/* ============================================================
   hst.css — High Schooler's Tool (Base + Home Page) v2.0
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

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

:root {
  /* Brand Colors */
  --primary:        #1a56db;
  --primary-light:  #3b82f6;
  --primary-dark:   #1e3a8a;
  --accent:         #f59e0b;
  --accent-light:   #fbbf24;
  --success:        #10b981;
  --danger:         #dc2626;
  --violet:         #8b5cf6;
  --rose:           #f43f5e;
  --cyan:           #06b6d4;

  /* Surface Colors */
  --bg:             #f1f5f9;
  --surface:        #ffffff;
  --surface-2:      #f8fafc;
  --border:         #e2e8f0;

  /* Text Colors */
  --text-primary:   #0f172a;
  --text-secondary: #475569;
  --text-muted:     #94a3b8;
  --text-inverse:   #ffffff;

  /* Shadows */
  --shadow-sm:  0 1px 3px rgba(0,0,0,.07);
  --shadow-md:  0 4px 18px rgba(0,0,0,.09);
  --shadow-lg:  0 12px 40px rgba(0,0,0,.11);
  --shadow-xl:  0 24px 60px rgba(0,0,0,.15);
  --shadow-2xl: 0 32px 80px rgba(0,0,0,.18);

  /* Radius */
  --radius-sm:  8px;
  --radius:     14px;
  --radius-lg:  20px;
  --radius-xl:  28px;
  --radius-full: 9999px;

  /* Transitions */
  --transition: 0.22s ease;
  --transition-slow: 0.35s ease;
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
  :root {
    --bg:             #0f172a;
    --surface:        #1e293b;
    --surface-2:      #334155;
    --border:         #334155;
    --text-primary:   #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted:     #64748b;
  }
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main { flex: 1; }

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Screen reader only */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Focus visible for accessibility */
a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}

/* ── Navbar ───────────────────────────────── */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 8px rgba(0,0,0,.06);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
}

.logo-img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  object-fit: cover;
  border: 1px solid var(--border);
  transition: transform var(--transition);
}

.logo:hover .logo-img { transform: scale(1.05); }

.logo-text h2 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 900;
  color: var(--text-primary);
  letter-spacing: -0.03em;
  line-height: 1;
}

.logo-text span {
  font-size: 0.7rem;
  color: var(--text-muted);
  font-weight: 500;
  display: block;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 2px;
}

.nav-links a {
  display: block;
  padding: 7px 13px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--transition);
  white-space: nowrap;
}

.nav-links a:hover {
  color: var(--text-primary);
  background: var(--surface-2);
}

.nav-links a.active {
  color: var(--primary);
  background: rgba(26,86,219,.08);
  font-weight: 700;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 38px;
  height: 38px;
  padding: 7px;
  background: none;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
}

.hamburger:hover { background: var(--surface-2); }

.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.28s ease;
  transform-origin: center;
}

.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ── Hero / Search ────────────────────────── */
.hero-search {
  background: linear-gradient(145deg, #1e3a8a 0%, #1d4ed8 50%, #4338ca 100%);
  padding: 80px 0 72px;
  position: relative;
  overflow: hidden;
  text-align: center;
}

/* Ambient orbs with animation */
.hero-bg-orb {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(90px);
  opacity: 0.22;
  animation: float 8s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(180deg); }
}

.orb-1 { width: 560px; height: 560px; background: #6366f1; top: -160px; right: -100px; animation-delay: 0s; }
.orb-2 { width: 400px; height: 400px; background: #10b981; bottom: -120px; left: -80px; animation-delay: 2s; }
.orb-3 { width: 300px; height: 300px; background: #f59e0b; top: 50%; left: 50%; transform: translate(-50%,-50%); opacity: 0.08; animation-delay: 4s; }

.hero-content { position: relative; z-index: 1; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,255,255,0.14);
  border: 1px solid rgba(255,255,255,0.28);
  color: white;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 6px 18px;
  border-radius: var(--radius-full);
  margin-bottom: 22px;
  letter-spacing: 0.04em;
  backdrop-filter: blur(6px);
}

