:root {
  --bg: #f3f6fb;
  --surface: #ffffff;
  --surface-soft: #f8fafc;
  --surface-strong: #edf2f7;
  --text: #0f172a;
  --text-soft: #64748b;
  --border: #e2e8f0;
  --primary: #3caff6;
  --primary-strong: #0a85d1;
  --danger: #ef4444;
  --success: #10b981;
  --warning: #f59e0b;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
}

body.dark {
  --bg: #101b22;
  --surface: #1c2a33;
  --surface-soft: #22323d;
  --surface-strong: #2c3f4d;
  --text: #e2e8f0;
  --text-soft: #94a3b8;
  --border: #334155;
  --primary: #4cb5f9;
  --primary-strong: #2498e0;
  --shadow: 0 12px 30px rgba(1, 6, 12, 0.5);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  background: radial-gradient(circle at top, #edf5ff 0%, var(--bg) 45%);
  color: var(--text);
  font-family: "Lexend", "Noto Sans SC", sans-serif;
}

body.dark {
  background: radial-gradient(circle at top, #0a161e 0%, var(--bg) 45%);
}

#app {
  display: flex;
  justify-content: center;
}

.phone {
  width: min(100vw, 430px);
  min-height: 100dvh;
  background: var(--surface);
  box-shadow: var(--shadow);
  position: relative;
}

.material-symbols-outlined {
  font-variation-settings:
    "FILL" 0,
    "wght" 450,
    "GRAD" 0,
    "opsz" 24;
}

.material-symbols-outlined.fill {
  font-variation-settings:
    "FILL" 1,
    "wght" 450,
    "GRAD" 0,
    "opsz" 24;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  padding: 14px 18px;
}

.title-main {
  margin: 0;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.title-sub {
  margin: 0 0 4px;
  color: var(--text-soft);
  font-size: 13px;
  font-weight: 500;
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.icon-btn {
  border: none;
  outline: none;
  cursor: pointer;
  width: 38px;
  height: 38px;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--text-soft);
  display: grid;
  place-items: center;
  transition: background 0.2s ease;
}

.icon-btn:hover {
  background: color-mix(in srgb, var(--primary) 18%, var(--surface-soft));
  color: var(--primary);
}

.avatar {
  width: 38px;
  height: 38px;
  border-radius: 999px;
  background: linear-gradient(135deg, #2dd4bf, #3b82f6);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  display: grid;
  place-items: center;
}

.content {
  padding: 16px 16px 92px;
  display: grid;
  gap: 14px;
}

.hero-title {
  margin: 0;
  font-size: 30px;
  line-height: 1.2;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 14px;
}

.soft-card {
  background: var(--surface-soft);
}

.card-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

.muted {
  color: var(--text-soft);
}

.label {
  font-size: 12px;
  color: var(--text-soft);
}

.value-lg {
  font-size: 42px;
  font-weight: 700;
  line-height: 1;
}

.value-xl {
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
}

.ring-wrap {
  width: 92px;
  height: 92px;
  position: relative;
}

.ring-wrap svg {
  width: 100%;
  height: 100%;
}

.ring-wrap .ring-bg {
  stroke: var(--surface-strong);
  fill: transparent;
  stroke-width: 8;
}

.ring-wrap .ring-progress {
  stroke: var(--primary);
  fill: transparent;
  stroke-width: 8;
  stroke-linecap: round;
  transform: rotate(-90deg);
  transform-origin: 50% 50%;
}

.ring-center {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: var(--primary);
}

.status-chip {
  border-radius: 999px;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 600;
}

.status-chip.success {
  background: color-mix(in srgb, var(--success) 20%, transparent);
  color: color-mix(in srgb, var(--success) 80%, #0c4a6e);
}

.progress {
  width: 100%;
  height: 10px;
  border-radius: 999px;
  background: var(--surface-strong);
  overflow: hidden;
}

.progress > span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--primary), var(--primary-strong));
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.quick-btn {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
  padding: 12px;
  text-align: left;
  cursor: pointer;
}

.quick-btn:hover {
  border-color: color-mix(in srgb, var(--primary) 45%, var(--border));
}

.bubble {
  width: 38px;
  height: 38px;
  border-radius: 999px;
  display: grid;
  place-items: center;
  margin-bottom: 8px;
}

.bubble.blue {
  background: #dbeafe;
  color: #2563eb;
}

.bubble.violet {
  background: #ede9fe;
  color: #7c3aed;
}

body.dark .bubble.blue {
  background: rgba(59, 130, 246, 0.2);
}

body.dark .bubble.violet {
  background: rgba(124, 58, 237, 0.2);
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.section-head h3 {
  margin: 0;
  font-size: 19px;
}

