:root {
  --bt-bg: #f7f9fb;
  --bt-bg-soft: #eef8fb;
  --bt-surface: #ffffff;
  --bt-surface-low: #f2f4f6;
  --bt-surface-mid: #eceef0;
  --bt-surface-high: #e6e8ea;
  --bt-surface-highest: #e0e3e5;
  --bt-text: #191c1e;
  --bt-muted: #484551;
  --bt-faint: #797582;
  --bt-outline: #cac4d3;
  --bt-primary: #6550a8;
  --bt-primary-soft: #e8deff;
  --bt-primary-mid: #b6a0ff;
  --bt-tertiary: #6735e8;
  --bt-cyan: #00e3fd;
  --bt-cyan-dark: #006875;
  --bt-cyan-soft: #dffaff;
  --bt-error: #ba1a1a;
  --bt-error-soft: #ffdad6;
  --bt-success: #0b8f67;
  --bt-success-soft: #dcfce7;
  --bt-shadow-soft: 0 24px 60px rgba(30, 41, 59, 0.10);
  --bt-shadow-card: 0 16px 44px rgba(101, 80, 168, 0.10);
  --bt-radius-sm: 8px;
  --bt-radius-md: 12px;
  --bt-radius-lg: 16px;
  --bt-radius-xl: 24px;
  --bt-radius-2xl: 32px;
  --bt-sidebar-width: 280px;
  --bt-font-body: "Manrope", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --bt-font-display: "Space Grotesk", "Manrope", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--bt-bg);
}

body {
  min-height: 100%;
  margin: 0;
  background:
    radial-gradient(circle at 12% 8%, rgba(0, 227, 253, 0.14), transparent 26rem),
    radial-gradient(circle at 94% 4%, rgba(182, 160, 255, 0.20), transparent 28rem),
    linear-gradient(135deg, #f7f9fb 0%, #eef8fb 48%, #f6f2ff 100%);
  color: var(--bt-text);
  font-family: var(--bt-font-body);
  letter-spacing: 0;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    radial-gradient(circle, rgba(0, 227, 253, 0.28) 0 1px, transparent 2px),
    radial-gradient(circle, rgba(101, 80, 168, 0.18) 0 1px, transparent 2px);
  background-position: 32px 42px, 90px 114px;
  background-size: 180px 180px, 220px 220px;
  opacity: 0.28;
}

a {
  color: inherit;
}

.bt-icon {
  width: 20px;
  height: 20px;
  display: inline-block;
  flex: 0 0 auto;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.bt-icon-fill {
  fill: currentColor;
  stroke: none;
}

.ml-auto {
  margin-left: auto;
}

.bt-logo-img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.bt-page-shell {
  min-height: 100vh;
  padding: 56px 64px;
}

.bt-page-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 24px;
  margin-bottom: 40px;
}

.bt-kicker {
  margin: 0 0 8px;
  color: var(--bt-cyan-dark);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.bt-page-title {
  margin: 0;
  color: var(--bt-primary);
  font-family: var(--bt-font-display);
  font-size: 56px;
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
}

.bt-page-subtitle {
  max-width: 760px;
  margin: 12px 0 0;
  color: var(--bt-muted);
  font-size: 18px;
  line-height: 1.55;
}

.bt-card,
.card {
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid rgba(202, 196, 211, 0.38);
  border-radius: var(--bt-radius-xl);
  box-shadow: var(--bt-shadow-card);
}

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

.bt-glass {
  background: rgba(255, 255, 255, 0.52);
  border: 1px solid rgba(0, 227, 253, 0.22);
  border-radius: var(--bt-radius-xl);
  box-shadow: var(--bt-shadow-soft);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.bt-button,
.btn-primary,
.btn-secondary,
.btn-destructive {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 11px 20px;
  border-radius: 999px;
  border: 0;
  font-family: var(--bt-font-body);
  font-size: 14px;
  font-weight: 800;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease, border-color 160ms ease, color 160ms ease, opacity 160ms ease;
}

.bt-button:hover,
.btn-primary:hover,
.btn-secondary:hover,
.btn-destructive:hover {
  transform: translateY(-1px);
}

.bt-button:active,
.btn-primary:active,
.btn-secondary:active,
.btn-destructive:active {
  transform: translateY(0) scale(0.98);
}