.hero-content h1 {
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  font-weight: 900;
  color: white;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 18px;
  animation: fadeInUp 0.8s ease;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.hero-gradient-text {
  background: linear-gradient(90deg, #fbbf24, #f472b6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-content > p {
  color: rgba(255,255,255,0.82);
  font-size: 1.1rem;
  max-width: 520px;
  margin: 0 auto 32px;
  line-height: 1.7;
  animation: fadeInUp 0.8s ease 0.15s both;
}

/* Hero stats */
.hero-stats {
  display: inline-flex;
  align-items: center;
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.18);
  border-radius: var(--radius-lg);
  overflow: hidden;
  backdrop-filter: blur(8px);
  margin-bottom: 44px;
  animation: fadeInUp 0.8s ease 0.3s both;
}

.hero-stat {
  padding: 16px 32px;
  text-align: center;
}

.hero-stat strong {
  display: block;
  font-size: 1.6rem;
  font-weight: 900;
  color: white;
  letter-spacing: -0.03em;
  line-height: 1;
}

.hero-stat span {
  font-size: 0.7rem;
  color: rgba(255,255,255,0.6);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  display: block;
  margin-top: 3px;
}

.hero-stat-divider {
  width: 1px;
  height: 36px;
  background: rgba(255,255,255,0.18);
  flex-shrink: 0;
}

/* Search */
.search-container {
  position: relative;
  z-index: 1;
  max-width: 680px;
  margin: 0 auto 44px;
  animation: fadeInUp 0.8s ease 0.45s both;
}

.search-form { margin-bottom: 14px; }

.search-input-group {
  display: flex;
  align-items: center;
  background: white;
  border-radius: var(--radius);
  box-shadow: 0 8px 32px rgba(0,0,0,0.22);
  overflow: hidden;
  border: 1.5px solid transparent;
  transition: all var(--transition);
}

.search-input-group:focus-within {
  border-color: rgba(99,102,241,0.5);
  box-shadow: 0 8px 32px rgba(0,0,0,0.22), 0 0 0 4px rgba(99,102,241,0.1);
}

.search-icon {
  padding: 0 14px;
  font-size: 1.1rem;
  flex-shrink: 0;
  color: var(--text-muted);
}

.search-input-group input {
  flex: 1;
  border: none;
  outline: none;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--text-primary);
  padding: 16px 8px;
  background: transparent;
}

.search-input-group input::placeholder { color: var(--text-muted); }

.search-btn {
  background: linear-gradient(135deg, var(--primary), #6366f1);
  color: white;
  border: none;
  padding: 12px 24px;
  margin: 6px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-weight: 700;
  font-size: 0.9rem;
  font-family: inherit;
  transition: all var(--transition);
  white-space: nowrap;
  box-shadow: 0 4px 12px rgba(26,86,219,0.35);
}

.search-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(26,86,219,0.45);
}

.search-btn:active { transform: translateY(0); }

/* Filter chips */
.quick-filters {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
}

.filter-label {
  font-size: 0.78rem;
  color: rgba(255,255,255,0.65);
  font-weight: 600;
}

.filter-chip {
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.22);
  color: white;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition);
  backdrop-filter: blur(4px);
}

.filter-chip:hover {
  background: rgba(255,255,255,0.24);
  transform: translateY(-1px);
}

.filter-chip:active { transform: translateY(0); }

/* Promo Swiper */
.promo-wrap {
  position: relative;
  z-index: 1;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: 0 16px 48px rgba(0,0,0,0.3);
  max-width: 900px;
  margin: 0 auto;
  border: 1px solid rgba(255,255,255,0.15);
  animation: fadeInUp 0.8s ease 0.6s both;
}

.promo-x {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 10;
  background: rgba(0,0,0,0.45);
  backdrop-filter: blur(6px);
  color: white;
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 50%;
  width: 32px;
  height: 32px;
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: inherit;
  transition: all var(--transition);
  line-height: 1;
}

