/* ============================================================
   阅微 v2 · 柔和现代 · 奶油薄荷
   A soft, warm interface for casual readers.
   Cream dominant, mint as rare accent, warm-dark text.
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,400;9..144,500;9..144,600;9..144,700&family=Plus+Jakarta+Sans:wght@400;500;600;700&family=Noto+Sans+SC:wght@400;500;700&display=swap');

:root {
  /* Color — OKLCH perceptual uniform */
  --cream-bg: oklch(97.5% 0.012 85);
  --cream-surface: oklch(99.2% 0.006 85);
  --cream-sunken: oklch(95.5% 0.014 85);
  --cream-border: oklch(90% 0.014 85);
  --cream-border-strong: oklch(85% 0.018 85);

  --mint: oklch(82% 0.095 158);
  --mint-hover: oklch(76% 0.115 158);
  --mint-press: oklch(70% 0.13 158);
  --mint-soft: oklch(93% 0.04 158);
  --mint-softer: oklch(96% 0.02 158);
  --mint-deep: oklch(42% 0.09 158);
  --mint-bubble: oklch(48% 0.11 158);

  --coral: oklch(76% 0.13 35);
  --coral-soft: oklch(94% 0.04 35);

  --amber: oklch(82% 0.12 75);

  --ink: oklch(28% 0.02 85);
  --ink-soft: oklch(42% 0.018 85);
  --ink-muted: oklch(58% 0.015 85);
  --ink-faint: oklch(72% 0.012 85);

  --error: oklch(60% 0.18 25);
  --error-soft: oklch(94% 0.04 25);

  /* Typography */
  --font-display: 'Fraunces', 'Noto Serif SC', 'Songti SC', Georgia, serif;
  --font-ui: 'Plus Jakarta Sans', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-body: 'Plus Jakarta Sans', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-mono: ui-monospace, 'SF Mono', 'JetBrains Mono', Consolas, monospace;

  /* Spacing — 4pt base */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-2xl: 24px;
  --radius-pill: 999px;

  /* Shadows — subtle, warm */
  --shadow-sm: 0 1px 2px rgba(45, 38, 32, 0.04);
  --shadow-md: 0 2px 8px rgba(45, 38, 32, 0.05), 0 1px 2px rgba(45, 38, 32, 0.04);
  --shadow-lg: 0 8px 24px rgba(45, 38, 32, 0.08), 0 2px 6px rgba(45, 38, 32, 0.04);
  --shadow-mint: 0 4px 14px oklch(82% 0.095 158 / 0.25);

  /* Motion */
  --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --dur-1: 120ms;
  --dur-2: 200ms;
  --dur-3: 320ms;
  --dur-4: 480ms;

  color-scheme: light;
}

/* ============================================================
   Reset & base
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }

[x-cloak] { display: none !important; }

html, body {
  background: var(--cream-bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  font-variant-numeric: tabular-nums;
  font-kerning: normal;
}

/* Subtle paper warmth — a faint radial wash, not a gradient hero */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(60% 50% at 85% 12%, oklch(93% 0.05 158 / 0.35), transparent 70%),
    radial-gradient(45% 35% at 8% 88%, oklch(94% 0.04 35 / 0.25), transparent 70%);
  z-index: -1;
}

button, input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

button { cursor: pointer; border: none; background: none; }

a { color: var(--mint-deep); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

::selection { background: var(--mint-soft); color: var(--mint-deep); }

/* Focus ring — keyboard only */
:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--mint);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* Scrollbar — slim, warm */
.messages::-webkit-scrollbar,
textarea::-webkit-scrollbar { width: 6px; }
.messages::-webkit-scrollbar-track,
textarea::-webkit-scrollbar-track { background: transparent; }
.messages::-webkit-scrollbar-thumb,
textarea::-webkit-scrollbar-thumb {
  background: var(--cream-border-strong);
  border-radius: var(--radius-pill);
}
.messages::-webkit-scrollbar-thumb:hover,
textarea::-webkit-scrollbar-thumb:hover { background: var(--ink-faint); }

