frontend/assets/styles.css

:root {
  --bg: #071015;
  --panel: rgba(13, 27, 35, 0.88);
  --panel-soft: rgba(18, 38, 48, 0.78);
  --line: rgba(103, 232, 221, 0.22);
  --text: #ecfbff;
  --muted: #91aab2;
  --cyan: #67e8dd;
  --green: #a7f3c4;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    linear-gradient(rgba(103, 232, 221, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(103, 232, 221, 0.035) 1px, transparent 1px),
    radial-gradient(circle at 50% 0%, rgba(103, 232, 221, 0.14), transparent 34rem),
    var(--bg);
  background-size: 36px 36px, 36px 36px, auto, auto;
}

button,
input {
  font: inherit;
}

.chat-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 28px;
}

.chat-card {
  width: min(980px, 100%);
  height: min(820px, calc(100vh - 56px));
  display: grid;
  grid-template-rows: auto 1fr auto auto;
  border: 1px solid var(--line);
  background: var(--panel);
  box-shadow: 0 24px 90px rgba(0, 0, 0, 0.45);
}

.chat-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 22px;
  border-bottom: 1px solid var(--line);
}

.chat-header p,
.chat-header h1 {
  margin: 0;
}

.chat-header p {
  color: var(--cyan);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.chat-header h1 {
  margin-top: 4px;
  font-size: clamp(24px, 4vw, 40px);
  letter-spacing: 0;
}

.status {
  border: 1px solid rgba(167, 243, 196, 0.34);
  color: var(--green);
  padding: 8px 10px;
  white-space: nowrap;
  background: rgba(167, 243, 196, 0.07);
}

.messages {
  overflow: auto;
  padding: 22px;
}

.message {
  display: flex;
  margin-bottom: 14px;
}

.message.user {
  justify-content: flex-end;
}

.bubble {
  max-width: min(720px, 88%);
  padding: 14px 16px;
  line-height: 1.6;
  white-space: pre-wrap;
  border: 1px solid rgba(145, 170, 178, 0.22);
}

.assistant .bubble {
  background: rgba(9, 19, 25, 0.82);
}

.user .bubble {
  background: rgba(103, 232, 221, 0.12);
  border-color: rgba(103, 232, 221, 0.34);
}

.sources-panel {
  border-top: 1px solid var(--line);
  background: rgba(4, 12, 16, 0.48);
  padding: 14px 22px;
}

.meta-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}

.meta-row span {
  border: 1px solid var(--line);
  color: #c9f7f4;
  background: rgba(103, 232, 221, 0.07);
  padding: 7px 9px;
  font-size: 13px;
}

.sources {
  display: grid;
  gap: 8px;
  max-height: 170px;
  overflow: auto;
}

.source {
  border: 1px solid rgba(145, 170, 178, 0.2);
  background: var(--panel-soft);
  padding: 10px;
}

.source strong {
  color: var(--cyan);
  font-size: 13px;
}

.source p,
.empty-source {
  margin: 7px 0 0;
  color: #d5e8ec;
  line-height: 1.45;
  font-size: 14px;
}

.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  padding: 18px 22px 22px;
  border-top: 1px solid var(--line);
}

.composer input {
  min-height: 48px;
  border: 1px solid rgba(145, 170, 178, 0.28);
  background: #08161d;
  color: var(--text);
  outline: none;
  padding: 0 14px;
}

.composer input:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(103, 232, 221, 0.1);
}

.composer button {
  min-width: 104px;
  border: 1px solid rgba(103, 232, 221, 0.55);
  color: var(--text);
  background: linear-gradient(135deg, #0fb9b1, #176e84);
  cursor: pointer;
  font-weight: 800;
}

.composer button:disabled {
  opacity: 0.65;
  cursor: wait;
}

@media (max-width: 640px) {
  .chat-shell {
    padding: 0;
  }

  .chat-card {
    min-height: 100vh;
    height: 100vh;
    border: 0;
  }

  .chat-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .composer {
    grid-template-columns: 1fr;
  }

  .composer button {
    min-height: 46px;
  }
}