/* ═══════════════════════════════════════════════════════════
   IELTS Vocabulary Mastery
   Design: Apple precision  ×  Retro Mario energy
   Font:   SF Pro (system-ui)
   Layout: Mobile 320px → Tablet 768px → Desktop 1024px+
   ═══════════════════════════════════════════════════════════ */

/* ── Design Tokens ───────────────────────────────────────── */
:root {
  /* Mario colour palette */
  --red:      #E52521;   /* Mario red  — primary CTA        */
  --red-d:    #C0201C;   /* Pressed red                     */
  --red-l:    #FCE8E8;   /* Red tint                        */
  --blue:     #049CD8;   /* Mario sky — info / secondary    */
  --blue-l:   #E5F5FD;   /* Blue tint                       */
  --green:    #43B047;   /* Mario pipe — success            */
  --green-l:  #E8F7E9;   /* Green tint                      */
  --yellow:   #F8B800;   /* Coin gold  — in-progress        */
  --yellow-l: #FFF8E1;   /* Yellow tint                     */

  /* Apple neutrals */
  --dark:     #1D1D1F;   /* Charcoal — borders, text        */
  --gray-1:   #3A3A3C;   /* Secondary text                  */
  --gray-2:   #6E6E73;   /* Tertiary text                   */
  --gray-3:   #AEAEB2;   /* Placeholder / disabled          */
  --gray-4:   #D1D1D6;   /* Borders                         */
  --gray-5:   #E5E5EA;   /* Dividers / tracks               */
  --bg:       #F5F5F7;   /* Page background                 */
  --surface:  #FFFFFF;   /* Card / panel background         */

  /* Pixel-art block style */
  --px-border:  3px solid var(--dark);
  --px-shadow:  4px 4px 0 0 var(--dark);
  --px-shadow-s:3px 3px 0 0 var(--dark);

  /* Geometry */
  --radius:   10px;
  --radius-s: 6px;
  --radius-l: 14px;

  /* Spacing (8-pt grid) */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 24px;
  --sp-6: 32px;
  --sp-7: 48px;
  --sp-8: 64px;
}

/* ── Reset ───────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 16px;
  -webkit-tap-highlight-color: transparent;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Text',
               'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--dark);
  min-height: 100vh;
  line-height: 1.5;
  overscroll-behavior-y: none;
  -webkit-font-smoothing: antialiased;
}

button { cursor: pointer; font-family: inherit; border: none; background: none; }
input  { font-family: inherit; }
strong { font-weight: 700; }

/* ── Screen Management ───────────────────────────────────── */
.screen        { display: none; flex-direction: column; min-height: 100vh; }
.screen.active { display: flex; }

/* Centred content wrapper */
.screen-inner {
  max-width: 620px;
  width: 100%;
  margin: 0 auto;
  padding: 0 var(--sp-4) var(--sp-7);
  flex: 1;
}


/* ═══════════════════════════════════════════════════════════
   SUBJECT HUB — Main Home Screen
   ═══════════════════════════════════════════════════════════ */

.hub-shell {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  padding: var(--sp-5) var(--sp-4) 80px;   /* 80px = bottom nav clearance */
  max-width: 560px;
  margin: 0 auto;
  width: 100%;
}

/* ── Hub header row ── */
.hub-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--sp-5);
}

.hub-wordmark {
  font-size: 2rem;
  font-weight: 900;
  letter-spacing: -1.5px;
  line-height: 1;
  color: var(--dark);
}
.hub-go {
  color: var(--red);
  font-size: 2.2rem;
}
.hub-tagline {
  font-size: .65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--gray-2);
  margin-top: var(--sp-1);
}

/* Decorative pixel coins */
.hub-coins {
  display: flex;
  gap: 6px;
  align-items: center;
  padding-top: 4px;
}
.hub-coin {
  display: block;
  width: 14px;
  height: 14px;
  background: var(--yellow);
  border: 2px solid var(--dark);
  border-radius: 50%;
  box-shadow: 2px 2px 0 0 var(--dark);
  animation: coin-bounce 1.4s ease-in-out infinite;
}
.hub-coin:nth-child(2) { animation-delay: .18s; }
.hub-coin:nth-child(3) { animation-delay: .36s; }
@keyframes coin-bounce {
  0%, 100% { transform: translateY(0);    }
  45%       { transform: translateY(-6px); }
}

/* ── Right side of the hub header (coins + auth slot stack vertically) ── */
.hub-header-right {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--sp-2);
}
.hub-auth-slot { display: flex; }

/* ── Auth: signed-out "Sign in" button ── */
.auth-signin-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--surface);
  border: 2px solid var(--dark);
  box-shadow: 2px 2px 0 0 var(--dark);
  border-radius: var(--radius-s);
  font-size: .68rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--dark);
  cursor: pointer;
  transition: transform .08s, box-shadow .08s;
}
.auth-signin-btn:active {
  transform: translate(2px, 2px);
  box-shadow: 0 0 0 0 var(--dark);
}

/* ── Auth: signed-in user pill ── */
.auth-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px 4px 4px;
  background: var(--surface);
  border: 2px solid var(--dark);
  box-shadow: 2px 2px 0 0 var(--dark);
  border-radius: 100px;
  font-size: .7rem;
  font-weight: 800;
  color: var(--dark);
  cursor: pointer;
  transition: transform .08s, box-shadow .08s;
  max-width: 160px;
}
.auth-pill:active {
  transform: translate(2px, 2px);
  box-shadow: 0 0 0 0 var(--dark);
}
.auth-avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--blue);
  color: #fff;
  border: 1.5px solid var(--dark);
  font-size: .7rem;
  font-weight: 900;
  flex-shrink: 0;
  object-fit: cover;
}
.auth-avatar-fallback { line-height: 1; }
.auth-name {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  letter-spacing: -.01em;
}

/* ── Sync status toast (top of hub, full width) ── */
.sync-toast {
  display: block;
  text-align: center;
  font-size: .65rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: .12em;
  padding: 6px 12px;
  border-radius: var(--radius-s);
  margin-bottom: var(--sp-3);
  border: 2px solid var(--dark);
  box-shadow: 2px 2px 0 0 var(--dark);
}
.sync-toast[hidden] { display: none; }
.sync-toast.sync-syncing { background: var(--yellow);  color: var(--dark); }
.sync-toast.sync-idle    { background: var(--green-l); color: var(--green); border-color: var(--green); box-shadow: 2px 2px 0 0 var(--green); }
.sync-toast.sync-error   { background: var(--red-l);   color: var(--red);   border-color: var(--red);   box-shadow: 2px 2px 0 0 var(--red); }
.sync-toast.sync-offline { background: var(--gray-5);  color: var(--gray-2); }

