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

:root {
  --bg: #0d0f14;
  --surface: #161a23;
  --surface2: #1e2330;
  --border: #2a2f3e;
  --accent: #6c63ff;
  --accent2: #00d4aa;
  --accent3: #ff6b6b;
  --text: #e8eaf0;
  --muted: #7a8099;
  --correct: #00d4aa;
  --wrong: #ff6b6b;
  --warn: #ffb347;
  --radius: 16px;
  --radius-sm: 10px;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', sans-serif;
  font-size: 15px;
  line-height: 1.6;
  min-height: 100vh;
}

/* ── Hero ─────────────────────────────────────────────────── */
.hero {
  background: linear-gradient(135deg, #1a1040 0%, #0d1a2e 50%, #0d0f14 100%);
  padding: 60px 24px 50px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 30% 50%, rgba(108,99,255,0.15) 0%, transparent 60%),
              radial-gradient(ellipse at 70% 30%, rgba(0,212,170,0.1) 0%, transparent 50%);
  pointer-events: none;
}
.hero-inner { position: relative; max-width: 700px; margin: 0 auto; }

.chip {
  display: inline-block;
  background: rgba(108,99,255,0.2);
  border: 1px solid rgba(108,99,255,0.4);
  color: #a89fff;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 5px 14px;
  border-radius: 999px;
  margin-bottom: 20px;
}

.hero h1 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  line-height: 1.15;
  color: #fff;
  margin-bottom: 12px;
}
.hero h1 .hl {
  background: linear-gradient(90deg, #6c63ff, #00d4aa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.sub {
  color: var(--muted);
  font-size: 14px;
  margin-bottom: 28px;
}
.sub strong { color: var(--text); }

/* Progress bar */
.progress-bar-wrap { display: flex; align-items: center; gap: 12px; justify-content: center; }
.progress-bar-track {
  flex: 1; max-width: 400px; height: 6px;
  background: rgba(255,255,255,0.08);
  border-radius: 999px; overflow: hidden;
}
.progress-bar-fill {
  height: 100%; width: 0%;
  background: linear-gradient(90deg, #6c63ff, #00d4aa);
  border-radius: 999px;
  transition: width 0.4s ease;
}
.progress-label { font-size: 12px; color: var(--muted); white-space: nowrap; }

/* ── Container ────────────────────────────────────────────── */
.container { max-width: 900px; margin: 0 auto; padding: 40px 20px 60px; }

/* ── Section ──────────────────────────────────────────────── */
.sec { margin-bottom: 48px; }

.sec-head {
  display: flex; align-items: flex-start; gap: 16px;
  margin-bottom: 24px;
}
.sec-badge {
  width: 44px; height: 44px; flex-shrink: 0;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 18px; font-weight: 700; color: #fff;
}
.sec-head h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.25rem; font-weight: 700;
  color: #fff; margin-bottom: 4px;
}
.sec-meta { font-size: 13px; color: var(--muted); }
.sec-meta strong { color: var(--accent2); }

/* ── Grid ─────────────────────────────────────────────────── */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
  gap: 16px;
}
.grid.single { grid-template-columns: 1fr; }

/* ── Card ─────────────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.card:hover { border-color: rgba(108,99,255,0.3); }
.card.correct { border-color: var(--correct); background: rgba(0,212,170,0.05); }
.card.wrong   { border-color: var(--wrong);   background: rgba(255,107,107,0.05); }

.qno {
  font-size: 11px; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--accent);
  margin-bottom: 8px; display: flex; align-items: center; gap: 8px;
}
.marks-badge {
  background: rgba(108,99,255,0.15);
  border: 1px solid rgba(108,99,255,0.3);
  color: #a89fff;
  font-size: 10px; padding: 2px 8px; border-radius: 999px;
  text-transform: none; letter-spacing: 0;
}

.qt { font-size: 14.5px; color: var(--text); margin-bottom: 14px; font-weight: 500; }

/* ── MCQ Options ──────────────────────────────────────────── */
.mcq-opts { display: flex; flex-direction: column; gap: 8px; }

.opt {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  text-align: left;
  font-size: 13.5px;
  cursor: pointer;
  transition: all 0.15s;
  font-family: 'Inter', sans-serif;
}
.opt:hover { border-color: var(--accent); color: #fff; background: rgba(108,99,255,0.1); }
.opt.selected { border-color: var(--accent); background: rgba(108,99,255,0.15); color: #fff; }
.opt.correct-ans { border-color: var(--correct) !important; background: rgba(0,212,170,0.15) !important; color: var(--correct) !important; }
.opt.wrong-ans   { border-color: var(--wrong)   !important; background: rgba(255,107,107,0.15) !important; color: var(--wrong)   !important; }
.opt:disabled { cursor: default; }

/* ── True / False ─────────────────────────────────────────── */
.tf-btns { display: flex; gap: 10px; }
.tf {
  flex: 1;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 10px;
  font-size: 13.5px;
  cursor: pointer;
  transition: all 0.15s;
  font-family: 'Inter', sans-serif;
}
.tf:hover { border-color: var(--accent); background: rgba(108,99,255,0.1); }
.tf.selected { border-color: var(--accent); background: rgba(108,99,255,0.15); color: #fff; }
.tf.correct-ans { border-color: var(--correct) !important; background: rgba(0,212,170,0.15) !important; color: var(--correct) !important; }
.tf.wrong-ans   { border-color: var(--wrong)   !important; background: rgba(255,107,107,0.15) !important; color: var(--wrong)   !important; }
.tf:disabled { cursor: default; }

