/* Corrigi - AI Exam Generator & Smart Grader Stylesheet */
:root {
  color-scheme: light;
  --bg: #0b0f19;
  --bg-card: #111827;
  --bg-card-subtle: #1f2937;
  --bg-card-elevated: #1e293b;
  --ink: #f8fafc;
  --ink-muted: #94a3b8;
  --ink-subtle: #64748b;
  --primary-ai: #6366f1;
  --primary-ai-glow: rgba(99, 102, 241, 0.35);
  --violet: #8b5cf6;
  --violet-glow: rgba(139, 92, 246, 0.25);
  --pink-ai: #ec4899;
  --border: #334155;
  --border-subtle: #1e293b;
  --border-focus: #818cf8;
  --success: #10b981;
  --success-glow: rgba(16, 185, 129, 0.25);
  --error: #f43f5e;
  --amber: #f59e0b;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 26px;
  --shadow-ai: 0 10px 30px -10px rgba(99, 102, 241, 0.4);
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background-color: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }

.header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(11, 15, 25, 0.88);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
}
.nav-container {
  max-width: 1200px; margin: 0 auto; padding: 0 20px;
  height: 70px; display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand-link {
  display: inline-flex; align-items: center; gap: 10px;
  font-weight: 850; font-size: 1.25rem; letter-spacing: -0.02em; color: #ffffff;
}
.brand-icon {
  width: 36px; height: 36px; border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--primary-ai), var(--pink-ai));
  color: #ffffff; display: grid; place-items: center;
  box-shadow: 0 4px 14px var(--primary-ai-glow);
}
.brand-icon svg { width: 22px; height: 22px; }
.nav-menu { display: flex; align-items: center; gap: 24px; }
.nav-item { color: var(--ink-muted); font-weight: 600; font-size: 0.95rem; transition: color 0.15s ease; }
.nav-item:hover { color: #ffffff; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 22px; font-weight: 700; font-size: 0.95rem;
  border-radius: var(--radius-md); cursor: pointer; border: 1px solid transparent; line-height: 1.2;
  transition: all 0.2s ease;
}
.btn-ai-primary {
  background: linear-gradient(135deg, var(--primary-ai), var(--violet));
  color: #ffffff; box-shadow: var(--shadow-ai);
}
.btn-ai-primary:hover {
  background: linear-gradient(135deg, #4f46e5, #7c3aed);
  transform: translateY(-2px);
  box-shadow: 0 12px 35px -5px rgba(99, 102, 241, 0.55);
}
.btn-ai-secondary {
  background: var(--bg-card-subtle); color: var(--ink);
  border-color: var(--border);
}
.btn-ai-secondary:hover {
  background: var(--bg-card-elevated); border-color: var(--primary-ai);
}
.btn-large { padding: 15px 30px; font-size: 1.05rem; border-radius: var(--radius-lg); }

.hero-section {
  padding: 64px 20px 56px;
  background: radial-gradient(circle at 50% -20%, rgba(99, 102, 241, 0.25) 0%, rgba(11, 15, 25, 0) 70%);
}
.hero-grid {
  max-width: 1200px; margin: 0 auto;
  display: grid; grid-template-columns: 1.15fr 1fr; gap: 48px; align-items: center;
}
.badge-tag {
  display: inline-flex; align-items: center; gap: 8px; padding: 7px 16px;
  background: rgba(99, 102, 241, 0.15); border: 1px solid rgba(139, 92, 246, 0.4);
  border-radius: 9999px; color: #c7d2fe; font-size: 0.85rem; font-weight: 700; margin-bottom: 20px;
}
.hero-title {
  font-size: clamp(2.3rem, 4.4vw, 3.6rem); font-weight: 900; line-height: 1.12;
  letter-spacing: -0.03em; color: #ffffff; margin: 0 0 20px;
}
.text-ai-gradient {
  background: linear-gradient(135deg, #a5b4fc, #c084fc, #f472b6);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-lead { font-size: 1.15rem; line-height: 1.6; color: var(--ink-muted); margin: 0 0 30px; max-width: 580px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 30px; }
.hero-proof-row { display: flex; flex-wrap: wrap; gap: 20px; padding-top: 20px; border-top: 1px solid var(--border-subtle); }
.proof-item { display: flex; align-items: center; gap: 8px; font-size: 0.88rem; font-weight: 600; color: var(--ink-muted); }
.proof-sparkle { color: #818cf8; font-size: 1.05rem; }