.link-btn {
  border: none;
  background: none;
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}

.study-card {
  display: flex;
  gap: 12px;
  align-items: stretch;
}

.study-cover {
  width: 95px;
  border-radius: 12px;
  background: linear-gradient(140deg, #3b82f6, #4338ca);
  color: rgba(255, 255, 255, 0.3);
  display: grid;
  place-items: center;
}

.pill {
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
}

.pill.orange {
  background: #fff7ed;
  color: #ea580c;
}

body.dark .pill.orange {
  background: rgba(234, 88, 12, 0.2);
}

.primary-btn {
  border: none;
  border-radius: 10px;
  background: var(--primary);
  color: #fff;
  font-weight: 600;
  padding: 7px 12px;
  cursor: pointer;
}

.primary-btn:hover {
  background: var(--primary-strong);
}

.auth-phone {
  background: #f8fafc;
}

.auth-login-page {
  min-height: 100dvh;
  padding: 12px 20px 18px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  overflow-x: hidden;
  position: relative;
  background-image:
    radial-gradient(circle at 10% 20%, rgba(60, 131, 246, 0.05) 0%, transparent 22%),
    radial-gradient(circle at 90% 80%, rgba(60, 131, 246, 0.05) 0%, transparent 22%),
    linear-gradient(rgba(248, 250, 252, 0.96), rgba(248, 250, 252, 0.96)),
    url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 63c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm57-13c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-9-21c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM60 91c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM35 41c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM12 60c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2z' fill='%2394a3b8' fill-opacity='0.08' fill-rule='evenodd'/%3E%3C/svg%3E");
}

.auth-register-page {
  min-height: 100dvh;
  padding: 12px 20px 20px;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  overflow-y: auto;
  background: #f5f7f8;
}

.auth-login-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 42px;
  z-index: 2;
}

.auth-register-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 42px;
}

.auth-register-top h2 {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1;
  color: #0f172a;
}

.auth-top-placeholder {
  width: 40px;
  height: 36px;
}

.auth-back-btn {
  border: none;
  width: 36px;
  height: 36px;
  border-radius: 999px;
  background: transparent;
  color: #111827;
  cursor: pointer;
  display: grid;
  place-items: center;
}

.auth-help-btn {
  border: none;
  background: transparent;
  color: #3c83f6;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
}

.auth-brand {
  text-align: center;
  margin-top: 26px;
  max-width: 360px;
  width: 100%;
  margin-left: auto;
  margin-right: auto;
}

.auth-brand-logo {
  width: 80px;
  height: 80px;
  margin: 0 auto 20px;
  border-radius: 20px;
  background: linear-gradient(135deg, #3c83f6, #1d4ed8);
  display: grid;
  place-items: center;
  transform: rotate(3deg);
  box-shadow: 0 14px 28px rgba(60, 131, 246, 0.33);
}

.auth-brand-logo .material-symbols-outlined {
  color: #fff;
  font-size: 38px;
}

.auth-brand h1 {
  margin: 0;
  font-size: 30px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: #0f172a;
}

.auth-brand-sub {
  margin: 6px 0 0;
  color: #64748b;
  font-size: 12px;
  letter-spacing: 0.12em;
  font-weight: 600;
  text-transform: uppercase;
}

.auth-brand-desc {
  margin: 14px 0 0;
  color: #94a3b8;
  font-size: 14px;
}

.auth-form-card {
  margin-top: 22px;
  max-width: 420px;
  margin-left: auto;
  margin-right: auto;
  width: 100%;
}

.auth-form-layout {
  display: grid;
  gap: 12px;
}

.auth-field-label {
  font-size: 14px;
  font-weight: 600;
  color: #111827;
  margin-top: 2px;
}

.auth-field-label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.auth-field-optional {
  color: #94a3b8;
  font-size: 12px;
  font-weight: 500;
}

.auth-input-wrap {
  position: relative;
  display: flex;
  align-items: center;
  width: 100%;
}

.auth-input-wrap > .material-symbols-outlined {
  position: absolute;
  left: 14px;
  color: #94a3b8;
  font-size: 22px;
  pointer-events: none;
}

.auth-input {
  width: 100%;
  height: 56px;
  border-radius: 12px;
  border: 1px solid #dde4ee;
  background: #fff;
  color: #0f172a;
  padding: 0 14px 0 44px;
  font-size: 16px;
  outline: none;
}