.bt-button:disabled,
.btn-primary:disabled,
.btn-secondary:disabled,
.btn-destructive:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.bt-button-primary,
.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--bt-cyan) 0%, #4b8cff 44%, var(--bt-tertiary) 100%);
  box-shadow: 0 18px 36px rgba(101, 80, 168, 0.24), 0 0 0 1px rgba(255, 255, 255, 0.32) inset;
}

.bt-button-primary:hover,
.btn-primary:hover {
  box-shadow: 0 22px 44px rgba(0, 227, 253, 0.20), 0 18px 40px rgba(101, 80, 168, 0.22);
}

.bt-button-secondary,
.btn-secondary {
  color: var(--bt-primary);
  background: rgba(255, 255, 255, 0.56);
  border: 1.5px solid rgba(0, 227, 253, 0.36);
}

.bt-button-secondary:hover,
.btn-secondary:hover {
  border-color: rgba(0, 227, 253, 0.95);
  background: rgba(223, 250, 255, 0.64);
}

.bt-button-danger,
.btn-destructive {
  color: #fff;
  background: linear-gradient(135deg, #ef4444, var(--bt-error));
  box-shadow: 0 14px 30px rgba(186, 26, 26, 0.22);
}

.bt-button-ghost {
  color: var(--bt-muted);
  background: transparent;
  border: 0;
  box-shadow: none;
}

.bt-icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  padding: 0;
  border: 0;
  border-radius: 14px;
  color: var(--bt-faint);
  background: transparent;
  cursor: pointer;
  transition: color 160ms ease, background 160ms ease, transform 160ms ease;
}

.bt-icon-button:hover {
  color: var(--bt-primary);
  background: rgba(232, 222, 255, 0.66);
}

.bt-icon-button-danger:hover {
  color: var(--bt-error);
  background: rgba(255, 218, 214, 0.72);
}

.bt-input,
.bt-textarea,
.input {
  width: 100%;
  min-height: 48px;
  padding: 13px 16px;
  border: 0;
  border-bottom: 1.5px solid rgba(121, 117, 130, 0.35);
  border-radius: var(--bt-radius-md) var(--bt-radius-md) 6px 6px;
  outline: none;
  color: var(--bt-text);
  background: rgba(241, 245, 249, 0.86);
  font-family: var(--bt-font-body);
  font-size: 15px;
  line-height: 1.45;
  transition: border-color 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.bt-input::placeholder,
.bt-textarea::placeholder,
.input::placeholder {
  color: rgba(72, 69, 81, 0.62);
}

.bt-input:focus,
.bt-textarea:focus,
.input:focus {
  border-color: var(--bt-cyan);
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 0 0 4px rgba(0, 227, 253, 0.14);
}

.bt-input:disabled,
.bt-textarea:disabled {
  opacity: 0.52;
  cursor: not-allowed;
}

.bt-label {
  display: block;
  margin: 0 0 8px;
  color: var(--bt-faint);
  font-size: 12px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.bt-field-error {
  display: none;
  margin: 6px 0 0;
  color: var(--bt-error);
  font-size: 13px;
  font-weight: 700;
}

.bt-toggle {
  position: relative;
  display: inline-block;
  width: 56px;
  height: 32px;
  flex: 0 0 auto;
  cursor: pointer;
}

.bt-toggle input {
  position: absolute;
  width: 0;
  height: 0;
  opacity: 0;
}

.bt-toggle-track,
.bt-pill-track,
.bt-toggle span:not(.bt-icon) {
  position: absolute;
  inset: 0;
  border-radius: 999px;
  background: #d8dadc;
  box-shadow: inset 0 0 0 1px rgba(121, 117, 130, 0.18);
  transition: background 180ms ease, box-shadow 180ms ease;
}

.bt-toggle-track::before,
.bt-pill-track::before,
.bt-toggle span:not(.bt-icon)::before {
  content: "";
  position: absolute;
  width: 24px;
  height: 24px;
  top: 4px;
  left: 4px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 4px 12px rgba(30, 41, 59, 0.22);
  transition: transform 180ms ease;
}

.bt-toggle input:checked + .bt-toggle-track,
.bt-pill-toggle input:checked + .bt-pill-track,
.bt-toggle input:checked + span {
  background: linear-gradient(135deg, var(--bt-cyan), var(--bt-primary));
  box-shadow: 0 0 0 4px rgba(0, 227, 253, 0.10);
}