/* ── Text Inputs ──────────────────────────────────────────── */
.txt-input, .txt-area {
  width: 100%;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  padding: 10px 14px;
  outline: none;
  transition: border-color 0.2s;
  resize: vertical;
}
.txt-input:focus, .txt-area:focus { border-color: var(--accent); }
.txt-input::placeholder, .txt-area::placeholder { color: var(--muted); }
.txt-input.correct-inp { border-color: var(--correct); background: rgba(0,212,170,0.05); }
.txt-input.wrong-inp   { border-color: var(--wrong);   background: rgba(255,107,107,0.05); }

/* ── Feedback ─────────────────────────────────────────────── */
.fb {
  margin-top: 10px;
  font-size: 13px;
  border-radius: 8px;
  padding: 0;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}
.fb.show {
  max-height: 200px;
  padding: 10px 12px;
}
.fb.ok  { background: rgba(0,212,170,0.1);  color: var(--correct); border: 1px solid rgba(0,212,170,0.25); }
.fb.err { background: rgba(255,107,107,0.1); color: var(--wrong);   border: 1px solid rgba(255,107,107,0.25); }
.fb.info { background: rgba(255,179,71,0.1); color: var(--warn);    border: 1px solid rgba(255,179,71,0.25); }

/* ── Case Box ─────────────────────────────────────────────── */
.case-box {
  background: linear-gradient(135deg, rgba(108,99,255,0.08), rgba(0,212,170,0.05));
  border: 1px solid rgba(108,99,255,0.25);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-bottom: 20px;
}
.case-title { font-weight: 700; color: #a89fff; margin-bottom: 10px; font-size: 13px; }
.case-text  { font-size: 14px; color: var(--text); line-height: 1.75; }

/* ── Submit Row ───────────────────────────────────────────── */
.submit-row {
  display: flex; gap: 12px; justify-content: center;
  margin: 40px 0 32px;
  flex-wrap: wrap;
}

.btn-submit {
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  color: #fff;
  border: none;
  border-radius: 12px;
  padding: 14px 36px;
  font-size: 15px; font-weight: 700;
  cursor: pointer;
  font-family: 'Space Grotesk', sans-serif;
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 4px 20px rgba(108,99,255,0.35);
}
.btn-submit:hover { transform: translateY(-2px); box-shadow: 0 8px 28px rgba(108,99,255,0.5); }
.btn-submit:active { transform: translateY(0); }

.btn-reset {
  background: var(--surface2);
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 28px;
  font-size: 15px; font-weight: 600;
  cursor: pointer;
  font-family: 'Space Grotesk', sans-serif;
  transition: all 0.15s;
}
.btn-reset:hover { border-color: var(--accent); color: var(--text); }

/* ── Results Panel ────────────────────────────────────────── */
.results-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 40px 32px;
  margin-bottom: 40px;
  text-align: center;
}
.results-inner { max-width: 600px; margin: 0 auto; }

.score-wrap {
  display: flex; align-items: baseline; justify-content: center;
  gap: 6px; margin-bottom: 12px;
}
.score-num {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 5rem; font-weight: 800;
  background: linear-gradient(135deg, #6c63ff, #00d4aa);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}
.score-out { font-size: 2rem; color: var(--muted); font-weight: 600; }

.grade-text {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.5rem; font-weight: 700;
  margin-bottom: 8px;
}
.grade-msg { color: var(--muted); font-size: 14px; margin-bottom: 28px; }

.improve-wrap, .strong-wrap {
  text-align: left;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 16px;
}
.improve-wrap h3, .strong-wrap h3 {
  font-size: 14px; font-weight: 700;
  margin-bottom: 12px; color: var(--text);
}
.improve-list, .strong-list { display: flex; flex-wrap: wrap; gap: 8px; }

.tag {
  font-size: 12px; font-weight: 600;
  padding: 5px 12px; border-radius: 999px;
}
.tag-err  { background: rgba(255,107,107,0.15); color: var(--wrong);   border: 1px solid rgba(255,107,107,0.3); }
.tag-ok   { background: rgba(0,212,170,0.15);   color: var(--correct); border: 1px solid rgba(0,212,170,0.3); }

.btn-retry {
  background: linear-gradient(135deg, var(--accent2), #00a884);
  color: #fff; border: none;
  border-radius: 12px; padding: 12px 32px;
  font-size: 14px; font-weight: 700;
  cursor: pointer; font-family: 'Space Grotesk', sans-serif;
  margin-top: 8px;
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 4px 16px rgba(0,212,170,0.3);
}
.btn-retry:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,212,170,0.45); }

/* ── Footer ───────────────────────────────────────────────── */
.footer {
  text-align: center;
  padding: 24px;
  color: var(--muted);
  font-size: 12px;
  border-top: 1px solid var(--border);
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 600px) {
  .grid { grid-template-columns: 1fr; }
  .hero { padding: 40px 16px 36px; }
  .container { padding: 28px 14px 48px; }
  .score-num { font-size: 3.5rem; }
  .results-panel { padding: 28px 18px; }
}