:root {
  --bg: #0b0e14;
  --bg-soft: #0f1320;
  --panel: #131827;
  --panel-2: #181f31;
  --border: #232b41;
  --text: #e7eaf3;
  --muted: #8e97ad;
  --accent: #6c8cff;
  --accent-strong: #8ba4ff;
  --accent-2: #22d3aa;
  --danger: #ff6b7a;
  --warning: #ffc46b;
  --radius: 12px;
  --radius-lg: 16px;
  --sidebar-width: 288px;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
  --font: "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  --mono: "Cascadia Code", "SF Mono", Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html, body, #root { height: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

button { font-family: inherit; cursor: pointer; }
input, textarea, select { font-family: inherit; }

::-webkit-scrollbar { width: 9px; height: 9px; }
::-webkit-scrollbar-thumb { background: #2a3350; border-radius: 8px; }
::-webkit-scrollbar-track { background: transparent; }

/* ---------------------------------------------------------------- layout */
.app-shell { display: flex; height: 100%; overflow: hidden; }

.main-column {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  background:
    radial-gradient(1200px 500px at 80% -10%, rgba(108, 140, 255, 0.07), transparent 60%),
    radial-gradient(900px 400px at 10% 110%, rgba(34, 211, 170, 0.05), transparent 60%),
    var(--bg);
}

/* ---------------------------------------------------------------- sidebar */
.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-soft);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 18px 16px 14px;
  font-weight: 700;
  font-size: 17px;
  letter-spacing: 0.2px;
}

.brand-logo {
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: grid;
  place-items: center;
  color: #0b0e14;
  flex-shrink: 0;
}

.new-chat-btn {
  margin: 0 14px 12px;
  padding: 10px 14px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: linear-gradient(135deg, rgba(108, 140, 255, 0.16), rgba(34, 211, 170, 0.1));
  color: var(--text);
  font-weight: 600;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: border-color 0.15s, transform 0.05s;
}
.new-chat-btn:hover { border-color: var(--accent); }
.new-chat-btn:active { transform: scale(0.98); }

.session-list { flex: 1; overflow-y: auto; padding: 4px 8px; }

.session-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 10px;
  border-radius: 10px;
  color: var(--muted);
  font-size: 13.5px;
  cursor: pointer;
  border: 1px solid transparent;
  margin-bottom: 2px;
  transition: background 0.12s;
}
.session-item:hover { background: var(--panel); color: var(--text); }
.session-item.active {
  background: var(--panel);
  color: var(--text);
  border-color: var(--border);
}
.session-title {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.session-item .icon-btn { opacity: 0; }
.session-item:hover .icon-btn, .session-item.active .icon-btn { opacity: 1; }

.sidebar-footer {
  border-top: 1px solid var(--border);
  padding: 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 9px 10px;
  background: none;
  border: none;
  border-radius: 10px;
  color: var(--muted);
  font-size: 13.5px;
  text-align: left;
}
.nav-btn:hover, .nav-btn.active { background: var(--panel); color: var(--text); }

.user-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  font-size: 13px;
  color: var(--muted);
}
.avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0b0e14;
  font-weight: 700;
  font-size: 12px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
}

/* ---------------------------------------------------------------- topbar */
.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  background: rgba(15, 19, 32, 0.6);
  backdrop-filter: blur(8px);
  min-height: 56px;
}
.topbar-title {
  font-weight: 600;
  font-size: 15px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.topbar-spacer { flex: 1; }

.model-select {
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 7px 10px;
  font-size: 13px;
  outline: none;
}
.model-select:focus { border-color: var(--accent); }

/* ---------------------------------------------------------------- chat */
.chat-scroll { flex: 1; overflow-y: auto; scroll-behavior: smooth; }
.chat-inner { max-width: 820px; margin: 0 auto; padding: 28px 20px 12px; }

.empty-state {
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  text-align: center;
  padding: 40px 24px;
}
.empty-logo {
  width: 64px;
  height: 64px;
  border-radius: 20px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  display: grid;
  place-items: center;
  color: #0b0e14;
  box-shadow: var(--shadow);
}
.empty-state h1 { margin: 4px 0 0; font-size: 26px; }
.empty-state p { margin: 0; color: var(--muted); max-width: 480px; }