.auth-input::placeholder {
  color: #a2afc3;
}

.auth-input:focus {
  border-color: #3c83f6;
  box-shadow: 0 0 0 3px rgba(60, 131, 246, 0.17);
}

.auth-eye-btn {
  border: none;
  background: transparent;
  color: #94a3b8;
  width: 34px;
  height: 34px;
  position: absolute;
  right: 8px;
  display: grid;
  place-items: center;
  cursor: pointer;
}

.auth-eye-btn .material-symbols-outlined {
  font-size: 21px;
}

.auth-submit-btn {
  width: 100%;
  height: 56px;
  border: none;
  border-radius: 12px;
  background: #3c83f6;
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 8px 18px rgba(60, 131, 246, 0.28);
}

.auth-submit-btn:hover {
  background: #2f74e5;
}

.auth-submit-btn:disabled {
  opacity: 0.65;
  cursor: not-allowed;
}

.auth-inline-links {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 2px 2px 0;
}

.auth-inline-links button {
  border: none;
  background: transparent;
  font-size: 13px;
  cursor: pointer;
}

.auth-inline-links button:first-child {
  color: #3c83f6;
  font-weight: 500;
}

.auth-inline-links button:last-child {
  color: #64748b;
}

.auth-terms {
  display: flex;
  align-items: flex-start;
  gap: 7px;
  font-size: 12px;
  color: #7c8ba1;
  line-height: 1.5;
}

.auth-terms input {
  margin-top: 2px;
}

.auth-terms a {
  color: #3c83f6;
  text-decoration: none;
}

.auth-error {
  border: 1px solid rgba(239, 68, 68, 0.35);
  background: rgba(239, 68, 68, 0.08);
  color: #b91c1c;
  border-radius: 10px;
  padding: 8px 10px;
  font-size: 12px;
}

.auth-notice {
  border: 1px solid rgba(16, 185, 129, 0.28);
  background: rgba(16, 185, 129, 0.08);
  color: #047857;
  border-radius: 10px;
  padding: 8px 10px;
  font-size: 12px;
}

.auth-other-login {
  margin-top: 26px;
  max-width: 420px;
  width: 100%;
  margin-left: auto;
  margin-right: auto;
}

.auth-divider {
  position: relative;
  text-align: center;
  margin-bottom: 16px;
}

.auth-divider::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  border-top: 1px solid #dbe1ea;
  transform: translateY(-50%);
}

.auth-divider span {
  position: relative;
  background: #f8fafc;
  padding: 0 10px;
  color: #94a3b8;
  font-size: 12px;
}

.auth-social-row {
  display: flex;
  justify-content: center;
  gap: 32px;
}

.auth-social-item {
  border: none;
  background: transparent;
  color: #64748b;
  display: grid;
  justify-items: center;
  gap: 6px;
  font-size: 14px;
  cursor: pointer;
}

.auth-social-icon {
  width: 50px;
  height: 50px;
  border-radius: 999px;
  border: 1px solid #dbe1ea;
  background: #fff;
  display: grid;
  place-items: center;
  color: #334155;
  font-size: 14px;
  font-weight: 700;
}

.auth-social-icon img {
  width: 28px;
  height: 28px;
}

.auth-copy {
  margin: 22px 0 0;
  text-align: center;
  color: #b4becd;
  font-size: 11px;
}

.auth-register-head {
  margin-top: 24px;
  max-width: 420px;
  width: 100%;
  margin-left: auto;
  margin-right: auto;
}

.auth-register-head h1 {
  margin: 0;
  color: #0f172a;
  font-size: 32px;
  line-height: 1.2;
  font-weight: 800;
}

.auth-register-head p {
  margin: 8px 0 0;
  color: #64748b;
  font-size: 16px;
}

.auth-register-foot {
  margin-top: auto;
  padding: 26px 0 10px;
  display: flex;
  justify-content: center;
  gap: 8px;
  color: #64748b;
  font-size: 14px;
}

.auth-register-foot button {
  border: none;
  background: transparent;
  color: #3c83f6;
  font-weight: 700;
  font-size: 14px;
  cursor: pointer;
}

.auth-form-tip {
  margin: 0 0 2px;
  color: #64748b;
  font-size: 13px;
  line-height: 1.5;
}

.auth-api-card {
  margin-top: 16px;
  max-width: 420px;
  width: 100%;
  margin-left: auto;
  margin-right: auto;
}

.api-config {
  margin-top: 12px;
  display: grid;
  gap: 8px;
  padding: 12px;
}