/* ============================================================
   Brand mark — mint dot + Fraunces wordmark
   ============================================================ */

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 22px;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.brand-dot {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-pill);
  background: var(--mint);
  box-shadow: 0 0 0 4px var(--mint-softer);
  flex-shrink: 0;
}
.brand-tag {
  font-family: var(--font-ui);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-left: 4px;
}

/* ============================================================
   Buttons
   ============================================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: var(--radius-pill);
  font-family: var(--font-ui);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.005em;
  transition: background var(--dur-1) var(--ease-out-quart),
              color var(--dur-1) var(--ease-out-quart),
              transform var(--dur-1) var(--ease-out-quart),
              box-shadow var(--dur-1) var(--ease-out-quart);
  white-space: nowrap;
  -webkit-tap-highlight-color: transparent;
}
.btn:active { transform: translateY(0.5px) scale(0.99); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

.btn-primary {
  background: var(--mint);
  color: oklch(99.5% 0.005 158);
  box-shadow: var(--shadow-mint);
}
.btn-primary:hover:not(:disabled) {
  background: var(--mint-hover);
  box-shadow: 0 6px 18px oklch(82% 0.095 158 / 0.35);
}
.btn-primary:active:not(:disabled) {
  background: var(--mint-press);
}

.btn-ghost {
  background: transparent;
  color: var(--ink-soft);
  padding: 9px 14px;
}
.btn-ghost:hover:not(:disabled) {
  background: var(--mint-softer);
  color: var(--mint-deep);
}

.btn-outline {
  background: var(--cream-surface);
  color: var(--ink);
  border: 1px solid var(--cream-border);
  padding: 10px 18px;
}
.btn-outline:hover:not(:disabled) {
  border-color: var(--mint);
  color: var(--mint-deep);
  background: var(--mint-softer);
}

.btn-text {
  background: none;
  color: var(--ink-muted);
  padding: 6px 10px;
  font-weight: 500;
  font-size: 13px;
}
.btn-text:hover:not(:disabled) {
  color: var(--mint-deep);
}

.btn-icon {
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: var(--radius-pill);
  background: var(--mint);
  color: oklch(99.5% 0.005 158);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: var(--shadow-mint);
  transition: background var(--dur-1) var(--ease-out-quart),
              transform var(--dur-1) var(--ease-out-quart);
}
.btn-icon:hover:not(:disabled) { background: var(--mint-hover); }
.btn-icon:active:not(:disabled) { transform: scale(0.94); }
.btn-icon:disabled { background: var(--cream-border-strong); box-shadow: none; }

/* ============================================================
   Inputs
   ============================================================ */

.input {
  width: 100%;
  padding: 13px 16px;
  background: var(--cream-surface);
  border: 1px solid var(--cream-border);
  border-radius: var(--radius-md);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.5;
  transition: border-color var(--dur-1) var(--ease-out-quart),
              background var(--dur-1) var(--ease-out-quart),
              box-shadow var(--dur-1) var(--ease-out-quart);
}
.input::placeholder { color: var(--ink-faint); }
.input:hover:not(:focus) { border-color: var(--cream-border-strong); }
.input:focus {
  outline: none;
  border-color: var(--mint);
  background: var(--cream-surface);
  box-shadow: 0 0 0 4px var(--mint-softer);
}

textarea.input {
  resize: none;
  min-height: 52px;
}

select.input {
  appearance: none;
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8' fill='none'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%236b6259' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
}

/* ============================================================
   Auth page
   ============================================================ */

.auth-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-8) var(--space-4);
  position: relative;
}

.auth-decor {
  position: absolute;
  pointer-events: none;
  opacity: 0.85;
}
.auth-decor--leaf-tl {
  top: 6%;
  left: 8%;
  width: 80px;
  color: var(--mint-soft);
}
.auth-decor--leaf-br {
  bottom: 8%;
  right: 10%;
  width: 110px;
  color: var(--coral-soft);
  transform: rotate(180deg);
}

