/* ============================================================
   Components — AI Tutor Academy SPA
   Applied: Visual Designer + CSS Animation Creator + UI/UX Pro Max
   ============================================================ */

/* ════════════════════════════════════════════════════════════
   LAYOUT
   ════════════════════════════════════════════════════════════ */
.page-wrapper {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--sp-16) var(--sp-20) 0;
  padding-bottom: calc(var(--bottom-bar-height) + var(--sp-20));
}

.screen-title {
  font-size: var(--fs-28);
  font-weight: var(--fw-700);
  color: var(--ink);
  margin: 0 0 var(--sp-24);
  letter-spacing: -0.02em;
}

.screen-subtitle {
  font-size: var(--fs-15);
  color: var(--ink-secondary);
  margin: calc(-1 * var(--sp-16)) 0 var(--sp-24);
  line-height: var(--lh-relaxed);
}

/* ════════════════════════════════════════════════════════════
   CARD (atom → molecule)
   Base: .card  Variants: .card-outlined .card-gradient-bar
   ════════════════════════════════════════════════════════════ */
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--r-16);
  padding: var(--sp-24);
  margin-bottom: var(--sp-20);
  box-shadow: var(--shadow-card);
  transition:
    box-shadow var(--dur-normal) var(--ease-out),
    transform  var(--dur-normal) var(--ease-out);
  will-change: transform;   /* GPU hint */
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-1px);
}

/* Gradient top bar variant */
.card-gradient-bar {
  border-top: 4px solid transparent;
  border-image: linear-gradient(
    135deg,
    var(--brand-600),
    var(--accent-500)
  ) 1;
}

/* Outlined variant (less emphasis) */
.card-outlined {
  background: transparent;
  box-shadow: none;
}
.card-outlined:hover {
  box-shadow: var(--shadow-sm);
}

/* Card header */
.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sp-16);
}
.card-title {
  font-size: var(--fs-17);
  font-weight: var(--fw-600);
  color: var(--ink);
}
.card-body {
  font-size: var(--fs-14);
  line-height: var(--lh-relaxed);
  color: var(--ink-secondary);
}

/* Step content card (preserve legacy selector) */
.step-content-card {
  composes: card;       /* note: not real CSS modules; kept as comment */
  min-height: 180px;
  display: flex;
  flex-direction: column;
  gap: var(--sp-20);
}

/* ════════════════════════════════════════════════════════════
   BUTTON
   Applied: CSS Animation Creator (squash & stretch)
   Sizes: sm (32px) / default (40px) / lg (48px)
   ════════════════════════════════════════════════════════════ */
.btn {
  --btn-h: 40px;
  --btn-px: var(--sp-16);
  --btn-fs: var(--fs-14);

  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-8);
  height: var(--btn-h);
  padding: 0 var(--btn-px);
  font-family: var(--font-sans);
  font-size: var(--btn-fs);
  font-weight: var(--fw-600);
  line-height: 1;
  border: 2px solid transparent;
  border-radius: var(--r-8);
  cursor: pointer;
  min-width: var(--touch-target-min);
  white-space: nowrap;
  text-decoration: none;

  user-select: none;
  transition:
    background-color var(--dur-fast) var(--ease-out),
    border-color     var(--dur-fast) var(--ease-out),
    color            var(--dur-fast) var(--ease-out),
    box-shadow       var(--dur-fast) var(--ease-out),
    transform        var(--dur-fast) var(--ease-out);
  will-change: transform;
}

/* Sizes */
.btn-sm  { --btn-h: 32px; --btn-px: var(--sp-12); --btn-fs: var(--fs-13); }
.btn-lg  { --btn-h: 48px; --btn-px: var(--sp-24); --btn-fs: var(--fs-15); }

/* Variants */
.btn-primary {
  background: linear-gradient(135deg, var(--brand-600), var(--brand-500));
  color: #FFF;
  box-shadow: var(--shadow-btn);
}
.btn-primary:hover {
  box-shadow: var(--shadow-btn-hover);
  transform: translateY(-1px);
}
.btn-primary:active {
  transform: scale(0.97);
}
.btn-primary:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

