba(255,255,255,.06);color:var(--paper)}
.folders a.active,.mailboxes a.active{background:rgba(255,255,255,.1);color:var(--paper);font-weight:600}
.ico{width:20px;text-align:center;opacity:.75;font-size:13px}
.badge{margin-left:auto;background:var(--paper);color:var(--ink);border-radius:999px;font-size:11px;padding:1px 7px;font-weight:600}
.badge:empty{display:none}
.section-title{font-size:11px;color:var(--grey);padding:14px 10px 2px;text-transform:uppercase;letter-spacing:.08em}
.mailboxes a span.addr{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.usage{padding:10px 6px}
.usage-text{display:flex;justify-content:space-between;font-size:12px;color:var(--muted);margin-bottom:6px}
.bar{height:6px;background:rgba(255,255,255,.08);border-radius:99px;overflow:hidden}
.bar i{display:block;height:100%;width:0;background:var(--paper);border-radius:99px;transition:width .3s}
.bar i.warn{background:#f59e0b}.bar i.full{background:var(--danger)}
.scrim{display:none}

.list-pane{width:400px;flex:none;display:flex;flex-direction:column;border-right:1px solid var(--line-soft);background:var(--bg);position:relative;min-width:0}
.topbar{display:flex;align-items:center;gap:6px;padding:calc(8px + var(--safe-t)) 10px 8px;min-height:56px;background:var(--bg)}
.topbar .title{flex:1;min-width:0}
.topbar h2{margin:0;font-size:18px;font-weight:600;letter-spacing:-.01em}
.topbar small{display:block;font-size:12px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.searchbar{padding:0 12px 8px}
.searchbar input{
  width:100%;padding:9px 12px;border-radius:10px;border:1px solid var(--line-soft);
  background:var(--card);outline:none;font-size:15px;color:var(--paper)
}
.searchbar input::placeholder{color:var(--grey)}
.searchbar input:focus{border-color:rgba(255,255,255,.28)}
.trash-bar{display:flex;align-items:center;gap:8px;justify-content:space-between;padding:6px 14px;font-size:13px;color:var(--muted);background:var(--bg-2);border-top:1px solid var(--line-soft);border-bottom:1px solid var(--line-soft)}
.list{list-style:none;margin:0;padding:0;overflow-y:auto;flex:1;-webkit-overflow-scrolling:touch}
.list li{display:flex;gap:12px;padding:12px 14px;border-bottom:1px solid var(--line-soft);cursor:pointer;position:relative}
.list li:hover{background:rgba(255,255,255,.04)}
.list li.active{background:rgba(255,255,255,.08)}
.list li .avatar{width:40px;height:40px;font-size:16px}
.li-main{flex:1;min-width:0}
.li-top{display:flex;align-items:baseline;gap:8px}
.li-from{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:15px}
.li-date{font-size:12px;color:var(--muted);flex:none}
.li-subject{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:14px;color:var(--grey-2)}
.li-snippet{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13px;color:var(--muted)}
.list li.unread .li-from,.list li.unread .li-subject{font-weight:650;color:var(--paper)}
.list li.unread::before{content:"";position:absolute;left:4px;top:28px;width:7px;height:7px;border-radius:50%;background:var(--unread)}
.clip{font-size:12px;margin-left:4px}
.empty{text-align:center;color:var(--muted);padding:60px 0}
.more{margin:10px 14px;width:auto}
.avatar{border-radius:50%;background:var(--ink-soft);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:600;flex:none;width:44px;height:44px;font-size:18px}
.fab{position:absolute;right:18px;bottom:calc(20px + var(--safe-b));width:56px;height:56px;border-radius:18px;border:0;color:var(--ink);font-size:22px;background:var(--paper);box-shadow:0 8px 24px rgba(0,0,0,.4);cursor:pointer}

