:root{
  --ink-950:#0b1f1b;
  --ink-900:#102a24;
  --ink-800:#16362e;
  --ink-700:#1e463c;
  --mint-500:#18b98a;
  --mint-400:#37d3a3;
  --mint-100:#e4faf2;
  --coral-500:#ff6a45;
  --coral-600:#e8552f;
  --paper:#f6f8f7;
  --paper-2:#ffffff;
  --line:#e4e9e6;
  --text-900:#12211d;
  --text-600:#4c635c;
  --text-400:#8ba39a;
  --font-display:'Sora', system-ui, sans-serif;
  --font-body:'Inter', system-ui, sans-serif;
  --radius-lg:20px;
  --radius-md:14px;
  --radius-sm:10px;
  --shadow-1:0 1px 2px rgba(16,42,36,.06), 0 8px 24px rgba(16,42,36,.06);
  --shadow-2:0 12px 32px rgba(16,42,36,.16);
}

*{box-sizing:border-box;}
html,body{height:100%;}
body{
  margin:0;
  font-family:var(--font-body);
  background:var(--paper);
  color:var(--text-900);
  -webkit-font-smoothing:antialiased;
}
.hidden{display:none !important;}
button{font-family:inherit;cursor:pointer;}
input{font-family:inherit;}

/* ===================== AUTH ===================== */
.auth-screen{
  min-height:100vh;
  display:flex;
  align-items:center;
  justify-content:center;
  background:
    radial-gradient(1100px 600px at 15% 0%, rgba(24,185,138,.20), transparent 60%),
    radial-gradient(900px 500px at 100% 100%, rgba(255,106,69,.15), transparent 55%),
    var(--ink-950);
  padding:24px;
}
.auth-card{
  width:100%;
  max-width:400px;
  background:var(--paper-2);
  border-radius:var(--radius-lg);
  padding:36px 32px 32px;
  box-shadow:var(--shadow-2);
}
.brand{
  font-family:var(--font-display);
  font-weight:800;
  font-size:30px;
  letter-spacing:-0.02em;
  display:flex;
  align-items:baseline;
  gap:1px;
}
.brand.small{font-size:20px;}
.brand-mark{color:var(--mint-500);}
.brand-rest{color:var(--text-900);}
.auth-tagline{
  color:var(--text-600);
  font-size:14px;
  line-height:1.5;
  margin:10px 0 26px;
}
.auth-tabs{
  display:flex;
  background:var(--paper);
  border-radius:999px;
  padding:4px;
  margin-bottom:24px;
}
.auth-tab{
  flex:1;
  border:none;
  background:transparent;
  padding:9px 0;
  border-radius:999px;
  font-weight:600;
  font-size:13.5px;
  color:var(--text-600);
  transition:all .18s ease;
}
.auth-tab.active{
  background:var(--ink-900);
  color:#fff;
}
.auth-form{display:flex;flex-direction:column;gap:16px;}
.auth-form.hidden{display:none;}
.auth-form label{
  display:flex;
  flex-direction:column;
  gap:6px;
  font-size:13px;
  font-weight:600;
  color:var(--text-600);
}
.auth-form .hint{font-weight:400;color:var(--text-400);}
.auth-form input{
  border:1.5px solid var(--line);
  border-radius:var(--radius-sm);
  padding:11px 14px;
  font-size:14.5px;
  color:var(--text-900);
  outline:none;
  transition:border-color .15s ease;
}
.auth-form input:focus{border-color:var(--mint-500);}
.auth-error{
  color:var(--coral-600);
  font-size:13px;
  margin:-6px 0 0;
  min-height:16px;
}
.btn-primary{
  background:var(--ink-900);
  color:#fff;
  border:none;
  border-radius:var(--radius-sm);
  padding:13px;
  font-weight:700;
  font-size:14.5px;
  margin-top:4px;
  transition:background .15s ease, transform .1s ease;
}
.btn-primary:hover{background:var(--mint-500);}
.btn-primary:active{transform:scale(.98);}

