/* ============================================================
   VieEdu Landing — Green theme
   ============================================================ */

:root {
  --primary: #16a34a;
  --primary-dark: #15803d;
  --primary-light: #22c55e;
  --primary-pale: #dcfce7;
  --primary-paler: #f0fdf4;
  --accent: #f59e0b;
  --text: #1f2937;
  --text-muted: #6b7280;
  --border: #e5e7eb;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: white;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

h1, h2, h3, h4 { color: var(--text); font-weight: 700; line-height: 1.25; }

/* ============ Buttons ============ */
.btn-primary, .btn-secondary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 22px; border-radius: 10px; font-weight: 600; font-size: 15px;
  border: 2px solid transparent; cursor: pointer; transition: all 0.2s; font-family: inherit;
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary-light), var(--primary));
  color: white; box-shadow: 0 2px 8px rgba(22, 163, 74, 0.25);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(22, 163, 74, 0.4);
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
}
.btn-secondary { background: white; color: var(--primary); border-color: var(--primary); }
.btn-secondary:hover { background: var(--primary-paler); }
.btn-primary.big, .btn-secondary.big { padding: 14px 32px; font-size: 16px; font-weight: 700; }

/* ============ Header ============ */
.site-header {
  position: sticky; top: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 50;
}
.nav { display: flex; justify-content: space-between; align-items: center; padding: 14px 24px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand img { width: 44px; height: 44px; border-radius: 10px; object-fit: contain; }
.brand-name { font-size: 22px; font-weight: 800; color: var(--primary-dark); }
.brand-name span { color: var(--accent); }
.nav nav { display: flex; align-items: center; gap: 28px; }
.nav nav a:not(.btn-primary) {
  color: var(--text); font-weight: 500; font-size: 15px; transition: color 0.15s;
}
.nav nav a:not(.btn-primary):hover { color: var(--primary); }

/* ============ Hero ============ */
.hero {
  background: linear-gradient(135deg, var(--primary-paler) 0%, var(--primary-pale) 100%);
  padding: 80px 0 100px; position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute;
  width: 600px; height: 600px;
  background: radial-gradient(circle, var(--primary-light) 0%, transparent 70%);
  opacity: 0.15; top: -200px; right: -200px; border-radius: 50%;
}
.hero-grid {
  display: grid; grid-template-columns: 1.5fr 1fr; gap: 48px; align-items: center; position: relative;
}
.hero-left { z-index: 2; }
.badge {
  display: inline-block; background: white; color: var(--primary-dark);
  padding: 8px 18px; border-radius: 999px; font-size: 13px; font-weight: 600;
  border: 1px solid var(--primary-pale); margin-bottom: 24px;
  box-shadow: 0 2px 8px rgba(22, 163, 74, 0.08);
}
.hero h1 {
  font-size: 56px; font-weight: 800; line-height: 1.15;
  margin-bottom: 20px; letter-spacing: -1px;
}
.hero h1 span {
  background: linear-gradient(135deg, var(--primary-light), var(--primary-dark));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.hero .lead { font-size: 18px; margin-bottom: 32px; max-width: 600px; line-height: 1.7; }
.hero .lead strong { color: var(--primary-dark); }
.cta-row { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 48px; }
.hero-stats { display: flex; gap: 36px; flex-wrap: wrap; }
.hero-stats > div { display: flex; flex-direction: column; }
.hero-stats strong { font-size: 32px; color: var(--primary-dark); font-weight: 800; line-height: 1; }
.hero-stats span { font-size: 14px; color: var(--text-muted); margin-top: 4px; }
.hero-right { display: flex; justify-content: center; align-items: center; }
.hero-logo {
  width: 100%; max-width: 380px;
  filter: drop-shadow(0 16px 40px rgba(22, 163, 74, 0.2));
  animation: float 4s ease-in-out infinite;
}
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-12px); } }

/* ============ Section general ============ */
section { padding: 80px 0; }
section h2 {
  font-size: 38px; text-align: center; margin-bottom: 12px;
  font-weight: 800; letter-spacing: -0.5px;
}
.section-sub {
  text-align: center; color: var(--text-muted); font-size: 17px;
  margin-bottom: 48px; max-width: 700px; margin-left: auto; margin-right: auto;
}

/* ============ Features ============ */
.features { background: white; }
.features .grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature {
  background: var(--primary-paler); padding: 32px 28px; border-radius: 16px;
  border: 1px solid var(--primary-pale); transition: transform 0.2s, box-shadow 0.2s;
}
.feature:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(22, 163, 74, 0.12); }
.feature .icon { font-size: 36px; margin-bottom: 16px; }
.feature h3 { font-size: 19px; margin-bottom: 8px; color: var(--primary-dark); }
.feature p { font-size: 15px; color: var(--text-muted); line-height: 1.65; }

/* ============ Meaning ============ */
.meaning { background: linear-gradient(180deg, var(--primary-paler) 0%, white 100%); }
.meaning-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.meaning-card {
  background: white; padding: 32px 28px; border-radius: 16px;
  border-left: 4px solid var(--primary); box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
  transition: transform 0.2s, box-shadow 0.2s;
}
.meaning-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(22, 163, 74, 0.12); }
.meaning-icon { font-size: 40px; margin-bottom: 12px; }
.meaning-card h3 { font-size: 18px; margin-bottom: 10px; color: var(--primary-dark); }
.meaning-card p { font-size: 15px; color: var(--text-muted); line-height: 1.7; }