.reader{flex:1;min-width:0;display:flex;flex-direction:column;background:var(--bg)}
.reader-empty{margin:auto}
.reader-inner{display:flex;flex-direction:column;height:100%}
.reader-bar{border-bottom:1px solid var(--line-soft)}
.msg-scroll{flex:1;overflow-y:auto;padding:16px 18px calc(24px + var(--safe-b));-webkit-overflow-scrolling:touch}
.m-subject{font-size:21px;margin:0 0 14px;line-height:1.35;word-break:break-word;font-weight:600;letter-spacing:-.02em}
.m-head{display:flex;gap:12px;margin-bottom:12px}
.m-meta{min-width:0;flex:1;font-size:14px}
.m-from{word-break:break-all}
.m-to{word-break:break-all;font-size:13px}
.m-date{font-size:12px}
.banner{background:rgba(245,158,11,.12);color:#fbbf24;font-size:13px;padding:8px 12px;border-radius:10px;display:flex;align-items:center;justify-content:space-between;gap:8px;margin-bottom:10px;border:1px solid rgba(245,158,11,.25)}
.m-frame{width:100%;border:0;min-height:0;height:0;display:block;background:transparent;border-radius:0;color:inherit;vertical-align:top}
.atts{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.att{display:flex;align-items:center;gap:8px;border:1px solid var(--line);border-radius:10px;padding:8px 10px;font-size:13px;max-width:100%;text-decoration:none;color:inherit;background:var(--card)}
.att .n{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:200px}
.att .x{border:0;background:none;cursor:pointer;color:var(--muted);font-size:14px;padding:0 2px}
.m-foot{margin-top:18px}
.m-foot a{color:var(--muted)}

/* compose */
.compose{position:fixed;inset:0;background:rgba(0,0,0,.55);z-index:50;display:flex;align-items:flex-end;justify-content:center}
.compose-card{background:var(--bg-2);width:100%;max-width:720px;height:100%;display:flex;flex-direction:column;border:1px solid var(--line-soft)}
.compose-card .topbar{border-bottom:1px solid var(--line-soft);background:var(--bg-2)}
.compose-card h2{font-size:17px;margin:0;font-weight:600}
.c-fields{flex:1;display:flex;flex-direction:column;overflow-y:auto}
.c-row{display:flex;align-items:center;gap:8px;border-bottom:1px solid var(--line-soft);padding:0 14px;min-height:48px}
.c-row>span{color:var(--muted);font-size:14px;width:52px;flex:none}
.c-row input,.c-row select{flex:1;border:0;outline:none;padding:12px 0;background:transparent;font-size:16px;min-width:0;color:var(--paper)}
.c-row select option{background:var(--bg-2);color:var(--paper)}
textarea#cText{flex:1;min-height:220px;border:0;outline:none;resize:none;padding:14px;font-size:16px;line-height:1.6;background:transparent;color:var(--paper)}
textarea#cText::placeholder{color:var(--grey)}
.c-atts{padding:10px 14px calc(14px + var(--safe-b));border-top:1px solid var(--line-soft);display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.c-atts .atts{margin:0;width:100%}
.c-atts .atts:empty{display:none}

.toast{position:fixed;left:50%;bottom:calc(90px + var(--safe-b));transform:translateX(-50%);background:rgba(255,255,255,.92);color:var(--ink);padding:10px 16px;border-radius:12px;font-size:14px;z-index:100;max-width:90vw;text-align:center;font-weight:500}

.only-mobile{display:none}

@media (min-width:900px){
  .compose{align-items:center;padding:24px}
  .compose-card{height:min(760px,100%);border-radius:16px;overflow:hidden;box-shadow:0 20px 60px rgba(0,0,0,.5)}
  .reader-bar [data-act=back]{display:none}
}
@media (max-width:1100px) and (min-width:900px){ .list-pane{width:340px} }
@media (max-width:899px){
  .only-mobile{display:inline-flex}
  .sidebar{position:fixed;left:0;top:0;bottom:0;z-index:40;transform:translateX(-100%);transition:transform .22s ease,box-shadow .22s}
  .app.menu-open .sidebar{box-shadow:0 0 40px rgba(0,0,0,.4)}
  .app.menu-open .sidebar{transform:none}
  .app.menu-open .scrim{display:block;position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:30}
  .list-pane{width:100%;border-right:0}
  .reader{position:fixed;inset:0;z-index:20;transform:translateX(105%);transition:transform .22s ease;background:var(--bg)}
  .app.reading .reader{transform:none}
  .reader-empty{display:none}
  .m-subject{font-size:19px}
}