/* ===================== APP LAYOUT ===================== */
.app-screen{
  height:100vh;
  display:grid;
  grid-template-columns:320px 1fr;
  background:var(--paper-2);
}
.sidebar{
  background:var(--ink-950);
  color:#fff;
  display:flex;
  flex-direction:column;
  border-right:1px solid rgba(255,255,255,.06);
}
.sidebar-header{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding:20px 18px 12px;
}
.icon-btn{
  background:rgba(255,255,255,.06);
  border:none;
  color:#fff;
  width:34px;height:34px;
  border-radius:10px;
  font-size:15px;
  display:flex;align-items:center;justify-content:center;
  transition:background .15s ease;
}
.icon-btn:hover{background:rgba(255,255,255,.14);}
.chat-header .icon-btn{background:var(--paper);color:var(--ink-900);}
.chat-header .icon-btn:hover{background:var(--mint-100);}

.me-card{
  display:flex;
  align-items:center;
  gap:12px;
  padding:12px 18px 18px;
  border-bottom:1px solid rgba(255,255,255,.08);
}
.me-name{font-weight:700;font-size:14.5px;}
.me-status{font-size:12px;color:var(--mint-400);}

.avatar{
  width:42px;height:42px;
  border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  font-family:var(--font-display);
  font-weight:700;
  color:#fff;
  font-size:15px;
  flex-shrink:0;
  position:relative;
}
.avatar.big{width:88px;height:88px;font-size:30px;}

.contact-search{padding:14px 18px 8px;}
.contact-search input{
  width:100%;
  background:rgba(255,255,255,.08);
  border:1px solid rgba(255,255,255,.1);
  border-radius:10px;
  padding:9px 12px;
  color:#fff;
  font-size:13.5px;
  outline:none;
}
.contact-search input::placeholder{color:rgba(255,255,255,.4);}

.contact-list{
  list-style:none;
  margin:0;padding:6px 8px 16px;
  overflow-y:auto;
  flex:1;
}
.contact-item{
  display:flex;
  align-items:center;
  gap:12px;
  padding:10px;
  border-radius:12px;
  cursor:pointer;
  transition:background .15s ease;
  position:relative;
}
.contact-item:hover{background:rgba(255,255,255,.06);}
.contact-item.active{background:var(--mint-500);}
.contact-item.active .contact-sub{color:rgba(255,255,255,.85);}
.contact-name{font-weight:600;font-size:14px;}
.contact-sub{font-size:12px;color:rgba(255,255,255,.45);}
.status-dot{
  width:9px;height:9px;border-radius:50%;
  background:var(--text-400);
  border:2px solid var(--ink-950);
  position:absolute;left:34px;top:32px;
}
.status-dot.online{background:var(--mint-400);}

/* ===================== CHAT PANE ===================== */
.chat-pane{position:relative;display:flex;flex-direction:column;}
.chat-empty{
  flex:1;
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  gap:14px;
  color:var(--text-400);
}
.empty-mark{
  font-family:var(--font-display);
  font-weight:800;
  font-size:52px;
  color:var(--mint-100);
  background:var(--ink-900);
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  background:linear-gradient(135deg,var(--mint-500),var(--ink-900));
}
.chat-active{display:flex;flex-direction:column;height:100%;}
.chat-header{
  display:flex;
  align-items:center;
  gap:12px;
  padding:14px 22px;
  border-bottom:1px solid var(--line);
  background:var(--paper-2);
}
.peer-info{flex:1;}
.peer-name{font-weight:700;font-size:15px;}
.peer-status{font-size:12px;color:var(--text-400);}
.chat-actions{display:flex;gap:8px;}

.messages{
  flex:1;
  overflow-y:auto;
  padding:24px;
  display:flex;
  flex-direction:column;
  gap:4px;
  background:
    radial-gradient(600px 300px at 100% 0%, rgba(24,185,138,.05), transparent),
    var(--paper);
}
.msg-row{display:flex;gap:8px;max-width:62%;}
.msg-row.mine{align-self:flex-end;flex-direction:row-reverse;}
.msg-bubble{
  padding:10px 14px;
  border-radius:16px;
  font-size:14px;
  line-height:1.45;
  background:var(--paper-2);
  border:1px solid var(--line);
  color:var(--text-900);
}
.msg-row.mine .msg-bubble{
  background:var(--mint-500);
  color:#fff;
  border-color:var(--mint-500);
}
.msg-bubble img,.msg-bubble video{
  max-width:260px;
  border-radius:10px;
  display:block;
}
.msg-meta{font-size:10.5px;color:var(--text-400);margin-top:3px;}
.msg-row.mine .msg-meta{text-align:right;}
.msg-day-sep{
  align-self:center;
  font-size:11.5px;
  color:var(--text-400);
  background:var(--line);
  padding:3px 12px;
  border-radius:999px;
  margin:10px 0;
}