/* ── Motivational quote card ── */
.quote-card {
  background: var(--dark);
  color: var(--surface);
  border: var(--px-border);
  box-shadow: var(--px-shadow);
  border-radius: var(--radius);
  padding: var(--sp-4) var(--sp-5);
  margin-bottom: var(--sp-5);
  transition: opacity .42s ease;
}
.quote-card.quote-fading { opacity: 0; }

.quote-ornament {
  display: block;
  font-size: 1.6rem;
  color: var(--yellow);
  line-height: 1;
  margin-bottom: var(--sp-2);
}
.quote-text {
  font-size: .95rem;
  font-style: italic;
  line-height: 1.65;
  margin: 0 0 var(--sp-2);
  color: var(--surface);
  min-height: 2.5em;   /* prevents layout shift while text changes */
}
.quote-author {
  font-size: .68rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--yellow);
  margin: 0;
}

/* ── Section label ── */
.hub-section-label {
  font-size: .65rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: .15em;
  color: var(--gray-2);
  margin-bottom: var(--sp-4);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}
.hub-pixel-sq { color: var(--red); font-size: .55rem; }

/* ── Subject cards grid ── */
.subject-grid {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}

.subject-card {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  background: var(--surface);
  border: var(--px-border);
  box-shadow: var(--px-shadow);
  border-radius: var(--radius);
  padding: var(--sp-4) var(--sp-5);
  transition: transform .08s, box-shadow .08s;
  position: relative;
}
.subject-card:not(.coming-soon) {
  cursor: pointer;
}
.subject-card:not(.coming-soon):active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 0 var(--dark);
}
.subject-card.coming-soon { opacity: .55; cursor: default; }

.subj-icon-wrap {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-s);
  border: 2px solid var(--dark);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.subj-vocab    .subj-icon-wrap { background: var(--red);   color: #fff; }
.subj-writing  .subj-icon-wrap { background: var(--blue);  color: #fff; }
.subj-para     .subj-icon-wrap { background: var(--green); color: #fff; }

.subj-info { flex: 1; min-width: 0; }
.subj-name {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--dark);
  letter-spacing: -.02em;
}
.subj-detail {
  font-size: .72rem;
  color: var(--gray-2);
  margin-top: 2px;
  line-height: 1.45;
}
.subj-progress-wrap {
  height: 5px;
  background: var(--gray-5);
  border-radius: 3px;
  margin-top: var(--sp-2);
  overflow: hidden;
  border: 1px solid var(--gray-4);
}
.subj-progress-fill {
  height: 100%;
  background: var(--green);
  border-radius: 3px;
  transition: width .7s ease;
}
.subj-progress-label {
  font-size: .62rem;
  font-weight: 600;
  color: var(--gray-2);
  margin-top: 4px;
}
.subj-arrow {
  font-size: 1.2rem;
  color: var(--gray-3);
  flex-shrink: 0;
}
.coming-soon-badge {
  font-size: .58rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: .1em;
  background: var(--gray-5);
  color: var(--gray-2);
  padding: 3px 8px;
  border-radius: 20px;
  border: 1.5px solid var(--gray-4);
  flex-shrink: 0;
}

/* ═══════════════════════════════════════════════════════════
   PERSISTENT BOTTOM NAVIGATION BAR — Mario Block Style
   Two ?-block buttons that bounce when tapped.
   ═══════════════════════════════════════════════════════════ */

.app-bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 72px;
  background: var(--bg);
  border-top: var(--px-border);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-7);
  padding-bottom: env(safe-area-inset-bottom, 0);
  z-index: 200;
  overflow: visible;           /* allow block-bump to fly above nav bar  */
}
.app-bottom-nav[hidden] { display: none; }

/* ── Mario block button ── */
.nav-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  width: 68px;
  height: 52px;
  background: var(--yellow);
  color: var(--dark);
  border: var(--px-border);
  box-shadow: 4px 4px 0 0 var(--dark);
  border-radius: var(--radius-s);
  cursor: pointer;
  padding: 0;
  position: relative;
  overflow: visible;
  transform-origin: center bottom;
  transition: none;            /* animation replaces transitions */
}

/* Coin sparkle spawns above the block on each hit */
.nav-btn::after {
  content: '★';
  position: absolute;
  top: -2px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--yellow);
  font-size: .95rem;
  line-height: 1;
  opacity: 0;
  pointer-events: none;
  z-index: 201;
  text-shadow: 0 0 0 var(--dark);  /* keeps star crisp */
}

/* Hover shimmer (desktop) */
.nav-btn:hover:not(:disabled) {
  background: #ffc928;
  outline: none;
}
.nav-btn:focus-visible:not(:disabled) {
  outline: 3px solid var(--blue);
  outline-offset: 2px;
}

/* Disabled = back on hub */
.nav-btn:disabled {
  opacity: .35;
  cursor: default;
  pointer-events: none;
  filter: grayscale(.6);
}

.nav-icon {
  display: block;
  width: 24px;
  height: 24px;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}
.nav-label {
  font-size: .52rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: .1em;
  line-height: 1;
}

/* ── Block-hit animation (triggered by JS adding .block-hit) ── */
.nav-btn.block-hit {
  animation: block-bump .52s cubic-bezier(.22, .68, .36, 1.2);
}
.nav-btn.block-hit::after {
  animation: coin-pop .52s ease forwards;
}

@keyframes block-bump {
  0%   { transform: translateY(0)     scaleY(1);    }
  18%  { transform: translateY(-14px) scaleY(1.06); }   /* flies up    */
  42%  { transform: translateY(-8px)  scaleY(1.02); }   /* float       */
  62%  { transform: translateY(0)     scaleY(0.94); }   /* land squish */
  78%  { transform: translateY(-4px)  scaleY(1.03); }   /* little hop  */
  100% { transform: translateY(0)     scaleY(1);    }
}

@keyframes coin-pop {
  0%   { opacity: 1; transform: translateX(-50%) translateY(0);     }
  55%  { opacity: 1; transform: translateX(-50%) translateY(-28px); }
  100% { opacity: 0; transform: translateX(-50%) translateY(-38px); }
}

.nav-divider { display: none; }   /* replaced by visual gap between blocks */

/* Add bottom clearance to all non-exercise screens */
#screen-hub,
#screen-home,
#screen-detail,
#screen-result,
#screen-report {
  padding-bottom: 80px;
}

/* ═══════════════════════════════════════════════════════════
   APP HEADER
   ═══════════════════════════════════════════════════════════ */
.app-header {
  background: var(--dark);
  color: var(--surface);
  padding: var(--sp-5) var(--sp-4) var(--sp-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-3);
  border-bottom: 4px solid var(--red);
}