.api-input {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 10px;
  font: inherit;
  color: var(--text);
  background: var(--surface);
}

.api-input:focus {
  outline: 2px solid color-mix(in srgb, var(--primary) 35%, transparent);
  border-color: var(--primary);
}

.list {
  display: grid;
  gap: 10px;
}

.chapter-card {
  display: flex;
  gap: 12px;
  align-items: center;
  padding: 12px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
  cursor: pointer;
}

.chapter-icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  display: grid;
  place-items: center;
}

.chapter-icon.blue {
  background: #dbeafe;
  color: #2563eb;
}
.chapter-icon.indigo {
  background: #e0e7ff;
  color: #4f46e5;
}
.chapter-icon.teal {
  background: #ccfbf1;
  color: #0f766e;
}
.chapter-icon.amber {
  background: #fef3c7;
  color: #b45309;
}
.chapter-icon.pink {
  background: #fce7f3;
  color: #be185d;
}
.chapter-icon.cyan {
  background: #cffafe;
  color: #0e7490;
}
.chapter-icon.rose {
  background: #ffe4e6;
  color: #be123c;
}
.chapter-icon.violet {
  background: #ede9fe;
  color: #6d28d9;
}
.chapter-icon.orange {
  background: #ffedd5;
  color: #c2410c;
}
.chapter-icon.green {
  background: #dcfce7;
  color: #15803d;
}

body.dark .chapter-icon.blue {
  background: rgba(37, 99, 235, 0.28);
}
body.dark .chapter-icon.indigo {
  background: rgba(79, 70, 229, 0.28);
}
body.dark .chapter-icon.teal {
  background: rgba(15, 118, 110, 0.28);
}
body.dark .chapter-icon.amber {
  background: rgba(180, 83, 9, 0.28);
}
body.dark .chapter-icon.pink {
  background: rgba(190, 24, 93, 0.28);
}
body.dark .chapter-icon.cyan {
  background: rgba(14, 116, 144, 0.28);
}
body.dark .chapter-icon.rose {
  background: rgba(190, 18, 60, 0.28);
}
body.dark .chapter-icon.violet {
  background: rgba(109, 40, 217, 0.28);
}
body.dark .chapter-icon.orange {
  background: rgba(194, 65, 12, 0.28);
}
body.dark .chapter-icon.green {
  background: rgba(21, 128, 61, 0.28);
}

.chapter-meta {
  font-size: 12px;
  color: var(--text-soft);
}

.mistake-banner {
  color: #fff;
  border: none;
  background: linear-gradient(140deg, #8b5cf6, #6d28d9);
  position: relative;
  overflow: hidden;
}

.mistake-banner::before {
  content: "";
  position: absolute;
  top: -35px;
  right: -20px;
  width: 110px;
  height: 110px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.16);
  filter: blur(5px);
}

.mistake-banner strong {
  color: #fff;
}

.search-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface-soft);
  padding: 10px 12px;
}

.search-wrap input {
  border: 0;
  background: transparent;
  color: var(--text);
  width: 100%;
  outline: none;
  font-size: 14px;
}

.chip-row {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 2px;
}

.chip-row::-webkit-scrollbar {
  display: none;
}

.chip {
  border: 1px solid transparent;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--text-soft);
  font-size: 12px;
  font-weight: 600;
  padding: 6px 12px;
  white-space: nowrap;
  cursor: pointer;
}

.chip.active {
  background: var(--primary);
  color: #fff;
}

.qb-overview {
  background: linear-gradient(150deg, color-mix(in srgb, var(--primary) 16%, var(--surface)), var(--surface));
}

.qb-kpi-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  margin-top: 10px;
}

.qb-kpi-box {
  border-radius: 12px;
  padding: 10px 8px;
  background: color-mix(in srgb, var(--surface) 75%, transparent);
  border: 1px solid var(--border);
  text-align: center;
  display: grid;
  gap: 4px;
}

.qb-kpi-box strong {
  font-size: 16px;
}

.qb-filters {
  display: grid;
  gap: 12px;
}

.qb-filter-group {
  display: grid;
  gap: 2px;
}

.chip-grid {
  display: grid;
  gap: 8px;
}

.chapter-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.chapter-chip {
  width: 100%;
  text-align: left;
  overflow: hidden;
  text-overflow: ellipsis;
}

.type-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.type-grid .chip {
  width: 100%;
  min-height: 44px;
  padding: 8px 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  white-space: normal;
  line-height: 1.25;
}

.qb-result-head {
  border-left: 3px solid var(--primary);
  padding-left: 8px;
}