.bt-toggle input:checked + .bt-toggle-track::before,
.bt-pill-toggle input:checked + .bt-pill-track::before,
.bt-toggle input:checked + span::before {
  transform: translateX(24px);
}

.bt-segmented {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: 1fr;
  gap: 4px;
  padding: 4px;
  border-radius: 18px;
  background: rgba(224, 227, 229, 0.74);
}

.bt-segmented label {
  min-width: 0;
}

.bt-segmented input {
  position: absolute;
  width: 0;
  height: 0;
  opacity: 0;
}

.bt-segmented span,
.tone-seg {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 10px 14px;
  border-radius: 14px;
  color: var(--bt-muted);
  font-size: 14px;
  font-weight: 800;
  cursor: pointer;
  transition: color 160ms ease, background 160ms ease, box-shadow 160ms ease;
}

.tone-seg[data-active="true"],
.bt-segmented input:checked + span {
  color: var(--bt-primary);
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 8px 20px rgba(30, 41, 59, 0.08);
}

.bt-badge,
.bt-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 26px;
  padding: 5px 10px;
  border-radius: 999px;
  color: var(--bt-primary);
  background: rgba(232, 222, 255, 0.72);
  font-size: 11px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.bt-badge-cyan {
  color: var(--bt-cyan-dark);
  background: rgba(1, 227, 253, 0.14);
}

.bt-badge-muted {
  color: var(--bt-muted);
  background: rgba(224, 227, 229, 0.80);
}

.bt-chip {
  color: var(--bt-primary);
  background: rgba(232, 222, 255, 0.75);
  border: 1px solid rgba(182, 160, 255, 0.46);
  font-size: 12px;
  letter-spacing: 0;
  text-transform: none;
}

.bt-toast,
.toast {
  min-width: 240px;
  max-width: 380px;
  padding: 13px 16px;
  border-radius: 18px;
  color: var(--bt-text);
  background: rgba(255, 255, 255, 0.88);
  box-shadow: var(--bt-shadow-soft);
  font-size: 13px;
  font-weight: 800;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  animation: bt-toast-in 180ms ease;
}

.bt-toast-success {
  border-left: 4px solid var(--bt-success);
}

.bt-toast-error {
  border-left: 4px solid var(--bt-error);
}

@keyframes bt-toast-in {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.bt-skeleton {
  position: relative;
  overflow: hidden;
  background: rgba(224, 227, 229, 0.74);
}

.bt-skeleton::after {
  content: "";
  position: absolute;
  inset: 0;
  transform: translateX(-100%);
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.62), transparent);
  animation: bt-shimmer 1.4s infinite;
}

@keyframes bt-shimmer {
  to {
    transform: translateX(100%);
  }
}

.bt-spinner {
  display: inline-block;
  width: 18px;
  height: 18px;
  border: 3px solid rgba(0, 227, 253, 0.18);
  border-top-color: var(--bt-cyan);
  border-radius: 50%;
  animation: bt-spin 0.8s linear infinite;
}

@keyframes bt-spin {
  to {
    transform: rotate(360deg);
  }
}

.bt-dashboard-layout {
  min-height: 100vh;
}

.bt-sidebar {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 50;
  display: flex;
  flex-direction: column;
  width: var(--bt-sidebar-width);
  height: 100vh;
  padding: 28px 24px;
  background: rgba(242, 244, 246, 0.84);
  border-right: 1px solid rgba(202, 196, 211, 0.30);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.bt-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 44px;
}

.bt-brand-mark {
  width: 46px;
  height: 46px;
  flex: 0 0 auto;
  border-radius: 16px;
  overflow: hidden;
  filter: drop-shadow(0 10px 18px rgba(101, 80, 168, 0.24));
}

.bt-brand-name {
  margin: 0;
  color: var(--bt-primary);
  font-family: var(--bt-font-display);
  font-size: 28px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
}

.bt-brand-subtitle {
  margin: 6px 0 0;
  color: var(--bt-faint);
  font-size: 10px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.bt-nav {
  display: flex;
  flex: 1;
  flex-direction: column;
  gap: 8px;
}

