/* ── LAYOUT ── */
.app {
  max-width: 1360px;
  margin: 0 auto;
  padding: 0 2rem 5rem;
}

/* ── HERO ── */
.hero {
  text-align: center;
  padding: 3.5rem 1rem 2.5rem;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -80px; left: 50%;
  transform: translateX(-50%);
  width: 600px; height: 300px;
  background: radial-gradient(ellipse at center, rgba(99,102,241,.22) 0%, transparent 70%);
  filter: blur(40px);
  pointer-events: none;
}
.hero-logo {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(2.5rem, 5vw, 3.6rem);
  font-weight: 700;
  background: linear-gradient(135deg, #a78bfa 0%, #818cf8 40%, #c4b5fd 80%, #e0d7ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -.03em;
  line-height: 1;
  animation: fadeSlideDown .7s ease both;
}
.hero-sub {
  font-size: .82rem;
  font-weight: 500;
  color: var(--text-3);
  letter-spacing: .22em;
  text-transform: uppercase;
  margin-top: .6rem;
  animation: fadeSlideDown .9s ease both;
}
.hero-line {
  height: 1px;
  background: linear-gradient(to right, transparent, #7c3aed, #818cf8, transparent);
  margin: 1.6rem auto 0;
  animation: expandLine 1s ease both;
}

/* ── GRID ── */
.main-grid {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 1.75rem;
  align-items: start;
  margin-top: 2rem;
}
@media (max-width: 860px) {
  .main-grid { grid-template-columns: 1fr; }
}

/* ── GLASS PANEL ── */
.glass-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 1.75rem;
  margin-bottom: 1.25rem;
  backdrop-filter: blur(12px);
  position: relative;
  overflow: hidden;
  animation: fadeIn .5s ease both;
  transition: border-color .3s, box-shadow .3s;
}
.glass-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(139,92,246,.06) 0%, transparent 60%);
  pointer-events: none;
}
.glass-panel:hover {
  border-color: var(--border-h);
  box-shadow: 0 8px 40px rgba(99,102,241,.1);
}

/* ── STEP HEADER ── */
.step-header {
  display: flex;
  align-items: center;
  gap: .875rem;
  margin-bottom: 1.4rem;
}
.step-badge {
  width: 32px; height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(99,102,241,.3), rgba(139,92,246,.2));
  border: 1px solid rgba(139,92,246,.45);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'JetBrains Mono', monospace;
  font-size: .65rem;
  color: var(--violet-l);
  flex-shrink: 0;
  animation: pulse-glow 3s ease-in-out infinite;
}
.step-title {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.2rem;
  font-weight: 600;
  color: #ede9fe;
  letter-spacing: -.01em;
}

/* ── STATUS CHIP ── */
.status-chip {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .3rem .9rem;
  border-radius: 100px;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  margin: .75rem 0 .25rem;
}
.chip-ready {
  background: rgba(52,211,153,.12);
  border: 1px solid rgba(52,211,153,.3);
  color: var(--green-l);
}
.chip-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--green);
  animation: dot-pulse 2s ease-in-out infinite;
}

/* ── FILE DROP ZONE ── */
.drop-zone {
  border: 1.5px dashed rgba(139,92,246,.3);
  border-radius: 14px;
  background: rgba(99,102,241,.04);
  padding: 2rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color .3s, background .3s, box-shadow .3s;
  position: relative;
  overflow: hidden;
}
.drop-zone:hover,
.drop-zone.dragging {
  border-color: rgba(139,92,246,.6);
  background: rgba(99,102,241,.09);
  box-shadow: 0 0 24px rgba(99,102,241,.12);
}
.drop-zone input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
  z-index: 2;
}
.drop-icon {
  font-size: 2rem;
  margin-bottom: .75rem;
  opacity: .5;
}
.drop-title {
  font-size: .88rem;
  font-weight: 600;
  color: var(--text-3);
  margin-bottom: .3rem;
}
.drop-sub {
  font-size: .72rem;
  color: var(--text-4);
  letter-spacing: .08em;
  text-transform: uppercase;
}
.file-chosen {
  display: flex;
  align-items: center;
  gap: .75rem;
  background: rgba(139,92,246,.08);
  border: 1px solid rgba(139,92,246,.25);
  border-radius: 10px;
  padding: .65rem 1rem;
  margin-top: .75rem;
}
.file-chosen-icon { font-size: 1.2rem; }
.file-chosen-name {
  font-size: .85rem;
  color: var(--violet-l);
  font-weight: 500;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  flex: 1;
}
.file-chosen-size { font-size: .72rem; color: var(--text-3); white-space: nowrap; }

