/* ═══════════════════════════════════════════
   StudyForge — AI-Powered Study Platform
   Premium ed-tech with warm amber accents on dark indigo
   ═══════════════════════════════════════════ */
@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,wght@0,400;0,500;0,600;0,700;1,400&family=DM+Serif+Display&display=swap');

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

:root {
  --bg: #0c0f1a;
  --bg-elevated: #141829;
  --bg-card: #1a1f35;
  --bg-card-hover: #222842;
  --text: #e8e6f0;
  --text-dim: #9795a8;
  --text-muted: #5f5d70;
  --accent: #f59e0b;
  --accent-soft: rgba(245,158,11,0.12);
  --accent-2: #6366f1;
  --accent-2-soft: rgba(99,102,241,0.12);
  --success: #34d399;
  --border: rgba(255,255,255,0.07);
  --radius: 20px;
  --radius-sm: 12px;
  --font: 'DM Sans', -apple-system, sans-serif;
  --font-display: 'DM Serif Display', Georgia, serif;
}

html { scroll-behavior: smooth; }
body {
  font-family: var(--font); background: var(--bg); color: var(--text);
  line-height: 1.7; overflow-x: hidden; -webkit-font-smoothing: antialiased;
}

/* ── Layout ──────────────────────────── */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section { padding: 120px 0; position: relative; }
.text-center { text-align: center; }

/* ── Typography ──────────────────────── */
.section-label {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; font-weight: 600; text-transform: uppercase;
  letter-spacing: 2px; color: var(--accent); margin-bottom: 20px;
}
.section-label::before {
  content: ''; width: 24px; height: 2px; background: var(--accent);
}
.section-title {
  font-family: var(--font-display); font-size: clamp(36px, 5vw, 56px);
  font-weight: 400; line-height: 1.15; margin-bottom: 20px; color: var(--text);
}
.section-sub { font-size: 17px; color: var(--text-dim); max-width: 560px; line-height: 1.8; }
.mx-auto { margin-left: auto; margin-right: auto; }

/* ── Buttons ─────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 15px 32px; border-radius: 100px;
  font-family: var(--font); font-size: 15px; font-weight: 600;
  cursor: pointer; border: none; transition: all 0.3s ease; text-decoration: none;
}
.btn-primary {
  background: var(--accent); color: #0c0f1a;
  box-shadow: 0 4px 24px rgba(245,158,11,0.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(245,158,11,0.4); }
.btn-ghost {
  background: transparent; color: var(--text); border: 1px solid var(--border);
}
.btn-ghost:hover { border-color: rgba(255,255,255,0.2); background: rgba(255,255,255,0.03); }

/* ── Navigation ──────────────────────── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 20px 0; transition: all 0.3s ease;
}
.nav.scrolled {
  background: rgba(12,15,26,0.9); backdrop-filter: blur(20px) saturate(1.2);
  border-bottom: 1px solid var(--border); padding: 12px 0;
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; }
.nav-brand {
  display: flex; align-items: center; gap: 12px;
  font-family: var(--font-display); font-size: 22px; text-decoration: none; color: var(--text);
}
.logo-mark {
  width: 40px; height: 40px; border-radius: 12px; overflow: hidden;
  background: linear-gradient(135deg, var(--accent) 0%, #fbbf24 100%);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 20px; color: #0c0f1a; font-family: var(--font-display);
}
.nav-links { display: flex; align-items: center; gap: 36px; list-style: none; }
.nav-links a {
  color: var(--text-dim); text-decoration: none; font-size: 14px;
  font-weight: 500; transition: color 0.2s; letter-spacing: 0.3px;
}
.nav-links a:hover { color: var(--text); }
.nav-cta { padding: 11px 24px; font-size: 14px; }

/* ── Hero ─────────────────────────────── */
.hero {
  padding: 180px 0 100px; position: relative; overflow: hidden;
  background: linear-gradient(180deg, rgba(99,102,241,0.06) 0%, transparent 60%);
}
.hero-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 80px;
  align-items: center; position: relative; z-index: 2;
}
.hero-eyebrow { margin-bottom: 28px; }
.hero-tag {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 18px; border-radius: 100px; font-size: 13px; font-weight: 600;
  background: var(--accent-soft); color: var(--accent); border: 1px solid rgba(245,158,11,0.2);
}
.hero-tag .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); animation: pulse-dot 2s infinite; }
.hero h1 {
  font-family: var(--font-display); font-size: clamp(44px, 6vw, 68px);
  font-weight: 400; line-height: 1.1; margin-bottom: 24px; letter-spacing: -0.5px;
}
.hero h1 em { font-style: italic; color: var(--accent); }
.hero-sub { font-size: 18px; color: var(--text-dim); margin-bottom: 40px; max-width: 460px; line-height: 1.8; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 48px; }