.btn-secondary {
  background: var(--bg-alt);
  color: var(--ink);
  border-color: var(--line);
}
.btn-secondary:hover {
  background: var(--line);
}
.btn-secondary:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

.btn-ghost {
  background: transparent;
  color: var(--ink-secondary);
}
.btn-ghost:hover {
  background: var(--bg-alt);
  color: var(--ink);
}

.btn-danger {
  background: var(--danger-500);
  color: #FFF;
}
.btn-danger:hover {
  background: var(--danger-600);
}

.btn-success {
  background: var(--success-500);
  color: #FFF;
}
.btn-success:hover {
  background: var(--success-600);
}

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
  box-shadow: none;
  transform: none;
}

/* Button with icon — preserve spacing */
.btn svg,
.btn .btn-icon {
  width:  1.15em;
  height: 1.15em;
  flex-shrink: 0;
}

/* Loading state */
.btn-loading {
  cursor: wait;
  position: relative;
}
.btn-loading::after {
  content: '';
  width:  0.85em;
  height: 0.85em;
  border: 2px solid transparent;
  border-top-color: currentColor;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  margin-left: var(--sp-6);
}

/* ════════════════════════════════════════════════════════════
   INPUT / TEXTAREA
   Applied: UI/UX Pro Max — proper labels, focus rings
   ════════════════════════════════════════════════════════════ */
.input-group {
  display: flex;
  flex-direction: column;
  gap: var(--sp-6);
}

.input-label {
  font-size: var(--fs-13);
  font-weight: var(--fw-600);
  color: var(--ink-secondary);
}

.input-label .required::after {
  content: ' *';
  color: var(--danger-500);
}

.input {
  width: 100%;
  padding: var(--sp-8) var(--sp-12);
  font-family: var(--font-sans);
  font-size: var(--fs-14);
  line-height: 1.5;
  color: var(--ink);
  background: var(--card);
  border: 1.5px solid var(--line);
  border-radius: var(--r-8);
  transition:
    border-color var(--dur-fast) var(--ease-out),
    box-shadow   var(--dur-fast) var(--ease-out);
  box-sizing: border-box;
}
.input::placeholder {
  color: var(--ink-tertiary);
}
.input:hover {
  border-color: var(--neutral-300);
}
.input:focus {
  outline: none;
  border-color: var(--brand-500);
  box-shadow: 0 0 0 3px var(--focus-ring-color);
}

.input-textarea {
  min-height: 120px;
  resize: vertical;
  field-sizing: content;       /* auto-grow in modern browsers */
}

/* ════════════════════════════════════════════════════════════
   STEP 23 — TEACHER REVIEW WORKSPACE
   A restrained, evidence-first review surface.
   ════════════════════════════════════════════════════════════ */
.step23-shell {
  --step23-navy: #10233f;
  --step23-blue: #2563eb;
  --step23-cyan: #0f8fa8;
  --step23-green: #087f5b;
  --step23-amber: #b35c00;
  display: grid;
  gap: var(--sp-16);
  color: var(--ink);
}

.step23-hero {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--sp-24);
  padding: var(--sp-8) 0 var(--sp-20);
  border-bottom: 1px solid var(--line);
}

.step23-hero__copy {
  max-width: 660px;
}

.step23-eyebrow {
  display: flex;
  align-items: center;
  gap: var(--sp-10);
  color: var(--brand);
  font-size: var(--fs-10);
  font-weight: var(--fw-800);
  letter-spacing: 0.12em;
}

.step23-eyebrow__divider {
  width: 28px;
  height: 1px;
  background: var(--brand-300);
}

.step23-hero h1 {
  margin: var(--sp-8) 0 var(--sp-6);
  color: var(--step23-navy);
  font-size: clamp(1.55rem, 2.8vw, 2.15rem);
  line-height: 1.25;
  letter-spacing: 0;
}

.step23-hero p {
  margin: 0;
  color: var(--ink-secondary);
  font-size: var(--fs-14);
  line-height: 1.75;
}

