:root {
--bg: #090910;
--panel: rgba(24, 24, 36, 0.88);
--panel-2: rgba(32, 33, 49, 0.88);
--text: #f4f4ff;
--muted: #a7a9c2;
--accent: #8b7bff;
--accent-2: #f7c948;
--success: #4ade80;
--danger: #fb7185;
--border: rgba(255,255,255,0.08);
--shadow: 0 18px 40px rgba(0,0,0,0.35);
--radius: 20px;
}

* { box-sizing: border-box; }

body {
margin: 0;
font-family: "DM Sans", sans-serif;
background:
radial-gradient(circle at 20% 20%, rgba(139,123,255,0.18), transparent 20%),
radial-gradient(circle at 80% 10%, rgba(90,220,255,0.16), transparent 18%),
radial-gradient(circle at 50% 80%, rgba(247,201,72,0.06), transparent 22%),
linear-gradient(180deg, #11111a, #07070c);
color: var(--text);
min-height: 100vh;
overflow-x: hidden;
}

.stars {
position: fixed;
inset: 0;
pointer-events: none;
background-image:
radial-gradient(2px 2px at 20px 30px, rgba(255,255,255,0.9), transparent),
radial-gradient(1px 1px at 80px 90px, rgba(255,255,255,0.7), transparent),
radial-gradient(1px 1px at 140px 140px, rgba(255,255,255,0.8), transparent),
radial-gradient(2px 2px at 200px 60px, rgba(255,255,255,0.7), transparent),
radial-gradient(1px 1px at 300px 120px, rgba(255,255,255,0.75), transparent);
background-size: 320px 180px;
opacity: 0.5;
z-index: 0;
}

.app {
position: relative;
z-index: 1;
min-height: 100vh;
display: flex;
flex-direction: column;
}

.header {
padding: 0 20px 0;
transform: translateY(-67px);
}

.header-inner,
.hero,
.topic-grid,
.badges-panel,
.practice-header,
.question-card,
.results-card,
.footer {
width: min(1100px, calc(100% - 32px));
margin: 0 auto;
}

.header-inner {
display: flex;
justify-content: space-between;
align-items: center;
gap: 16px;
}

.logo {
display: flex;
align-items: center;
gap: 8px;
}

.logo-icon {
width: 300px;
height: auto;
display: block;
}

.header-stats {
display: flex;
gap: 12px;
}

.stat-pill {
background: rgba(255,255,255,0.05);
border: 1px solid var(--border);
border-radius: 999px;
padding: 10px 14px;
min-width: 82px;
text-align: center;
box-shadow: var(--shadow);
backdrop-filter: blur(8px);
}

.stat-label {
display: block;
font-size: 0.7rem;
color: var(--muted);
text-transform: uppercase;
letter-spacing: 0.08em;
}

.stat-value {
display: block;
font-size: 1.1rem;
margin-top: 2px;
font-weight: 700;
}

.main {
padding: 12px 0 20px;
margin-top: 100px;
}

.hero {
display: grid;
grid-template-columns: 1.3fr 0.7fr;
gap: 20px;
align-items: center;
margin: 0 auto -240px;
min-height: auto;
padding-top: 10px;
}

.hero-copy {
display: flex;
flex-direction: column;
justify-content: center;

transform: translateY(-250px);
}

.hero h2 {
font-family: "Space Grotesk", sans-serif;
font-size: clamp(2rem, 4vw, 3.3rem);
margin: 0 0 12px;
}

.hero p {
max-width: 760px;
margin: 0;
color: var(--muted);
font-size: 1.05rem;
line-height: 1.7;
}

.hero-art {
position: relative;
min-height: 220px;

transform: translateY(-275px);
}

.study-blob {
position: absolute;
top: 20px;
left: 10px;
width: 100px;
height: 100px;
border-radius: 28px;
display: grid;
place-items: center;
font-size: 2.4rem;
background: rgba(139,123,255,0.18);
border: 1px solid rgba(139,123,255,0.32);
box-shadow: var(--shadow);
animation: floaty 4s ease-in-out infinite;
}

.blob-2 {
left: 120px;
top: 80px;
animation-delay: 0.8s;
}

.blob-3 {
left: 40px;
top: 130px;
animation-delay: 1.5s;
}

@keyframes floaty {
0%, 100% { transform: translateY(0px); }
50% { transform: translateY(-10px); }
}

.subject-selector {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto 40px;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0;
  border-bottom: 2px solid rgba(255,255,255,0.12);
}