.mistake-card {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface);
  padding: 12px;
}

.question-card {
  border: 1px solid var(--border);
  border-radius: 16px;
  background: var(--surface);
  padding: 10px 11px 11px;
  display: grid;
  gap: 8px;
  border-left-width: 4px;
}

.question-card.single {
  border-left-color: #3b82f6;
}

.question-card.multi {
  border-left-color: #8b5cf6;
}

.question-card.judge {
  border-left-color: #10b981;
}

.question-card.essay {
  border-left-color: #f59e0b;
}

.question-topic {
  font-size: 11px;
  color: var(--text-soft);
  background: color-mix(in srgb, var(--surface-strong) 70%, transparent);
  border-radius: 9px;
  padding: 4px 8px;
}

.question-stem {
  font-size: 14px;
  line-height: 1.62;
  margin: 0;
  letter-spacing: 0.005em;
}

.question-stem-rich {
  display: grid;
  gap: 10px;
}

.stem-material-block {
  border: 1px solid color-mix(in srgb, var(--border) 82%, transparent);
  background: color-mix(in srgb, var(--surface-soft) 72%, white 28%);
  border-radius: 14px;
  padding: 12px;
}

body.dark .stem-material-block {
  background: color-mix(in srgb, var(--surface-soft) 82%, transparent);
}

.stem-material-label {
  display: inline-flex;
  align-items: center;
  min-height: 22px;
  padding: 0 9px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 18%, white 82%);
  color: var(--accent-strong);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.stem-material-text {
  margin: 8px 0 0;
  color: var(--text);
}

.stem-material-hint {
  margin-top: 8px;
  font-size: 12px;
  color: var(--text-soft);
}

.stem-prompt-list {
  display: grid;
  gap: 8px;
}

.stem-prompt-item {
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid color-mix(in srgb, var(--border) 72%, transparent);
  background: color-mix(in srgb, var(--surface) 84%, transparent);
}

.question-options {
  display: grid;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
  color: var(--text-soft);
}

.question-options.compact {
  gap: 5px;
}

.question-option {
  line-height: 1.45;
  font-size: 13px;
  display: block;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0;
  background: color-mix(in srgb, var(--surface) 80%, var(--surface-soft));
}

.question-option.active {
  border-color: color-mix(in srgb, var(--primary) 60%, var(--border));
  background: color-mix(in srgb, var(--primary) 18%, var(--surface));
}

.option-btn {
  width: 100%;
  border: 0;
  background: transparent;
  color: inherit;
  padding: 8px 9px;
  cursor: pointer;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 9px;
  align-items: start;
  text-align: left;
}

.option-key {
  width: 22px;
  height: 22px;
  border-radius: 999px;
  display: inline-grid;
  place-items: center;
  font-size: 11px;
  font-weight: 700;
  color: var(--primary-strong);
  background: color-mix(in srgb, var(--primary) 18%, transparent);
}

.quiz-screen {
  gap: 12px;
}

.quiz-shell {
  display: grid;
  gap: 10px;
  padding: 12px;
}

.quiz-progress-meta {
  display: grid;
  gap: 4px;
}

.quiz-progress-track {
  width: 100%;
  height: 6px;
  border-radius: 999px;
  overflow: hidden;
  background: var(--surface-strong);
}

.quiz-progress-fill {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--primary), #60c7ff);
}

.quiz-submit-btn {
  white-space: nowrap;
}

.quiz-focus-card {
  border-radius: 18px;
  padding: 12px;
  gap: 9px;
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.06);
}

body.dark .quiz-focus-card {
  box-shadow: 0 12px 24px rgba(1, 6, 12, 0.28);
}

.quiz-stem {
  font-size: 15px;
  line-height: 1.68;
}

.quiz-stem.question-stem-rich {
  gap: 12px;
}

.quiz-stem .stem-material-block {
  padding: 13px;
}

.quiz-stem .stem-prompt-item {
  padding: 11px 12px;
}

.quiz-answer-chip {
  padding: 7px 9px;
}

.quiz-index {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-soft);
}

.quiz-action-bar {
  position: sticky;
  bottom: 14px;
  z-index: 18;
  padding: 10px 12px;
  background: color-mix(in srgb, var(--surface) 95%, transparent);
  backdrop-filter: blur(10px);
  box-shadow: 0 12px 32px rgba(15, 23, 42, 0.1);
}

body.dark .quiz-action-bar {
  box-shadow: 0 12px 32px rgba(1, 6, 12, 0.34);
}

.qb-answer-feedback {
  border-radius: 10px;
  padding: 8px 10px;
  font-size: 12px;
  line-height: 1.5;
  border: 1px solid var(--border);
}