.bt-nav-section {
  margin: 18px 0 4px;
  padding: 0 14px;
  color: var(--bt-faint);
  font-size: 11px;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.bt-nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 50px;
  width: 100%;
  padding: 0 16px;
  border: 0;
  border-radius: 18px;
  color: var(--bt-muted);
  background: transparent;
  font-family: var(--bt-font-body);
  font-size: 15px;
  font-weight: 750;
  text-align: left;
  text-decoration: none;
  cursor: pointer;
  transition: color 160ms ease, background 160ms ease, box-shadow 160ms ease, transform 160ms ease;
}

.bt-nav-item:hover {
  color: var(--bt-primary);
  background: rgba(255, 255, 255, 0.62);
}

.bt-nav-item.is-active {
  color: var(--bt-primary);
  background: rgba(232, 222, 255, 0.72);
  box-shadow: inset 0 0 0 1px rgba(182, 160, 255, 0.16);
}

.bt-nav-spacer {
  flex: 1;
}

.bt-settings-wrap {
  position: relative;
  padding-top: 18px;
  border-top: 1px solid rgba(202, 196, 211, 0.26);
}

.bt-settings-menu {
  position: absolute;
  left: 0;
  right: 0;
  bottom: calc(100% + 10px);
  padding: 8px;
  border: 1px solid rgba(0, 227, 253, 0.28);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.72);
  box-shadow: var(--bt-shadow-soft);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.bt-settings-menu[hidden] {
  display: none;
}

.bt-settings-menu-item {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 42px;
  padding: 0 12px;
  border-radius: 14px;
  color: var(--bt-muted);
  font-size: 14px;
  font-weight: 800;
  text-decoration: none;
}

.bt-settings-menu-item:hover,
.bt-settings-menu-item.is-active {
  color: var(--bt-primary);
  background: rgba(232, 222, 255, 0.72);
}

.bt-main {
  min-height: 100vh;
  margin-left: var(--bt-sidebar-width);
  padding: 64px;
}

.bt-grid {
  display: grid;
  gap: 24px;
}

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

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

.bt-form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.bt-form-section {
  padding: 28px;
}

.bt-form-actions {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
  margin-top: 24px;
}

.bt-auth-page {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 40px 20px;
}

.bt-auth-wrap {
  width: min(100%, 480px);
}

.bt-auth-brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  margin-bottom: 28px;
  text-align: center;
}

.bt-auth-logo {
  width: 68px;
  height: 68px;
  filter: drop-shadow(0 16px 24px rgba(101, 80, 168, 0.26));
}

.bt-auth-title {
  margin: 0;
  color: var(--bt-primary);
  font-family: var(--bt-font-display);
  font-size: 32px;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.bt-auth-card {
  padding: 44px 48px;
}

.bt-auth-heading {
  margin: 0;
  color: var(--bt-text);
  font-family: var(--bt-font-display);
  font-size: 31px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.bt-auth-copy {
  margin: 8px 0 32px;
  color: var(--bt-muted);
  font-size: 15px;
  line-height: 1.5;
}

.bt-auth-divider {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 22px 0;
  color: var(--bt-outline);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.10em;
  text-transform: uppercase;
}

.bt-auth-divider::before,
.bt-auth-divider::after {
  content: "";
  height: 1px;
  flex: 1;
  background: rgba(202, 196, 211, 0.45);
}

.bt-link {
  color: var(--bt-primary);
  font-weight: 850;
  text-decoration: none;
}

.bt-link:hover {
  text-decoration: underline;
}

.bt-empty-state {
  padding: 56px 32px;
  text-align: center;
  border: 2px dashed rgba(202, 196, 211, 0.50);
  border-radius: var(--bt-radius-2xl);
  background: rgba(255, 255, 255, 0.46);
}

.bt-empty-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 86px;
  height: 86px;
  margin-bottom: 20px;
  border-radius: 50%;
  color: var(--bt-primary);
  background: rgba(232, 222, 255, 0.70);
}

.bt-empty-title {
  margin: 0 0 8px;
  color: var(--bt-text);
  font-family: var(--bt-font-display);
  font-size: 22px;
  font-weight: 800;
}

.bt-empty-copy {
  max-width: 460px;
  margin: 0 auto 22px;
  color: var(--bt-muted);
  font-size: 15px;
  line-height: 1.55;
}

.bt-knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
  align-items: start;
}

.bt-knowledge-card {
  display: flex;
  flex-direction: column;
  min-height: 280px;
  padding: 24px;
  border-radius: var(--bt-radius-2xl);
  background: rgba(255, 255, 255, 0.82);
  box-shadow: var(--bt-shadow-card);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.bt-knowledge-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 24px 60px rgba(101, 80, 168, 0.14);
}