/* ── FORM CONTROLS ── */
.form-group { margin-bottom: 1rem; }
.form-label {
  display: block;
  font-size: .7rem;
  font-weight: 700;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: .12em;
  margin-bottom: .45rem;
}
.form-input,
.form-select {
  width: 100%;
  background: rgba(255,255,255,.04);
  border: 1px solid rgba(139,92,246,.22);
  border-radius: 10px;
  color: var(--text);
  font-family: 'Inter', sans-serif;
  font-size: .9rem;
  padding: .6rem .9rem;
  outline: none;
  transition: border-color .25s, box-shadow .25s;
  appearance: none;
  -webkit-appearance: none;
}
.form-input:focus,
.form-select:focus {
  border-color: rgba(139,92,246,.55);
  box-shadow: 0 0 0 3px rgba(99,102,241,.12);
}
.form-select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' fill='none'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%236d6a8a' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right .85rem center;
  padding-right: 2.2rem;
  cursor: pointer;
}
.form-select option { background: #1a1730; }
.form-number-wrap { position: relative; }
.form-number-wrap input[type="number"] {
  padding-right: 2.5rem;
  -moz-appearance: textfield;
}
.form-number-wrap input[type="number"]::-webkit-inner-spin-button,
.form-number-wrap input[type="number"]::-webkit-outer-spin-button { -webkit-appearance: none; }
.num-btns {
  position: absolute;
  right: 0; top: 0; bottom: 0;
  display: flex;
  flex-direction: column;
  border-left: 1px solid rgba(139,92,246,.18);
}
.num-btn {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--text-3);
  cursor: pointer;
  font-size: .6rem;
  padding: 0 .55rem;
  transition: color .2s, background .2s;
  line-height: 1;
}
.num-btn:hover { color: var(--violet-l); background: rgba(139,92,246,.1); }
.num-btn:first-child { border-bottom: 1px solid rgba(139,92,246,.18); border-radius: 0 8px 0 0; }
.num-btn:last-child  { border-radius: 0 0 8px 0; }

/* ── BUTTONS ── */
.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  width: 100%;
  font-family: 'Inter', sans-serif;
  font-size: .87rem;
  font-weight: 600;
  letter-spacing: .04em;
  border-radius: 10px;
  border: 1px solid rgba(139,92,246,.4);
  background: linear-gradient(135deg, rgba(99,102,241,.18), rgba(139,92,246,.12));
  color: var(--violet-ll);
  padding: .7rem 1.5rem;
  cursor: pointer;
  transition: transform .22s, box-shadow .22s, background .22s, border-color .22s, color .22s;
  position: relative;
  overflow: hidden;
}
.btn:hover:not(:disabled) {
  border-color: rgba(139,92,246,.7);
  background: linear-gradient(135deg, rgba(99,102,241,.28), rgba(139,92,246,.22));
  color: #ede9fe;
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(99,102,241,.22);
}
.btn:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: 0 2px 8px rgba(99,102,241,.15);
}
.btn:disabled {
  opacity: .45;
  cursor: not-allowed;
}
.btn-ghost {
  background: transparent;
  border-color: rgba(139,92,246,.2);
  color: var(--text-3);
  font-size: .82rem;
}
.btn-ghost:hover:not(:disabled) {
  background: rgba(139,92,246,.08);
  border-color: rgba(139,92,246,.4);
  color: var(--text-2);
  box-shadow: none;
}
.btn-danger {
  border-color: rgba(239,68,68,.3);
  background: rgba(239,68,68,.08);
  color: #fca5a5;
}
.btn-danger:hover:not(:disabled) {
  border-color: rgba(239,68,68,.6);
  background: rgba(239,68,68,.15);
  color: #fee2e2;
  box-shadow: 0 6px 24px rgba(239,68,68,.15);
}

