:root{
  color-scheme:dark;
  --ground:#000; --sc-low:#0a0b0e; --sc:#111319; --sc-high:#191b23; --sc-highest:#22242e;
  --outline:#3b3d47; --outline-faint:#232530;
  --on:#e7e8ee; --on-dim:#b7b9c4; --on-faint:#8b8d99;
  --primary:#a8c7fa; --primary-dim:#7ba7ec; --on-primary:#0a2744;
  --primary-container:#243b5c; --on-primary-container:#d6e3ff;
  --sent-bg:#183454; --sent-ink:#e3edff;
  --sim:#6ee0be; --good:#6ee0be; --danger:#ff9a94; --pill:999px;
}
*{box-sizing:border-box;}
html,body{height:100%;}
body{margin:0;background:var(--ground);color:var(--on);
  font-family:"Roboto","Helvetica Neue",Arial,sans-serif;font-size:14px;line-height:1.45;
  -webkit-font-smoothing:antialiased;overflow:hidden;}
button{font:inherit;color:inherit;border:0;background:none;cursor:pointer;}
::selection{background:color-mix(in srgb,var(--primary) 32%,transparent);color:#fff;}
::-webkit-scrollbar{width:10px;} ::-webkit-scrollbar-thumb{background:var(--sc-highest);border-radius:99px;border:2px solid var(--ground);}
.msr{font-family:"Material Symbols Rounded";font-weight:normal;font-style:normal;line-height:1;
  font-variation-settings:'FILL' 0,'wght' 400,'opsz' 24;user-select:none;}
.fill{font-variation-settings:'FILL' 1,'wght' 500,'opsz' 24;}
h1{font-family:"Roboto Flex",sans-serif;margin:0;font-weight:700;font-variation-settings:'opsz' 32;}

.btn{height:48px;border-radius:var(--pill);display:inline-flex;align-items:center;justify-content:center;
  gap:8px;font-weight:600;font-size:15px;padding:0 20px;transition:filter .15s,background .15s;}
.btn.primary{background:var(--primary);color:var(--on-primary);}
.btn.primary:hover{filter:brightness(1.06);}
.btn.block{width:100%;}
.icon-btn{width:40px;height:40px;border-radius:50%;display:grid;place-items:center;color:var(--on-dim);flex:none;}
.icon-btn:hover{background:var(--sc-high);color:var(--on);} .icon-btn .msr{font-size:22px;}
.linkbtn{color:var(--primary);font-weight:600;font-size:13.5px;margin-top:16px;}

/* ---- auth ---- */
.auth{position:fixed;inset:0;display:grid;place-items:center;padding:24px;}
.auth-card{width:100%;max-width:360px;text-align:center;}
.brandmark{width:64px;height:64px;border-radius:19px;margin:0 auto 18px;
  background:linear-gradient(150deg,var(--primary),var(--sim));display:grid;place-items:center;color:#08122a;}
.brandmark .msr{font-size:34px;font-variation-settings:'FILL' 1,'wght' 600;}
.auth h1{font-size:24px;letter-spacing:-.02em;}
.auth .sub{color:var(--on-dim);margin:8px 0 28px;}
.auth form{display:flex;flex-direction:column;gap:12px;text-align:left;}
.auth label{display:flex;flex-direction:column;gap:6px;font-size:12.5px;color:var(--on-faint);font-weight:600;}
.auth input{height:48px;border-radius:14px;background:var(--sc);border:1px solid var(--outline-faint);
  color:var(--on);padding:0 14px;font-size:15px;outline:none;transition:box-shadow .15s,background .15s;}
.auth input:focus{background:var(--sc-high);box-shadow:0 0 0 2px var(--primary-dim);}
.auth .err{color:var(--danger);font-size:13px;margin:2px 0 0;}
.auth .btn{margin-top:6px;}

/* ---- app shell ---- */
.app{display:grid;grid-template-columns:clamp(300px,30vw,360px) 1fr;height:100%;}
.rail{display:flex;flex-direction:column;min-width:0;border-right:1px solid var(--outline-faint);}
.rail-top{padding:14px 12px 8px;display:flex;flex-direction:column;gap:10px;}
.brand{display:flex;align-items:center;gap:10px;}
.brand .glyph{width:30px;height:30px;border-radius:9px;flex:none;
  background:linear-gradient(145deg,var(--primary),var(--sim));display:grid;place-items:center;color:#08122a;}
.brand .glyph .msr{font-size:19px;font-variation-settings:'FILL' 1,'wght' 600;}
.brand .spacer{flex:1;}
.devpick{display:inline-flex;align-items:center;gap:6px;height:36px;padding:0 8px 0 12px;border-radius:var(--pill);
  background:var(--sc);font-weight:600;font-size:15px;max-width:190px;}
.devpick:hover{background:var(--sc-high);} .devpick .msr:first-child{font-size:19px;color:var(--on-dim);}
.devpick .dev-name{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.devpick .caret{font-size:20px;color:var(--on-dim);}
.status{display:flex;align-items:center;gap:8px;padding:6px 10px;background:var(--sc);border-radius:var(--pill);font-size:12px;color:var(--on-dim);}
.dot{width:8px;height:8px;border-radius:50%;background:var(--good);flex:none;}
.dot.bad{background:var(--danger);}