/* Hero Image Card */
.hero-visual { position: relative; }
.hero-img-card {
  border-radius: var(--radius); overflow: hidden; position: relative;
  border: 1px solid var(--border); box-shadow: 0 24px 80px rgba(0,0,0,0.4);
}
.hero-img-card img { width: 100%; height: 400px; object-fit: cover; display: block; }
.hero-img-overlay {
  position: absolute; bottom: 0; left: 0; right: 0;
  padding: 32px; background: linear-gradient(transparent, rgba(12,15,26,0.95));
}
.hero-img-stat { display: flex; gap: 24px; }
.hero-img-stat div { }
.hero-img-stat .num { font-family: var(--font-display); font-size: 28px; color: var(--accent); }
.hero-img-stat .label { font-size: 12px; color: var(--text-dim); text-transform: uppercase; letter-spacing: 1px; margin-top: 2px; }

/* Floating badges on hero */
.float-tag {
  position: absolute; padding: 12px 20px; border-radius: var(--radius-sm);
  background: var(--bg-card); border: 1px solid var(--border);
  backdrop-filter: blur(12px); font-size: 14px; font-weight: 600;
  box-shadow: 0 8px 32px rgba(0,0,0,0.3);
  animation: float-y 5s ease-in-out infinite;
}
.float-tag.t1 { top: -16px; right: -16px; color: var(--success); animation-delay: 0s; }
.float-tag.t2 { bottom: 80px; left: -24px; color: var(--accent); animation-delay: 1.5s; }

/* Trusted by logos */
.trust-bar { padding: 80px 0; border-bottom: 1px solid var(--border); }
.trust-label {
  text-align: center; font-size: 12px; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: 3px; margin-bottom: 36px;
}
.trust-logos {
  display: flex; align-items: center; justify-content: center; gap: 56px;
  flex-wrap: wrap; opacity: 0.35;
}
.trust-logos span {
  font-family: var(--font-display); font-size: 20px; color: var(--text-dim);
  letter-spacing: 3px;
}

/* ── Process ─────────────────────────── */
.process-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; margin-top: 64px; }
.process-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 40px 32px;
  transition: all 0.4s cubic-bezier(0.16,1,0.3,1); position: relative;
}
.process-card:hover { transform: translateY(-6px); border-color: rgba(245,158,11,0.3); box-shadow: 0 16px 48px rgba(0,0,0,0.2); }
.process-icon {
  width: 56px; height: 56px; border-radius: 16px; margin-bottom: 24px;
  display: flex; align-items: center; justify-content: center; font-size: 24px;
}
.process-icon.i1 { background: var(--accent-soft); }
.process-icon.i2 { background: var(--accent-2-soft); }
.process-icon.i3 { background: rgba(52,211,153,0.12); }
.process-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 12px; }
.process-card p { font-size: 15px; color: var(--text-dim); line-height: 1.7; }
.process-step-label {
  position: absolute; top: 16px; right: 20px; font-size: 12px; font-weight: 600;
  color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px;
}

/* ── Stats ────────────────────────────── */
.stats-section { padding: 80px 0; }
.stats-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px;
}
.stat-card {
  text-align: center; padding: 40px 24px;
  background: var(--bg-elevated); border: 1px solid var(--border);
  border-radius: var(--radius);
}
.stat-num {
  font-family: var(--font-display); font-size: 48px; color: var(--accent);
  margin-bottom: 8px;
}
.stat-label { font-size: 13px; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1.5px; }

/* ── Feature Showcase (with image) ───── */
.feature-split {
  display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center;
}
.feature-split.reverse { direction: rtl; }
.feature-split.reverse > * { direction: ltr; }
.feature-img {
  border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--border); box-shadow: 0 16px 48px rgba(0,0,0,0.3);
}
.feature-img img { width: 100%; height: 360px; object-fit: cover; display: block; }
.feature-text .section-label { margin-bottom: 16px; }
.feature-text h3 {
  font-family: var(--font-display); font-size: 36px; margin-bottom: 16px; line-height: 1.2;
}
.feature-text p { font-size: 16px; color: var(--text-dim); margin-bottom: 24px; line-height: 1.8; }
.feature-list { list-style: none; }
.feature-list li {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 0; font-size: 15px; color: var(--text-dim);
}
.feature-list li .check { color: var(--success); font-weight: 700; }