.auth-card {
  width: 100%;
  max-width: 420px;
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
  animation: rise var(--dur-4) var(--ease-out-expo) both;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.auth-head {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
}
.auth-head .brand { font-size: 26px; }
.auth-tagline {
  font-family: var(--font-display);
  font-size: clamp(22px, 4vw, 28px);
  font-weight: 500;
  font-variation-settings: 'opsz' 36;
  letter-spacing: -0.015em;
  color: var(--ink);
  line-height: 1.25;
  margin-top: var(--space-2);
}
.auth-tagline em {
  font-style: italic;
  color: var(--mint-deep);
  font-weight: 500;
}
.auth-sub {
  font-size: 14px;
  color: var(--ink-muted);
  max-width: 32ch;
  line-height: 1.55;
}

/* Pill toggle for login/register */
.auth-toggle {
  display: inline-flex;
  align-self: center;
  padding: 4px;
  background: var(--cream-sunken);
  border-radius: var(--radius-pill);
  position: relative;
}
.auth-toggle button {
  position: relative;
  z-index: 1;
  padding: 8px 22px;
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-muted);
  border-radius: var(--radius-pill);
  transition: color var(--dur-2) var(--ease-out-quart);
}
.auth-toggle button[aria-selected="true"] {
  color: var(--mint-deep);
}
.auth-toggle::before {
  content: '';
  position: absolute;
  z-index: 0;
  top: 4px;
  bottom: 4px;
  left: 4px;
  width: calc(50% - 4px);
  background: var(--cream-surface);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-sm);
  transition: transform var(--dur-3) var(--ease-out-expo);
}
.auth-toggle[data-mode="register"]::before {
  transform: translateX(100%);
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.auth-field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.auth-label {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--ink-muted);
  padding-left: 4px;
}
.auth-label[hidden] { display: none; }

.auth-code-row {
  display: flex;
  gap: var(--space-2);
  align-items: stretch;
}
.auth-code-row .input { flex: 1; }
.auth-code-btn {
  flex-shrink: 0;
  padding: 0 16px;
  background: var(--mint-softer);
  color: var(--mint-deep);
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 600;
  font-family: var(--font-ui);
  transition: background var(--dur-1) var(--ease-out-quart);
  white-space: nowrap;
}
.auth-code-btn:hover:not(:disabled) { background: var(--mint-soft); }
.auth-code-btn:disabled { color: var(--ink-faint); cursor: not-allowed; }

.auth-error {
  font-size: 13px;
  color: var(--error);
  background: var(--error-soft);
  padding: 10px 14px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  gap: 8px;
  animation: shake var(--dur-3) var(--ease-out-quart);
}
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-2px); }
  40%, 80% { transform: translateX(2px); }
}

.auth-submit {
  margin-top: var(--space-2);
  width: 100%;
  padding: 14px 20px;
  font-size: 15px;
}

.auth-foot {
  text-align: center;
  font-size: 12px;
  color: var(--ink-faint);
  letter-spacing: 0.02em;
}

/* ============================================================
   Chat layout
   ============================================================ */

.chat-shell {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  max-width: 880px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.chat-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-5) 0 var(--space-4);
  border-bottom: 1px solid var(--cream-border);
  gap: var(--space-3);
}
.chat-topbar .brand { font-size: 20px; }
.chat-topbar .brand-sub {
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 500;
  color: var(--ink-muted);
  margin-left: 4px;
  letter-spacing: 0;
}
.chat-actions {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  scrollbar-gutter: stable;
  padding: var(--space-6) var(--space-2) var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

