:root {
  --bg: #0b0e14;
  --panel: #121828;
  --panel2: #0f1524;
  --text: #e7eaf0;
  --muted: #a8b0c2;
  --border: #24304a;
  --accent: #4b7dff;
  --danger: #ff4b55;
  --shadow: rgba(0,0,0,.25);
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, #0e1320, #0b0e14);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand { display: flex; align-items: center; gap: 12px; }
.logo { font-size: 26px; }
.brand-title { font-weight: 800; letter-spacing: .2px; }
.brand-sub { color: var(--muted); font-size: 13px; margin-top: 2px; }

.topbar-actions { display: flex; gap: 10px; }

.layout {
  display: grid;
  grid-template-columns: 360px 1fr;
  min-height: calc(100vh - 60px);
}

.sidebar {
  border-right: 1px solid var(--border);
  padding: 14px;
  background: var(--panel2);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px;
  box-shadow: 0 10px 30px var(--shadow);
}

.panel-title {
  font-weight: 800;
  margin-bottom: 10px;
}

.input, .select, .textarea {
  width: 100%;
  border: 1px solid var(--border);
  background: #0c1120;
  color: var(--text);
  border-radius: 12px;
  padding: 10px 12px;
  outline: none;
}

.textarea { resize: none; }

.filters {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 10px;
}

.writers-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 44vh;
  overflow: auto;
  padding-right: 4px;
}

.writer-card {
  display: flex;
  gap: 10px;
  align-items: center;
  padding: 10px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #0c1120;
  cursor: pointer;
  user-select: none;
}

.writer-card:hover { border-color: #39508a; }
.writer-card.active {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(75,125,255,.2);
}

.writer-card .avatar { font-size: 22px; width: 30px; text-align: center; }
.writer-card .name { font-weight: 800; }
.writer-card .meta { color: var(--muted); font-size: 12px; margin-top: 2px; }

.modes { display: grid; gap: 8px; }
.radio { display: flex; align-items: center; gap: 10px; color: var(--muted); }
.radio input { transform: scale(1.05); }

.sidebar-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 10px; }
.hint { color: var(--muted); font-size: 12px; margin-top: 10px; }

.chat {
  display: flex;
  flex-direction: column;
  padding: 14px;
  gap: 12px;
}

.chat-header {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 10px 30px var(--shadow);
}

.chat-writer { display: flex; align-items: center; gap: 12px; }
.writer-avatar { font-size: 28px; }
.writer-name { font-weight: 900; }
.writer-meta { color: var(--muted); font-size: 12px; margin-top: 2px; }

.chip {
  border: 1px solid var(--border);
  padding: 6px 10px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 12px;
}

.messages {
  flex: 1;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px;
  overflow: auto;
  box-shadow: 0 10px 30px var(--shadow);
}

.msg {
  max-width: 78%;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid var(--border);
  margin: 10px 0;
  white-space: pre-wrap;
}

.msg.user {
  margin-left: auto;
  background: #0c1120;
}

.msg.ai {
  margin-right: auto;
  background: #0d1426;
}

.msg .who {
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 6px;
  font-weight: 700;
}

.composer {
  display: grid;
  grid-template-columns: 1fr 140px;
  gap: 10px;
  align-items: stretch;
}

.btn {
  border: 1px solid var(--border);
  background: #0c1120;
  color: var(--text);
  padding: 10px 12px;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 800;
}

.btn:hover { border-color: #3b4d7c; }
.btn:disabled { opacity: .6; cursor: not-allowed; }

.btn-primary {
  background: linear-gradient(180deg, #5a86ff, #3c6fff);
  border-color: rgba(75,125,255,.55);
}

.btn-danger {
  background: linear-gradient(180deg, #ff5a62, #ff3b45);
  border-color: rgba(255,75,85,.55);
}

@media (max-width: 980px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { border-right: none; border-bottom: 1px solid var(--border); }
}