.subject-tab {
  position: relative;
  background: none;
  border: none;
  padding: 14px 40px;
  font-size: 1.05rem;
  font-weight: 700;
  color: #777;
  cursor: pointer;
  transition: color 0.2s ease;
}

.subject-tab:hover {
  color: #333;
}

.subject-tab.active {
  color: #d94b4b;
}

/* Active underline */
.subject-tab.active::after {
  content: "";
  position: absolute;
  left: 20px;
  right: 20px;
  bottom: -2px;
  height: 3px;
  background: #d94b4b;
  border-radius: 3px 3px 0 0;
}

/* Geometry color */
.subject-tab[data-subject="geometry"].active {
  color: #4b7bd9;
}

.subject-tab[data-subject="geometry"].active::after {
  background: #4b7bd9;
}

.subject-tab[data-subject="fundamentals"].active {
  color: #f08acb;
}

.subject-tab[data-subject="fundamentals"].active::after {
  background: #f08acb;
}

.update-tab.active {
  color: white;
}

.update-tab.active::after {
  background: white;
}

.fundamentals-notice {
  text-align: center;
  margin: 0 auto 20px;
  color: var(--muted);
}

.topic-grid {
display: grid;
grid-template-columns: repeat(3, minmax(0, 1fr));
gap: 18px;
margin-top: 0;

transition: opacity 350ms ease, transform 350ms ease;
}

.topic-grid.topics-fading {
opacity: 0;
transform: translateY(8px);
}

.topic-grid.topics-fading-in {
animation: topicsFadeIn 350ms ease forwards;
}

@keyframes topicsFadeIn {
from {
  opacity: 0;
  transform: translateY(8px);
}

to {
  opacity: 1;
  transform: translateY(0);
}
} /* <-- THIS was missing */

.screen-transition {
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.screen-transitioning {
  opacity: 0;
  transform: translateY(8px);
}

.question-transition {
  opacity: 0;
  transform: translateY(8px);
}

.question-transition-active {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.topic-card {
background: linear-gradient(180deg, rgba(255,255,255,0.05), rgba(255,255,255,0.02));
border: 1px solid var(--border);
border-radius: var(--radius);
padding: 22px;
box-shadow: var(--shadow);
cursor: pointer;
transition: transform 0.22s ease, border-color 0.22s ease, box-shadow 0.22s ease;
color: var(--text);
text-align: left;
}

.coming-soon {
  grid-column: span 2;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: default;
}

.coming-soon:hover {
  transform: none;
  border-color: var(--border);
  box-shadow: var(--shadow);
}

.coming-soon h3 {
  text-align: center;
  font-size: 2rem;
  margin: 0;
}

.topic-card:hover {
transform: scale(1.03);
border-color: rgba(139,123,255,0.8);
box-shadow: 0 0 0 1px rgba(139,123,255,0.35), 0 0 22px rgba(139,123,255,0.35), var(--shadow);
}

.topic-card h3 {
  margin: 14px 0 8px;
  font-size: 1.15rem;
}

.coming-soon h3 {
  text-align: center;
  font-size: 2.75rem;
  margin: 0;
}

.topic-card p {
margin: 0 0 14px;
color: var(--muted);
line-height: 1.5;
}

.topic-meta {
display: flex;
justify-content: space-between;
align-items: center;
color: var(--accent);
font-weight: 600;
font-size: 0.95rem;
}

.badges-panel {
margin-top: 24px;
background: rgba(255,255,255,0.03);
border: 1px solid var(--border);
border-radius: var(--radius);
padding: 20px;
transform: translateY(10px);
}

.badges-panel h3 {
margin: 0 0 14px;
font-family: "Space Grotesk", sans-serif;
}

.badge-shelf {
display: flex;
flex-wrap: wrap;
gap: 12px;
}

.badge {
background: rgba(247,201,72,0.12);
border: 1px solid rgba(247,201,72,0.35);
color: #ffd86b;
padding: 10px 14px;
border-radius: 999px;
font-weight: 700;
}

.empty-state {
color: var(--muted);
margin: 0;
}

.screen {
display: none;
opacity: 0;
transform: translateY(10px) scale(0.985);
transition: opacity 360ms ease, transform 360ms ease;
}

.screen.active {
display: block;
opacity: 1;
transform: translateY(0) scale(1);
}

.practice-header {
display: flex;
justify-content: space-between;
align-items: center;
margin-bottom: 20px;
transform: translateY(-250px);
}