/* spinner inside btn */
.btn-spinner {
  width: 14px; height: 14px;
  border: 2px solid rgba(196,181,253,.3);
  border-top-color: #c4b5fd;
  border-radius: 50%;
  animation: spin .7s linear infinite;
}

/* ── DIVIDER ── */
.divider {
  border: none;
  border-top: 1px solid rgba(139,92,246,.1);
  margin: 1rem 0;
}

/* ── QUESTION CARD ── */
.q-card {
  background: rgba(255,255,255,.025);
  border: 1px solid rgba(139,92,246,.14);
  border-radius: 14px;
  padding: 1.4rem 1.6rem;
  margin-bottom: 1.1rem;
  position: relative;
  overflow: hidden;
  transition: border-color .25s, box-shadow .25s;
  animation: fadeIn .4s ease both;
}
.q-card::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(to right, transparent, rgba(139,92,246,.3), transparent);
}
.q-card:hover {
  border-color: rgba(139,92,246,.3);
  box-shadow: 0 4px 24px rgba(99,102,241,.08);
}
.q-index {
  font-family: 'JetBrains Mono', monospace;
  font-size: .63rem;
  color: #7c3aed;
  letter-spacing: .18em;
  text-transform: uppercase;
  margin-bottom: .4rem;
}
.q-text {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1rem;
  font-weight: 500;
  color: #ede9fe;
  line-height: 1.65;
  margin-bottom: 1rem;
}

/* ── RADIO OPTIONS ── */
.radio-group { display: flex; flex-direction: column; gap: .45rem; }
.radio-option {
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: .6rem .85rem;
  border-radius: 9px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .2s, border-color .2s;
}
.radio-option:hover { background: rgba(139,92,246,.08); border-color: rgba(139,92,246,.25); }
.radio-option.selected {
  background: rgba(99,102,241,.12);
  border-color: rgba(99,102,241,.4);
}
.radio-circle {
  width: 17px; height: 17px;
  border-radius: 50%;
  border: 2px solid rgba(139,92,246,.4);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: border-color .2s;
}
.radio-option.selected .radio-circle { border-color: var(--indigo); }
.radio-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--indigo);
  transform: scale(0);
  transition: transform .2s;
}
.radio-option.selected .radio-dot { transform: scale(1); }
.radio-label {
  font-size: .9rem;
  color: var(--text-2);
  transition: color .2s;
}
.radio-option.selected .radio-label { color: var(--text); }

/* ── ALERTS ── */
.alert {
  display: flex;
  align-items: flex-start;
  gap: .65rem;
  padding: .8rem 1rem;
  border-radius: 10px;
  font-size: .86rem;
  line-height: 1.5;
  margin-bottom: 1rem;
  border-left: 3px solid;
  animation: fadeIn .3s ease both;
}
.alert-warning {
  background: rgba(245,158,11,.08);
  border-color: var(--amber);
  color: #fcd34d;
}
.alert-error {
  background: rgba(239,68,68,.08);
  border-color: var(--red);
  color: var(--red-l);
}
.alert-success {
  background: rgba(52,211,153,.08);
  border-color: var(--green);
  color: var(--green-l);
}

/* ── SCORE HERO ── */
.score-wrap {
  text-align: center;
  padding: 2.5rem 1rem 2rem;
  position: relative;
}
.score-wrap::before {
  content: '';
  position: absolute;
  top: 0; left: 50%;
  transform: translateX(-50%);
  width: 400px; height: 200px;
  background: radial-gradient(ellipse at center, rgba(99,102,241,.2) 0%, transparent 70%);
  filter: blur(30px);
  pointer-events: none;
}
.score-num {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(4rem, 10vw, 6rem);
  font-weight: 700;
  background: linear-gradient(135deg, #a78bfa 0%, #818cf8 50%, #e0d7ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  animation: fadeSlideDown .6s ease both;
}
.score-denom {
  font-size: .4em;
  color: var(--text-4);
  -webkit-text-fill-color: var(--text-4);
}
.score-label-text {
  font-size: .78rem;
  font-weight: 700;
  color: var(--text-4);
  text-transform: uppercase;
  letter-spacing: .2em;
  margin-top: .4rem;
}
.score-bar-bg {
  background: rgba(255,255,255,.06);
  border-radius: 100px;
  height: 6px;
  margin: 1.5rem auto;
  max-width: 320px;
  overflow: hidden;
}
.score-bar-fill {
  height: 100%;
  border-radius: 100px;
  background: linear-gradient(to right, #7c3aed, #6366f1, #a78bfa);
  width: 0%;
  transition: width 1.2s cubic-bezier(.4,0,.2,1);
}
.score-msg {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--text-3);
  font-style: italic;
}

