/* 计量师 AI 助手 — Mobile-first responsive theme
 * Palette (ADR-009): 靛蓝 #3D5AFE primary + 琥珀 #F59E0B accent
 * Dark base for PWA standalone feel; works light too.
 */

:root {
  --indigo-50:  #EEF1FF;
  --indigo-100: #D9DEFF;
  --indigo-300: #8E9DFF;
  --indigo-500: #3D5AFE;  /* brand */
  --indigo-600: #2E48E0;
  --indigo-700: #2338B8;

  --amber-300: #FCD34D;
  --amber-500: #F59E0B;   /* accent */
  --amber-600: #D97706;

  --bg:        #0F172A;
  --bg-2:      #131C33;
  --surface:   #1A2340;
  --surface-2: #222C4E;
  --border:    #2C365B;
  --text:      #E6EBFF;
  --text-dim:  #9AA3C7;
  --text-mute: #6B7499;

  --danger:    #EF4444;
  --success:   #10B981;

  --radius-sm: 6px;
  --radius:    12px;
  --radius-lg: 18px;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
  --shadow:    0 4px 14px rgba(0,0,0,0.25);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.35);

  --header-h:  56px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg:        #F4F6FF;
    --bg-2:      #FFFFFF;
    --surface:   #FFFFFF;
    --surface-2: #F0F3FF;
    --border:    #DDE3FF;
    --text:      #1A2138;
    --text-dim:  #4B557A;
    --text-mute: #7B85A8;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.55;
  color: var(--text);
  background:
    radial-gradient(1100px 600px at 80% -10%, rgba(61,90,254,0.18), transparent 60%),
    radial-gradient(900px 500px at -10% 110%, rgba(245,158,11,0.10), transparent 60%),
    var(--bg);
  min-height: 100vh;
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--indigo-300); text-decoration: none; }
a:hover { color: var(--indigo-500); }

/* ---------------- header ---------------- */
.lx-header {
  position: sticky;
  top: 0;
  z-index: 10;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border);
}
@media (prefers-color-scheme: light) {
  .lx-header { background: rgba(255,255,255,0.85); }
}

.lx-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
}
.lx-brand:hover { color: var(--text); }
.lx-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--indigo-500), var(--indigo-700));
  color: #fff;
  font-weight: 800;
  letter-spacing: -1px;
  box-shadow: 0 4px 10px rgba(61,90,254,0.4);
}
.lx-brand-text { font-size: 16px; }
.lx-brand-sub {
  font-size: 12px;
  color: var(--text-mute);
  font-weight: 500;
  display: none;
}
@media (min-width: 768px) {
  .lx-brand-sub { display: inline; margin-left: 6px; }
}

.lx-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}
.lx-nav a {
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  color: var(--text-dim);
  font-size: 14px;
}
.lx-nav a:hover { color: var(--text); background: var(--surface); }
.lx-nav a.is-active { color: var(--text); background: var(--surface); }

/* ---------------- buttons ---------------- */
.lx-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: transform .05s ease, background .15s ease, border-color .15s ease;
  font-family: inherit;
}
.lx-btn:active { transform: translateY(1px); }
.lx-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.lx-btn-primary {
  background: var(--indigo-500);
  color: #fff;
  border-color: var(--indigo-500);
}
.lx-btn-primary:hover { background: var(--indigo-600); border-color: var(--indigo-600); }

.lx-btn-accent {
  background: var(--amber-500);
  color: #1A1A1A;
  border-color: var(--amber-500);
}
.lx-btn-accent:hover { background: var(--amber-600); border-color: var(--amber-600); }

.lx-btn-ghost {
  background: transparent;
  color: var(--text-dim);
  border-color: var(--border);
}
.lx-btn-ghost:hover { background: var(--surface); color: var(--text); }

.lx-btn-block { width: 100%; }
.lx-btn-lg { padding: 12px 18px; font-size: 15px; }
.lx-btn-sm { padding: 5px 10px; font-size: 12px; border-radius: 6px; }

/* ---------------- layout ---------------- */
.lx-page {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px;
}
.lx-page-title {
  margin: 4px 0 16px;
  font-size: 20px;
  font-weight: 700;
}
.lx-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow-sm);
}
.lx-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: 1fr;
}
@media (min-width: 768px) {
  .lx-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .lx-grid-3 { grid-template-columns: repeat(3, 1fr); }
}
.lx-stack > * + * { margin-top: 12px; }
.lx-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.lx-row-between { display: flex; align-items: center; justify-content: space-between; gap: 12px; }