.app-title {
  font-size: 1.45rem;
  font-weight: 900;
  letter-spacing: -.6px;
  line-height: 1.1;
}

.app-subtitle {
  font-size: .75rem;
  font-weight: 500;
  color: var(--gray-3);
  margin-top: 3px;
  letter-spacing: .02em;
}

.overall-stats {
  font-size: .75rem;
  font-weight: 700;
  background: var(--red);
  color: #fff;
  padding: 5px 12px;
  border-radius: 20px;
  white-space: nowrap;
  letter-spacing: .03em;
  border: 2px solid rgba(255,255,255,.2);
}


/* ═══════════════════════════════════════════════════════════
   SCREEN 1 — VOCABULARY UNIT GRID
   Each card represents one Unit (3 mini-lessons / 45 words).
   Units are grouped by Cambridge Book + Test via section headers
   that span the full grid width.
   ═══════════════════════════════════════════════════════════ */
.lesson-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--sp-4);
  max-width: 720px;
  width: 100%;
  margin: 0 auto;
  padding: var(--sp-5) var(--sp-4) var(--sp-7);
  flex: 1;
}
@media (min-width: 768px) {
  .lesson-grid {
    grid-template-columns: 1fr 1fr;
    max-width: 1000px;
    gap: var(--sp-5);
  }
}

/* ── Test-level section header (Book 8 · Test 1, etc.) ── */
.test-section-header {
  grid-column: 1 / -1;                /* span full grid width */
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: .7rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: .15em;
  color: var(--gray-2);
  padding: var(--sp-4) 0 var(--sp-2);
  border-bottom: 3px solid var(--dark);
  margin-top: var(--sp-3);
  position: relative;
}
.test-section-header::before {
  content: '';
  display: inline-block;
  width: 10px;
  height: 10px;
  background: var(--red);
  border: 2px solid var(--dark);
  box-shadow: 2px 2px 0 0 var(--dark);
  margin-right: var(--sp-1);
}
.test-section-header:first-child { margin-top: 0; }

.test-section-book {
  color: var(--dark);
  font-weight: 900;
}
.test-section-dot  { color: var(--gray-3); font-size: 1rem; line-height: 0; }
.test-section-test { color: var(--red); }

/* ── Unit card ── */
.unit-card {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  background: var(--surface);
  border: var(--px-border);
  box-shadow: var(--px-shadow);
  border-radius: var(--radius);
  padding: var(--sp-4) var(--sp-4);
  transition: transform .08s, box-shadow .08s;
  user-select: none;
  position: relative;
}
.unit-card[role="button"]         { cursor: pointer; }
.unit-card[role="button"]:hover   { transform: translate(-1px,-1px); box-shadow: 5px 5px 0 0 var(--dark); }
.unit-card[role="button"]:active  { transform: translate(2px,2px);   box-shadow: 1px 1px 0 0 var(--dark); }

/* Status — coloured left rail */
.unit-card-available   { border-left: 7px solid var(--blue);   }
.unit-card-in-progress { border-left: 7px solid var(--yellow); }
.unit-card-complete    { border-left: 7px solid var(--green);  }
.unit-card-locked {
  background:    var(--gray-5);
  color:         var(--gray-3);
  border-color:  #999;
  box-shadow:    4px 4px 0 0 #999;
  cursor:        default;
}

/* Big unit number on the left */
.unit-card-num {
  font-size:    2.4rem;
  font-weight:  900;
  letter-spacing: -2px;
  line-height:  1;
  color:        var(--dark);
  width:        52px;
  text-align:   center;
  flex-shrink:  0;
}
.unit-card-locked .unit-card-num { color: var(--gray-3); }

.unit-card-body { flex: 1; min-width: 0; }

.unit-card-passage {
  font-size:    1rem;
  font-weight:  800;
  color:        var(--dark);
  letter-spacing: -.01em;
  line-height:  1.25;
  margin-bottom: var(--sp-2);
}
.unit-card-locked .unit-card-passage { color: var(--gray-3); }

.unit-card-meta {
  display:     flex;
  align-items: center;
  gap:         var(--sp-3);
  margin-bottom: var(--sp-2);
  flex-wrap:   wrap;
}

/* Three dots = the three mini-lessons */
.unit-card-lessons { display: inline-flex; gap: 5px; }
.lesson-dot {
  display:       inline-block;
  width:         9px;
  height:        9px;
  border-radius: 50%;
  border:        2px solid var(--gray-4);
  background:    var(--surface);
}
.lesson-dot.dot-done   { background: var(--green);  border-color: var(--green); }
.lesson-dot.dot-tried  { background: var(--yellow); border-color: var(--yellow); }
.lesson-dot.dot-empty  { background: var(--gray-5); border-color: var(--gray-4); }
.lesson-dot.dot-locked { background: var(--gray-4); border-color: transparent; }

/* "N to review" badge */
.unit-card-badge {
  display:        inline-block;
  font-size:      .55rem;
  font-weight:    900;
  text-transform: uppercase;
  letter-spacing: .08em;
  background:     var(--red-l);
  color:          var(--red);
  border:         1.5px solid var(--red);
  padding:        2px 8px;
  border-radius:  20px;
}

/* Inline mastery bar */
.unit-card-progress-wrap {
  height:        6px;
  background:    var(--gray-5);
  border:        1px solid var(--gray-4);
  border-radius: 3px;
  overflow:      hidden;
}
.unit-card-progress-fill {
  height:     100%;
  background: var(--green);
  transition: width .7s ease;
}
.unit-card-progress-label {
  font-size:  .65rem;
  font-weight: 600;
  color:      var(--gray-2);
  margin-top: 4px;
}
.unit-card-locked .unit-card-progress-label { color: var(--gray-3); }

.unit-card-arrow {
  font-size: 1.4rem;
  font-weight: 900;
  color:     var(--gray-3);
  flex-shrink: 0;
}
.unit-card-available   .unit-card-arrow { color: var(--blue); }
.unit-card-in-progress .unit-card-arrow { color: #B07300; }
.unit-card-complete    .unit-card-arrow { color: var(--green); }


/* ═══════════════════════════════════════════════════════════
   SCREEN 1.5 — UNIT DETAIL (lessons + dashboard)
   ═══════════════════════════════════════════════════════════ */

.unit-header {
  padding-top: var(--sp-5);
  margin-bottom: var(--sp-4);
}
.unit-detail-num {
  font-size:      .68rem;
  font-weight:    900;
  text-transform: uppercase;
  letter-spacing: .15em;
  color:          var(--red);
  margin-bottom:  var(--sp-2);
}
.unit-detail-passage {
  font-size:    1.7rem;
  font-weight:  900;
  letter-spacing: -.6px;
  color:        var(--dark);
  line-height:  1.1;
}

