:root {
  --bg: #0f1115;
  --panel: #171a21;
  --panel-2: #1f242d;
  --border: #2a313d;
  --text: #e8ecf2;
  --muted: #97a1b1;
  --accent: #7aa2ff;
  --professor: #e89b5a;
  --professor-bg: #2a1f12;
  --professor-border: #5a3d1f;
  --partner: #5fc7a8;
  --partner-bg: #122621;
  --partner-border: #1f5a48;
  --learner: #b0b8c7;
  --learner-bg: #1a1d24;
  --score-bg: #2c3242;
  --danger: #e76b6b;
  --ok: #6bc66b;
}
* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0; height: 100%;
  background: var(--bg); color: var(--text);
  font: 15px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
button { cursor: pointer; }
input, textarea, select, button { font: inherit; color: inherit; }
textarea, input[type=text], input[type=password], input[type=url], select {
  background: var(--panel-2); border: 1px solid var(--border); border-radius: 8px;
  padding: 10px 12px; color: var(--text); width: 100%;
}
textarea { resize: vertical; min-height: 90px; }
button.primary {
  background: var(--accent); color: #0a0e16; border: none; border-radius: 8px;
  padding: 10px 16px; font-weight: 600;
}
button.primary:hover { filter: brightness(1.08); }
button.primary:disabled { opacity: 0.5; cursor: not-allowed; }
button.secondary {
  background: var(--panel-2); color: var(--text); border: 1px solid var(--border);
  border-radius: 8px; padding: 8px 14px;
}
button.secondary:hover { background: var(--border); }
button.danger {
  background: transparent; color: var(--danger); border: 1px solid var(--danger);
  border-radius: 8px; padding: 8px 14px;
}
.hidden { display: none !important; }

header.app-header {
  padding: 14px 20px; display: flex; align-items: center; justify-content: space-between;
  border-bottom: 1px solid var(--border); background: var(--panel);
}
header.app-header h1 { font-size: 18px; margin: 0; font-weight: 600; letter-spacing: 0.2px; }
header.app-header .right { display: flex; gap: 8px; align-items: center; }
header.app-header .paper-title {
  color: var(--muted); font-size: 13px;
  max-width: 32vw; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.session-code-badge {
  background: var(--panel-2); border: 1px solid var(--border); border-radius: 999px;
  padding: 4px 12px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 13px; letter-spacing: 1px;
}

.setup-wrap { max-width: 880px; margin: 32px auto; padding: 0 20px; }
.card {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 22px; margin-bottom: 18px;
}
.card h2 { margin: 0 0 12px 0; font-size: 16px; }
.row { display: flex; gap: 12px; align-items: center; }
.row > * { flex: 1; }
label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.field { margin-bottom: 14px; }
.tabs { display: flex; gap: 4px; margin-bottom: 12px; border-bottom: 1px solid var(--border); }
.tab {
  padding: 8px 14px; background: transparent; border: none; color: var(--muted);
  border-bottom: 2px solid transparent;
}
.tab.active { color: var(--text); border-bottom-color: var(--accent); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }
.hint { color: var(--muted); font-size: 12.5px; margin-top: 6px; }
.pill {
  display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 11.5px;
  background: var(--score-bg); color: var(--text); margin-left: 6px;
}

.session {
  display: grid; grid-template-rows: auto 1fr auto;
  height: calc(100% - 53px);
}
.session-bar {
  display: flex; gap: 16px; align-items: center; padding: 8px 16px;
  border-bottom: 1px solid var(--border); background: var(--panel-2);
  font-size: 13px; color: var(--muted); flex-wrap: wrap;
}
.session-bar .participants { display: flex; gap: 4px; align-items: center; flex-wrap: wrap; }
.participant-chip {
  background: var(--panel); border: 1px solid var(--border); border-radius: 999px;
  padding: 2px 10px; font-size: 12px; color: var(--text);
}
.participant-chip.me { border-color: var(--accent); color: var(--accent); }
.agents {
  display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--border);
  overflow: hidden; min-height: 0;
}
.agent-pane { background: var(--panel); display: flex; flex-direction: column; min-height: 0; }
.agent-header {
  padding: 12px 16px; border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 10px; background: var(--panel-2);
}
.agent-dot { width: 10px; height: 10px; border-radius: 50%; }
.professor-pane .agent-dot { background: var(--professor); box-shadow: 0 0 0 3px rgba(232,155,90,0.18); }
.partner-pane .agent-dot { background: var(--partner); box-shadow: 0 0 0 3px rgba(95,199,168,0.18); }
.agent-name { font-weight: 600; }
.agent-role { color: var(--muted); font-size: 12.5px; }
select.agent-model, .agent-model {
  margin-left: auto; align-self: center;
  font: 11px/1.2 ui-monospace, SFMono-Regular, Menlo, monospace;
  color: var(--muted);
  background: var(--panel); border: 1px solid var(--border);
  padding: 4px 22px 4px 10px; border-radius: 999px;
  letter-spacing: 0.3px; white-space: nowrap;
  width: auto; max-width: 240px; height: auto;
  appearance: none; -webkit-appearance: none;
  background-image:
    linear-gradient(45deg, transparent 50%, var(--muted) 50%),
    linear-gradient(135deg, var(--muted) 50%, transparent 50%);
  background-position: right 10px top 50%, right 6px top 50%;
  background-size: 4px 4px, 4px 4px;
  background-repeat: no-repeat;
  cursor: pointer;
}
select.agent-model:hover { border-color: var(--accent); color: var(--text); }
select.agent-model:focus { outline: none; border-color: var(--accent); }
select.agent-model:disabled { cursor: default; opacity: 0.7; }
.messages { flex: 1; overflow-y: auto; padding: 16px; display: flex; flex-direction: column; gap: 10px; }
.messages::-webkit-scrollbar { width: 10px; }
.messages::-webkit-scrollbar-thumb { background: var(--border); border-radius: 6px; }