.typing-indicator{
  padding:0 24px 6px;
  font-size:12px;
  color:var(--text-400);
  font-style:italic;
}

.composer{
  display:flex;
  align-items:center;
  gap:10px;
  padding:14px 20px;
  border-top:1px solid var(--line);
  background:var(--paper-2);
}
.composer input[type=text]{
  flex:1;
  border:1.5px solid var(--line);
  border-radius:999px;
  padding:11px 18px;
  font-size:14px;
  outline:none;
}
.composer input[type=text]:focus{border-color:var(--mint-500);}
.btn-send{
  background:var(--mint-500);
  color:#fff;
  border:none;
  width:40px;height:40px;
  border-radius:50%;
  font-size:15px;
  flex-shrink:0;
}
.btn-send:hover{background:var(--coral-500);}
.composer .icon-btn{background:var(--paper);color:var(--ink-900);}

/* ===================== CALL OVERLAY ===================== */
.call-overlay{
  position:fixed;inset:0;
  background:rgba(11,31,27,.92);
  display:flex;align-items:center;justify-content:center;
  z-index:60;
}
.call-panel{
  width:min(420px,92vw);
  display:flex;flex-direction:column;align-items:center;gap:18px;
  position:relative;
}
.call-peer{display:flex;flex-direction:column;align-items:center;gap:10px;}
.call-name{color:#fff;font-family:var(--font-display);font-weight:700;font-size:20px;}
.call-state{color:var(--mint-400);font-size:13px;}
.remote-video{width:100%;border-radius:var(--radius-md);background:#000;max-height:60vh;}
.local-video{
  position:fixed;bottom:110px;right:24px;
  width:140px;border-radius:12px;border:2px solid #fff;
  box-shadow:var(--shadow-2);
}
.call-controls{display:flex;gap:16px;margin-top:6px;}
.call-btn{
  width:56px;height:56px;border-radius:50%;
  border:none;font-size:20px;
  background:rgba(255,255,255,.14);
  color:#fff;
  display:flex;align-items:center;justify-content:center;
  transition:background .15s ease, transform .1s ease;
}
.call-btn:hover{background:rgba(255,255,255,.24);}
.call-btn.end{background:var(--coral-500);}
.call-btn.end:hover{background:var(--coral-600);}
.call-btn.accept{background:var(--mint-500);}
.call-btn.muted{background:var(--coral-500);}

.incoming-call{
  position:fixed;top:20px;right:20px;
  background:var(--paper-2);
  border-radius:var(--radius-md);
  box-shadow:var(--shadow-2);
  padding:14px 16px;
  display:flex;align-items:center;gap:12px;
  z-index:70;
  animation:slidein .25s ease;
}
@keyframes slidein{from{transform:translateY(-14px);opacity:0;}to{transform:translateY(0);opacity:1;}}
.incoming-name{font-weight:700;font-size:14px;}
.incoming-type{font-size:12px;color:var(--text-400);}
.incoming-call .call-btn{width:38px;height:38px;font-size:14px;}

/* ===================== SCROLLBARS ===================== */
.contact-list::-webkit-scrollbar,.messages::-webkit-scrollbar{width:6px;}
.contact-list::-webkit-scrollbar-thumb{background:rgba(255,255,255,.15);border-radius:6px;}
.messages::-webkit-scrollbar-thumb{background:var(--line);border-radius:6px;}

/* ===================== RESPONSIVE ===================== */
@media (max-width:820px){
  .app-screen{grid-template-columns:1fr;}
  .sidebar{
    position:fixed;inset:0;
    transform:translateX(0);
    z-index:40;
    width:100%;
  }
  .sidebar.chat-open{display:none;}
  .chat-pane{width:100%;}
  .msg-row{max-width:82%;}
  .local-video{right:12px;bottom:130px;width:100px;}
}

/* focus visibility */
button:focus-visible, input:focus-visible{
  outline:2px solid var(--mint-500);
  outline-offset:2px;
}