:root {
  /* Brand */
  --vd-primary: #003B7D;
  --vd-warm: #F29158;
  --vd-neutral: #7BDBAE;
  --vd-cold: #99C9FF;
  --vd-cold-dark: #74B0F5;

  /* Deep Professional palette */
  --vd-bg-app: #022B5C;
  --vd-bg-nav: #003B7D;
  --vd-bg-elevated: #05305E;
  --vd-bg-hover: #0D3964;

  --vd-surface: #FFFFFF;

  --vd-text-on-dark: #FFFFFF;
  --vd-text-primary: #0C2340;
  --vd-border: #DCE3EC;

  /* Semantic */
  --vd-success: #7BDBAE;
  --vd-warning: #F29158;
  --vd-info: #99C9FF;
  --vd-danger: #D95050;

  /* Radius */
  --vd-radius-sm: 8px;
  --vd-radius-md: 12px;
  --vd-radius-lg: 16px;
  --vd-radius-xl: 24px;

  /* Spacing (4px grid) */
  --vd-space-1: 4px;
  --vd-space-2: 8px;
  --vd-space-3: 12px;
  --vd-space-4: 16px;
  --vd-space-5: 24px;
  --vd-space-6: 32px;
  --vd-space-7: 48px;

  /* Shadow */
  --vd-shadow-card: 0 8px 24px rgba(0, 25, 60, 0.14);
  --vd-shadow-float: 0 12px 36px rgba(0, 25, 60, 0.20);

  /* Motion */
  --vd-transition-fast: 140ms ease;
  --vd-transition-normal: 220ms ease;

  --vd-font: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--vd-bg-app);
  color: var(--vd-text-on-dark);
  font-family: var(--vd-font);
  height: 100%;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
    animation: none !important;
  }
}

button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--vd-cold);
  outline-offset: 2px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: var(--vd-space-3);
  padding: calc(env(safe-area-inset-top, 0px) + var(--vd-space-4)) var(--vd-space-3) var(--vd-space-4);
  background: var(--vd-bg-nav);
  color: var(--vd-text-on-dark);
}

.topbar h1 {
  flex: 1;
  margin: 0;
  text-align: center;
}

.topbar-title {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--vd-space-1);
}

.brand-logo {
  height: 28px;
  width: auto;
  flex-shrink: 0;
}

#appTitleText {
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.01em;
  color: rgba(255, 255, 255, 0.8);
}

.icon-btn {
  background: rgba(255, 255, 255, 0.15);
  border: none;
  color: #fff;
  font-size: 20px;
  line-height: 1;
  width: 44px;
  height: 44px;
  border-radius: var(--vd-radius-md);
  cursor: pointer;
  transition: background-color var(--vd-transition-fast);
}
.icon-btn:hover { background: rgba(255, 255, 255, 0.22); }
.icon-btn:active { background: rgba(255, 255, 255, 0.3); }

.menu-panel {
  position: absolute;
  top: 100%;
  right: 12px;
  margin-top: 6px;
  min-width: 220px;
  max-width: 280px;
  background: var(--vd-bg-elevated);
  color: var(--vd-text-on-dark);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--vd-radius-lg);
  box-shadow: var(--vd-shadow-float);
  padding: var(--vd-space-2) 0;
  z-index: 20;
}

.menu-heading {
  padding: var(--vd-space-2) var(--vd-space-4);
  font-size: 13px;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.6);
}

.menu-list, .menu-submenu {
  list-style: none;
  margin: 0;
  padding: 0;
}

.menu-item-label {
  display: block;
  padding: var(--vd-space-3) var(--vd-space-4);
  font-size: 14px;
}

.menu-list > .menu-item > .menu-item-label {
  font-weight: 600;
}

.menu-submenu .menu-item-label {
  padding-left: 28px;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.6);
}

.menu-item-btn {
  display: block;
  width: 100%;
  text-align: left;
  padding: var(--vd-space-3) var(--vd-space-4);
  font-size: 14px;
  border: none;
  background: transparent;
  color: var(--vd-text-on-dark);
  cursor: pointer;
  transition: background-color var(--vd-transition-fast), color var(--vd-transition-fast);
}

.menu-list > .menu-item > .menu-item-btn {
  font-weight: 600;
}

.menu-submenu .menu-item-btn {
  padding-left: 28px;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.6);
}

.menu-list-flat > .menu-item > .menu-item-btn {
  padding-left: 28px;
  font-weight: 400;
  color: rgba(255, 255, 255, 0.6);
}

.menu-item-btn:hover,
.menu-item-btn:active {
  background: rgba(255, 255, 255, 0.1);
  color: var(--vd-text-on-dark);
}

.menu-divider {
  height: 1px;
  margin: var(--vd-space-2) 0;
  background: rgba(255, 255, 255, 0.12);
}

.breadcrumb {
  display: flex;
  align-items: center;
  min-height: 36px;
  padding: var(--vd-space-2) var(--vd-space-4);
  font-size: 12px;
  font-weight: 600;
  line-height: 1.4;
  color: rgba(255, 255, 255, 0.85);
  background: transparent;
  overflow-x: auto;
  white-space: nowrap;
}

.content {
  flex: 1 0 auto;
  width: 100%;
  max-width: 640px;
  margin: 0 auto;
  padding: var(--vd-space-4);
  padding-bottom: var(--vd-space-6);
}