.step23-refresh {
  min-height: 42px;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: var(--sp-8);
  padding: 0 var(--sp-14);
  border: 1px solid var(--line);
  border-radius: var(--r-8);
  background: var(--card);
  color: var(--ink);
  font: inherit;
  font-size: var(--fs-13);
  font-weight: var(--fw-700);
  cursor: pointer;
  box-shadow: var(--shadow-xs);
  transition: border-color var(--dur-fast) var(--ease-out),
              background var(--dur-fast) var(--ease-out),
              color var(--dur-fast) var(--ease-out);
}

.step23-refresh:hover {
  border-color: var(--brand-300);
  background: var(--brand-50);
  color: var(--brand-700);
}

.step23-refresh:focus-visible,
.step23-comment:focus-visible {
  outline: var(--focus-ring-width) solid var(--focus-ring-color);
  outline-offset: var(--focus-ring-offset);
}

.step23-refresh:disabled {
  cursor: wait;
  opacity: 0.7;
}

.step23-ready {
  min-height: 270px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: var(--sp-24);
  padding: var(--sp-32);
  border: 1px solid var(--line);
  border-radius: var(--r-8);
  background:
    linear-gradient(120deg, rgba(37, 99, 235, 0.055), rgba(15, 143, 168, 0.02)),
    var(--card);
  box-shadow: var(--shadow-sm);
}

.step23-ready__mark {
  width: 74px;
  height: 74px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  align-items: end;
  gap: 5px;
  padding: 15px;
  border-radius: var(--r-8);
  background: var(--step23-navy);
}

.step23-ready__mark span {
  display: block;
  border-radius: 2px 2px 0 0;
  background: #fff;
}

.step23-ready__mark span:nth-child(1) { height: 38%; opacity: 0.55; }
.step23-ready__mark span:nth-child(2) { height: 66%; opacity: 0.76; }
.step23-ready__mark span:nth-child(3) { height: 92%; }

.step23-ready h2 {
  margin: 0 0 var(--sp-6);
  color: var(--step23-navy);
  font-size: var(--fs-20);
}

.step23-ready p {
  margin: 0;
  color: var(--ink-secondary);
  font-size: var(--fs-14);
}

.step23-ready__list {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--sp-8);
  margin: 0;
  padding: var(--sp-20) 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.step23-ready__list li {
  display: flex;
  align-items: center;
  gap: var(--sp-8);
  color: var(--ink-secondary);
  font-size: var(--fs-13);
  font-weight: var(--fw-600);
}

.step23-ready__list span {
  color: var(--brand);
  font-size: var(--fs-10);
  font-weight: var(--fw-800);
}

.step23-preview-note {
  display: flex;
  align-items: center;
  gap: var(--sp-10);
  margin-bottom: var(--sp-10);
  padding: var(--sp-8) var(--sp-12);
  border: 1px solid #f1c58b;
  border-radius: var(--r-6);
  background: #fff8ec;
  color: #7a4300;
  font-size: var(--fs-12);
}

.step23-preview-note strong {
  flex-shrink: 0;
}

.step23-overview,
.step23-panel,
.step23-approval {
  border: 1px solid var(--line);
  border-radius: var(--r-8);
  background: var(--card);
  box-shadow: var(--shadow-sm);
}

.step23-overview {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(230px, 0.7fr);
  overflow: hidden;
}

.step23-overview__main {
  padding: var(--sp-24);
}

.step23-student-line {
  display: flex;
  align-items: center;
  gap: var(--sp-10);
}

.step23-avatar {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  border-radius: var(--r-8);
  background: var(--step23-navy);
  color: #fff;
  font-size: var(--fs-12);
  font-weight: var(--fw-800);
}

.step23-student-line__meta {
  color: var(--ink-tertiary);
  font-size: var(--fs-10);
  font-weight: var(--fw-600);
}

.step23-student-line__name {
  color: var(--ink);
  font-size: var(--fs-14);
  font-weight: var(--fw-700);
}

.step23-overview__main > h2 {
  margin: var(--sp-20) 0 var(--sp-8);
  color: var(--step23-navy);
  font-size: var(--fs-22);
  line-height: 1.45;
}

.step23-overview__main > p {
  margin: 0;
  color: var(--ink-secondary);
  font-size: var(--fs-13);
  line-height: 1.8;
}