/* ---------------- home ---------------- */
.lx-hero {
  background:
    linear-gradient(135deg, rgba(61,90,254,0.18), rgba(61,90,254,0.04) 60%),
    var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  position: relative;
  overflow: hidden;
}
.lx-hero h1 {
  margin: 0 0 6px;
  font-size: 22px;
}
.lx-hero p { color: var(--text-dim); margin: 0 0 14px; }
.lx-hero .lx-greeting { color: var(--amber-300); }

.lx-task-card {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.lx-task-card .lx-task-icon {
  flex: 0 0 36px;
  width: 36px; height: 36px;
  border-radius: 8px;
  background: var(--indigo-500);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
}
.lx-task-card .lx-task-meta {
  font-size: 12px;
  color: var(--text-mute);
  margin-top: 2px;
}

.lx-progress {
  height: 6px;
  background: var(--surface-2);
  border-radius: 999px;
  overflow: hidden;
  border: 1px solid var(--border);
}
.lx-progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--indigo-500), var(--amber-500));
  border-radius: inherit;
  transition: width .3s ease;
}

/* ---------------- login ---------------- */
.lx-login-wrap {
  display: grid;
  place-items: center;
  min-height: calc(100vh - var(--header-h));
  padding: 24px 16px;
}
.lx-login-card {
  width: 100%;
  max-width: 420px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-lg);
}
.lx-login-card h1 { margin: 0 0 6px; font-size: 22px; }
.lx-login-card p.sub { color: var(--text-dim); margin: 0 0 18px; }
.lx-qr {
  display: grid;
  place-items: center;
  width: 180px;
  height: 180px;
  margin: 0 auto 16px;
  border-radius: var(--radius);
  border: 1px dashed var(--indigo-500);
  background:
    repeating-linear-gradient(45deg, var(--surface-2) 0 8px, transparent 8px 16px);
  color: var(--text-mute);
  text-align: center;
  font-size: 12px;
  padding: 12px;
}
.lx-field { display: block; margin-bottom: 12px; }
.lx-field label {
  display: block;
  font-size: 12px;
  color: var(--text-dim);
  margin-bottom: 4px;
}
.lx-field input {
  width: 100%;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-2);
  color: var(--text);
  font-size: 14px;
  font-family: inherit;
  outline: none;
  transition: border-color .15s ease, box-shadow .15s ease;
}
.lx-field input:focus {
  border-color: var(--indigo-500);
  box-shadow: 0 0 0 3px rgba(61,90,254,0.18);
}
.lx-status { font-size: 13px; color: var(--danger); min-height: 18px; margin-top: 8px; }
.lx-divider {
  height: 1px;
  background: var(--border);
  margin: 16px 0;
}
.lx-help {
  font-size: 12px;
  color: var(--text-mute);
  text-align: center;
}

/* ---------------- chat ---------------- */
.lx-chat-shell {
  display: grid;
  grid-template-rows: 1fr auto;
  height: calc(100vh - var(--header-h));
  height: calc(100dvh - var(--header-h));
  max-width: 960px;
  margin: 0 auto;
  padding: 12px 12px 0;
}
@media (min-width: 768px) {
  .lx-chat-shell { padding: 16px 16px 0; }
}

#chat-list {
  overflow-y: auto;
  padding: 8px 4px 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  scroll-behavior: smooth;
}
.lx-msg { display: flex; }
.lx-msg-user { justify-content: flex-end; }
.lx-msg-ai { justify-content: flex-start; }
.lx-bubble {
  max-width: min(82%, 640px);
  padding: 10px 14px;
  border-radius: 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  white-space: pre-wrap;
  word-wrap: break-word;
  font-size: 15px;
  line-height: 1.5;
  box-shadow: var(--shadow-sm);
}
.lx-msg-user .lx-bubble {
  background: var(--indigo-500);
  border-color: var(--indigo-500);
  color: #fff;
  border-bottom-right-radius: 4px;
}
.lx-msg-ai .lx-bubble {
  border-bottom-left-radius: 4px;
}

/* ---------------- streaming caret (Plane #18 / SSE) ---------------- */
@keyframes lx-caret-blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}
.lx-bubble.is-streaming::after {
  content: '\u258D'; /* ▍ left half block — typewriter caret */
  display: inline-block;
  margin-left: 2px;
  color: var(--indigo-500);
  font-weight: 700;
  animation: lx-caret-blink 1s steps(1) infinite;
  vertical-align: baseline;
  /* ensure caret renders after the last visible char even on white-space: pre-wrap */
}
.lx-sources {
  margin-top: 6px;
  font-size: 12px;
  color: var(--text-mute);
}
.lx-sources summary { cursor: pointer; user-select: none; }
.lx-sources ul { margin: 6px 0 0 18px; padding: 0; }
.lx-sources li { margin: 2px 0; }

