/* ===== Design Tokens ===== */
:root {
  --bg: #FBF8F4;
  --surface: #FFFFFF;
  --text: #2C2418;
  --text-secondary: #6B5D4D;
  --text-muted: #A89A8A;
  --accent: #8B7355;
  --accent-soft: rgba(139, 115, 85, 0.1);
  --bird-blue: #7BADC8;
  --bird-blue-soft: rgba(123, 173, 200, 0.12);
  --border: #E8E0D6;
  --radius: 16px;
  --radius-sm: 10px;

  --font: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* ===== Layout ===== */
.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 96px 0;
}

/* ===== Nav ===== */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(251, 248, 244, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
}

.nav-brand img {
  width: 34px;
  height: 34px;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 24px;
}

.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 6px 12px;
  transition: border-color 0.2s, color 0.2s;
  white-space: nowrap;
}

.lang-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.lang-toggle svg {
  flex-shrink: 0;
}

.nav-cta {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  transition: opacity 0.2s;
}

.nav-cta:hover { opacity: 0.7; }

/* ===== Hero ===== */
.hero {
  padding: 80px 0 40px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.hero-logo {
  width: 170px;
  height: 170px;
  margin: 0 auto 32px;
}

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.hero-subtitle {
  font-size: 20px;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 40px;
  line-height: 1.6;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 36px;
  border-radius: var(--radius);
  background: var(--accent);
  color: #fff;
  font-size: 17px;
  font-weight: 600;
  transition: transform 0.2s, opacity 0.2s;
}

.hero-cta:hover { opacity: 0.9; transform: translateY(-1px); }

.hero-reassurance {
  margin-top: 16px;
  font-size: 14px;
  color: var(--text-muted);
}

/* ===== Section headers ===== */
.section-title {
  font-size: 36px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
  letter-spacing: -0.3px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 18px;
  max-width: 520px;
  margin: 0 auto 56px;
}

/* ===== How it works ===== */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.step {
  position: relative;
  text-align: center;
  padding: 40px 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.step-number {
  position: absolute;
  top: 14px;
  left: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--bird-blue-soft);
  color: var(--bird-blue);
  font-size: 12px;
  font-weight: 700;
}

.step-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  color: var(--bird-blue);
}

.step h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 10px;
}

.step p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.6;
}

/* ===== Science ===== */
.science {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.science-content {
  display: flex;
  align-items: center;
  gap: 64px;
}

.science-text { flex: 1; }

.science-text h2 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 16px;
}

.science-text p {
  color: var(--text-secondary);
  font-size: 17px;
  line-height: 1.7;
}

.science-illustration {
  flex-shrink: 0;
  width: 200px;
  height: 200px;
  color: var(--bird-blue);
}

/* ===== Features ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.feature {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.feature-icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  color: var(--bird-blue);
}

.feature h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 6px;
}

.feature p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* ===== Testimonials ===== */
.testimonials {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial {
  padding: 32px;
  background: var(--bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.testimonial-quote {
  font-size: 16px;
  font-style: italic;
  line-height: 1.65;
  color: var(--text);
  margin-bottom: 16px;
}

.testimonial-author {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
}

/* ===== FAQ ===== */
.faq-list {
  max-width: 680px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-item summary {
  padding: 20px 24px;
  font-size: 17px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  transition: color 0.2s;
}

.faq-item summary:hover { color: var(--accent); }

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: '+';
  font-size: 20px;
  font-weight: 400;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: transform 0.2s;
}

.faq-item[open] summary::after {
  content: '\2212';
}

.faq-item p {
  padding: 0 24px 20px;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.65;
}

/* ===== Download CTA ===== */
.download {
  text-align: center;
}

.download h2 {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 16px;
}

.download p {
  color: var(--text-secondary);
  font-size: 18px;
  margin-bottom: 36px;
}

/* ===== Footer ===== */
footer {
  padding: 48px 0;
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.footer-links {
  display: flex;
  gap: 32px;
}

.footer-links a {
  font-size: 14px;
  color: var(--text-secondary);
  transition: color 0.2s;
}

.footer-links a:hover { color: var(--accent); }

.footer-copy {
  font-size: 13px;
  color: var(--text-muted);
}

/* ===== Scroll animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: none;
}

/* ===== Legal pages ===== */
.legal-header {
  padding: 64px 0 32px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.legal-header h1 {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 8px;
}

.legal-header p {
  color: var(--text-muted);
  font-size: 15px;
}

.legal-content {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 24px 96px;
}

.legal-content h2 {
  font-size: 22px;
  font-weight: 700;
  margin: 40px 0 12px;
}

.legal-content h2:first-child { margin-top: 0; }

.legal-content p,
.legal-content li {
  color: var(--text-secondary);
  font-size: 16px;
  line-height: 1.7;
  margin-bottom: 12px;
}

.legal-content ul {
  list-style: disc;
  padding-left: 24px;
  margin-bottom: 16px;
}

.legal-content a {
  color: var(--accent);
  text-decoration: underline;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  section { padding: 64px 0; }

  .hero h1 { font-size: 34px; }
  .hero-subtitle { font-size: 17px; }
  .hero-logo { width: 110px; height: 110px; }

  .section-title { font-size: 28px; }
  .section-subtitle { font-size: 16px; }

  .steps { grid-template-columns: 1fr; gap: 16px; }
  .features-grid { grid-template-columns: 1fr; }
  .testimonials-grid { grid-template-columns: 1fr; }

  .science-content { flex-direction: column; gap: 32px; text-align: center; }
  .science-illustration { width: 140px; height: 140px; }

  .footer-inner { flex-direction: column; gap: 20px; text-align: center; }
  .footer-links { flex-wrap: wrap; justify-content: center; }

  .download h2 { font-size: 28px; }
}