:root {
  --ink:      #0E1C26;
  --rail:     #142935;
  --rail-2:   #1D3948;
  --line:     #22404F;
  --paper:    #F1F3F1;
  --card:     #FFFFFF;
  --text:     #16242C;
  --muted:    #61757F;
  --accent:   #0F7A72;
  --accent-2: #C9E4E0;
  --danger:   #A33A2E;
  --radius:   10px;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans Sinhala", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  font-family: var(--sans);
  color: var(--text);
  background: var(--paper);
  -webkit-text-size-adjust: 100%;
}

.eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 6px;
}

.muted { color: var(--muted); font-size: 14px; }
.error { color: var(--danger); font-size: 14px; margin: 6px 0; }
.warn  { color: var(--danger); font-size: 13px; margin-top: 20px; }

a { color: var(--accent); }

/* ---------- buttons + fields ---------- */

.btn {
  display: inline-block;
  border: 0;
  border-radius: var(--radius);
  background: var(--accent);
  color: #fff;
  font: 600 15px/1 var(--sans);
  padding: 13px 20px;
  cursor: pointer;
  text-decoration: none;
}
.btn:hover { background: #0C665F; }
.btn:focus-visible, input:focus-visible, textarea:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

input, textarea {
  width: 100%;
  font: 15px/1.45 var(--sans);
  color: var(--text);
  background: #fff;
  border: 1px solid #CBD4D3;
  border-radius: var(--radius);
  padding: 11px 12px;
}

label {
  display: block;
  margin: 14px 0;
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
}
label input { margin-top: 6px; font-weight: 400; color: var(--text); }

/* ---------- sign in / sign up ---------- */

.auth-page {
  display: grid;
  place-items: center;
  padding: 24px;
  background:
    radial-gradient(900px 500px at 50% -10%, #E3EBE9 0%, var(--paper) 60%);
}

.auth-card {
  width: 100%;
  max-width: 380px;
  background: var(--card);
  border: 1px solid #DCE3E1;
  border-radius: 14px;
  padding: 32px 28px;
}
.auth-card h1 { margin: 0 0 4px; font-size: 24px; letter-spacing: -.01em; }
.auth-card .btn { width: 100%; margin-top: 8px; }

/* ---------- app shell ---------- */

.app { overflow: hidden; }

.shell {
  display: grid;
  grid-template-columns: 268px 1fr;
  height: 100dvh;
}

/* ---------- left rail ---------- */

.rail {
  background: var(--rail);
  color: #DCE7EC;
  display: flex;
  flex-direction: column;
  min-height: 0;
  border-right: 1px solid var(--line);
}

.rail-head { padding: 20px 18px 12px; border-bottom: 1px solid var(--line); }
.rail-head .eyebrow { color: #6E8C9B; }
.wordmark { margin: 0; font-size: 17px; font-weight: 650; letter-spacing: -.01em; color: #F2F7F8; }

.channels { flex: 1; overflow-y: auto; padding: 14px 10px 20px; min-height: 0; }

.rail-label {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: #6E8C9B;
  margin: 16px 8px 8px;
}

.rail-empty { color: #6E8C9B; font-size: 13px; padding: 4px 8px; }

.convo {
  display: flex;
  align-items: center;
  gap: 9px;
  width: 100%;
  border: 0;
  background: transparent;
  color: #C9DAE1;
  font: 15px/1.2 var(--sans);
  text-align: left;
  padding: 9px 10px;
  border-radius: 8px;
  cursor: pointer;
}
.convo:hover { background: var(--rail-2); }
.convo.is-active { background: var(--rail-2); color: #fff; box-shadow: inset 3px 0 0 var(--accent); }

.convo-mark { font-family: var(--mono); color: #6E8C9B; }
.convo-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: #4A6675;
  flex: none;
}
.dot.is-online { background: #46C08B; }

.badge {
  font: 600 11px/1 var(--sans);
  background: var(--accent);
  color: #fff;
  border-radius: 999px;
  padding: 4px 7px;
  flex: none;
}

.rail-foot {
  border-top: 1px solid var(--line);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}
.who { display: flex; align-items: center; gap: 8px; min-width: 0; }
.who-name { font-size: 13px; color: #E6EFF2; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.signout { font-size: 12px; color: #8FB3BF; text-decoration: none; flex: none; }
.signout:hover { color: #fff; text-decoration: underline; }

/* ---------- message pane ---------- */

.pane { display: flex; flex-direction: column; min-width: 0; min-height: 0; }

.pane-head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 22px;
  background: var(--card);
  border-bottom: 1px solid #DCE3E1;
}
.pane-head h2 { margin: 0; font-size: 16px; font-weight: 650; }
.pane-sub { margin: 2px 0 0; font-size: 12.5px; color: var(--muted); }

.rail-toggle {
  display: none;
  border: 1px solid #CBD4D3;
  background: #fff;
  border-radius: 8px;
  font-size: 16px;
  padding: 7px 11px;
  cursor: pointer;
}

.stream {
  flex: 1;
  overflow-y: auto;
  padding: 20px 22px 8px;
  min-height: 0;
  scroll-behavior: smooth;
}
.stream-empty { color: var(--muted); font-size: 14px; text-align: center; margin-top: 40px; }

.day {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--muted);
  text-align: center;
  margin: 22px 0 14px;
}

.msg { margin: 0 0 6px; max-width: min(640px, 78%); }
.msg.is-mine { margin-left: auto; }

.msg-who {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 14px 0 5px 2px;
}
.msg.is-mine .msg-who { text-align: right; margin-right: 2px; }

.bubble {
  background: var(--card);
  border: 1px solid #DFE5E3;
  border-radius: 4px 12px 12px 12px;
  padding: 9px 12px 7px;
  display: flex;
  align-items: flex-end;
  gap: 10px;
}
.msg.is-mine .bubble {
  background: var(--accent-2);
  border-color: #AFD3CE;
  border-radius: 12px 4px 12px 12px;
}

.msg-text { white-space: pre-wrap; overflow-wrap: anywhere; font-size: 15px; line-height: 1.45; }
.msg-time { font-family: var(--mono); font-size: 10.5px; color: var(--muted); flex: none; padding-bottom: 2px; }

/* ---------- composer ---------- */

.composer {
  display: flex;
  gap: 10px;
  align-items: flex-end;
  padding: 14px 22px 18px;
  background: var(--card);
  border-top: 1px solid #DCE3E1;
}
.composer textarea { resize: none; max-height: 160px; }
.send { flex: none; }

.notice {
  margin: 0;
  padding: 9px 22px;
  background: #FBE9E6;
  color: var(--danger);
  font-size: 13.5px;
}

/* ---------- small screens ---------- */

@media (max-width: 760px) {
  .shell { grid-template-columns: 1fr; }
  .rail {
    position: fixed;
    inset: 0 auto 0 0;
    width: 260px;
    transform: translateX(-100%);
    transition: transform .2s ease;
    z-index: 20;
  }
  .rail.is-open { transform: translateX(0); }
  .rail-toggle { display: block; }
  .msg { max-width: 88%; }
  .stream, .composer, .pane-head { padding-left: 14px; padding-right: 14px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}