.step23-overview__decision {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-10);
  margin-top: var(--sp-20);
  padding-top: var(--sp-16);
  border-top: 1px solid var(--line-light);
}

.step23-signal {
  width: 9px;
  height: 9px;
  flex-shrink: 0;
  margin-top: 5px;
  border-radius: 50%;
}

.step23-signal--good {
  background: var(--step23-green);
  box-shadow: 0 0 0 4px rgba(8, 127, 91, 0.12);
}

.step23-overview__decision strong,
.step23-overview__decision span {
  display: block;
}

.step23-overview__decision strong {
  color: var(--step23-green);
  font-size: var(--fs-13);
}

.step23-overview__decision span {
  margin-top: 2px;
  color: var(--ink-secondary);
  font-size: var(--fs-12);
  line-height: 1.6;
}

.step23-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 0;
  background: var(--neutral-900);
  color: #fff;
}

.step23-metrics div {
  min-height: 110px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: var(--sp-16);
  border-right: 1px solid rgba(255, 255, 255, 0.1);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.step23-metrics dt {
  color: rgba(255, 255, 255, 0.58);
  font-size: var(--fs-10);
  font-weight: var(--fw-600);
}

.step23-metrics dd {
  margin: var(--sp-4) 0 0;
  font-size: var(--fs-24);
  font-weight: var(--fw-700);
  line-height: 1;
}

.step23-metrics dd span {
  margin-left: 4px;
  color: rgba(255, 255, 255, 0.55);
  font-size: var(--fs-11);
  font-weight: var(--fw-500);
}

.step23-content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(280px, 0.85fr);
  gap: var(--sp-12);
  margin-top: var(--sp-12);
}

.step23-panel {
  padding: var(--sp-20);
}

.step23-section-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--sp-12);
  margin-bottom: var(--sp-16);
}

.step23-section-heading__kicker {
  display: block;
  margin-bottom: 2px;
  color: var(--brand);
  font-size: var(--fs-9, 0.5625rem);
  font-weight: var(--fw-800);
  letter-spacing: 0.12em;
}

.step23-section-heading h2 {
  margin: 0;
  color: var(--step23-navy);
  font-size: var(--fs-17);
}

.step23-section-note {
  color: var(--ink-tertiary);
  font-size: var(--fs-10);
  line-height: 1.5;
  text-align: right;
}

.step23-status-pill {
  display: inline-flex;
  align-items: center;
  min-height: 25px;
  padding: 0 var(--sp-8);
  border-radius: var(--r-full);
  font-size: var(--fs-10);
  font-weight: var(--fw-800);
  white-space: nowrap;
}

.step23-status-pill--ready {
  background: var(--success-bg);
  color: var(--step23-green);
}

.step23-status-pill--pending {
  background: var(--warning-bg);
  color: var(--step23-amber);
}

.step23-phases {
  display: grid;
}

.step23-phase {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  min-height: 60px;
}

.step23-phase__rail {
  position: relative;
  display: flex;
  justify-content: center;
}

.step23-phase__rail::after {
  content: '';
  position: absolute;
  top: 28px;
  bottom: -3px;
  width: 1px;
  background: var(--line);
}

.step23-phase:last-child .step23-phase__rail::after {
  display: none;
}

.step23-phase__rail span {
  position: relative;
  z-index: 1;
  width: 25px;
  height: 25px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--card);
  color: var(--ink-tertiary);
  font-size: var(--fs-10);
  font-weight: var(--fw-800);
}

.step23-phase--complete .step23-phase__rail span {
  border-color: var(--step23-green);
  background: var(--step23-green);
  color: #fff;
}

.step23-phase__body {
  display: flex;
  justify-content: space-between;
  gap: var(--sp-10);
  padding: 2px 0 var(--sp-16) var(--sp-8);
}

.step23-phase__body strong,
.step23-phase__body span {
  display: block;
}

.step23-phase__body strong {
  color: var(--ink);
  font-size: var(--fs-13);
}

.step23-phase__body div span,
.step23-phase__body > span {
  color: var(--ink-tertiary);
  font-size: var(--fs-10);
}