/* Empty state */
.chat-empty {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: var(--space-4);
  padding: var(--space-12) var(--space-4);
  animation: rise var(--dur-4) var(--ease-out-expo) both;
}
.chat-empty-leaf {
  width: 64px;
  height: 64px;
  color: var(--mint);
  margin-bottom: var(--space-2);
}
.chat-empty-title {
  font-family: var(--font-display);
  font-size: clamp(22px, 4vw, 28px);
  font-weight: 500;
  font-variation-settings: 'opsz' 36;
  letter-spacing: -0.015em;
  color: var(--ink);
  line-height: 1.3;
}
.chat-empty-title em {
  font-style: italic;
  color: var(--mint-deep);
}
.chat-empty-hint {
  font-size: 14px;
  color: var(--ink-muted);
  max-width: 36ch;
  line-height: 1.6;
}
.chat-empty-suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  justify-content: center;
  margin-top: var(--space-4);
  max-width: 480px;
}
.chat-suggestion {
  padding: 8px 14px;
  background: var(--cream-surface);
  border: 1px solid var(--cream-border);
  border-radius: var(--radius-pill);
  font-size: 13px;
  color: var(--ink-soft);
  transition: border-color var(--dur-1) var(--ease-out-quart),
              color var(--dur-1) var(--ease-out-quart),
              background var(--dur-1) var(--ease-out-quart);
}
.chat-suggestion:hover {
  border-color: var(--mint);
  color: var(--mint-deep);
  background: var(--mint-softer);
}

/* Message row */
.msg-row {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  animation: msg-in var(--dur-3) var(--ease-out-expo) both;
}
@keyframes msg-in {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}
.msg-row.user { align-items: flex-end; }
.msg-row.agent { align-items: stretch; }

.msg {
  max-width: 78%;
  padding: 12px 16px;
  font-size: 15px;
  line-height: 1.65;
  word-break: break-word;
  white-space: pre-wrap;
}
.msg.user {
  background: var(--mint-bubble);
  color: oklch(99.5% 0.005 158);
  border-radius: var(--radius-lg) var(--radius-lg) var(--radius-sm) var(--radius-lg);
  box-shadow: var(--shadow-mint);
  font-weight: 500;
}
.msg.agent {
  background: transparent;
  color: var(--ink);
  border: none;
  border-radius: 0;
  max-width: none;
  padding: 0;
}

/* Markdown rendering inside agent messages */
.msg.agent p { margin: 0 0 var(--space-3); }
.msg.agent p:last-child { margin-bottom: 0; }
.msg.agent h1, .msg.agent h2, .msg.agent h3 {
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: var(--space-4) 0 var(--space-2);
  line-height: 1.3;
}
.msg.agent h1 { font-size: 20px; }
.msg.agent h2 { font-size: 17px; }
.msg.agent h3 { font-size: 15px; }
.msg.agent ul, .msg.agent ol { margin: var(--space-2) 0 var(--space-3); padding-left: 22px; }
.msg.agent li { margin: 4px 0; }
.msg.agent code {
  background: var(--cream-sunken);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--mint-deep);
}
.msg.agent pre {
  background: var(--cream-sunken);
  border: 1px solid var(--cream-border);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  overflow-x: auto;
  margin: var(--space-3) 0;
}
.msg.agent pre code {
  background: transparent;
  padding: 0;
  font-size: 13px;
  color: var(--ink);
}
.msg.agent blockquote {
  border-left: 3px solid var(--mint);
  margin: var(--space-3) 0;
  padding: 2px 14px;
  color: var(--ink-soft);
  font-style: italic;
}
.msg.agent strong { font-weight: 600; color: var(--ink); }
.msg.agent a { color: var(--mint-deep); text-decoration: underline; text-underline-offset: 2px; }
.msg.agent table { border-collapse: collapse; margin: var(--space-3) 0; font-size: 13px; }
.msg.agent th, .msg.agent td {
  border: 1px solid var(--cream-border);
  padding: 6px 10px;
  text-align: left;
}
.msg.agent th { background: var(--cream-sunken); font-weight: 600; }

/* Citations */
.citation-group {
  margin-top: var(--space-2);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.citation-toggle {
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px 6px 12px;
  background: var(--mint-softer);
  color: var(--mint-deep);
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 600;
  font-family: var(--font-ui);
  letter-spacing: 0.01em;
  transition: background var(--dur-1) var(--ease-out-quart);
}
.citation-toggle:hover { background: var(--mint-soft); }
.citation-toggle svg { transition: transform var(--dur-2) var(--ease-out-quart); }
.citation-toggle[data-collapsed="false"] svg { transform: rotate(90deg); }