/* ── RESULT CARDS ── */
.r-card {
  border-radius: 14px;
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
  border: 1px solid;
  position: relative;
  overflow: hidden;
  animation: fadeIn .4s ease both;
}
.r-correct {
  background: rgba(52,211,153,.05);
  border-color: rgba(52,211,153,.22);
}
.r-incorrect {
  background: rgba(239,68,68,.05);
  border-color: rgba(239,68,68,.22);
}
.r-badge {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  padding: .18rem .65rem;
  border-radius: 100px;
  margin-bottom: .65rem;
}
.badge-ok  { background: rgba(52,211,153,.12); color: var(--green-l); border: 1px solid rgba(52,211,153,.3); }
.badge-no  { background: rgba(239,68,68,.12);  color: var(--red-l);   border: 1px solid rgba(239,68,68,.3); }
.r-question {
  font-family: 'Space Grotesk', sans-serif;
  font-size: .96rem;
  font-weight: 500;
  color: #ede9fe;
  line-height: 1.6;
  margin-bottom: .7rem;
}
.answer-grid {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
  margin-bottom: .6rem;
}
.a-label {
  font-size: .65rem;
  font-weight: 700;
  color: var(--text-4);
  text-transform: uppercase;
  letter-spacing: .14em;
  margin-bottom: .2rem;
}
.a-val-wrong { font-family: 'JetBrains Mono', monospace; font-size: .87rem; color: var(--red-l); }
.a-val-right { font-family: 'JetBrains Mono', monospace; font-size: .87rem; color: var(--violet-l); }
.concept-pill {
  display: inline-block;
  font-size: .66rem;
  font-weight: 600;
  color: var(--text-3);
  border: 1px solid rgba(139,92,246,.2);
  border-radius: 100px;
  padding: .14rem .6rem;
  margin-top: .45rem;
  letter-spacing: .08em;
}
.expl-box {
  background: rgba(99,102,241,.07);
  border-left: 2px solid rgba(99,102,241,.4);
  border-radius: 0 10px 10px 0;
  padding: .7rem 1rem;
  margin-top: .7rem;
}
.expl-label { font-size: .65rem; font-weight: 700; color: var(--text-3); text-transform: uppercase; letter-spacing: .15em; margin-bottom: .28rem; }
.expl-text  { font-size: .86rem; color: var(--text-2); line-height: 1.7; font-style: italic; }

/* ── EMPTY STATE ── */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 420px;
  text-align: center;
  animation: fadeIn .6s ease both;
}
.empty-icon  { font-size: 3.2rem; margin-bottom: 1.2rem; opacity: .18; filter: grayscale(1); }
.empty-title { font-family: 'Space Grotesk', sans-serif; font-size: 1.1rem; font-weight: 500; color: var(--text-4); font-style: italic; margin-bottom: .45rem; }
.empty-sub   { font-size: .74rem; font-weight: 600; color: #2d2b40; text-transform: uppercase; letter-spacing: .12em; }

/* ── LOADING OVERLAY ── */
.loading-spinner {
  width: 36px; height: 36px;
  border: 3px solid rgba(139,92,246,.2);
  border-top-color: var(--violet-l);
  border-radius: 50%;
  animation: spin .8s linear infinite;
  margin: 0 auto 1rem;
}
.loading-text {
  font-size: .88rem;
  color: var(--text-3);
  text-align: center;
  font-style: italic;
}