.promo-x:hover { background: rgba(0,0,0,0.7); transform: scale(1.1); }

.promo-swiper { width: 100%; }

.promo-swiper .swiper-slide img {
  width: 100%;
  height: 320px;
  object-fit: cover;
  display: block;
}

.promo-swiper .swiper-pagination-bullet {
  background: rgba(255,255,255,0.6);
  opacity: 1;
}

.promo-swiper .swiper-pagination-bullet-active {
  background: white;
  transform: scale(1.2);
}

/* ── Features Section ─────────────────────── */
.features {
  padding: 80px 0 88px;
}

.section-header {
  text-align: center;
  margin-bottom: 52px;
}

.section-eyebrow {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--primary);
  margin-bottom: 10px;
}

.section-title {
  font-size: clamp(1.7rem, 3.5vw, 2.4rem);
  font-weight: 900;
  color: var(--text-primary);
  letter-spacing: -0.03em;
  margin-bottom: 12px;
  line-height: 1.15;
}

.section-sub {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.7;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px 24px 24px;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2.5px;
  opacity: 0;
  transition: opacity var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: #c7d7fd;
}

.feature-card:hover::before { opacity: 1; }

/* Per-card accent line colors */
.feature-card:nth-child(1)::before { background: linear-gradient(90deg, #3b82f6, #6366f1); }
.feature-card:nth-child(2)::before { background: linear-gradient(90deg, #8b5cf6, #a78bfa); }
.feature-card:nth-child(3)::before { background: linear-gradient(90deg, #f59e0b, #fbbf24); }
.feature-card:nth-child(4)::before { background: linear-gradient(90deg, #10b981, #34d399); }
.feature-card:nth-child(5)::before { background: linear-gradient(90deg, #ec4899, #f472b6); }
.feature-card:nth-child(6)::before { background: linear-gradient(90deg, #06b6d4, #22d3ee); }

.feature-icon-wrap {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 4px;
  flex-shrink: 0;
  transition: transform var(--transition);
}

.feature-card:hover .feature-icon-wrap { transform: scale(1.1); }

.icon-blue   { background: rgba(59,130,246,0.12);  }
.icon-violet { background: rgba(139,92,246,0.12);  }
.icon-amber  { background: rgba(245,158,11,0.12);  }
.icon-emerald{ background: rgba(16,185,129,0.12);  }
.icon-rose   { background: rgba(236,72,153,0.12);  }
.icon-cyan   { background: rgba(6,182,212,0.12);   }

.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.015em;
}

.feature-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.65;
  flex: 1;
}

.feature-link {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--primary);
  display: inline-block;
  margin-top: 4px;
  transition: gap var(--transition);
}

.feature-card:hover .feature-link { letter-spacing: 0.02em; }

/* ── CTA Section ──────────────────────────── */
.cta {
  background: linear-gradient(135deg, #1e3a8a 0%, #1d4ed8 55%, #4338ca 100%);
  padding: 80px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-bg-orb {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(80px);
  opacity: 0.2;
  animation: float 7s ease-in-out infinite;
}

.cta-orb-1 { width: 400px; height: 400px; background: #6366f1; top: -100px; right: -60px; animation-delay: 0s; }
.cta-orb-2 { width: 300px; height: 300px; background: #10b981; bottom: -80px; left: -40px; animation-delay: 2.5s; }

.cta-inner { position: relative; z-index: 1; }

.cta-badge {
  display: inline-flex;
  background: rgba(255,255,255,0.14);
  border: 1px solid rgba(255,255,255,0.25);
  color: white;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 5px 16px;
  border-radius: var(--radius-full);
  margin-bottom: 20px;
  letter-spacing: 0.04em;
}

.cta h2 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 900;
  color: white;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
  line-height: 1.15;
}

.cta > .container > .cta-inner > p {
  color: rgba(255,255,255,0.78);
  font-size: 1rem;
  margin-bottom: 32px;
  max-width: 440px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.65;
}