.qb-answer-feedback.pending {
  background: var(--surface-soft);
  color: var(--text-soft);
}

.qb-answer-feedback.correct {
  background: color-mix(in srgb, var(--success) 14%, var(--surface));
  border-color: color-mix(in srgb, var(--success) 36%, var(--border));
  color: color-mix(in srgb, var(--success) 85%, var(--text));
}

.qb-answer-feedback.wrong {
  background: color-mix(in srgb, var(--danger) 12%, var(--surface));
  border-color: color-mix(in srgb, var(--danger) 34%, var(--border));
  color: color-mix(in srgb, var(--danger) 85%, var(--text));
}

.qb-essay-box {
  display: grid;
  gap: 8px;
}

.qb-essay-input {
  width: 100%;
  min-height: 110px;
  resize: vertical;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 10px;
  font-size: 13px;
  line-height: 1.55;
  background: var(--surface-soft);
  color: var(--text);
  font-family: "Lexend", "Noto Sans SC", sans-serif;
}

.qb-essay-input:focus {
  outline: none;
  border-color: color-mix(in srgb, var(--primary) 55%, var(--border));
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--primary) 14%, transparent);
}

.answer-wrap {
  border-top: 1px dashed color-mix(in srgb, var(--border) 75%, transparent);
  padding-top: 8px;
  font-size: 12px;
  color: var(--text-soft);
}

.answer-wrap summary {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  color: var(--primary);
  font-weight: 700;
  margin-bottom: 6px;
}

.answer-surface {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px;
  background: color-mix(in srgb, var(--surface-soft) 75%, transparent);
  display: grid;
  gap: 8px;
}

.answer-item {
  display: grid;
  gap: 5px;
}

.answer-title {
  font-weight: 700;
  color: var(--text);
  font-size: 12px;
}

.admin-field {
  width: 100%;
  min-height: 72px;
  resize: vertical;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px 10px;
  font-size: 13px;
  line-height: 1.45;
  background: var(--surface-soft);
  color: var(--text);
  font-family: "Lexend", "Noto Sans SC", sans-serif;
}

.invite-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface-soft);
  padding: 10px;
}

.admin-kpi-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.admin-topbar {
  padding: 11px 14px;
}

.admin-topbar .title-main {
  font-size: 18px;
}

.admin-content {
  padding: 10px 12px 26px;
  gap: 10px;
  grid-template-columns: minmax(0, 1fr);
  align-content: start;
}

.phone {
  overflow-x: hidden;
}

.admin-content,
.admin-content > *,
.admin-content .row,
.admin-content .row > *,
.admin-content .list,
.admin-content .list > * {
  min-width: 0;
}

.admin-content .card {
  padding: 11px;
  border-radius: 14px;
}

.admin-panel {
  gap: 10px;
}

.admin-content .qb-kpi-grid {
  gap: 6px;
  margin-top: 8px;
}

.admin-content .qb-kpi-box {
  padding: 8px 6px;
  border-radius: 11px;
  gap: 3px;
}

.admin-content .qb-kpi-box strong {
  font-size: 15px;
}

.admin-chip-row {
  margin-top: 8px;
  gap: 6px;
}

.admin-action-row {
  margin-top: 8px;
  flex-wrap: wrap;
}

.admin-panel-head {
  align-items: flex-start;
  gap: 8px;
}

.admin-toolbar {
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.admin-toolbar .api-input {
  flex: 1 1 180px;
  max-width: none !important;
  min-width: 0;
}

.admin-list {
  gap: 8px;
}

.admin-issues-list {
  grid-template-columns: minmax(0, 1fr);
}

.admin-pager {
  padding: 8px 10px;
}

.admin-content .chip {
  padding: 5px 10px;
  font-size: 11px;
}

.admin-content .chip-row {
  flex-wrap: wrap;
  overflow: visible;
}

.admin-content select.chip {
  max-width: 100%;
}

.admin-panel-head .chip-row {
  justify-content: flex-end;
}

.admin-content .invite-card {
  padding: 9px;
  border-radius: 11px;
}

.admin-content .question-card {
  padding: 10px;
  border-radius: 14px;
}

.admin-content .admin-field {
  min-height: 64px;
  padding: 7px 9px;
  font-size: 12px;
}

.admin-content .student-card {
  border-radius: 14px;
  padding: 10px;
  gap: 8px;
  box-shadow: 0 6px 16px rgba(15, 23, 42, 0.04);
}