/* ── Pricing ─────────────────────────── */
.pricing-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 64px; }
.price-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 40px 32px;
  transition: all 0.4s ease; position: relative;
}
.price-card.featured {
  border-color: var(--accent); box-shadow: 0 0 48px rgba(245,158,11,0.1);
  background: linear-gradient(180deg, rgba(245,158,11,0.04) 0%, var(--bg-card) 100%);
}
.popular-tag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  padding: 6px 20px; border-radius: 100px; font-size: 11px; font-weight: 700;
  text-transform: uppercase; letter-spacing: 1.5px;
  background: var(--accent); color: #0c0f1a;
}
.price-name { font-size: 16px; font-weight: 600; color: var(--text-dim); margin-bottom: 12px; text-transform: uppercase; letter-spacing: 1px; }
.price-amount { font-family: var(--font-display); font-size: 52px; margin-bottom: 6px; color: var(--text); }
.price-amount span { font-family: var(--font); font-size: 16px; font-weight: 400; color: var(--text-muted); }
.price-desc { font-size: 14px; color: var(--text-dim); margin-bottom: 32px; }
.price-features { list-style: none; margin-bottom: 32px; }
.price-features li {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 0; font-size: 14px; color: var(--text-dim);
  border-bottom: 1px solid rgba(255,255,255,0.04);
}
.price-features li .check { color: var(--success); }
.price-features li.off { opacity: 0.3; }
.price-features li.off .check { color: var(--text-muted); }
.price-card .btn { width: 100%; justify-content: center; }

/* ── Testimonials ────────────────────── */
.testimonials-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 64px; }
.testi-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 36px;
}
.testi-stars { color: var(--accent); font-size: 16px; margin-bottom: 20px; letter-spacing: 3px; }
.testi-quote { font-size: 16px; color: var(--text-dim); font-style: italic; margin-bottom: 24px; line-height: 1.8; }
.testi-author { display: flex; align-items: center; gap: 14px; }
.testi-avatar {
  width: 44px; height: 44px; border-radius: 50%; object-fit: cover;
  border: 2px solid var(--border);
}
.testi-avatar-placeholder {
  width: 44px; height: 44px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent) 0%, #fbbf24 100%);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 18px; color: #0c0f1a;
}
.testi-name { font-size: 15px; font-weight: 600; }
.testi-role { font-size: 12px; color: var(--text-muted); }

/* ── FAQ ──────────────────────────────── */
.faq-list { max-width: 720px; margin: 64px auto 0; }
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q {
  display: flex; align-items: center; justify-content: space-between;
  padding: 28px 0; cursor: pointer; font-size: 17px; font-weight: 600;
  color: var(--text); background: none; border: none; width: 100%;
  font-family: var(--font); text-align: left; transition: color 0.2s;
}
.faq-q:hover { color: var(--accent); }
.faq-icon { font-size: 22px; transition: transform 0.3s; color: var(--text-muted); font-weight: 300; }
.faq-item.open .faq-icon { transform: rotate(45deg); color: var(--accent); }
.faq-a { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; }
.faq-a-inner { padding: 0 0 28px; font-size: 15px; color: var(--text-dim); line-height: 1.8; }
.faq-item.open .faq-a { max-height: 400px; }

/* ── CTA ──────────────────────────────── */
.cta-section {
  padding: 120px 0; text-align: center; position: relative;
  background: radial-gradient(ellipse at center, rgba(245,158,11,0.06) 0%, transparent 60%);
}
.cta-section h2 { font-family: var(--font-display); font-size: clamp(36px, 5vw, 52px); margin-bottom: 16px; }
.cta-section h2 em { font-style: italic; color: var(--accent); }
.cta-section p { font-size: 18px; color: var(--text-dim); margin-bottom: 40px; max-width: 500px; margin-left: auto; margin-right: auto; }

/* ── Footer ──────────────────────────── */
.footer {
  padding: 48px 0; border-top: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  font-size: 13px; color: var(--text-muted);
}
.footer-links { display: flex; gap: 24px; }
.footer-links a { color: var(--text-muted); text-decoration: none; transition: color 0.2s; }
.footer-links a:hover { color: var(--text); }

/* ── Animations ──────────────────────── */
@keyframes pulse-dot { 0%, 100% { opacity: 1; transform: scale(1); } 50% { opacity: 0.4; transform: scale(0.8); } }
@keyframes float-y { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-14px); } }

.animate { opacity: 0; transform: translateY(32px); transition: all 0.9s cubic-bezier(0.16,1,0.3,1); }
.animate.visible { opacity: 1; transform: translateY(0); }
.d1 { transition-delay: 0.1s; } .d2 { transition-delay: 0.2s; }
.d3 { transition-delay: 0.3s; } .d4 { transition-delay: 0.4s; }

/* ── Responsive ──────────────────────── */
@media (max-width: 900px) {
  .hero-grid, .feature-split { grid-template-columns: 1fr; gap: 48px; }
  .feature-split.reverse { direction: ltr; }
  .hero { text-align: center; padding-top: 140px; }
  .hero-sub { margin: 0 auto 40px; }
  .hero-actions { justify-content: center; }
  .process-grid, .pricing-grid, .testimonials-grid { grid-template-columns: 1fr; max-width: 420px; margin-left: auto; margin-right: auto; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .nav-links { display: none; }
  .float-tag { display: none; }
  .footer { flex-direction: column; gap: 16px; text-align: center; }
}