.msg {
  max-width: 88%; padding: 10px 12px; border-radius: 10px;
  white-space: pre-wrap; word-wrap: break-word; line-height: 1.5;
}
.msg .meta { font-size: 11.5px; color: var(--muted); margin-bottom: 4px; }
.msg.from-professor { background: var(--professor-bg); border: 1px solid var(--professor-border); align-self: flex-start; }
.msg.from-partner   { background: var(--partner-bg);   border: 1px solid var(--partner-border);   align-self: flex-start; }
.msg.from-learner   { background: var(--learner-bg);   border: 1px solid var(--border);           align-self: flex-end; }
.msg.from-learner.someone-else { align-self: flex-start; opacity: 0.92; }
.msg.note {
  background: transparent; border: 1px dashed var(--border); color: var(--muted);
  align-self: stretch; max-width: 100%; font-size: 13px;
}
.score-line {
  display: inline-flex; align-items: center; gap: 6px; margin-top: 8px;
  padding: 4px 10px; background: var(--score-bg); border-radius: 999px; font-size: 12.5px;
}
.score-line strong { color: var(--professor); }

.composer { background: var(--panel); border-top: 1px solid var(--border); padding: 12px 16px; }
.composer-row { display: flex; gap: 8px; align-items: stretch; }
.composer-row select { flex: 0 0 220px; }
.composer-row textarea { flex: 1; min-height: 56px; max-height: 200px; }
.composer-row .send { flex: 0 0 110px; }
.composer-actions {
  display: flex; gap: 8px; align-items: center; justify-content: space-between;
  margin-top: 10px; flex-wrap: wrap;
}
.left-actions, .right-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.composer .status { color: var(--muted); font-size: 12.5px; }

.modal-back {
  position: fixed; inset: 0; background: rgba(0,0,0,0.65);
  display: flex; align-items: center; justify-content: center; z-index: 10;
}
.modal {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 18px; width: min(900px, 92vw); max-height: 86vh;
  display: flex; flex-direction: column;
}
.modal h3 { margin: 0 0 12px 0; }
.modal pre {
  flex: 1; overflow: auto; background: var(--panel-2); padding: 14px; border-radius: 8px;
  border: 1px solid var(--border); white-space: pre-wrap; word-wrap: break-word;
  font: 13px/1.55 ui-monospace, SFMono-Regular, Menlo, monospace;
}
.modal .actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 12px; }

.report-grid { display: grid; grid-template-columns: auto 1fr; gap: 12px 18px; align-items: center; }
.big-score {
  font-size: 44px; font-weight: 700; color: var(--professor);
  padding: 18px 22px; border-radius: 12px;
  background: var(--professor-bg); border: 1px solid var(--professor-border);
  text-align: center; min-width: 140px;
}
.scoreboard table { width: 100%; border-collapse: collapse; margin-top: 8px; }
.scoreboard th, .scoreboard td {
  text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--border);
  font-size: 13.5px; vertical-align: top;
}
.scoreboard th { color: var(--muted); font-weight: 500; font-size: 12.5px; }

@media (max-width: 900px) {
  .agents { grid-template-columns: 1fr; }
  .composer-row { flex-direction: column; }
  .composer-row select, .composer-row .send { flex: none; width: 100%; }
}

.typing { display: inline-flex; gap: 3px; align-items: center; color: var(--muted); font-size: 12.5px; }
.typing .dot {
  width: 5px; height: 5px; border-radius: 50%; background: var(--muted);
  animation: bounce 1.2s infinite;
}
.typing .dot:nth-child(2) { animation-delay: 0.15s; }
.typing .dot:nth-child(3) { animation-delay: 0.30s; }
@keyframes bounce {
  0%, 80%, 100% { transform: translateY(0); opacity: 0.4; }
  40%           { transform: translateY(-3px); opacity: 1; }
}

.ws-status {
  display: inline-flex; align-items: center; gap: 6px; font-size: 12px; color: var(--muted);
}
.ws-status .ws-dot {
  width: 8px; height: 8px; border-radius: 50%; background: var(--danger);
}
.ws-status.connected .ws-dot { background: var(--ok); }

.session-browser {
  display: flex; flex-direction: column; gap: 6px;
  max-height: 320px; overflow-y: auto;
  padding: 6px; background: var(--panel-2);
  border: 1px solid var(--border); border-radius: 8px;
}
.session-browser-empty {
  color: var(--muted); font-size: 13px; padding: 18px; text-align: center;
}
.session-row {
  display: grid; grid-template-columns: 1fr auto; gap: 2px 12px;
  padding: 10px 12px; background: var(--panel);
  border: 1px solid var(--border); border-radius: 8px;
  cursor: pointer; transition: border-color 0.12s, background 0.12s;
}
.session-row:hover { border-color: var(--accent); }
.session-row.selected { border-color: var(--accent); background: rgba(122,162,255,0.10); }
.session-row .title {
  font-weight: 600; font-size: 13.5px;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0;
}
.session-row .code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px; color: var(--accent); letter-spacing: 0.5px;
  align-self: center;
}
.session-row .meta {
  color: var(--muted); font-size: 12px; grid-column: 1 / -1;
  display: flex; gap: 10px; flex-wrap: wrap;
}
.session-row .ended-pill {
  background: var(--score-bg); color: var(--muted);
  font-size: 10.5px; padding: 1px 7px; border-radius: 999px;
  text-transform: uppercase; letter-spacing: 0.5px;
}