.admin-content .student-card-top {
  gap: 4px;
}

.admin-content .student-name {
  font-size: 14px;
}

.admin-content .student-phone {
  font-size: 11px;
}

.admin-content .student-inline-meta {
  gap: 6px;
}

.admin-content .student-inline-chip {
  min-height: 28px;
  padding: 0 8px;
  font-size: 10.5px;
}

.admin-content .student-inline-chip .material-symbols-outlined {
  font-size: 13px;
}

.admin-content .student-stat-row {
  gap: 6px;
}

.admin-content .student-stat-pill {
  padding: 8px;
  border-radius: 11px;
}

.admin-content .student-stat-pill strong {
  font-size: 14px;
}

.student-card {
  border: 1px solid color-mix(in srgb, var(--primary) 12%, var(--border));
  border-radius: 16px;
  background: linear-gradient(180deg, color-mix(in srgb, var(--surface) 88%, white 12%), var(--surface-soft));
  padding: 12px;
  display: grid;
  gap: 10px;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.04);
}

.student-card-top {
  display: grid;
  gap: 6px;
}

.student-identity {
  display: grid;
  gap: 4px;
}

.student-name-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.student-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.student-phone {
  font-size: 12px;
  color: var(--text-soft);
}

.student-inline-meta {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 2px;
}

.student-inline-meta::-webkit-scrollbar {
  display: none;
}

.student-inline-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 32px;
  padding: 0 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: color-mix(in srgb, var(--surface) 82%, transparent);
  color: var(--text-soft);
  white-space: nowrap;
  font-size: 11px;
  font-weight: 600;
}

.student-inline-chip .material-symbols-outlined {
  font-size: 14px;
}

.student-stat-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.student-stat-pill {
  display: grid;
  gap: 3px;
  padding: 9px 10px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: color-mix(in srgb, var(--surface) 78%, transparent);
}

.student-stat-pill strong {
  font-size: 15px;
  line-height: 1.2;
}

.invite-code {
  font-family: "Courier New", monospace;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.answer-block {
  line-height: 1.55;
  white-space: pre-wrap;
}

.pager {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
}

.pager.card {
  padding: 10px 12px;
}

.pager button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.tag {
  border-radius: 7px;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 700;
}

.tag.single {
  color: #2563eb;
  background: #dbeafe;
}

.tag.multi {
  color: #7c3aed;
  background: #ede9fe;
}

.tag.judge {
  color: #059669;
  background: #d1fae5;
}

.tag.essay {
  color: #b45309;
  background: #fef3c7;
}

body.dark .tag.essay {
  color: #fbbf24;
  background: rgba(180, 83, 9, 0.2);
}

.danger-tag {
  color: var(--danger);
  background: color-mix(in srgb, var(--danger) 15%, transparent);
  border-radius: 6px;
  padding: 2px 6px;
  font-size: 11px;
  font-weight: 700;
}

.outline-btn {
  border: none;
  border-radius: 9px;
  padding: 7px 11px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  color: var(--primary);
  background: color-mix(in srgb, var(--primary) 15%, transparent);
}

.outline-btn:hover {
  background: color-mix(in srgb, var(--primary) 23%, transparent);
}

.pwa-stack {
  position: fixed;
  left: 50%;
  bottom: 86px;
  transform: translateX(-50%);
  width: min(calc(100vw - 24px), 398px);
  display: grid;
  gap: 10px;
  z-index: 55;
}

.pwa-banner {
  border-radius: 16px;
  border: 1px solid var(--border);
  background: color-mix(in srgb, var(--surface) 94%, transparent);
  backdrop-filter: blur(10px);
  box-shadow: 0 16px 34px rgba(15, 23, 42, 0.14);
  padding: 12px 14px;
  display: grid;
  gap: 10px;
}

.pwa-banner-update {
  border-color: color-mix(in srgb, var(--warning) 34%, var(--border));
}

.pwa-banner-offline {
  border-color: color-mix(in srgb, var(--danger) 26%, var(--border));
}

.pwa-banner-install {
  border-color: color-mix(in srgb, var(--primary) 24%, var(--border));
}

.pwa-banner-copy {
  display: grid;
  gap: 4px;
}

.pwa-banner-copy strong {
  font-size: 14px;
}

.pwa-banner-copy span {
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-soft);
}

@media (max-width: 380px) {
  .pwa-stack {
    width: calc(100vw - 16px);
    bottom: 82px;
  }
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.stat-card {
  text-align: center;
  padding: 14px 8px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
}