.unit-lessons {
  margin: var(--sp-4) 0 var(--sp-5);
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
}

/* ── Unit dashboard panel ── */
.unit-dashboard {
  background:    var(--surface);
  border:        var(--px-border);
  box-shadow:    var(--px-shadow);
  border-radius: var(--radius);
  padding:       var(--sp-5);
  margin-bottom: var(--sp-6);
}

.unit-dashboard-title {
  font-size:      .68rem;
  font-weight:    900;
  text-transform: uppercase;
  letter-spacing: .15em;
  color:          var(--gray-2);
  margin-bottom:  var(--sp-3);
  display:        flex;
  align-items:    center;
  gap:            var(--sp-2);
}

/* Big mastery bar */
.mastery-bar-wrap {
  height:        10px;
  background:    var(--gray-5);
  border:        2px solid var(--dark);
  border-radius: 5px;
  overflow:      hidden;
  box-shadow:    2px 2px 0 0 var(--dark);
}
.mastery-bar-fill {
  height:     100%;
  background: var(--green);
  transition: width .7s ease;
}
.mastery-bar-label {
  font-size:    .78rem;
  font-weight:  700;
  color:        var(--gray-2);
  margin-top:   8px;
  margin-bottom: var(--sp-4);
}

/* 4-column breakdown pills */
.mastery-breakdown {
  display:              grid;
  grid-template-columns: repeat(4, 1fr);
  gap:                  var(--sp-2);
  margin-bottom:        var(--sp-4);
}
.mastery-pill {
  display:        flex;
  flex-direction: column;
  align-items:    center;
  padding:        var(--sp-3) var(--sp-1);
  border:         2px solid var(--dark);
  border-radius:  var(--radius-s);
  background:     var(--surface);
  box-shadow:     2px 2px 0 0 var(--dark);
}
.pill-num {
  font-size:   1.4rem;
  font-weight: 900;
  line-height: 1;
}
.pill-label {
  font-size:      .55rem;
  font-weight:    900;
  text-transform: uppercase;
  letter-spacing: .06em;
  color:          var(--gray-2);
  margin-top:     5px;
}
.mastery-mastered  { background: var(--green-l); }
.mastery-mastered  .pill-num { color: var(--green); }
.mastery-learning  { background: var(--blue-l); }
.mastery-learning  .pill-num { color: var(--blue); }
.mastery-review    { background: var(--red-l); }
.mastery-review    .pill-num { color: var(--red); }
.mastery-untouched { background: var(--bg); }
.mastery-untouched .pill-num { color: var(--gray-2); }

/* Last R5 score chips */
.r5-chip-row {
  display:       flex;
  gap:           var(--sp-2);
  margin-bottom: var(--sp-4);
  flex-wrap:     wrap;
}
.r5-chip {
  font-size:     .7rem;
  font-weight:   800;
  padding:       5px 11px;
  border-radius: 20px;
  border:        1.5px solid var(--gray-4);
  background:    var(--surface);
  color:         var(--gray-2);
}
.r5-chip-pass  { background: var(--green-l); color: var(--green); border-color: var(--green); }
.r5-chip-fail  { background: var(--red-l);   color: var(--red);   border-color: var(--red); }
.r5-chip-empty { color: var(--gray-3); }

/* Review button — inherits .btn-primary, just full width */
.unit-review-btn { width: 100%; }

.unit-review-empty {
  text-align:    center;
  padding:       var(--sp-3) var(--sp-4);
  color:         var(--green);
  font-weight:   700;
  font-size:     .85rem;
  background:    var(--green-l);
  border:        2px solid var(--green);
  border-radius: var(--radius-s);
}


/* ═══════════════════════════════════════════════════════════
   SCREEN 2 — LESSON DETAIL
   ═══════════════════════════════════════════════════════════ */
.btn-back {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  font-size: .88rem;
  font-weight: 700;
  color: var(--red);
  padding: var(--sp-4) 0 var(--sp-3);
  min-height: 48px;
  letter-spacing: -.01em;
}
.btn-back:hover { text-decoration: underline; }

/* Lesson detail header card */
.detail-header {
  background: var(--surface);
  border: var(--px-border);
  border-radius: var(--radius);
  padding: var(--sp-5) var(--sp-5);
  margin-bottom: var(--sp-4);
  box-shadow: var(--px-shadow);
  border-left: 6px solid var(--red);
}
.detail-lesson-id {
  font-size: .68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--red);
  margin-bottom: var(--sp-1);
}
.detail-lesson-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--dark);
  letter-spacing: -.3px;
  line-height: 1.25;
}
.detail-passage {
  font-size: .82rem;
  color: var(--gray-2);
  margin-top: var(--sp-1);
}
.detail-word-count {
  display: inline-block;
  margin-top: var(--sp-3);
  font-size: .7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  background: var(--bg);
  color: var(--gray-2);
  padding: 4px 10px;
  border-radius: 20px;
  border: 1.5px solid var(--gray-4);
}

/* Round cards */
.rounds-list { display: flex; flex-direction: column; gap: var(--sp-3); }

.round-card {
  background: var(--surface);
  border: var(--px-border);
  border-radius: var(--radius-s);
  padding: var(--sp-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--px-shadow-s);
  transition: transform .08s, box-shadow .08s;
}
.round-card[role="button"]:hover  { transform: translate(-1px,-1px); box-shadow: 4px 4px 0 0 var(--dark); }
.round-card[role="button"]:active { transform: translate(2px,2px);  box-shadow: 1px 1px 0 0 var(--dark); }

.round-card-locked   { opacity: .5; box-shadow: 2px 2px 0 0 #999; border-color: #999; }
.round-card-passed   { border-left: 5px solid var(--green); }
.round-card-available{ border-left: 5px solid var(--red); }

.round-card-left { display: flex; align-items: center; gap: var(--sp-3); }

.round-num {
  font-size: .72rem;
  font-weight: 800;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--gray-4);
  flex-shrink: 0;
  letter-spacing: .02em;
}
.round-card-passed   .round-num { background: var(--green-l); color: var(--green); border-color: var(--green); }
.round-card-available .round-num { background: var(--red-l);   color: var(--red);   border-color: var(--red);   }

.round-name  { font-size: .92rem; font-weight: 700; letter-spacing: -.2px; }
.round-score { font-size: .73rem; color: var(--gray-2); margin-top: 2px; }

.round-card-right { font-size: 1rem; font-weight: 800; }
.round-check { color: var(--green); }
.round-arrow { color: var(--red); }
.round-lock  { color: var(--gray-3); font-size: .85rem; }


/* ═══════════════════════════════════════════════════════════
   SCREEN 3 — EXERCISE SHELL
   ═══════════════════════════════════════════════════════════ */
.exercise-shell {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 720px;
  margin: 0 auto;
  width: 100%;
}