/* Interactive AI Prompt Simulator */
.ai-cockpit-card {
  background: var(--bg-card); border-radius: var(--radius-xl); border: 1px solid var(--border);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6), 0 0 30px rgba(99, 102, 241, 0.15);
  padding: 24px; position: relative; overflow: hidden;
}
.ai-topbar {
  display: flex; align-items: center; justify-content: space-between; padding-bottom: 14px;
  margin-bottom: 16px; border-bottom: 1px solid var(--border-subtle);
}
.ai-status {
  display: flex; align-items: center; gap: 8px; font-size: 0.82rem; font-weight: 700;
  color: #34d399; background: rgba(16, 185, 129, 0.12); border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 4px 12px; border-radius: 9999px;
}
.ai-pulse-dot {
  width: 8px; height: 8px; border-radius: 50%; background: #10b981;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.3);
}
.ai-latency { font-size: 0.82rem; font-weight: 600; color: var(--ink-subtle); }

.prompt-bar {
  background: var(--bg-card-subtle); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 12px 16px; margin-bottom: 16px; display: flex; align-items: center; gap: 12px;
}
.prompt-icon { color: #818cf8; font-size: 1.2rem; flex-shrink: 0; }
.prompt-text {
  font-size: 0.88rem; color: #e2e8f0; font-family: ui-monospace, monospace;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; flex: 1;
}
.prompt-badge {
  background: rgba(99, 102, 241, 0.2); color: #c7d2fe; font-size: 0.72rem;
  font-weight: 700; padding: 3px 8px; border-radius: 6px; text-transform: uppercase;
}

.ai-output-box {
  background: var(--bg-card-elevated); border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md); padding: 16px; margin-bottom: 16px;
}
.ai-output-header {
  display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px;
  font-size: 0.75rem; font-weight: 700; color: #818cf8; text-transform: uppercase; letter-spacing: 0.05em;
}
.ai-question-title { font-size: 0.95rem; font-weight: 750; color: #ffffff; margin: 0 0 8px; }
.ai-question-alternatives { display: flex; flex-direction: column; gap: 6px; }
.ai-alt-item {
  display: flex; align-items: center; gap: 8px; font-size: 0.84rem; padding: 6px 10px;
  border-radius: var(--radius-sm); background: var(--bg-card); border: 1px solid var(--border-subtle);
}
.ai-alt-item.correct {
  background: rgba(16, 185, 129, 0.1); border-color: rgba(16, 185, 129, 0.4); color: #a7f3d0;
}
.ai-alt-letter {
  width: 20px; height: 20px; border-radius: 50%; background: #334155;
  display: grid; place-items: center; font-size: 0.72rem; font-weight: 800; color: #ffffff;
}
.ai-alt-item.correct .ai-alt-letter { background: #10b981; }

.ai-vision-strip {
  background: rgba(139, 92, 246, 0.1); border: 1px solid rgba(139, 92, 246, 0.3);
  border-radius: var(--radius-md); padding: 12px 14px; display: flex; align-items: center;
  justify-content: space-between; font-size: 0.84rem; color: #ddd6fe;
}
.vision-confidence { font-weight: 700; color: #34d399; }

/* Sections */
.section { padding: 76px 20px; }
.section-alt { background: #0e1320; border-top: 1px solid var(--border-subtle); border-bottom: 1px solid var(--border-subtle); }
.container { max-width: 1200px; margin: 0 auto; }
.section-header { text-align: center; max-width: 740px; margin: 0 auto 52px; }
.section-kicker { font-size: 0.85rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.1em; color: #818cf8; margin-bottom: 12px; }
.section-title { font-size: clamp(1.9rem, 3.2vw, 2.7rem); font-weight: 850; line-height: 1.2; letter-spacing: -0.02em; color: #ffffff; margin: 0 0 16px; }
.section-desc { font-size: 1.05rem; color: var(--ink-muted); line-height: 1.6; margin: 0; }