/* ── TEXT ANSWER ── */
.text-answer {
  width: 100%;
  background: rgba(255,255,255,.04);
  border: 1px solid rgba(139,92,246,.22);
  border-radius: 10px;
  color: var(--text);
  font-family: 'Inter', sans-serif;
  font-size: .9rem;
  padding: .6rem .9rem;
  outline: none;
  resize: vertical;
  min-height: 70px;
  transition: border-color .25s, box-shadow .25s;
}
.text-answer:focus {
  border-color: rgba(139,92,246,.55);
  box-shadow: 0 0 0 3px rgba(99,102,241,.12);
}
.text-answer::placeholder { color: var(--text-4); }

/* ── PROGRESS BAR (quiz progress) ── */
.quiz-progress-wrap { margin-bottom: 1.25rem; }
.quiz-progress-label {
  display: flex;
  justify-content: space-between;
  font-size: .7rem;
  font-weight: 600;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: .1em;
  margin-bottom: .45rem;
}
.quiz-progress-bar-bg {
  background: rgba(255,255,255,.06);
  border-radius: 100px;
  height: 4px;
  overflow: hidden;
}
.quiz-progress-bar-fill {
  height: 100%;
  border-radius: 100px;
  background: linear-gradient(to right, #7c3aed, #6366f1, #a78bfa);
  transition: width .5s ease;
}

/* ── SPACER ── */
.spacer { height: 1rem; }
.spacer-sm { height: .5rem; }
.spacer-lg { height: 2rem; }

/* ── RESPONSIVENESS & MEDIA QUERIES ── */

/* Tablets and below (max-width: 1024px) */
@media (max-width: 1024px) {
  .app {
    padding: 0 1.5rem 4rem;
  }
  .main-grid {
    gap: 1.25rem;
    margin-top: 1.5rem;
  }
  .glass-panel {
    padding: 1.5rem;
  }
}

/* Small tablets / landscape phones (max-width: 860px) */
@media (max-width: 860px) {
  .app {
    padding: 0 1.25rem 3.5rem;
  }
  .hero {
    padding: 2.5rem 1rem 1.75rem;
  }
  .hero-logo {
    font-size: clamp(2rem, 6vw, 3rem);
  }
  .main-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }
  .glass-panel {
    padding: 1.25rem;
    margin-bottom: 1rem;
  }
  .q-card {
    padding: 1.2rem 1.35rem;
  }
  .r-card {
    padding: 1.1rem 1.35rem;
  }
  .answer-grid {
    gap: 1.25rem;
  }
}

/* Phones (max-width: 480px) */
@media (max-width: 480px) {
  html, body {
    overflow-x: hidden;
  }
  .app {
    padding: 0 0.75rem 2.5rem;
    overflow-x: hidden;
    max-width: 100%;
  }
  .hero {
    padding: 2rem 0.25rem 1.25rem;
  }
  .hero-logo {
    font-size: 2.2rem;
  }
  .hero-sub {
    font-size: 0.68rem;
    letter-spacing: 0.12em;
    padding: 0 0.5rem;
  }
  .glass-panel {
    padding: 1rem;
    border-radius: 14px;
  }
  .step-header {
    margin-bottom: 1rem;
  }
  .step-title {
    font-size: 1.1rem;
  }
  .step-badge {
    width: 28px;
    height: 28px;
    font-size: 0.6rem;
  }
  .drop-zone {
    padding: 1.5rem 0.75rem;
  }
  .drop-icon {
    font-size: 1.6rem;
    margin-bottom: 0.5rem;
  }
  .drop-title {
    font-size: 0.82rem;
  }
  .drop-sub {
    font-size: 0.68rem;
  }
  .q-card {
    padding: 1rem;
    border-radius: 12px;
  }
  .r-card {
    padding: 1rem;
    border-radius: 12px;
  }
  .q-text {
    font-size: 0.95rem;
    line-height: 1.55;
  }
  .radio-option {
    padding: 0.55rem 0.75rem;
    gap: 0.65rem;
  }
  .radio-label {
    font-size: 0.86rem;
  }
  .answer-grid {
    flex-direction: column;
    gap: 0.85rem;
  }
  .score-num {
    font-size: 4.5rem;
  }
  .score-msg {
    font-size: 0.95rem;
  }
  .btn {
    padding: 0.65rem 1.25rem;
    font-size: 0.84rem;
  }
  .empty-state {
    min-height: 280px;
  }
}