/* Exercise header bar */
.ex-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-2) var(--sp-3);
  background: var(--surface);
  padding: var(--sp-3) var(--sp-4) 0;
  border-bottom: var(--px-border);
  flex-shrink: 0;
}

.btn-exit {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--gray-4);
  color: var(--gray-2);
  font-size: .95rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-weight: 700;
  transition: background .15s, border-color .15s;
}
.btn-exit:hover  { background: var(--red-l); border-color: var(--red); color: var(--red); }
.btn-exit:active { background: var(--red);   color: #fff; }

.ex-meta {
  flex: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-width: 0;
}
.ex-round-label {
  font-size: .78rem;
  font-weight: 700;
  color: var(--red);
  letter-spacing: .03em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.ex-count {
  font-size: .78rem;
  font-weight: 600;
  color: var(--gray-2);
  white-space: nowrap;
  margin-left: var(--sp-2);
}

/* Coin-bar progress indicator */
.ex-progress-bar {
  flex-basis: 100%;
  height: 12px;
  background: var(--gray-5);
  border: 2px solid var(--dark);
  border-radius: var(--radius-s);
  overflow: hidden;
  margin-bottom: var(--sp-3);
}
.ex-progress-fill {
  height: 100%;
  background: var(--yellow);
  border-radius: 4px 0 0 4px;
  transition: width .35s ease;
  position: relative;
}
.ex-progress-fill::after {
  content: '';
  position: absolute;
  top: 2px; left: 4px; right: 4px;
  height: 3px;
  background: rgba(255,255,255,.45);
  border-radius: 2px;
}

/* Exercise body */
.ex-body {
  flex: 1;
  padding: var(--sp-5) var(--sp-4) var(--sp-7);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}


/* ═══════════════════════════════════════════════════════════
   SHARED EXERCISE — TYPOGRAPHY
   ═══════════════════════════════════════════════════════════ */
.question-prompt {
  font-size: .72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--gray-2);
  margin-bottom: var(--sp-3);
}


/* ═══════════════════════════════════════════════════════════
   R1 — DEFINITION MATCH
   ═══════════════════════════════════════════════════════════ */
.word-card {
  background: var(--surface);
  border: var(--px-border);
  border-radius: var(--radius);
  padding: var(--sp-6) var(--sp-5);
  margin-bottom: var(--sp-5);
  box-shadow: var(--px-shadow);
  text-align: center;
}

.word-title {
  font-size: 2.2rem;
  font-weight: 900;
  color: var(--dark);
  letter-spacing: -1px;
  line-height: 1.05;
  margin-bottom: var(--sp-2);
}

.word-meta {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--sp-2);
  margin-bottom: var(--sp-4);
  flex-wrap: wrap;
}
.word-pron {
  font-size: .82rem;
  color: var(--gray-2);
  font-style: italic;
}
.word-pos {
  font-size: .65rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--blue);
  background: var(--blue-l);
  padding: 3px 9px;
  border-radius: 20px;
  border: 1.5px solid var(--blue);
}

/* Speaker button — pixel-art Mario-style yellow block */
.btn-speak {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background: var(--yellow);
  color: var(--dark);
  border: var(--px-border);
  box-shadow: var(--px-shadow);
  border-radius: 4px;
  cursor: pointer;
  padding: 0;
  flex-shrink: 0;
  transition: transform .08s, box-shadow .08s;
}
.btn-speak:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 0 var(--dark);
}
.btn-speak.speaking {
  background: var(--green);
  color: #fff;
}

.word-def {
  font-size: .97rem;
  color: var(--gray-1);
  line-height: 1.6;
  font-weight: 400;
}
.word-def-2 {
  margin-top: var(--sp-3);
  padding-top: var(--sp-3);
  border-top: 1.5px solid var(--gray-5);
  color: var(--gray-2);
}

/* Synonym options */
.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-3);
  margin-bottom: var(--sp-4);
}

.option-btn {
  background: var(--surface);
  border: var(--px-border);
  border-radius: var(--radius-s);
  padding: var(--sp-4) var(--sp-3);
  font-size: .9rem;
  font-weight: 700;
  color: var(--dark);
  text-align: center;
  min-height: 56px;
  line-height: 1.3;
  box-shadow: var(--px-shadow-s);
  transition: transform .08s, box-shadow .08s;
}
.option-btn:not(:disabled):hover  { border-color: var(--blue); color: var(--blue); }
.option-btn:not(:disabled):active { transform: translate(2px,2px); box-shadow: 1px 1px 0 0 var(--dark); }
.option-btn:disabled { cursor: default; }

.option-btn.correct {
  background: var(--green-l);
  border-color: var(--green);
  color: #166534;
  box-shadow: 3px 3px 0 0 var(--green);
}
.option-btn.wrong {
  background: var(--red-l);
  border-color: var(--red);
  color: var(--red);
  box-shadow: 3px 3px 0 0 var(--red);
  animation: shake .35s ease;
}

/* Word detail reveal */
.word-detail-box {
  background: var(--bg);
  border: 2px solid var(--gray-4);
  border-radius: var(--radius-s);
  padding: var(--sp-4);
  margin-top: var(--sp-1);
  animation: fade-in .25s ease both;
}
.word-detail-box.hidden { display: none; }

.detail-row {
  display: flex;
  flex-direction: column;
  margin-bottom: var(--sp-3);
}
.detail-row:last-of-type { margin-bottom: var(--sp-4); }

.detail-label {
  font-size: .62rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--gray-3);
  margin-bottom: 3px;
}
.detail-val {
  font-size: .85rem;
  color: var(--gray-1);
  line-height: 1.55;
}
.detail-val em { color: var(--blue); font-style: normal; font-weight: 600; }
.wf-pos        { font-size: .65rem; color: var(--gray-2); }

/* Next button */
.btn-next {
  display: block;
  width: 100%;
  background: var(--dark);
  color: #fff;
  border: var(--px-border);
  border-radius: var(--radius-s);
  padding: var(--sp-4);
  font-size: .92rem;
  font-weight: 800;
  text-align: center;
  box-shadow: var(--px-shadow-s);
  transition: transform .08s, box-shadow .08s;
  letter-spacing: .01em;
}
.btn-next:active { transform: translate(2px,2px); box-shadow: 1px 1px 0 0 var(--dark); }


/* ═══════════════════════════════════════════════════════════
   R2 — TYPE SPELLING
   ═══════════════════════════════════════════════════════════ */
.definition-box {
  background: var(--surface);
  border: var(--px-border);
  border-radius: var(--radius);
  padding: var(--sp-5);
  font-size: .98rem;
  font-weight: 500;
  color: var(--dark);
  line-height: 1.65;
  box-shadow: var(--px-shadow);
  margin-bottom: var(--sp-5);
}
.definition-box-2 {
  margin-top: var(--sp-3);
  padding-top: var(--sp-3);
  border-top: 1.5px solid var(--gray-5);
  color: var(--gray-2);
}