.step23-review-list {
  display: grid;
  gap: var(--sp-12);
}

.step23-review-item {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  align-items: start;
  gap: var(--sp-10);
}

.step23-review-item__icon {
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  border-radius: var(--r-6);
  font-size: var(--fs-11);
  font-weight: var(--fw-800);
}

.step23-review-item__icon--ok {
  background: var(--success-bg);
  color: var(--step23-green);
}

.step23-review-item__icon--attention {
  background: var(--warning-bg);
  color: var(--step23-amber);
}

.step23-review-item strong,
.step23-review-item span {
  display: block;
}

.step23-review-item strong {
  color: var(--ink);
  font-size: var(--fs-12);
}

.step23-review-item span {
  margin-top: 2px;
  color: var(--ink-tertiary);
  font-size: var(--fs-10);
  line-height: 1.55;
}

.step23-attention {
  margin-top: var(--sp-16);
  padding: var(--sp-12);
  border-left: 3px solid var(--step23-cyan);
  background: rgba(15, 143, 168, 0.06);
}

.step23-attention__label {
  color: var(--step23-cyan);
  font-size: var(--fs-10);
  font-weight: var(--fw-800);
}

.step23-attention p {
  margin: var(--sp-4) 0 0;
  color: var(--ink-secondary);
  font-size: var(--fs-11);
  line-height: 1.6;
}

.step23-milestones {
  margin-top: var(--sp-12);
}

.step23-milestone-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--sp-10);
}

.step23-milestone {
  padding: var(--sp-14);
  border: 1px solid var(--line-light);
  border-radius: var(--r-6);
  background: var(--neutral-50);
}

.step23-milestone > span {
  color: var(--brand);
  font-size: var(--fs-9, 0.5625rem);
  font-weight: var(--fw-800);
  letter-spacing: 0.08em;
}

.step23-milestone h3 {
  margin: var(--sp-6) 0 var(--sp-4);
  color: var(--step23-navy);
  font-size: var(--fs-12);
}

.step23-milestone p {
  margin: 0;
  color: var(--ink-secondary);
  font-size: var(--fs-10);
  line-height: 1.65;
}

.step23-approval {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.8fr);
  overflow: hidden;
}

.step23-approval[hidden] {
  display: none;
}

.step23-approval__main,
.step23-approval__action {
  padding: var(--sp-20);
}

.step23-approval__action {
  border-left: 1px solid var(--line);
  background: var(--neutral-50);
}

.step23-checklist {
  display: grid;
  gap: var(--sp-8);
}

.step23-checklist__item {
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr);
  align-items: center;
  gap: var(--sp-8);
  min-height: 44px;
  padding: var(--sp-8) var(--sp-10);
  border: 1px solid var(--line-light);
  border-radius: var(--r-6);
}

.step23-checklist__item > span {
  width: 22px;
  height: 22px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  font-size: var(--fs-10);
  font-weight: var(--fw-800);
}

.step23-checklist__item--ok > span {
  background: var(--success-bg);
  color: var(--step23-green);
}

.step23-checklist__item--attention > span {
  background: var(--warning-bg);
  color: var(--step23-amber);
}

.step23-checklist__item strong {
  color: var(--ink-secondary);
  font-size: var(--fs-11);
  line-height: 1.5;
}

.step23-label {
  display: block;
  color: var(--ink);
  font-size: var(--fs-12);
  font-weight: var(--fw-700);
}

.step23-label span {
  display: block;
  margin-top: 2px;
  color: var(--ink-tertiary);
  font-size: var(--fs-10);
  font-weight: var(--fw-400);
  line-height: 1.55;
}

.step23-comment {
  width: 100%;
  min-height: 122px;
  margin-top: var(--sp-8);
  padding: var(--sp-12);
  border: 1px solid var(--line);
  border-radius: var(--r-8);
  background: var(--card);
  color: var(--ink);
  font: inherit;
  font-size: var(--fs-12);
  line-height: 1.7;
  resize: vertical;
}

.step23-action-row {
  display: flex;
  justify-content: flex-end;
  gap: var(--sp-8);
  margin-top: var(--sp-12);
}