.suggestions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 10px;
  margin-top: 14px;
  width: 100%;
  max-width: 640px;
}
.suggestion-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  font-size: 13.5px;
  color: var(--muted);
  text-align: left;
  transition: border-color 0.15s, color 0.15s;
}
.suggestion-card:hover { border-color: var(--accent); color: var(--text); }
.suggestion-card b { color: var(--text); display: block; margin-bottom: 3px; }

.message-row { display: flex; gap: 12px; margin-bottom: 26px; }
.message-avatar {
  width: 32px;
  height: 32px;
  border-radius: 10px;
  flex-shrink: 0;
  display: grid;
  place-items: center;
  font-size: 13px;
  font-weight: 700;
  margin-top: 2px;
}
.message-avatar.user { background: var(--panel-2); color: var(--accent-strong); border: 1px solid var(--border); }
.message-avatar.assistant { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #0b0e14; }

.message-body { flex: 1; min-width: 0; }
.message-author { font-size: 13px; font-weight: 700; margin-bottom: 4px; }
.message-content { font-size: 15px; overflow-wrap: break-word; }
.message-content > *:first-child { margin-top: 0; }
.message-content > *:last-child { margin-bottom: 0; }
.message-content p { margin: 0.5em 0; }
.message-content h1, .message-content h2, .message-content h3 { margin: 0.9em 0 0.4em; }
.message-content ul, .message-content ol { margin: 0.4em 0; padding-left: 1.4em; }
.message-content a { color: var(--accent-strong); }
.message-content blockquote {
  margin: 0.6em 0;
  padding: 2px 14px;
  border-left: 3px solid var(--accent);
  color: var(--muted);
}
.message-content table { border-collapse: collapse; margin: 0.6em 0; font-size: 14px; }
.message-content th, .message-content td { border: 1px solid var(--border); padding: 6px 10px; }
.message-content th { background: var(--panel); }
.message-content code {
  background: var(--panel-2);
  border: 1px solid var(--border);
  padding: 1.5px 6px;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 13px;
}
.message-content pre {
  background: #0d1119;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  overflow-x: auto;
  margin: 0.7em 0;
}
.message-content pre code { background: none; border: none; padding: 0; font-size: 13px; }

.streaming-cursor::after {
  content: "▍";
  color: var(--accent);
  animation: blink 1s step-end infinite;
}
@keyframes blink { 50% { opacity: 0; } }

.tool-chips { display: flex; flex-wrap: wrap; gap: 6px; margin: 8px 0; }
.tool-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--panel);
  border: 1px solid var(--border);
  color: var(--muted);
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 999px;
}
.tool-chip.running { border-color: var(--accent); color: var(--accent-strong); }
.tool-chip.done { border-color: rgba(34, 211, 170, 0.5); color: var(--accent-2); }
.tool-chip .spin { animation: rotate 1s linear infinite; }
@keyframes rotate { to { transform: rotate(360deg); } }

.citations-box {
  margin-top: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--panel);
  overflow: hidden;
}
.citations-header {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
  background: none;
  border: none;
  color: var(--muted);
  font-size: 12.5px;
  font-weight: 600;
  padding: 9px 12px;
  text-align: left;
}
.citation-item {
  border-top: 1px solid var(--border);
  padding: 9px 12px;
  font-size: 12.5px;
  color: var(--muted);
}
.citation-source { color: var(--accent-2); font-weight: 700; margin-bottom: 3px; }

.message-meta {
  display: flex;
  gap: 12px;
  margin-top: 8px;
  font-size: 11.5px;
  color: #5d6478;
}

.error-banner {
  background: rgba(255, 107, 122, 0.1);
  border: 1px solid rgba(255, 107, 122, 0.4);
  color: var(--danger);
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 13.5px;
  margin-bottom: 16px;
}