.spelling-feedback {
  min-height: 28px;
  margin-bottom: var(--sp-2);
  font-size: .9rem;
}
.feedback-correct {
  color: var(--green);
  font-weight: 700;
  font-size: .97rem;
}

.input-row {
  display: flex;
  gap: var(--sp-2);
}
.spelling-input {
  flex: 1;
  background: var(--surface);
  border: var(--px-border);
  border-radius: var(--radius-s);
  padding: var(--sp-3) var(--sp-4);
  font-size: 1rem;
  font-weight: 700;
  color: var(--dark);
  min-height: 54px;
  transition: border-color .15s, box-shadow .15s;
  box-shadow: var(--px-shadow-s);
}
.spelling-input:focus {
  outline: none;
  border-color: var(--red);
  box-shadow: 3px 3px 0 0 var(--red);
}
.spelling-input.shake { animation: shake .35s ease; }

.btn-check {
  background: var(--red);
  color: #fff;
  border: var(--px-border);
  border-radius: var(--radius-s);
  padding: var(--sp-3) var(--sp-5);
  font-size: .88rem;
  font-weight: 800;
  min-height: 54px;
  letter-spacing: .02em;
  box-shadow: var(--px-shadow-s);
  flex-shrink: 0;
  transition: transform .08s, box-shadow .08s;
}
.btn-check:active   { transform: translate(2px,2px); box-shadow: 1px 1px 0 0 var(--dark); background: var(--red-d); }
.btn-check:disabled { background: var(--gray-4); color: var(--gray-3); cursor: default; box-shadow: none; }

.attempts-hint {
  font-size: .77rem;
  color: var(--gray-2);
  margin-top: var(--sp-2);
  min-height: 1.1em;
  font-weight: 500;
}
.attempts-hint.reveal {
  color: var(--red);
  font-weight: 700;
  font-size: .88rem;
}
.attempts-hint.reveal strong { color: var(--dark); }

/* Char-by-char feedback */
.char-compare {
  font-family: 'SF Mono', 'Courier New', monospace;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .1em;
}
.char-right   { color: var(--green); }
.char-wrong   { color: var(--red);    text-decoration: underline; }
.char-missing { color: var(--yellow); }
.char-hint    { font-size: .78rem; color: var(--gray-2); letter-spacing: 0; font-weight: 400; font-family: inherit; }


/* ═══════════════════════════════════════════════════════════
   R3 — CONTEXT TAP
   ═══════════════════════════════════════════════════════════ */
.context-sentence-wrap { margin-bottom: var(--sp-5); }

.context-sentence {
  background: var(--surface);
  border: var(--px-border);
  border-radius: var(--radius);
  padding: var(--sp-5);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--dark);
  box-shadow: var(--px-shadow);
}

.blank {
  display: inline-block;
  min-width: 90px;
  padding: 1px 8px;
  border-bottom: 3px solid var(--red);
  background: var(--red-l);
  border-radius: 4px;
  text-align: center;
  font-weight: 800;
  color: var(--red);
  transition: background .18s, color .18s, border-color .18s;
}
.blank.filled        { background: var(--bg);      color: var(--dark);  border-bottom-color: transparent; }
.blank.blank-correct { background: var(--green-l); color: #166534;      border-bottom-color: var(--green); }
.blank.blank-wrong   { background: var(--red-l);   color: var(--red);   border-bottom-color: var(--red);   animation: shake .35s ease; }

.chips-area {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
  justify-content: center;
}
.chip {
  background: var(--surface);
  border: var(--px-border);
  border-radius: 24px;
  padding: 11px var(--sp-5);
  font-size: .9rem;
  font-weight: 700;
  color: var(--dark);
  min-height: 50px;
  box-shadow: var(--px-shadow-s);
  transition: transform .08s, box-shadow .08s, background .12s;
}
.chip:not(:disabled):hover  { border-color: var(--blue); color: var(--blue); }
.chip:not(:disabled):active { transform: translate(2px,2px); box-shadow: 1px 1px 0 0 var(--dark); }
.chip:disabled { cursor: default; }
.chip.chip-correct { background: var(--green-l); border-color: var(--green); color: #166534; box-shadow: 3px 3px 0 0 var(--green); }
.chip.chip-wrong   { background: var(--red-l);   border-color: var(--red);   color: var(--red);   box-shadow: 3px 3px 0 0 var(--red);   animation: shake .35s ease; }


/* ═══════════════════════════════════════════════════════════
   R4 — CAMBRIDGE MCQ
   ═══════════════════════════════════════════════════════════ */
.cambridge-card {
  background: var(--surface);
  border: var(--px-border);
  border-left: 6px solid var(--blue);
  border-radius: var(--radius);
  padding: var(--sp-5);
  margin-bottom: var(--sp-5);
  box-shadow: var(--px-shadow);
}
.cambridge-tag {
  font-size: .64rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--blue);
  margin-bottom: var(--sp-3);
}
.cambridge-sentence {
  font-size: .97rem;
  line-height: 1.7;
  color: var(--dark);
}

.mcq-question {
  font-size: .88rem;
  color: var(--gray-1);
  margin-bottom: var(--sp-4);
  font-weight: 500;
}

.mcq-options {
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
}
.mcq-btn {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  background: var(--surface);
  border: var(--px-border);
  border-radius: var(--radius-s);
  padding: var(--sp-4);
  font-size: .88rem;
  color: var(--dark);
  text-align: left;
  min-height: 56px;
  line-height: 1.4;
  box-shadow: var(--px-shadow-s);
  transition: transform .08s, box-shadow .08s;
}
.mcq-btn:not(:disabled):hover  { border-color: var(--blue); }
.mcq-btn:not(:disabled):active { transform: translate(2px,2px); box-shadow: 1px 1px 0 0 var(--dark); }
.mcq-btn:disabled { cursor: default; }

.mcq-btn.mcq-correct { background: var(--green-l); border-color: var(--green); color: #166534; box-shadow: 3px 3px 0 0 var(--green); }
.mcq-btn.mcq-wrong   { background: var(--red-l);   border-color: var(--red);   color: var(--red);   box-shadow: 3px 3px 0 0 var(--red);   animation: shake .35s ease; }

.mcq-letter {
  font-weight: 900;
  font-size: .7rem;
  color: var(--gray-2);
  background: var(--bg);
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  border: 2px solid var(--gray-4);
  letter-spacing: .03em;
}
.mcq-btn.mcq-correct .mcq-letter { background: var(--green); color: #fff; border-color: var(--green); }
.mcq-btn.mcq-wrong   .mcq-letter { background: var(--red);   color: #fff; border-color: var(--red);   }
.mcq-text { flex: 1; font-weight: 500; }