.step23-result {
  display: grid;
  gap: 2px;
  margin-top: var(--sp-12);
  padding: var(--sp-10) var(--sp-12);
  border-radius: var(--r-6);
  font-size: var(--fs-11);
}

.step23-result[hidden] {
  display: none;
}

.step23-result strong,
.step23-result span {
  display: block;
}

.step23-result--success {
  background: var(--success-bg);
  color: var(--step23-green);
}

.step23-result--return {
  background: var(--warning-bg);
  color: var(--step23-amber);
}

.step23-result span {
  opacity: 0.8;
}

.step23-loading {
  display: grid;
  gap: var(--sp-12);
  padding: var(--sp-24);
  border: 1px solid var(--line);
  border-radius: var(--r-8);
  background: var(--card);
}

.step23-loading__line,
.step23-loading__grid > div,
.step23-loading__panel {
  background: linear-gradient(90deg, var(--neutral-100), var(--neutral-50), var(--neutral-100));
  background-size: 200% 100%;
  animation: step23-shimmer 1.35s linear infinite;
}

.step23-loading__line {
  height: 12px;
  border-radius: 3px;
}

.step23-loading__line--short { width: 22%; }
.step23-loading__line--title { width: 58%; height: 28px; }

.step23-loading__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-10);
}

.step23-loading__grid > div {
  height: 82px;
  border-radius: var(--r-6);
}

.step23-loading__panel {
  height: 180px;
  border-radius: var(--r-6);
}

@keyframes step23-shimmer {
  0% { background-position: 100% 0; }
  100% { background-position: -100% 0; }
}

[data-theme="dark"] .step23-shell {
  --step23-navy: #e2e8f0;
  --step23-cyan: #67e8f9;
  --step23-green: #34d399;
  --step23-amber: #fbbf24;
}

[data-theme="dark"] .step23-metrics {
  background: #020617;
}

[data-theme="dark"] .step23-milestone,
[data-theme="dark"] .step23-approval__action {
  background: var(--bg);
}

[data-theme="dark"] .step23-preview-note {
  border-color: #854d0e;
  background: #2a1b05;
  color: #fde68a;
}

@media (max-width: 1180px) {
  .step23-overview,
  .step23-approval {
    grid-template-columns: 1fr;
  }

  .step23-metrics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .step23-metrics div {
    min-height: 90px;
  }

  .step23-approval__action {
    border-top: 1px solid var(--line);
    border-left: 0;
  }
}

@media (max-width: 760px) {
  .step23-hero {
    align-items: stretch;
    flex-direction: column;
  }

  .step23-refresh {
    justify-content: center;
    width: 100%;
  }

  .step23-ready,
  .step23-content-grid {
    grid-template-columns: 1fr;
  }

  .step23-ready__list,
  .step23-milestone-grid {
    grid-template-columns: 1fr;
  }

  .step23-metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .step23-overview__main > h2 {
    font-size: var(--fs-18);
  }
}

@media (max-width: 480px) {
  .step23-overview__main,
  .step23-panel,
  .step23-approval__main,
  .step23-approval__action,
  .step23-ready {
    padding: var(--sp-16);
  }

  .step23-action-row {
    align-items: stretch;
    flex-direction: column-reverse;
  }

  .step23-action-row .btn {
    width: 100%;
  }

  .step23-preview-note {
    align-items: flex-start;
    flex-direction: column;
    gap: 2px;
  }
}

/* The stage bar uses percentage flex-basis plus gaps. Clip the decorative
   emphasis so it never expands the document on narrow screens. */
.research-stage-bar {
  overflow: hidden;
}

/* Validation states */
.input-error {
  border-color: var(--danger-400);
}
.input-error:focus {
  box-shadow: 0 0 0 3px rgba(239,68,68,0.2);
}
.input-success {
  border-color: var(--success-400);
}

.input-feedback {
  font-size: var(--fs-12);
  margin-top: var(--sp-4);
}
.input-feedback.error {
  color: var(--danger-500);
}
.input-feedback.success {
  color: var(--success-500);
}