/* ---------------------------------------------------------------- composer */
.composer-wrap { padding: 8px 20px 18px; }
.composer {
  max-width: 820px;
  margin: 0 auto;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 10px 12px;
  display: flex;
  align-items: flex-end;
  gap: 10px;
  transition: border-color 0.15s;
  box-shadow: var(--shadow);
}
.composer:focus-within { border-color: var(--accent); }
.composer textarea {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text);
  font-size: 15px;
  line-height: 1.5;
  resize: none;
  max-height: 200px;
  padding: 6px 2px;
}
.composer textarea::placeholder { color: #5d6478; }

.send-btn {
  width: 38px;
  height: 38px;
  border-radius: 11px;
  border: none;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0b0e14;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  transition: opacity 0.15s, transform 0.05s;
}
.send-btn:disabled { opacity: 0.35; cursor: default; }
.send-btn:not(:disabled):active { transform: scale(0.95); }
.send-btn.stop { background: var(--danger); color: #fff; }

.composer-hint {
  max-width: 820px;
  margin: 8px auto 0;
  text-align: center;
  font-size: 11.5px;
  color: #5d6478;
}

/* ---------------------------------------------------------------- buttons */
.icon-btn {
  background: none;
  border: none;
  color: var(--muted);
  padding: 5px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  transition: background 0.12s, color 0.12s;
}
.icon-btn:hover { background: var(--panel-2); color: var(--text); }
.icon-btn.danger:hover { color: var(--danger); }

.btn {
  padding: 9px 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  transition: border-color 0.15s;
}
.btn:hover { border-color: var(--accent); }
.btn.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0b0e14;
  border: none;
}
.btn.primary:disabled { opacity: 0.5; cursor: default; }

/* ---------------------------------------------------------------- auth */
.auth-page {
  height: 100%;
  display: grid;
  grid-template-columns: 1.1fr 1fr;
}
@media (max-width: 860px) { .auth-page { grid-template-columns: 1fr; } .auth-hero { display: none; } }

.auth-hero {
  background:
    radial-gradient(800px 400px at 20% 20%, rgba(108, 140, 255, 0.25), transparent 55%),
    radial-gradient(700px 500px at 80% 80%, rgba(34, 211, 170, 0.18), transparent 55%),
    var(--bg-soft);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 64px;
  border-right: 1px solid var(--border);
}
.auth-hero h1 { font-size: 40px; margin: 18px 0 10px; line-height: 1.15; }
.auth-hero p { color: var(--muted); font-size: 16px; max-width: 440px; margin: 0 0 26px; }
.hero-feature { display: flex; gap: 12px; align-items: flex-start; margin-bottom: 16px; }
.hero-feature .bullet {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: var(--panel);
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  color: var(--accent-2);
  flex-shrink: 0;
}
.hero-feature b { display: block; font-size: 14.5px; }
.hero-feature span { color: var(--muted); font-size: 13px; }

.auth-form-side { display: flex; align-items: center; justify-content: center; padding: 32px; }
.auth-card { width: 100%; max-width: 380px; }
.auth-card h2 { margin: 0 0 6px; font-size: 24px; }
.auth-card .sub { color: var(--muted); font-size: 14px; margin: 0 0 24px; }

.field { margin-bottom: 14px; }
.field label { display: block; font-size: 13px; font-weight: 600; color: var(--muted); margin-bottom: 6px; }
.field input {
  width: 100%;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  font-size: 14.5px;
  padding: 11px 13px;
  outline: none;
  transition: border-color 0.15s;
}
.field input:focus { border-color: var(--accent); }

.auth-error {
  background: rgba(255, 107, 122, 0.1);
  border: 1px solid rgba(255, 107, 122, 0.4);
  color: var(--danger);
  border-radius: 10px;
  padding: 9px 12px;
  font-size: 13px;
  margin-bottom: 14px;
}
.auth-switch { margin-top: 18px; text-align: center; font-size: 13.5px; color: var(--muted); }
.auth-switch button { background: none; border: none; color: var(--accent-strong); font-weight: 600; font-size: 13.5px; }