.citation-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding-left: 14px;
  border-left: 2px solid var(--mint-soft);
  margin-left: 4px;
  animation: cite-in var(--dur-3) var(--ease-out-expo) both;
}
@keyframes cite-in {
  from { opacity: 0; transform: translateX(-4px); }
  to { opacity: 1; transform: translateX(0); }
}

.citation {
  position: relative;
  padding: 12px 16px 12px 18px;
  background: var(--cream-surface);
  border: 1px solid var(--cream-border);
  border-radius: var(--radius-md);
  font-size: 14px;
  line-height: 1.65;
  color: var(--ink-soft);
}
.citation::before {
  content: '';
  position: absolute;
  left: -2px;
  top: 14px;
  bottom: 14px;
  width: 3px;
  background: var(--mint);
  border-radius: var(--radius-pill);
}
.citation-num {
  display: inline-block;
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--mint-deep);
  margin-right: 6px;
  font-size: 15px;
  font-variation-settings: 'opsz' 14;
}
.citation-src {
  display: block;
  font-size: 12px;
  color: var(--ink-faint);
  margin-top: var(--space-2);
  font-family: var(--font-ui);
  letter-spacing: 0.01em;
}
.citation-src::before { content: '— '; opacity: 0.6; }
.citation-action {
  display: inline-block;
  margin-top: var(--space-2);
  font-size: 12px;
  font-weight: 600;
  color: var(--mint-deep);
  font-family: var(--font-ui);
  padding: 2px 0;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-1) var(--ease-out-quart);
}
.citation-action:hover { border-color: var(--mint); }

/* Thinking indicator */
.chat-thinking {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0 var(--space-2);
  font-size: 13px;
  color: var(--ink-muted);
  font-family: var(--font-ui);
}
.chat-thinking .dots {
  display: inline-flex;
  gap: 3px;
}
.chat-thinking .dots span {
  width: 5px;
  height: 5px;
  border-radius: var(--radius-pill);
  background: var(--mint);
  opacity: 0.4;
  animation: dot-pulse 1.4s var(--ease-out-quart) infinite;
}
.chat-thinking .dots span:nth-child(2) { animation-delay: 0.2s; }
.chat-thinking .dots span:nth-child(3) { animation-delay: 0.4s; }
@keyframes dot-pulse {
  0%, 60%, 100% { opacity: 0.4; transform: scale(1); }
  30% { opacity: 1; transform: scale(1.2); }
}

/* Input bar */
.chat-inputbar {
  padding: var(--space-3) 0 var(--space-5);
  display: flex;
  gap: var(--space-2);
  align-items: flex-end;
}
.chat-inputbar .input {
  flex: 1;
  min-height: 52px;
  max-height: 160px;
  padding: 14px 18px;
  border-radius: var(--radius-pill);
  background: var(--cream-surface);
  font-size: 15px;
  line-height: 1.5;
}
.chat-inputbar .input:focus {
  box-shadow: 0 0 0 4px var(--mint-softer);
}
.chat-inputbar .input::placeholder { color: var(--ink-faint); }

/* ============================================================
   Modal
   ============================================================ */

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: oklch(28% 0.02 85 / 0.32);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: var(--space-4);
  animation: backdrop-in var(--dur-2) var(--ease-out-quart) both;
}
@keyframes backdrop-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal {
  width: 100%;
  max-width: 460px;
  background: var(--cream-bg);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-lg);
  animation: modal-in var(--dur-3) var(--ease-out-expo) both;
  max-height: 90vh;
  overflow-y: auto;
}
@keyframes modal-in {
  from { opacity: 0; transform: translateY(20px) scale(0.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.modal-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-6);
}
.modal-title {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  font-variation-settings: 'opsz' 24;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.modal-close {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-pill);
  color: var(--ink-muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background var(--dur-1) var(--ease-out-quart),
              color var(--dur-1) var(--ease-out-quart);
}
.modal-close:hover { background: var(--cream-sunken); color: var(--ink); }

.modal-body { display: flex; flex-direction: column; gap: var(--space-4); }
.modal-foot {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-2);
  margin-top: var(--space-6);
}