.lx-empty {
  margin: auto;
  color: var(--text-mute);
  text-align: center;
  padding: 32px 12px;
  font-size: 14px;
}

.lx-chat-form {
  display: flex;
  gap: 8px;
  padding: 10px 4px calc(10px + env(safe-area-inset-bottom));
  background: linear-gradient(180deg, transparent, var(--bg) 30%);
}
.lx-chat-form input[type="text"] {
  flex: 1;
  padding: 12px 14px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 15px;
  font-family: inherit;
  outline: none;
}
.lx-chat-form input[type="text"]:focus {
  border-color: var(--indigo-500);
  box-shadow: 0 0 0 3px rgba(61,90,254,0.18);
}
.lx-chat-form .lx-btn { border-radius: 999px; padding: 10px 16px; }

/* ---------------- toast ---------------- */
#lx-toast-host {
  position: fixed;
  left: 0; right: 0;
  bottom: calc(20px + env(safe-area-inset-bottom));
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  z-index: 1000;
  pointer-events: none;
}
.lx-toast {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 13px;
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity .2s ease, transform .2s ease;
}
.lx-toast.is-in { opacity: 1; transform: translateY(0); }
.lx-toast-success { border-color: var(--success); }
.lx-toast-error   { border-color: var(--danger); }

/* ---------------- install hint ---------------- */
.lx-install-hint {
  position: fixed;
  right: 12px;
  bottom: calc(80px + env(safe-area-inset-bottom));
  z-index: 50;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 12px;
  font-size: 13px;
  box-shadow: var(--shadow);
}

/* ---------------- footer ---------------- */
.lx-footer {
  padding: 24px 16px 32px;
  text-align: center;
  color: var(--text-mute);
  font-size: 12px;
}

/* ---------------- home: today content ---------------- */
.lx-section { margin-top: 24px; }
.lx-section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}
.lx-section-head .lx-page-title { margin: 0; }
.lx-section-meta {
  font-size: 12px;
  color: var(--text-mute);
}

/* ----- skeleton ----- */
@keyframes lx-skel-pulse {
  0%, 100% { opacity: 0.55; }
  50%      { opacity: 0.95; }
}
.lx-skel-card { padding: 16px; }
.lx-skel-bar {
  height: 14px;
  margin: 8px 0;
  border-radius: 6px;
  background: linear-gradient(90deg, var(--surface-2) 0%, var(--border) 50%, var(--surface-2) 100%);
  background-size: 200% 100%;
  animation: lx-skel-pulse 1.4s ease-in-out infinite;
}
.lx-skel-w30 { width: 30%; }
.lx-skel-w40 { width: 40%; }
.lx-skel-w60 { width: 60%; }
.lx-skel-w70 { width: 70%; }
.lx-skel-w80 { width: 80%; }
.lx-skel-row {
  display: flex;
  gap: 10px;
  margin: 10px 0;
}
.lx-skel-row .lx-skel-bar { margin: 0; }

/* ----- today card (morning) ----- */
.lx-tcard { padding: 4px 4px 12px; }
.lx-tcard-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.lx-tcard-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px 8px;
  border-bottom: 1px dashed var(--border);
}
.lx-tcard-item:last-child { border-bottom: 0; }
.lx-tcard-order {
  flex: 0 0 26px;
  width: 26px; height: 26px;
  border-radius: 50%;
  background: var(--indigo-500);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px;
  font-weight: 700;
}
.lx-tcard-body { flex: 1; min-width: 0; }
.lx-tcard-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 2px;
}
.lx-tcard-topic {
  display: inline-block;
  font-size: 12px;
  color: var(--amber-300);
  font-weight: 600;
  padding: 2px 8px;
  background: rgba(245, 158, 11, 0.10);
  border: 1px solid rgba(245, 158, 11, 0.25);
  border-radius: 999px;
}
.lx-tcard-min {
  font-size: 12px;
  color: var(--text-mute);
  white-space: nowrap;
}
.lx-tcard-task {
  font-size: 14px;
  color: var(--text);
  line-height: 1.5;
  word-break: break-word;
}