/* ---------------------------------------------------------------- demo */
.demo-banner {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 16px;
  font-size: 13px;
  color: var(--text);
  background: linear-gradient(90deg, rgba(108, 140, 255, 0.16), rgba(34, 211, 170, 0.12));
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.demo-banner-icon { color: var(--accent-strong); flex-shrink: 0; }
.demo-banner-text { flex: 1; min-width: 0; }
.demo-banner-text b { color: var(--accent-2); }
.demo-banner-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  font-size: 12.5px;
  padding: 5px 11px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--panel);
  white-space: nowrap;
  transition: border-color 0.15s;
}
.demo-banner-link:hover { border-color: var(--accent); }

.demo-cta {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  font-size: 15px;
  padding: 12px 16px;
}

.demo-points {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.demo-points li {
  position: relative;
  padding-left: 20px;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.45;
}
.demo-points li::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 7px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
}

.repo-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin-top: 16px;
  font-size: 13px;
  color: var(--accent-strong);
  text-decoration: none;
  font-weight: 600;
}
.repo-link:hover { text-decoration: underline; }

.auth-divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 24px 0 18px;
  color: #5d6478;
  font-size: 12px;
}
.auth-divider::before,
.auth-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* ---------------------------------------------------------------- documents */
.drawer-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(4, 6, 10, 0.55);
  z-index: 40;
}
.drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(420px, 92vw);
  background: var(--bg-soft);
  border-left: 1px solid var(--border);
  z-index: 50;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow);
  animation: slide-in 0.18s ease-out;
}
@keyframes slide-in { from { transform: translateX(30px); opacity: 0; } }

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  font-weight: 700;
}
.drawer-body { flex: 1; overflow-y: auto; padding: 16px 18px; }

.dropzone {
  border: 1.5px dashed var(--border);
  border-radius: var(--radius);
  padding: 26px 16px;
  text-align: center;
  color: var(--muted);
  font-size: 13.5px;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
  margin-bottom: 16px;
}
.dropzone:hover, .dropzone.dragging { border-color: var(--accent); background: rgba(108, 140, 255, 0.05); }

.doc-item {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 12px;
  margin-bottom: 8px;
}
.doc-info { flex: 1; min-width: 0; }
.doc-name { font-size: 13.5px; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.doc-sub { font-size: 12px; color: var(--muted); }
.badge { font-size: 11px; font-weight: 700; padding: 2.5px 8px; border-radius: 999px; }
.badge.ready { background: rgba(34, 211, 170, 0.12); color: var(--accent-2); }
.badge.processing { background: rgba(255, 196, 107, 0.12); color: var(--warning); }
.badge.failed { background: rgba(255, 107, 122, 0.12); color: var(--danger); }

/* ---------------------------------------------------------------- analytics */
.analytics-scroll { flex: 1; overflow-y: auto; }
.analytics-inner { max-width: 1020px; margin: 0 auto; padding: 28px 20px 40px; }
.analytics-inner h2 { margin: 0 0 4px; }
.analytics-sub { color: var(--muted); font-size: 13.5px; margin: 0 0 22px; }

.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 12px; margin-bottom: 20px; }
.stat-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
}
.stat-label { font-size: 12px; color: var(--muted); font-weight: 600; text-transform: uppercase; letter-spacing: 0.4px; display: flex; align-items: center; gap: 7px; }
.stat-value { font-size: 26px; font-weight: 700; margin-top: 6px; }
.stat-hint { font-size: 12px; color: var(--muted); margin-top: 2px; }

.chart-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 14px;
}
.chart-card h3 { margin: 0 0 14px; font-size: 15px; }
.chart-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media (max-width: 820px) { .chart-row { grid-template-columns: 1fr; } }

.tool-usage-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 13.5px;
}
.tool-usage-row:last-child { border-bottom: none; }
.tool-usage-bar { height: 7px; border-radius: 4px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); }

.centered-note { color: var(--muted); text-align: center; padding: 30px 0; font-size: 13.5px; }

/* ---------------------------------------------------------------- misc */
.fade-in { animation: fade-in 0.25s ease-out; }
@keyframes fade-in { from { opacity: 0; transform: translateY(4px); } }

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: rotate 0.8s linear infinite;
}