/* ============================================================
   Upload dropzone
   ============================================================ */

.dropzone {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-10) var(--space-6);
  border: 2px dashed var(--cream-border-strong);
  border-radius: var(--radius-xl);
  background: var(--cream-surface);
  color: var(--ink-muted);
  cursor: pointer;
  transition: border-color var(--dur-2) var(--ease-out-quart),
              background var(--dur-2) var(--ease-out-quart),
              color var(--dur-2) var(--ease-out-quart);
}
.dropzone:hover,
.dropzone[data-dragging="true"] {
  border-color: var(--mint);
  background: var(--mint-softer);
  color: var(--mint-deep);
}
.dropzone-icon {
  width: 40px;
  height: 40px;
  color: var(--mint);
  margin-bottom: var(--space-3);
}
.dropzone-text {
  font-size: 14px;
  font-weight: 500;
}
.dropzone-hint {
  font-size: 12px;
  color: var(--ink-faint);
  margin-top: var(--space-1);
}
.dropzone-file {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: var(--mint-softer);
  color: var(--mint-deep);
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 600;
  font-family: var(--font-ui);
}

.upload-progress {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-4) 0;
}
.upload-progress-meta {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  color: var(--ink-muted);
  font-family: var(--font-ui);
}
.upload-progress-bar {
  height: 6px;
  background: var(--cream-sunken);
  border-radius: var(--radius-pill);
  overflow: hidden;
}
.upload-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--mint), var(--mint-press));
  border-radius: var(--radius-pill);
  transition: width var(--dur-3) var(--ease-out-quart);
}

/* ============================================================
   Feedback form
   ============================================================ */

.fb-label {
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--ink-muted);
  padding-left: 4px;
  margin-bottom: var(--space-2);
  display: block;
}
.fb-category {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.fb-category-pill {
  padding: 8px 14px;
  background: var(--cream-surface);
  border: 1px solid var(--cream-border);
  border-radius: var(--radius-pill);
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-soft);
  font-family: var(--font-ui);
  transition: all var(--dur-1) var(--ease-out-quart);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.fb-category-pill:hover { border-color: var(--mint); color: var(--mint-deep); }
.fb-category-pill[aria-pressed="true"] {
  background: var(--mint);
  border-color: var(--mint);
  color: oklch(99.5% 0.005 158);
}
.fb-counter {
  text-align: right;
  font-size: 12px;
  color: var(--ink-faint);
  font-family: var(--font-ui);
  margin-top: var(--space-1);
}

/* ============================================================
   Toast
   ============================================================ */

.toast {
  position: fixed;
  top: var(--space-6);
  left: 50%;
  transform: translateX(-50%);
  background: var(--ink);
  color: var(--cream-bg);
  padding: 12px 22px;
  border-radius: var(--radius-pill);
  font-size: 14px;
  font-weight: 500;
  font-family: var(--font-ui);
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  animation: toast-in var(--dur-3) var(--ease-out-expo) both;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.toast::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: var(--radius-pill);
  background: var(--mint);
}
@keyframes toast-in {
  from { opacity: 0; transform: translate(-50%, -8px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

.error-msg {
  color: var(--error);
  font-size: 13px;
  background: var(--error-soft);
  padding: 10px 14px;
  border-radius: var(--radius-md);
}

/* ============================================================
   Responsive
   ============================================================ */

@media (max-width: 640px) {
  .chat-shell { padding: 0 var(--space-3); }
  .chat-topbar { padding: var(--space-4) 0 var(--space-3); }
  .chat-topbar .brand-sub { display: none; }
  .chat-actions .btn-text { display: none; }
  .msg { max-width: 88%; }
  .modal { padding: var(--space-6); border-radius: var(--radius-xl); }
  .auth-decor { display: none; }
}

@media (pointer: coarse) {
  .btn:hover:not(:disabled) { transform: none; }
}

/* ============================================================
   Reduced motion
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .msg-row, .chat-empty, .auth-card, .modal, .toast, .citation-list {
    animation: none !important;
  }
}