.cta-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.cta-btn-primary {
  display: inline-block;
  background: white;
  color: var(--primary-dark);
  font-weight: 800;
  font-size: 0.92rem;
  padding: 13px 28px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  box-shadow: 0 4px 20px rgba(0,0,0,0.2);
  transition: all var(--transition);
  letter-spacing: 0.01em;
}

.cta-btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0,0,0,0.28);
}

.cta-btn-ghost {
  display: inline-block;
  background: rgba(255,255,255,0.12);
  border: 1.5px solid rgba(255,255,255,0.28);
  color: white;
  font-weight: 600;
  font-size: 0.92rem;
  padding: 13px 28px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: all var(--transition);
}

.cta-btn-ghost:hover { background: rgba(255,255,255,0.22); }

/* Legacy support */
.cta-button {
  display: inline-block;
  background: white;
  color: var(--primary-dark);
  font-weight: 800;
  font-size: 0.92rem;
  padding: 13px 28px;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  font-family: inherit;
  box-shadow: 0 4px 20px rgba(0,0,0,0.2);
  transition: all var(--transition);
}

.cta-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0,0,0,0.28);
}

/* ── Footer ───────────────────────────────── */
.footer {
  background: #0f172a;
  color: rgba(255,255,255,0.6);
  padding: 60px 0 0;
  margin-top: auto;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.footer-logo-mark {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--primary), #6366f1);
  color: white;
  font-size: 0.72rem;
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.footer-brand-section p {
  font-size: 0.85rem;
  line-height: 1.65;
  margin-bottom: 18px;
}

.footer-social {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.social-link {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.12);
  color: rgba(255,255,255,0.75);
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition);
}

.social-link:hover {
  background: rgba(255,255,255,0.15);
  color: white;
}

.footer-section h3 {
  font-size: 0.95rem;
  font-weight: 800;
  color: white;
  margin-bottom: 10px;
}

.footer-section h4 {
  font-size: 0.7rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: rgba(255,255,255,0.35);
  margin-bottom: 16px;
}

.footer-section p {
  font-size: 0.85rem;
  margin-bottom: 5px;
  line-height: 1.65;
}

.footer-section ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-section ul li a,
.footer-section a {
  color: rgba(255,255,255,0.58);
  text-decoration: none;
  font-size: 0.85rem;
  transition: color var(--transition);
}

.footer-section ul li a:hover,
.footer-section a:hover {
  color: var(--accent-light);
}

.footer-bottom {
  padding: 22px 0;
  text-align: center;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.28);
}

/* ── Responsive ───────────────────────────── */
@media (max-width: 960px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-content { grid-template-columns: 1fr 1fr; }
  .footer-brand-section { grid-column: 1 / -1; }
}

@media (max-width: 768px) {
  .hamburger { display: flex; }
  .navbar { position: relative; }

  .nav-links {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: white;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 10px 16px 14px;
    gap: 2px;
    box-shadow: 0 8px 24px rgba(0,0,0,.1);
    z-index: 999;
  }

  .nav-links.active { display: flex; }
  .nav-links a { padding: 10px 12px; }

  .hero-search { padding: 56px 0 52px; }

  .hero-stats {
    flex-direction: column;
    width: 100%;
    max-width: 220px;
  }

  .hero-stat-divider { width: 100px; height: 1px; }
  .hero-content h1 { font-size: 2rem; }

  .feature-grid { grid-template-columns: 1fr; gap: 14px; }
  .features { padding: 56px 0 60px; }

  .cta { padding: 56px 0; }
  .cta-actions { flex-direction: column; align-items: center; }
  .cta-btn-primary, .cta-btn-ghost { width: 100%; max-width: 280px; text-align: center; }

  .promo-swiper .swiper-slide img { height: 200px; }

  .footer-content { grid-template-columns: 1fr; gap: 32px; }
  .footer-brand-section { grid-column: auto; }
}

@media (max-width: 480px) {
  .quick-filters { gap: 6px; }
  .filter-chip { font-size: 0.75rem; padding: 5px 11px; }
  .hero-stat { padding: 12px 22px; }
}