/* ----- warmup (collapsible inside today card) ----- */
.lx-warmup {
  margin: 12px 8px 4px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  overflow: hidden;
}
.lx-warmup > summary {
  list-style: none;
  cursor: pointer;
  padding: 10px 12px;
  display: flex;
  align-items: center;
  gap: 10px;
  user-select: none;
}
.lx-warmup > summary::-webkit-details-marker { display: none; }
.lx-warmup-badge {
  font-size: 11px;
  font-weight: 700;
  color: #fff;
  background: var(--amber-500);
  padding: 2px 8px;
  border-radius: 999px;
}
.lx-warmup-kp {
  flex: 1;
  font-size: 13px;
  color: var(--text-dim);
}
.lx-warmup-caret {
  font-size: 12px;
  color: var(--text-mute);
  transition: transform .2s ease;
}
.lx-warmup[open] .lx-warmup-caret { transform: rotate(180deg); }
.lx-warmup-body {
  padding: 0 12px 12px;
  border-top: 1px dashed var(--border);
}
.lx-warmup-q {
  margin: 10px 0 8px;
  font-size: 14px;
  color: var(--text);
}
.lx-warmup-opts {
  margin: 6px 0 8px 18px;
  padding: 0;
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.6;
}
.lx-warmup-answer {
  margin: 6px 0 4px;
  font-size: 13px;
  color: var(--success);
}
.lx-warmup-answer b { font-size: 15px; }
.lx-warmup-explain {
  margin: 4px 0 0;
  font-size: 12px;
  color: var(--text-mute);
  line-height: 1.5;
}

/* ----- quiz (evening) ----- */
.lx-quiz-item { padding: 0; overflow: hidden; }
.lx-quiz-head {
  width: 100%;
  background: transparent;
  border: 0;
  padding: 12px 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  text-align: left;
  color: var(--text);
  font-family: inherit;
  transition: background .15s ease;
}
.lx-quiz-head:hover { background: var(--surface-2); }
.lx-quiz-num {
  flex: 0 0 26px;
  width: 26px; height: 26px;
  border-radius: 50%;
  background: var(--indigo-500);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px;
  font-weight: 700;
}
.lx-quiz-tags {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 6px;
  min-width: 0;
}
.lx-quiz-subj {
  font-size: 11px;
  color: var(--text-mute);
  padding: 2px 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 999px;
}
.lx-quiz-kp {
  font-size: 11px;
  color: var(--amber-300);
  padding: 2px 6px;
  background: rgba(245, 158, 11, 0.10);
  border: 1px solid rgba(245, 158, 11, 0.25);
  border-radius: 999px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 140px;
}
.lx-quiz-hint {
  font-size: 12px;
  color: var(--text-mute);
  white-space: nowrap;
}
.lx-quiz-caret {
  font-size: 12px;
  color: var(--text-mute);
  transition: transform .2s ease;
}
.lx-quiz-item.is-open .lx-quiz-caret { transform: rotate(180deg); }
.lx-quiz-item.is-open .lx-quiz-hint { display: none; }
.lx-quiz-item.is-open .lx-quiz-head { background: var(--surface-2); border-bottom: 1px dashed var(--border); }

.lx-quiz-body {
  padding: 0 14px 14px;
  display: none;
}
.lx-quiz-item.is-open .lx-quiz-body { display: block; }
.lx-quiz-q {
  margin: 10px 0 8px;
  font-size: 14px;
  line-height: 1.55;
  color: var(--text);
}
.lx-quiz-opts {
  margin: 6px 0 10px 18px;
  padding: 0;
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.7;
}
.lx-quiz-foot {
  border-top: 1px dashed var(--border);
  padding-top: 10px;
  margin-top: 4px;
}
.lx-quiz-answer {
  margin: 0 0 4px;
  font-size: 13px;
  color: var(--success);
}
.lx-quiz-answer b { font-size: 15px; }
.lx-quiz-explain {
  margin: 4px 0 0;
  font-size: 12px;
  color: var(--text-mute);
  line-height: 1.55;
}

/* ----- state boxes (error / empty / warn) ----- */
.lx-state {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 16px;
}
.lx-state-icon {
  flex: 0 0 36px;
  width: 36px; height: 36px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700;
  font-size: 18px;
}
.lx-state-body { flex: 1; min-width: 0; }
.lx-state-body strong { display: block; margin-bottom: 4px; font-size: 14px; }
.lx-state-msg {
  margin: 0 0 10px;
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.5;
}

.lx-state-error { border-color: rgba(239, 68, 68, 0.35); background: rgba(239, 68, 68, 0.06); }
.lx-state-error .lx-state-icon { background: rgba(239, 68, 68, 0.15); color: var(--danger); }

.lx-state-empty { border-style: dashed; }
.lx-state-empty .lx-state-icon { background: var(--surface-2); color: var(--text-mute); }

.lx-state-warn { border-color: rgba(245, 158, 11, 0.35); background: rgba(245, 158, 11, 0.06); }
.lx-state-warn .lx-state-icon { background: rgba(245, 158, 11, 0.15); font-size: 16px; }

.lx-mute { color: var(--text-mute); font-size: 13px; }

/* ---------------- a11y ---------------- */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

/* Avoid bouncy-overscroll scroll-jank on iOS */
html, body { overscroll-behavior-y: contain; }