/* ═══════════════════════════════════════════════════════════
   SCREEN 4 — ROUND RESULT
   ═══════════════════════════════════════════════════════════ */
.result-header {
  border: var(--px-border);
  border-radius: var(--radius);
  padding: var(--sp-7) var(--sp-5);
  text-align: center;
  margin-bottom: var(--sp-5);
  box-shadow: var(--px-shadow);
}
.result-header.result-pass { background: var(--green-l); border-color: var(--green); box-shadow: 4px 4px 0 0 var(--green); }
.result-header.result-fail { background: var(--yellow-l); border-color: var(--yellow); box-shadow: 4px 4px 0 0 var(--yellow); }

.result-score  { font-size: 3rem; font-weight: 900; letter-spacing: -2px; line-height: 1; margin-bottom: var(--sp-2); }
.result-status { font-size: 1.1rem; font-weight: 800; margin-bottom: var(--sp-1); letter-spacing: -.2px; }
.result-round  { font-size: .78rem; color: var(--gray-2); font-weight: 500; }

.result-pass .result-score, .result-pass .result-status { color: #166534; }
.result-fail .result-score, .result-fail .result-status { color: #7A4F00; }

.result-missed {
  background: var(--surface);
  border: 2px solid var(--gray-4);
  border-radius: var(--radius);
  padding: var(--sp-4);
  margin-bottom: var(--sp-5);
}
.result-missed h3 {
  font-size: .68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--gray-2);
  margin-bottom: var(--sp-3);
}
.missed-list { display: flex; flex-direction: column; gap: var(--sp-3); }
.missed-item {
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--gray-5);
}
.missed-item:last-child { border-bottom: none; padding-bottom: 0; }
.missed-word { font-weight: 800; font-size: .9rem; display: block; }
.missed-def  { font-size: .8rem; color: var(--gray-2); margin-top: 2px; display: block; }

.perfect-msg {
  text-align: center;
  font-weight: 700;
  color: var(--green);
  margin-bottom: var(--sp-5);
  font-size: .95rem;
}


/* ═══════════════════════════════════════════════════════════
   SCREEN 5 — R5 DASHBOARD REPORT
   ═══════════════════════════════════════════════════════════ */
.report-header {
  border: var(--px-border);
  border-radius: var(--radius);
  padding: var(--sp-7) var(--sp-5);
  text-align: center;
  margin-bottom: var(--sp-5);
  box-shadow: var(--px-shadow);
}
.report-header.report-pass { background: var(--green-l); border-color: var(--green); box-shadow: 4px 4px 0 0 var(--green); }
.report-header.report-fail { background: var(--yellow-l); border-color: var(--yellow); box-shadow: 4px 4px 0 0 var(--yellow); }

.report-score  { font-size: 3rem; font-weight: 900; letter-spacing: -2px; line-height: 1; margin-bottom: var(--sp-2); }
.report-status { font-size: 1.1rem; font-weight: 800; margin-bottom: var(--sp-1); letter-spacing: -.2px; }
.report-label  { font-size: .78rem; color: var(--gray-2); font-weight: 500; }

.report-pass .report-score, .report-pass .report-status { color: #166534; }
.report-fail .report-score, .report-fail .report-status { color: #7A4F00; }

.report-section {
  background: var(--surface);
  border: 2px solid var(--gray-4);
  border-radius: var(--radius);
  padding: var(--sp-4);
  margin-bottom: var(--sp-4);
}

.section-title {
  font-size: .68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  margin-bottom: var(--sp-3);
}
.section-mastered { color: var(--green); }
.section-review   { color: var(--red);   }

.word-pill-row { display: flex; flex-wrap: wrap; gap: var(--sp-2); }
.word-pill {
  font-size: .8rem;
  font-weight: 700;
  padding: 5px 12px;
  border-radius: 20px;
  border: 2px solid transparent;
}
.pill-green { background: var(--green-l); color: #166534; border-color: var(--green); }

.review-rows { display: flex; flex-direction: column; gap: var(--sp-3); }
.review-row {
  padding-bottom: var(--sp-3);
  border-bottom: 1px solid var(--gray-5);
}
.review-row:last-child { border-bottom: none; padding-bottom: 0; }
.review-word { font-weight: 800; font-size: .9rem; display: block; }
.review-def  { font-size: .8rem; color: var(--gray-2); margin-top: 2px; display: block; }


/* ═══════════════════════════════════════════════════════════
   SHARED BUTTONS — Mario block press style
   ═══════════════════════════════════════════════════════════ */
.btn-primary, .btn-secondary, .btn-ghost {
  display: block;
  width: 100%;
  padding: var(--sp-4) var(--sp-5);
  border-radius: var(--radius-s);
  font-size: .92rem;
  font-weight: 800;
  text-align: center;
  letter-spacing: .01em;
  transition: transform .08s, box-shadow .08s;
}
.btn-primary {
  background: var(--red);
  color: #fff;
  border: var(--px-border);
  box-shadow: var(--px-shadow-s);
}
.btn-primary:active { background: var(--red-d); transform: translate(2px,2px); box-shadow: 1px 1px 0 0 var(--dark); }

.btn-secondary {
  background: var(--surface);
  color: var(--red);
  border: var(--px-border);
  box-shadow: var(--px-shadow-s);
}
.btn-secondary:active { transform: translate(2px,2px); box-shadow: 1px 1px 0 0 var(--dark); }

.btn-ghost {
  background: transparent;
  color: var(--gray-2);
  border: 2px solid var(--gray-4);
  box-shadow: none;
  font-weight: 600;
}
.btn-ghost:hover  { border-color: var(--gray-2); color: var(--dark); }
.btn-ghost:active { opacity: .7; }

.result-actions, .report-actions {
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  margin-top: var(--sp-2);
}


/* ═══════════════════════════════════════════════════════════
   LOADING & ERROR STATES
   ═══════════════════════════════════════════════════════════ */
.loading-msg {
  text-align: center;
  color: var(--gray-2);
  padding: var(--sp-7) var(--sp-5);
  font-size: .9rem;
  font-weight: 500;
}
.error-msg {
  background: var(--red-l);
  border: 2px solid var(--red);
  border-radius: var(--radius);
  padding: var(--sp-5);
  margin: var(--sp-4);
  font-size: .88rem;
  color: var(--red);
  line-height: 1.6;
  text-align: center;
}


