:root {
  --bg: #eef2f7;
  --surface: #ffffff;
  --surface-strong: #0f172a;
  --text: #122033;
  --muted: #536273;
  --line: #d7dfeb;
  --accent: #0f766e;
  --accent-soft: #d8f3f1;
  --danger: #b42318;
  --warning: #b54708;
  --ready: #166534;
  --shadow: 0 18px 50px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "IBM Plex Sans", "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(15, 118, 110, 0.09), transparent 25%),
    linear-gradient(180deg, #f8fbff 0%, var(--bg) 100%);
}

.shell {
  display: grid;
  grid-template-columns: 360px 1fr;
  min-height: 100vh;
}

.sidebar {
  padding: 28px;
  border-right: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
}

.main-panel {
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.brand h1,
.hero-card h2,
.section-header h2,
.empty-state h3 {
  margin: 0;
  font-family: "Space Grotesk", "Avenir Next", sans-serif;
}

.eyebrow {
  margin: 0 0 8px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 12px;
  color: var(--accent);
  font-weight: 700;
}

.subcopy,
.muted,
.helper {
  color: var(--muted);
}

.library-helper {
  margin: 0 0 14px;
}

.upload-card,
.hero-card,
.chat-panel,
.evidence-panel,
.document-item {
  border: 1px solid rgba(215, 223, 235, 0.9);
  background: var(--surface);
  box-shadow: var(--shadow);
  border-radius: 20px;
}

.upload-card,
.hero-card,
.chat-panel,
.evidence-panel {
  padding: 20px;
}

.upload-card {
  display: grid;
  gap: 12px;
  margin: 24px 0;
}

.upload-label {
  font-weight: 700;
}

input[type="file"],
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px 14px;
  font: inherit;
  background: #fbfcfe;
}

button {
  border: none;
  border-radius: 999px;
  padding: 12px 18px;
  font: inherit;
  font-weight: 700;
  color: white;
  background: linear-gradient(135deg, var(--accent) 0%, #155eef 100%);
  cursor: pointer;
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.secondary-button {
  background: var(--accent-soft);
  color: var(--accent);
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
  flex-direction: column;
}

.document-list,
.chat-messages,
.sources-list {
  display: grid;
  gap: 12px;
}

.document-item {
  padding: 16px;
  transition: transform 0.18s ease, border-color 0.18s ease;
}

.document-item:hover,
.document-item.active {
  transform: translateY(-1px);
  border-color: rgba(21, 94, 239, 0.45);
}

.document-item button {
  width: 100%;
  margin-top: 12px;
}

.badge,
.chip {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 5px 10px;
  font-size: 12px;
  font-weight: 700;
}

.badge.queued,
.badge.processing {
  color: var(--warning);
  background: #fff4e5;
}

.badge.ready {
  color: var(--ready);
  background: #dcfce7;
}

.badge.failed {
  color: var(--danger);
  background: #fee4e2;
}

.chip {
  background: #e9efff;
  color: #1648c2;
}

.prompt-pills {
  margin-top: 20px;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.prompt-pills span {
  background: #eff6ff;
  color: #1548be;
  border-radius: 999px;
  padding: 8px 12px;
  font-size: 13px;
}

.chat-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(280px, 0.8fr);
  gap: 22px;
  min-height: 0;
  flex: 1;
}

.chat-panel {
  display: flex;
  flex-direction: column;
  min-height: 540px;
}

.chat-messages {
  flex: 1;
  overflow: auto;
  padding-right: 6px;
}

.message {
  padding: 14px 16px;
  border-radius: 18px;
  max-width: 86%;
  line-height: 1.5;
}

.message.user {
  justify-self: end;
  background: #edf4ff;
}

.message.assistant {
  justify-self: start;
  background: #f4f9f9;
}

.message-meta {
  margin-bottom: 8px;
  font-size: 12px;
  font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.question-form {
  display: grid;
  gap: 12px;
  padding-top: 18px;
}

.question-form-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.question-form-meta {
  display: grid;
  gap: 10px;
  min-width: 0;
}

.mode-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #f8fbff;
  width: fit-content;
}

.mode-toggle-button {
  padding: 10px 14px;
  color: var(--muted);
  background: transparent;
  border: 1px solid transparent;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.mode-toggle-button.active {
  color: #1548be;
  background: #e9efff;
  border-color: rgba(21, 94, 239, 0.16);
}

.source-card {
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 14px;
  background: #fbfdff;
}

.source-card h3 {
  margin: 0 0 6px;
  font-size: 15px;
}

.source-label {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
}

.source-meta {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 12px;
}

.empty-state,
.empty-evidence {
  padding: 24px;
  border: 1px dashed var(--line);
  border-radius: 18px;
  text-align: center;
  background: #fbfcff;
}

@media (max-width: 1080px) {
  .shell,
  .chat-layout {
    grid-template-columns: 1fr;
  }

  .sidebar {
    border-right: none;
    border-bottom: 1px solid var(--line);
  }
}

@media (max-width: 720px) {
  .question-form-footer {
    flex-direction: column;
    align-items: stretch;
  }

  .mode-toggle {
    width: 100%;
    justify-content: space-between;
  }

  .mode-toggle-button {
    flex: 1;
  }
}