.ai-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.ai-card {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 32px 26px; transition: all 0.25s ease; display: flex; flex-direction: column;
}
.ai-card:hover {
  border-color: var(--primary-ai); transform: translateY(-4px);
  box-shadow: 0 16px 30px -10px var(--primary-ai-glow);
}
.ai-card-icon {
  width: 48px; height: 48px; border-radius: var(--radius-md);
  background: rgba(99, 102, 241, 0.15); border: 1px solid rgba(139, 92, 246, 0.3);
  display: grid; place-items: center; font-size: 1.4rem; margin-bottom: 20px;
}
.ai-card-title { font-size: 1.25rem; font-weight: 800; color: #ffffff; margin: 0 0 12px; }
.ai-card-text { font-size: 0.95rem; color: var(--ink-muted); line-height: 1.6; margin: 0; }

/* Comparison Table */
.comparison-wrapper {
  background: var(--bg-card); border-radius: var(--radius-lg); border: 1px solid var(--border);
  overflow: hidden; max-width: 980px; margin: 0 auto; box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}
.table-responsive { width: 100%; overflow-x: auto; }
.comparison-table { width: 100%; border-collapse: collapse; text-align: left; }
.comparison-table th, .comparison-table td { padding: 16px 20px; border-bottom: 1px solid var(--border-subtle); font-size: 0.92rem; }
.comparison-table th { background: var(--bg-card-subtle); font-weight: 800; color: #ffffff; }
.comparison-table th.col-highlight { background: rgba(99, 102, 241, 0.2); color: #c7d2fe; border-top: 3px solid var(--primary-ai); }
.comparison-table td.col-highlight { background: rgba(99, 102, 241, 0.08); font-weight: 700; color: #ffffff; }

/* Ad Relevance Context */
.ad-relevance-context {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 32px; margin: 48px auto 0; max-width: 1080px;
}
.ad-relevance-context h3 { font-size: 1.25rem; font-weight: 800; color: #ffffff; margin: 0 0 12px; }
.ad-relevance-context p { color: var(--ink-muted); font-size: 0.95rem; line-height: 1.6; margin: 0 0 14px; }
.keyword-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.keyword-chip {
  display: inline-flex; align-items: center; padding: 5px 13px;
  background: var(--bg-card-subtle); border: 1px solid var(--border); border-radius: 9999px;
  font-size: 0.82rem; font-weight: 600; color: #c7d2fe;
}

.faq-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; max-width: 1040px; margin: 0 auto; }
.faq-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 24px; }
.faq-q { font-size: 1.05rem; font-weight: 800; color: #ffffff; margin: 0 0 10px; }
.faq-a { font-size: 0.92rem; color: var(--ink-muted); line-height: 1.6; margin: 0; }

.final-cta {
  background: radial-gradient(circle at 50% 50%, #1e1b4b 0%, #0b0f19 100%);
  border: 1px solid var(--border); color: #ffffff; padding: 72px 20px; text-align: center;
  border-radius: var(--radius-xl); max-width: 1140px; margin: 40px auto;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.7);
}
.final-cta h2 { font-size: clamp(2rem, 3.6vw, 2.8rem); font-weight: 900; margin: 0 0 16px; line-height: 1.2; }
.final-cta p { font-size: 1.15rem; color: #c7d2fe; max-width: 620px; margin: 0 auto 32px; line-height: 1.6; }

.footer { border-top: 1px solid var(--border-subtle); background: var(--bg); padding: 36px 20px; font-size: 0.88rem; color: var(--ink-subtle); }
.footer-container { max-width: 1200px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 16px; }

@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .ai-grid { grid-template-columns: 1fr; }
  .faq-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav-menu { display: none; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }
}