/* ============ Screenshots ============ */
.screenshots { background: var(--primary-paler); }
.screenshot-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.screenshot {
  background: white; border-radius: 14px; overflow: hidden;
  box-shadow: 0 8px 30px rgba(22, 163, 74, 0.15); transition: transform 0.25s;
}
.screenshot:hover { transform: translateY(-6px) scale(1.02); box-shadow: 0 16px 40px rgba(22, 163, 74, 0.25); }
.screenshot img {
  width: 100%; display: block; aspect-ratio: 16/10;
  object-fit: cover; object-position: top center;
  border-bottom: 1px solid var(--border);
  background: var(--primary-paler);
}
.screenshot figcaption { padding: 18px 20px; }
.screenshot figcaption strong { display: block; font-size: 16px; color: var(--primary-dark); margin-bottom: 4px; }
.screenshot figcaption span { font-size: 14px; color: var(--text-muted); }

/* ============ Subjects ============ */
.subjects { background: white; }
.subj-grid {
  display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px;
  max-width: 980px; margin: 0 auto;
}
.subj-grid span {
  background: var(--primary-paler); border: 1px solid var(--primary-pale);
  padding: 14px 16px; border-radius: 10px; text-align: center;
  font-weight: 600; font-size: 14px; color: var(--primary-dark); transition: all 0.15s;
}
.subj-grid span:hover { background: var(--primary-pale); transform: scale(1.03); }

/* ============ Schools ============ */
.schools { background: linear-gradient(180deg, white 0%, var(--primary-paler) 100%); }
.cols { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; margin-bottom: 48px; }
.cols > div {
  background: white; padding: 32px; border-radius: 16px;
  border: 1px solid var(--border); box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04);
}
.cols h3 { color: var(--primary-dark); margin-bottom: 16px; font-size: 20px; }
.cols ul { list-style: none; }
.cols li {
  padding: 8px 0; padding-left: 28px; position: relative;
  color: var(--text); font-size: 15px;
}
.cols li::before { content: '✓'; position: absolute; left: 0; color: var(--primary); font-weight: 700; }
.cols code {
  background: var(--primary-paler); color: var(--primary-dark);
  padding: 2px 8px; border-radius: 4px; font-family: 'SF Mono', Consolas, monospace; font-size: 13px;
}

#lead-form {
  background: white; padding: 32px; border-radius: 16px;
  border: 2px solid var(--primary-pale); max-width: 900px; margin: 0 auto;
}
#lead-form h3 { color: var(--primary-dark); margin-bottom: 18px; text-align: center; font-size: 20px; }
.form-row { display: grid; grid-template-columns: 1.5fr 1.5fr 1fr auto; gap: 10px; }
.form-row input {
  padding: 12px 16px; border: 1.5px solid var(--border); border-radius: 8px;
  font-size: 15px; font-family: inherit;
}
.form-row input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(22, 163, 74, 0.12); }
#lead-msg { margin-top: 12px; text-align: center; color: var(--primary-dark); font-weight: 600; }

/* ============ Final CTA ============ */
.cta-final {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: white; text-align: center;
}
.cta-final h2 { color: white; font-size: 40px; margin-bottom: 16px; }
.cta-final p { color: rgba(255, 255, 255, 0.9); font-size: 18px; margin-bottom: 32px; }
.cta-final .btn-primary { background: white; color: var(--primary-dark); box-shadow: 0 4px 16px rgba(0,0,0,0.2); }
.cta-final .btn-primary:hover { background: var(--primary-paler); }
.cta-final .btn-secondary { background: transparent; color: white; border-color: white; }
.cta-final .btn-secondary:hover { background: rgba(255, 255, 255, 0.1); }

/* ============ Footer ============ */
.site-footer { background: #0f1419; color: #d1d5db; padding: 60px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 32px; margin-bottom: 32px; }
.site-footer .brand { margin-bottom: 12px; }
.site-footer .brand-name { color: white; }
.site-footer .brand-name span { color: var(--accent); }
.site-footer p { color: #9ca3af; font-size: 14px; line-height: 1.6; max-width: 360px; }
.site-footer h4 { color: white; font-size: 15px; margin-bottom: 16px; }
.site-footer a { display: block; color: #9ca3af; font-size: 14px; padding: 4px 0; transition: color 0.15s; }
.site-footer a:hover { color: var(--primary-light); }
.copy { border-top: 1px solid #1f2937; padding-top: 20px; text-align: center; font-size: 13px; color: #6b7280; }

/* ============ Responsive ============ */
@media (max-width: 968px) {
  .hero-grid { grid-template-columns: 1fr; gap: 32px; }
  .hero-right { order: -1; }
  .hero-logo { max-width: 220px; }
  .hero h1 { font-size: 40px; }
  .features .grid, .meaning-grid, .screenshot-grid { grid-template-columns: repeat(2, 1fr); }
  .subj-grid { grid-template-columns: repeat(3, 1fr); }
  .cols { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  section h2 { font-size: 30px; }
  .cta-final h2 { font-size: 30px; }
}

@media (max-width: 600px) {
  .nav nav { gap: 12px; font-size: 13px; }
  .nav nav a:not(.btn-primary) { display: none; }
  .hero { padding: 48px 0 56px; }
  .hero h1 { font-size: 32px; }
  .hero .lead { font-size: 16px; }
  .hero-stats { gap: 20px; }
  .hero-stats strong { font-size: 24px; }
  section { padding: 56px 0; }
  section h2 { font-size: 24px; }
  .features .grid, .meaning-grid, .screenshot-grid { grid-template-columns: 1fr; }
  .subj-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }
}