/* ════════════════════════════════════════════════════════════
   TAG / BADGE
   Applied: Visual Designer (color usage)
   ════════════════════════════════════════════════════════════ */
.tag {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-4);
  padding: var(--sp-4) var(--sp-10);
  font-family: var(--font-sans);
  font-size: var(--fs-12);
  font-weight: var(--fw-600);
  line-height: 1.4;
  border-radius: var(--r-full);
  white-space: nowrap;
  user-select: none;
}

.tag-brand   { background: var(--brand-bg);  color: var(--brand-700); }
.tag-accent  { background: var(--accent-bg);  color: var(--accent-700); }
.tag-success { background: var(--success-bg); color: var(--success-600); }
.tag-warning { background: var(--warning-bg); color: var(--warning-600); }
.tag-danger  { background: var(--danger-bg);  color: var(--danger-600); }
.tag-neutral { background: var(--bg-alt);     color: var(--ink-secondary); }

/* ════════════════════════════════════════════════════════════
   STEPPER (step navigation)
   Applied: CSS Animation Creator (pose-to-pose)
   ════════════════════════════════════════════════════════════ */
.stepper {
  position: sticky;
  top: 0;
  z-index: var(--z-stepper);
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  height: var(--stepper-height);
  padding: 0 var(--sp-20);
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
  overflow-x: auto;
  scrollbar-width: none;
}
.stepper::-webkit-scrollbar { display: none; }

.stepper-step {
  position: relative;
  flex-shrink: 0;
  min-width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-sans);
  font-size: var(--fs-13);
  font-weight: var(--fw-600);
  border-radius: var(--r-full);
  cursor: pointer;
  transition:
    background var(--dur-normal) var(--ease-out),
    color      var(--dur-normal) var(--ease-out),
    box-shadow var(--dur-normal) var(--ease-out);
  user-select: none;
}

.stepper-step.current {
  background: linear-gradient(135deg, var(--brand-600), var(--brand-500));
  color: #FFF;
  box-shadow: var(--shadow-btn);
}
.stepper-step.completed {
  background: var(--success-50);
  color: var(--success-600);
}
.stepper-step.completed:hover {
  background: var(--success-400);
  color: #FFF;
}
.stepper-step.locked {
  background: var(--bg-alt);
  color: var(--ink-tertiary);
  cursor: not-allowed;
}

.stepper-connector {
  flex-shrink: 0;
  width: 24px;
  height: 2px;
  border-radius: 1px;
  background: var(--line);
  transition: background var(--dur-slow) var(--ease-out);
}
.stepper-connector.done {
  background: var(--success-400);
}

/* ════════════════════════════════════════════════════════════
   TOAST
   Applied: CSS Animation Creator (bounce entry, GPU)
   ════════════════════════════════════════════════════════════ */
.toast-container {
  position: fixed;
  top: var(--sp-20);
  right: var(--sp-20);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--sp-12);
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--sp-10);
  padding: var(--sp-14) var(--sp-20);
  background: var(--neutral-900);
  color: #FFF;
  font-family: var(--font-sans);
  font-size: var(--fs-14);
  font-weight: var(--fw-500);
  border-radius: var(--r-12);
  box-shadow: var(--shadow-xl);
  pointer-events: auto;

  /* entry */
  animation: toast-in var(--dur-slow) var(--ease-bounce) both;
  /* exit handled by JS adding .toast-exit */
}
.toast-exit {
  animation: toast-out var(--dur-fast) var(--ease-in) both;
}

@keyframes toast-in {
  from {
    opacity: 0;
    transform: translateX(80px) scale(0.92);
  }
  to {
    opacity: 1;
    transform: translateX(0) scale(1);
  }
}
@keyframes toast-out {
  to {
    opacity: 0;
    transform: translateY(-12px) scale(0.96);
  }
}

/* ════════════════════════════════════════════════════════════
   MODAL
   Applied: CSS Animation Creator (scale fade + GPU)
   ════════════════════════════════════════════════════════════ */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--sp-24);
  background: var(--overlay);
  animation: modal-overlay-in var(--dur-slow) var(--ease-out) both;
}