/* ═══════════════════════════════════════════════════════════
   ANIMATIONS
   ═══════════════════════════════════════════════════════════ */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  18%       { transform: translateX(-8px); }
  36%       { transform: translateX(8px); }
  54%       { transform: translateX(-5px); }
  72%       { transform: translateX(5px); }
  90%       { transform: translateX(-2px); }
}

@keyframes fade-in {
  from { opacity: 0; transform: translateY(7px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes pop-in {
  0%   { opacity: 0; transform: scale(.82); }
  65%  { transform: scale(1.04); }
  100% { opacity: 1; transform: scale(1); }
}

.animate-in { animation: fade-in .22s ease both; }


/* ═══════════════════════════════════════════════════════════
   RESPONSIVE — TABLET  768px+
   ═══════════════════════════════════════════════════════════ */
@media (min-width: 768px) {
  .app-header   { padding: var(--sp-5) var(--sp-6) var(--sp-4); }
  .app-title    { font-size: 1.6rem; }
  .lesson-grid  { padding: var(--sp-6) var(--sp-6) var(--sp-8); }

  .word-title   { font-size: 2.6rem; }
  .options-grid { gap: var(--sp-4); }
  .option-btn   { font-size: .95rem; min-height: 60px; }

  .mcq-btn      { font-size: .92rem; min-height: 60px; }

  .ex-body { padding: var(--sp-6) var(--sp-6) var(--sp-8); }
  .screen-inner { padding: 0 var(--sp-6) var(--sp-8); }
}


/* ═══════════════════════════════════════════════════════════
   RESPONSIVE — DESKTOP  1024px+
   ═══════════════════════════════════════════════════════════ */
@media (min-width: 1024px) {
  /* Full-width header */
  .app-header { padding: var(--sp-5) var(--sp-8) var(--sp-4); }
  .app-title  { font-size: 1.7rem; }

  /* Unit grid: 2 columns with more breathing room */
  .lesson-grid {
    grid-template-columns: 1fr 1fr;
    max-width: 1100px;
    padding: var(--sp-7) var(--sp-8) var(--sp-8);
    gap: var(--sp-5);
  }

  /* Exercise: wider, more breathing room */
  .exercise-shell { max-width: 820px; }
  .ex-body { padding: var(--sp-7) var(--sp-8) var(--sp-8); }

  /* Word card gets more space */
  .word-card { padding: var(--sp-7) var(--sp-8); }
  .word-title { font-size: 3rem; }

  /* R4: sentence card + MCQ side-by-side */
  .r4-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-5);
    align-items: start;
  }
  .r4-layout .cambridge-card   { margin-bottom: 0; }
  .r4-layout .mcq-question     { margin-top: var(--sp-2); }

  .screen-inner { max-width: 720px; }
  .result-header, .report-header { padding: var(--sp-8); }
  .result-score, .report-score   { font-size: 3.5rem; }
}


/* ═══════════════════════════════════════════════════════════
   RESPONSIVE — LARGE DESKTOP  1280px+
   ═══════════════════════════════════════════════════════════ */
@media (min-width: 1280px) {
  .lesson-grid  { max-width: 1200px; padding: var(--sp-7) var(--sp-8) var(--sp-8); }
}


/* ═══════════════════════════════════════════════════════════
   MARIO TRACK — R5 Mini Test progress bar
   Replaces the standard gold bar with a pixel-art course.
   Mario moves right on correct answers, shakes on wrong.
   ═══════════════════════════════════════════════════════════ */

/* Override the standard bar dimensions & style */
.ex-progress-bar.mario-track-active {
  height: 60px !important;
  background: #5B9BD5;          /* Mario sky blue              */
  border: 2px solid var(--dark);
  border-radius: var(--radius-s);
  overflow: hidden;
  position: relative;
  margin-bottom: var(--sp-3);
}

/* Brick ground strip */
.mt-ground {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 18px;
  border-top: 2px solid var(--dark);
  /* Brick rows: horizontal mortar lines + vertical joints */
  background:
    repeating-linear-gradient(
      90deg,
      transparent 0,  transparent 23px,
      rgba(0,0,0,.22) 23px, rgba(0,0,0,.22) 25px
    ),
    repeating-linear-gradient(
      0deg,
      transparent 0,  transparent 8px,
      rgba(0,0,0,.12) 8px,  rgba(0,0,0,.12) 9px
    ),
    #C84B0C;
}

/* Cloud decoration in the sky (pure CSS) */
.mario-track-active::before {
  content: '';
  position: absolute;
  top: 6px;
  left: 15%;
  width: 36px;
  height: 12px;
  background: rgba(255,255,255,.75);
  border-radius: 8px;
  box-shadow: 50px 4px 0 rgba(255,255,255,.6), 100px 0px 0 rgba(255,255,255,.5);
}

/* Mario figure */
.mt-runner {
  position: absolute;
  bottom: 18px;              /* sits on top of the ground     */
  left: 3%;
  transform-origin: bottom center;
  transition: left .45s cubic-bezier(.34, 1.56, .64, 1);  /* springy forward move */
  line-height: 0;
  z-index: 2;
}

/* Correct answer: Mario jumps */
.mt-runner.mt-jump {
  animation: mt-jump .45s ease;
}

/* Wrong answer: Mario shakes in place */
.mt-runner.mt-wrong {
  animation: mt-wrong .42s ease;
}

/* Perfect score: Mario does a victory dance */
.mt-runner.mt-victory {
  animation: mt-victory .65s ease 3;
}

/* Finish flag */
.mt-flag {
  position: absolute;
  bottom: 18px;
  right: 8px;
  line-height: 0;
  z-index: 2;
}

/* "GOAL" ground marker under the flag */
.mt-flag::after {
  content: 'GOAL';
  display: block;
  font-size: .48rem;
  font-weight: 900;
  letter-spacing: .08em;
  color: var(--dark);
  text-align: center;
  margin-top: 2px;
}

/* ── Mario track keyframes ── */

@keyframes mt-jump {
  0%   { transform: translateY(0)      scaleX(1);    }
  30%  { transform: translateY(-22px)  scaleX(1.08); }
  65%  { transform: translateY(-22px)  scaleX(1);    }
  85%  { transform: translateY(-3px)   scaleX(1);    }
  100% { transform: translateY(0)      scaleX(1);    }
}

@keyframes mt-wrong {
  0%,100% { transform: translateX(0)    rotate(0);    }
  20%     { transform: translateX(-5px) rotate(-8deg);}
  50%     { transform: translateX(5px)  rotate(8deg); }
  75%     { transform: translateX(-3px) rotate(-4deg);}
}

@keyframes mt-victory {
  0%,100% { transform: translateY(0)     rotate(0);     }
  25%     { transform: translateY(-18px) rotate(-12deg);}
  75%     { transform: translateY(-18px) rotate(12deg); }
}