.card {
  background: var(--vd-bg-elevated);
  color: var(--vd-text-on-dark);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--vd-radius-lg);
  padding: var(--vd-space-5);
  margin-bottom: var(--vd-space-4);
  box-shadow: var(--vd-shadow-card);
}

.card h2 {
  font-weight: 700;
  font-size: 22px;
  margin: 0 0 var(--vd-space-3);
}

.node-image {
  display: block;
  max-width: 240px;
  width: 100%;
  height: auto;
  border-radius: var(--vd-radius-sm);
  margin: 0 0 var(--vd-space-4);
}

.card p.intro {
  color: rgba(255, 255, 255, 0.7);
  margin: 0 0 var(--vd-space-4);
}

.steps {
  margin: 0;
  padding-left: 20px;
}
.steps li {
  margin-bottom: var(--vd-space-2);
  line-height: 1.4;
}
.steps li::marker {
  font-weight: 700;
  color: var(--vd-warm);
}

.step-image {
  display: block;
  max-width: 200px;
  width: 100%;
  height: auto;
  border-radius: var(--vd-radius-sm);
  margin-top: var(--vd-space-2);
}

.reference {
  margin-top: var(--vd-space-4);
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
}

.question {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: var(--vd-space-4);
}

.options {
  display: flex;
  flex-direction: column;
  gap: var(--vd-space-2);
}

.option-btn {
  width: 100%;
  min-height: 44px;
  text-align: left;
  padding: var(--vd-space-3) var(--vd-space-4);
  font-size: 15px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: var(--vd-bg-hover);
  border-radius: var(--vd-radius-md);
  cursor: pointer;
  color: var(--vd-text-on-dark);
  transition: background-color var(--vd-transition-fast);
}
.option-btn:hover { background: var(--vd-cold); color: var(--vd-primary); }
.option-btn:active { background: var(--vd-cold-dark); color: var(--vd-primary); }

.option-btn--with-image {
  display: flex;
  align-items: center;
  gap: var(--vd-space-3);
}

.option-img {
  width: 56px;
  height: 56px;
  object-fit: contain;
  border-radius: var(--vd-radius-sm);
  background: rgba(255, 255, 255, 0.1);
  flex-shrink: 0;
}

.card-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--vd-space-4);
}

.primary-btn {
  min-height: 44px;
  padding: 0 var(--vd-space-5);
  background: var(--vd-neutral);
  color: var(--vd-text-primary);
  border: none;
  border-radius: var(--vd-radius-md);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: filter var(--vd-transition-fast);
}
.primary-btn:hover { filter: brightness(1.05); }
.primary-btn:active { filter: brightness(0.95); }

.back-btn {
  min-height: 44px;
  padding: 0 var(--vd-space-4);
  background: transparent;
  color: var(--vd-text-on-dark);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--vd-radius-md);
  font-size: 14px;
  cursor: pointer;
  transition: background-color var(--vd-transition-fast);
}
.back-btn:hover,
.back-btn:active { background: rgba(255, 255, 255, 0.08); }

.todo-banner,
.done-banner,
.warning-banner {
  padding: var(--vd-space-3) var(--vd-space-4);
  border-radius: var(--vd-radius-sm);
  border-left: 4px solid transparent;
  font-size: 14px;
  margin-bottom: var(--vd-space-4);
}

.todo-banner,
.warning-banner {
  background: rgba(242, 145, 88, 0.16);
  border-left-color: var(--vd-warning);
  color: var(--vd-warning);
}

.warning-banner {
  font-weight: 600;
}

.done-banner {
  background: rgba(123, 219, 174, 0.16);
  border-left-color: var(--vd-success);
  color: var(--vd-success);
}

.app-footer {
  text-align: center;
  padding: var(--vd-space-2) var(--vd-space-3) var(--vd-space-5);
  font-size: 12px;
  color: rgba(255, 255, 255, 0.5);
}

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 30;
  align-items: center;
  justify-content: center;
  padding: var(--vd-space-4);
}
.modal-overlay:not([hidden]) {
  display: flex;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
}

.modal-box {
  position: relative;
  width: 100%;
  max-width: 320px;
  background: var(--vd-bg-elevated);
  color: var(--vd-text-on-dark);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--vd-radius-lg);
  padding: var(--vd-space-5);
  box-shadow: var(--vd-shadow-float);
}

.modal-box h3 {
  margin: 0 0 var(--vd-space-1);
  font-size: 18px;
  font-weight: 600;
}

.modal-sub {
  margin: 0 0 var(--vd-space-4);
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
}

.lock-modal-input {
  width: 100%;
  min-height: 44px;
  padding: 0 var(--vd-space-4);
  font-size: 16px;
  border: 1px solid var(--vd-border);
  border-radius: var(--vd-radius-md);
  margin-bottom: var(--vd-space-2);
  background: var(--vd-surface);
  color: var(--vd-text-primary);
}
.lock-modal-input:focus {
  outline: none;
  border-color: var(--vd-cold);
  box-shadow: 0 0 0 3px rgba(153, 201, 255, 0.30);
}

.lock-modal-error {
  margin: 0 0 var(--vd-space-2);
  font-size: 13px;
  color: var(--vd-danger);
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: var(--vd-space-3);
  margin-top: var(--vd-space-3);
}

.offline-badge {
  position: fixed;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--vd-bg-elevated);
  color: var(--vd-text-on-dark);
  padding: var(--vd-space-2) var(--vd-space-4);
  border-radius: 999px;
  font-size: 12px;
  box-shadow: var(--vd-shadow-float);
}