.modal {
  width: 100%;
  max-width: 520px;
  max-height: 85vh;
  overflow-y: auto;
  background: var(--card);
  border-radius: var(--r-16);
  box-shadow: var(--shadow-modal);
  animation: modal-in var(--dur-slow) var(--ease-bounce) both;
}
.modal-close-overlay {
  animation: modal-overlay-out var(--dur-fast) var(--ease-in) both;
}
.modal-exit {
  animation: modal-out var(--dur-fast) var(--ease-in) both;
}

@keyframes modal-overlay-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes modal-overlay-out {
  from { opacity: 1; }
  to   { opacity: 0; }
}
@keyframes modal-in {
  from {
    opacity: 0;
    transform: scale(0.92) translateY(24px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}
@keyframes modal-out {
  to {
    opacity: 0;
    transform: scale(0.95) translateY(12px);
  }
}

/* ════════════════════════════════════════════════════════════
   STEP GUIDE / CONCEPT CARD (learning UI specific)
   ════════════════════════════════════════════════════════════ */
.step-guide {
  padding: var(--sp-16) var(--sp-20);
  background: var(--brand-bg);
  border-left: 4px solid var(--brand-500);
  border-radius: 0 var(--r-8) var(--r-8) 0;
  font-size: var(--fs-14);
  line-height: var(--lh-relaxed);
  color: var(--brand-900);
  margin-bottom: var(--sp-16);
}

.step-guide p {
  margin: 0;
}
.step-guide p + p {
  margin-top: var(--sp-8);
}

.concept-card {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-12);
  padding: var(--sp-16);
  background: var(--bg-alt);
  border-radius: var(--r-12);
  border: 1px solid var(--line);
  transition: box-shadow var(--dur-normal) var(--ease-out);
}
.concept-card:hover {
  box-shadow: var(--shadow-sm);
}

.concept-icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--brand-bg);
  color: var(--brand-600);
  border-radius: var(--r-8);
  font-size: var(--fs-18);
}

/* ════════════════════════════════════════════════════════════
   SKELETON (loading placeholder)
   ════════════════════════════════════════════════════════════ */
.skeleton {
  background: linear-gradient(
    110deg,
    var(--line-light) 30%,
    var(--line)      50%,
    var(--line-light) 70%
  );
  background-size: 200% 100%;
  animation: skeleton-wave 1.6s ease-in-out infinite;
  border-radius: var(--r-6);
}
.skeleton-text {
  height: 1em;
  margin-bottom: var(--sp-8);
}
.skeleton-title {
  height: 1.4em;
  width: 60%;
  margin-bottom: var(--sp-12);
}
.skeleton-card {
  height: 140px;
  border-radius: var(--r-16);
}
@keyframes skeleton-wave {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

/* ════════════════════════════════════════════════════════════
   STEP ENTRY / FADE IN
   ════════════════════════════════════════════════════════════ */
.step-fade-in {
  animation: step-enter var(--dur-slow) var(--ease-out) both;
}
@keyframes step-enter {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ════════════════════════════════════════════════════════════
   MISC ANIMATIONS
   ════════════════════════════════════════════════════════════ */
@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%      { transform: translateX(-6px); }
  40%      { transform: translateX(6px); }
  60%      { transform: translateX(-4px); }
  80%      { transform: translateX(4px); }
}
.shake {
  animation: shake 0.5s var(--ease-out);
}

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

.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-8  { gap: var(--sp-8); }
.gap-12 { gap: var(--sp-12); }
.gap-16 { gap: var(--sp-16); }
.gap-20 { gap: var(--sp-20); }
.mt-8  { margin-top: var(--sp-8); }
.mt-16 { margin-top: var(--sp-16); }
.mt-20 { margin-top: var(--sp-20); }
.mb-8  { margin-bottom: var(--sp-8); }
.mb-16 { margin-bottom: var(--sp-16); }
.mb-20 { margin-bottom: var(--sp-20); }

.fw-600 { font-weight: var(--fw-600); }
.fw-700 { font-weight: var(--fw-700); }

.text-sm      { font-size: var(--fs-13); }
.text-secondary{ color: var(--ink-secondary); }
.text-tertiary { color: var(--ink-tertiary); }
.text-center  { text-align: center; }