.bt-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 22px;
}

.bt-card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 50px;
  height: 50px;
  border-radius: 18px;
  color: var(--bt-cyan-dark);
  background: rgba(0, 227, 253, 0.14);
}

.bt-mode-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  min-height: 26px;
  padding: 5px 11px 5px 8px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 850;
  letter-spacing: 0.08em;
  line-height: 1;
  text-transform: uppercase;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.72);
}

.bt-mode-badge::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 999px;
}

.bt-mode-auto {
  color: #265b64;
  border: 1px solid rgba(0, 184, 207, 0.28);
  background: linear-gradient(180deg, rgba(220, 253, 255, 0.94), rgba(234, 248, 250, 0.72));
}

.bt-mode-auto::before {
  background: var(--bt-cyan);
  box-shadow: 0 0 0 3px rgba(0, 227, 253, 0.16);
}

.bt-mode-manual {
  color: #5b407f;
  border: 1px solid rgba(101, 80, 168, 0.24);
  background: linear-gradient(180deg, rgba(243, 238, 255, 0.96), rgba(248, 244, 255, 0.72));
}

.bt-mode-manual::before {
  background: var(--bt-primary);
  box-shadow: 0 0 0 3px rgba(101, 80, 168, 0.14);
}

.bt-card-title {
  margin: 0 0 8px;
  color: var(--bt-text);
  font-family: var(--bt-font-display);
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.bt-card-copy {
  margin: 0;
  color: var(--bt-muted);
  font-size: 14px;
  line-height: 1.55;
}

.bt-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: auto;
  padding-top: 18px;
  color: var(--bt-muted);
  border-top: 1px solid rgba(202, 196, 211, 0.24);
  font-size: 12px;
  font-weight: 850;
}

.bt-modal-surface {
  padding: 24px;
  border-radius: var(--bt-radius-xl);
  background: rgba(255, 255, 255, 0.84);
  box-shadow: var(--bt-shadow-soft);
}

.bt-account-type-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
  background:
    radial-gradient(circle at 20% 15%, rgba(0, 227, 253, 0.16), transparent 26rem),
    radial-gradient(circle at 80% 20%, rgba(182, 160, 255, 0.24), transparent 28rem),
    rgba(247, 249, 251, 0.96);
}

.bt-choice-card {
  position: relative;
  flex: 1;
  min-width: 230px;
  min-height: 250px;
  padding: 30px;
  border: 1px solid rgba(202, 196, 211, 0.45);
  border-radius: var(--bt-radius-2xl);
  background: rgba(255, 255, 255, 0.72);
  text-align: left;
  cursor: pointer;
  transition: transform 180ms ease, border-color 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.bt-choice-card:hover,
.bt-choice-card.is-selected {
  transform: translateY(-2px);
  border-color: var(--bt-cyan);
  box-shadow: 0 24px 60px rgba(0, 227, 253, 0.14), inset 0 0 0 1px rgba(0, 227, 253, 0.20);
}

.bt-choice-card.is-selected::after {
  content: "";
  position: absolute;
  top: 18px;
  right: 18px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--bt-cyan);
  box-shadow: 0 8px 18px rgba(0, 227, 253, 0.28);
}

@media (max-width: 1100px) {
  .bt-knowledge-grid,
  .bt-grid-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 899px) {
  :root {
    --bt-sidebar-width: 0px;
  }

  .bt-sidebar {
    position: static;
    width: auto;
    height: auto;
    margin: 16px;
    border: 1px solid rgba(202, 196, 211, 0.30);
    border-radius: var(--bt-radius-xl);
  }

  .bt-dashboard-layout {
    display: block;
  }

  .bt-main {
    margin-left: 0;
    padding: 24px 16px 40px;
  }

  .bt-page-shell {
    padding: 32px 16px;
  }

  .bt-page-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .bt-page-title {
    font-size: 38px;
  }

  .bt-form-grid,
  .bt-grid-2,
  .bt-grid-3,
  .bt-knowledge-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .bt-auth-card {
    padding: 32px 24px;
  }

  .bt-auth-title {
    font-size: 28px;
  }

  .bt-auth-heading {
    font-size: 27px;
  }

  .bt-choice-card {
    min-height: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
  }
}