/* settings */
.settings{position:fixed;inset:0;background:rgba(0,0,0,.5);z-index:60;display:flex;align-items:center;justify-content:center;padding:20px}
.settings-card{width:100%;max-width:400px;background:var(--bg-2);border:1px solid var(--line);border-radius:14px;overflow:hidden;box-shadow:0 20px 50px rgba(0,0,0,.4)}
.settings-card .topbar{border-bottom:1px solid var(--line-soft);background:var(--bg-2)}
.settings-card h2{margin:0;font-size:17px;font-weight:600}
.settings-body{padding:18px 16px 22px}
.settings-row{display:flex;align-items:center;justify-content:space-between;gap:12px}
.settings-label{font-size:14px;color:var(--muted)}
.theme-toggle{display:flex;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:rgba(0,0,0,.2)}
.theme-opt{border:0;background:transparent;color:var(--muted);padding:8px 16px;cursor:pointer;font-weight:500}
.theme-opt.active{background:var(--paper);color:var(--primary-ink)}

/* light theme (mailbox UI only; login unchanged) */
html[data-theme="light"]{
  --bg:#f4f4f5;
  --bg-2:#ffffff;
  --card:#ececee;
  --card-2:#e4e4e7;
  --line:rgba(0,0,0,.12);
  --line-soft:rgba(0,0,0,.08);
  --text:#121212;
  --muted:#6b6b6b;
  --grey:#6b6b6b;
  --grey-2:#3f3f46;
  --paper:#121212;
  --primary-ink:#ffffff;
  --danger:#dc2626;
  --unread:#121212;
}
html[data-theme="light"] .logo,
html[data-theme="light"] .brand-logo{color:#121212}
html[data-theme="light"] .btn.primary{background:#121212;color:#fff}
html[data-theme="light"] .btn.primary:hover{background:#2a2a2a}
html[data-theme="light"] .btn.ghost{border-color:rgba(0,0,0,.14)}
html[data-theme="light"] .btn.ghost:hover{background:rgba(0,0,0,.04)}
html[data-theme="light"] .folders a,
html[data-theme="light"] .mailboxes a{color:#3f3f46}
html[data-theme="light"] .folders a:hover,
html[data-theme="light"] .mailboxes a:hover{background:rgba(0,0,0,.05);color:#121212}
html[data-theme="light"] .folders a.active,
html[data-theme="light"] .mailboxes a.active{background:rgba(0,0,0,.08);color:#121212}
html[data-theme="light"] .badge{background:#121212;color:#fff}
html[data-theme="light"] .bar{background:rgba(0,0,0,.08)}
html[data-theme="light"] .bar i{background:#121212}
html[data-theme="light"] .searchbar input{background:#ececee;color:#121212}
html[data-theme="light"] .list li:hover{background:rgba(0,0,0,.04)}
html[data-theme="light"] .list li.active{background:rgba(0,0,0,.07)}
html[data-theme="light"] .list li.unread .li-from,
html[data-theme="light"] .list li.unread .li-subject{color:#121212}
html[data-theme="light"] .list li.unread::before{background:#121212}
html[data-theme="light"] .icon-btn{color:#52525b}
html[data-theme="light"] .icon-btn:hover{background:rgba(0,0,0,.06);color:#121212}
html[data-theme="light"] .fab{background:#121212;color:#fff}
html[data-theme="light"] .compose{background:rgba(0,0,0,.35)}
html[data-theme="light"] .theme-toggle{background:rgba(0,0,0,.04)}
html[data-theme="light"] .theme-opt.active{background:#121212;color:#fff}
html[data-theme="light"] .toast{background:rgba(20,20,20,.92);color:#fff}
html[data-theme="light"] .settings{background:rgba(0,0,0,.35)}
html[data-theme="light"] .banner{background:#fff7ed;color:#9a3412;border-color:#fed7aa}