.stat-value {
  font-size: 26px;
  font-weight: 700;
}

.radar-wrap {
  height: 220px;
  position: relative;
}

.radar-wrap svg {
  width: 100%;
  height: 100%;
}

.heatmap-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.heatmap-cell {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px;
  background: var(--surface-soft);
  display: grid;
  gap: 6px;
}

.heatmap-cell.level-0 {
  background: color-mix(in srgb, var(--surface-soft) 82%, #ef4444 18%);
}

.heatmap-cell.level-1 {
  background: color-mix(in srgb, var(--surface-soft) 82%, #f59e0b 18%);
}

.heatmap-cell.level-2 {
  background: color-mix(in srgb, var(--surface-soft) 82%, #facc15 18%);
}

.heatmap-cell.level-3 {
  background: color-mix(in srgb, var(--surface-soft) 82%, #22c55e 18%);
}

.heatmap-cell.level-4 {
  background: color-mix(in srgb, var(--surface-soft) 82%, #16a34a 18%);
}

.heatmap-name {
  font-size: 13px;
  font-weight: 600;
  line-height: 1.4;
}

.heatmap-rate {
  font-size: 17px;
  font-weight: 700;
}

.setting-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}

.setting-row:last-child {
  border-bottom: none;
}

.toggle {
  border: none;
  width: 46px;
  height: 26px;
  border-radius: 999px;
  background: var(--surface-strong);
  cursor: pointer;
  padding: 2px;
  transition: background 0.2s ease;
}

.toggle > span {
  display: block;
  width: 22px;
  height: 22px;
  border-radius: 999px;
  background: #fff;
  transition: transform 0.2s ease;
}

.toggle.on {
  background: var(--primary);
}

.toggle.on > span {
  transform: translateX(20px);
}

.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: min(100vw, 430px);
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: blur(8px);
  border-top: 1px solid var(--border);
  padding: 8px 10px 10px;
  z-index: 40;
}

.bottom-nav ul {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-btn {
  border: none;
  background: transparent;
  color: var(--text-soft);
  width: 100%;
  display: grid;
  justify-items: center;
  gap: 2px;
  padding: 4px 0;
  cursor: pointer;
}

.nav-btn.active {
  color: var(--primary);
  font-weight: 600;
}

.nav-btn span:last-child {
  font-size: 11px;
}

.row {
  display: flex;
  align-items: center;
}

.row.between {
  justify-content: space-between;
}

.row.gap-8 {
  gap: 8px;
}

.row.gap-10 {
  gap: 10px;
}

.small {
  font-size: 12px;
}

.tiny {
  font-size: 11px;
}

.section-title {
  margin: 4px 0 8px;
  font-size: 21px;
}

.empty {
  text-align: center;
  color: var(--text-soft);
  padding: 32px 12px;
}

@media (max-width: 380px) {
  .auth-register-page {
    padding: 8px 12px 14px;
  }

  .auth-register-page .auth-register-head {
    margin-top: 12px;
  }

  .auth-register-page .auth-register-head p {
    margin-top: 6px;
  }

  .auth-register-page .auth-field-label {
    margin-top: 2px;
  }

  .auth-register-page .auth-register-foot {
    padding-top: 14px;
    gap: 6px;
  }

  .value-lg {
    font-size: 34px;
  }

  .hero-title {
    font-size: 26px;
  }

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

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

  .qb-kpi-grid {
    grid-template-columns: 1fr;
  }

  .student-stat-row {
    grid-template-columns: 1fr;
  }

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


.qb-screen {
  gap: 12px;
}

.qb-stage-compact {
  display: grid;
  gap: 12px;
  padding: 14px;
  border-radius: 18px;
  border: 1px solid color-mix(in srgb, var(--primary) 18%, var(--border));
  background:
    radial-gradient(circle at top right, rgba(60, 175, 246, 0.12), transparent 36%),
    linear-gradient(155deg, color-mix(in srgb, var(--surface) 80%, #eef7ff 20%), var(--surface));
}

.qb-stage-compact-row {
  align-items: flex-start;
  gap: 12px;
}

.qb-stage-compact-copy {
  display: grid;
  gap: 4px;
}

.qb-stage-compact-copy strong {
  font-size: 17px;
  line-height: 1.2;
}

.qb-stage-compact .primary-btn,
.qb-stage-compact .outline-btn {
  min-height: 42px;
}

.qb-stage-actions {
  align-items: center;
}

.qb-draft-note {
  margin-top: 10px;
}

.qb-guide-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}