.practice-meta {
text-align: right;
}

.topic-label {
display: block;
color: var(--accent-2);
font-weight: 700;
}

.progress-text {
display: block;
color: var(--muted);
margin-top: 4px;
}

.progress-bar {
width: min(1100px, calc(100% - 32px));
margin: 0 auto 18px;
height: 12px;
background: rgba(255,255,255,0.08);
border-radius: 999px;
overflow: hidden;
transform: translateY(-250px);
}

.progress-fill {
height: 100%;
width: 5%;
background: linear-gradient(90deg, var(--accent), #5dd6ff);
border-radius: 999px;
transition: width 0.18s ease;
}

.question-card,
.results-card {
background: var(--panel);
border: 1px solid var(--border);
border-radius: var(--radius);
box-shadow: var(--shadow);
padding: 24px;
backdrop-filter: blur(10px);
transition: opacity 0.18s ease, transform 0.18s ease;
transform: translateY(-250px);
}

.footer.practice-footer {
    transform: translateY(-222px);
    margin-bottom: -222px;
}

.app.practice-mode {
  height: 100vh;
  overflow: hidden;
}

.app.practice-mode .footer {
  display: none;
}

.question-type {
color: var(--accent-2);
font-weight: 700;
margin-bottom: 10px;
}

.question-prompt {
margin: 0 0 8px;
font-size: 1.6rem;
}

.question-context {
margin: 0 0 18px;
color: var(--muted);
line-height: 1.6;
}

.answer-area {
margin-bottom: 16px;
}

.answer-input,
.answer-select {
width: 100%;
max-width: 420px;
background: #0f1018;
color: var(--text);
border: 1px solid var(--border);
border-radius: 14px;
padding: 14px 16px;
font: inherit;
}

.question-actions,
.results-actions {
display: flex;
gap: 12px;
flex-wrap: wrap;
}

.btn {
border: 0;
border-radius: 14px;
padding: 12px 16px;
font: inherit;
font-weight: 700;
cursor: pointer;
}

.btn-primary {
background: var(--accent);
color: white;
}

.btn-ghost {
background: rgba(255,255,255,0.06);
color: var(--text);
border: 1px solid var(--border);
}

.feedback,
.hint-box {
margin-top: 14px;
padding: 14px 16px;
border-radius: 14px;
line-height: 1.5;
}

.feedback {
background: rgba(255,255,255,0.04);
}

.feedback.correct {
border: 1px solid rgba(74,222,128,0.4);
color: #bbf7d0;
margin-bottom: 20px;
}	

.feedback.wrong {
border: 1px solid rgba(251,113,133,0.4);
color: #fecdd3;
margin-bottom: 20px;
}

.hint-box {
background: rgba(139,123,255,0.12);
border: 1px solid rgba(139,123,255,0.3);
color: #ddd7ff;
}

.results-card {
text-align: center;
margin-top: 40px;
}

.results-badge {
font-size: 3rem;
margin-bottom: 10px;
}

.results-score,
.results-message {
color: var(--muted);
line-height: 1.6;
}

.footer {
padding: 12px 0 20px;
text-align: center;
color: var(--muted);
font-size: 0.92rem;
}

.hidden {
display: none !important;
}

@media (max-width: 900px) {
.hero {
grid-template-columns: 1fr;
}

.topic-grid {
grid-template-columns: 1fr 1fr;
}
}

@media (max-width: 640px) {
.header-inner,
.practice-header {
flex-direction: column;
align-items: flex-start;
}

.header-stats {
width: 100%;
}

.topic-grid {
grid-template-columns: 1fr;
}

.answer-option {
  width: 100%;
  padding: 14px;
  margin: 8px 0;
  border-radius: 12px;
  border: 1px solid #444;
  background: var(--panel-2);
  color: var(--text);
  cursor: pointer;
  font-size: 1rem;
}

.answer-option.selected {
  border-color: var(--accent);
}

.practice-meta {
text-align: left;
}

.hero-art {
min-height: 180px;
}
}

.logo {
display: flex;
align-items: center;
gap: 12px;
text-decoration: none;
color: var(--text);
}

.logo-img {
width: 44px;
height: 44px;
object-fit: contain;
display: block;
}

.logo h1 {
margin: 0;
font-family: "Space Grotesk", sans-serif;
font-size: 1.4rem;
}

.coming-soon {
  cursor: default;
}

.coming-soon:hover {
  transform: none;
  border-color: var(--border);
  box-shadow: var(--shadow);
}