.list{flex:1;overflow-y:auto;padding:6px 8px 24px;}
.conv{display:grid;grid-template-columns:auto 1fr auto;gap:12px;align-items:center;padding:10px 12px;
  border-radius:18px;cursor:pointer;position:relative;transition:background .14s;}
.conv:hover{background:var(--sc-low);}
.conv[aria-selected="true"]{background:var(--sc);}
.conv[aria-selected="true"]::before{content:"";position:absolute;left:-8px;top:14px;bottom:14px;width:4px;border-radius:99px;background:var(--primary);}
.avatar{width:46px;height:46px;border-radius:50%;flex:none;display:grid;place-items:center;
  font-family:"Roboto Flex";font-weight:600;font-size:17px;color:#08122a;
  background:linear-gradient(145deg,#9aa2f0,#a8c7fa);}
.conv .mid{min-width:0;}
.conv .row1{display:flex;align-items:baseline;gap:8px;}
.conv .name{font-weight:600;font-size:15px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;flex:1;}
.conv[data-unread="1"] .name{font-weight:700;}
.conv .time{font-size:12px;color:var(--on-faint);flex:none;font-variant-numeric:tabular-nums;}
.conv .snip{font-size:13.5px;color:var(--on-faint);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;margin-top:2px;}
.badge{min-width:20px;height:20px;padding:0 6px;border-radius:99px;background:var(--primary);color:var(--on-primary);
  font-size:12px;font-weight:700;display:grid;place-items:center;}

.thread{display:flex;flex-direction:column;min-width:0;}
.t-head{display:flex;align-items:center;gap:12px;padding:12px 14px;border-bottom:1px solid var(--outline-faint);}
.t-head .avatar{width:40px;height:40px;font-size:15px;}
.t-head .who{min-width:0;flex:1;}
.t-head .who .nm{font-family:"Roboto Flex";font-weight:600;font-size:17px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.t-head .who .sub{font-size:12.5px;color:var(--on-faint);}
.back{display:none;}
.scroll{flex:1;overflow-y:auto;padding:16px clamp(16px,6vw,60px);display:flex;flex-direction:column;gap:3px;}
.empty{margin:auto;color:var(--on-faint);font-size:14px;}
.msg{max-width:min(560px,76%);display:flex;flex-direction:column;gap:2px;}
.msg.in{align-self:flex-start;} .msg.out{align-self:flex-end;align-items:flex-end;}
.msg.gap{margin-top:9px;}
.bubble{padding:10px 14px;font-size:14.5px;border-radius:20px;white-space:pre-wrap;word-wrap:break-word;}
.in .bubble{background:var(--sc-high);color:var(--on);border-bottom-left-radius:6px;}
.out .bubble{background:var(--sent-bg);color:var(--sent-ink);border-bottom-right-radius:6px;box-shadow:inset -3px 0 0 0 var(--sim);}
.meta{font-size:11.5px;color:var(--on-faint);padding:0 6px;font-variant-numeric:tabular-nums;}

.composer{padding:10px clamp(12px,4vw,40px) 16px;border-top:1px solid var(--outline-faint);}
.field{height:52px;border-radius:26px;background:var(--sc);display:flex;align-items:center;gap:10px;padding:0 18px;color:var(--on-faint);}
.field.disabled{cursor:not-allowed;} .field .msr{font-size:20px;} .field .txt{font-size:14px;}

.toast{position:fixed;left:50%;bottom:20px;transform:translateX(-50%);background:var(--sc-high);
  border:1px solid var(--outline-faint);border-radius:12px;padding:10px 16px;font-size:13px;
  box-shadow:0 12px 30px rgba(0,0,0,.6);z-index:50;}

/* ---- add-phone overlay ---- */
.overlay{position:fixed;inset:0;z-index:60;display:grid;place-items:center;padding:20px;
  background:rgba(0,0,0,.66);backdrop-filter:blur(3px);}
.sheet{position:relative;width:100%;max-width:440px;background:var(--sc);border:1px solid var(--outline-faint);
  border-radius:24px;padding:24px 22px;box-shadow:0 30px 70px -20px rgba(0,0,0,.85);}
.sheet .close{position:absolute;top:12px;right:12px;}
.sheet h2{font-family:"Roboto Flex",sans-serif;font-weight:700;font-size:21px;margin:0 0 10px;}
.sheet .muted{color:var(--on-dim);font-size:13px;line-height:1.5;margin:0 0 16px;}
.sheet .muted b{color:var(--on);font-weight:600;}
.fld{display:flex;flex-direction:column;gap:6px;font-size:12.5px;color:var(--on-faint);font-weight:600;margin-bottom:12px;}
.fld input,.fld textarea{background:var(--sc-low);border:1px solid var(--outline-faint);border-radius:12px;
  color:var(--on);padding:10px 12px;font-size:14px;font-family:inherit;outline:none;resize:vertical;
  transition:box-shadow .15s,background .15s;}
.fld textarea{font-family:ui-monospace,"SF Mono",Menlo,monospace;font-size:12px;line-height:1.4;}
.fld input:focus,.fld textarea:focus{background:var(--sc-high);box-shadow:0 0 0 2px var(--primary-dim);}
.sheet .err{color:var(--danger);font-size:13px;margin:0 0 10px;}
.emoji{font-size:76px;line-height:1.1;text-align:center;margin:6px 0 14px;}
.spinner{width:28px;height:28px;margin:8px auto 0;border-radius:50%;
  border:3px solid var(--sc-highest);border-top-color:var(--primary);animation:spin 0.9s linear infinite;}
@keyframes spin{to{transform:rotate(360deg);}}
.empty .btn{margin-top:14px;}

@media (max-width:760px){
  .app{grid-template-columns:1fr;}
  .app[data-view="thread"] .rail{display:none;}
  .app[data-view="list"] .thread{display:none;}
  .back{display:grid;}
}