:root {
  --primary-500: #F48FA8;
  --primary-600: #CC3B69;
  --accent-ttc: #B79DDB;
  --accent-pregnancy: #F6A77B;
  --accent-parenting: #7AB8E8;
  --accent-ai: #E0B64F;
  --accent-mom: #F48FA8;
  --text: #1F1E19;
  --text-soft: #5b5950;
  --bg: #ffffff;
  --bg-soft: #FFF5F8;
  --border: #f0d9e2;
  --radius: 14px;
  --shadow: 0 8px 24px rgba(204, 59, 105, 0.08);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: Arial, system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

a { color: var(--primary-600); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 50;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 20px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 18px;
}
.brand:hover { text-decoration: none; }
.brand-logo {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  object-fit: cover;
}
.brand-name { letter-spacing: 0.2px; }

.site-nav { display: none; gap: 22px; }
.site-nav a {
  color: var(--text);
  font-weight: 500;
  font-size: 15px;
}
.site-nav a:hover { color: var(--primary-600); text-decoration: none; }

.lang-toggle {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--bg-soft);
  color: var(--text);
  font-family: inherit;
  font-weight: 600;
  font-size: 13px;
  padding: 8px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s ease;
}
.lang-toggle:hover { background: #ffe4ec; }
.lang-toggle .lang-sep { margin: 0 6px; color: var(--text-soft); }
.lang-toggle .lang-vi,
.lang-toggle .lang-en {
  opacity: 0.45;
  transition: opacity 0.15s ease, color 0.15s ease;
}
html[lang="vi"] .lang-toggle .lang-vi,
html[lang="en"] .lang-toggle .lang-en {
  opacity: 1;
  color: var(--primary-600);
}

@media (min-width: 768px) {
  .site-nav { display: flex; }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  font-family: inherit;
  font-weight: 700;
  font-size: 16px;
  padding: 14px 24px;
  border-radius: 12px;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.1s ease, box-shadow 0.15s ease, background 0.15s ease;
  min-height: 48px;
}
.btn-primary {
  background: var(--primary-600);
  color: #fff;
  box-shadow: var(--shadow);
}
.btn-primary:hover {
  background: #b22f5a;
  text-decoration: none;
  transform: translateY(-1px);
}

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(180deg, var(--bg-soft) 0%, #ffffff 100%);
  padding: 48px 0 56px;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: center;
}
.hero-text h1 {
  font-size: 38px;
  margin: 0 0 6px;
  color: var(--primary-600);
  letter-spacing: -0.5px;
}
.tagline {
  font-size: 20px;
  font-weight: 700;
  margin: 0 0 18px;
  color: var(--text);
}
.hero-desc {
  font-size: 16px;
  color: var(--text-soft);
  margin: 0 0 24px;
  max-width: 540px;
}
.hero-cta-row { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-visual { display: flex; justify-content: center; }
.phone-frame {
  width: 250px;
  max-width: 80vw;
  padding: 10px;
  background: #1F1E19;
  border-radius: 42px;
  box-shadow: 0 20px 40px rgba(204, 59, 105, 0.18);
}
.phone-frame img {
  width: 100%;
  border-radius: 32px;
}

@media (min-width: 768px) {
  .hero { padding: 80px 0 96px; }
  .hero-inner { grid-template-columns: 1.2fr 1fr; gap: 56px; }
  .hero-text h1 { font-size: 56px; }
  .tagline { font-size: 24px; }
  .phone-frame { width: 300px; }
}

/* ---------- Section common ---------- */
.section-title {
  font-size: 28px;
  margin: 0 0 8px;
  text-align: center;
  color: var(--text);
}
.section-sub {
  text-align: center;
  color: var(--text-soft);
  margin: 0 auto 36px;
  max-width: 640px;
  font-size: 15px;
}
@media (min-width: 768px) {
  .section-title { font-size: 36px; }
  .section-sub { font-size: 17px; margin-bottom: 48px; }
}

/* ---------- Features ---------- */
.features { padding: 64px 0; background: #fff; }
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
.feature-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 22px;
  box-shadow: var(--shadow);
  border-top: 6px solid var(--primary-500);
}
.feature-card.card-ttc        { border-top-color: var(--accent-ttc); }
.feature-card.card-pregnancy  { border-top-color: var(--accent-pregnancy); }
.feature-card.card-parenting  { border-top-color: var(--accent-parenting); }
.feature-card.card-ai         { border-top-color: var(--accent-ai); }
.feature-card.card-mom        { border-top-color: var(--accent-mom); }

.feature-icon {
  font-size: 36px;
  line-height: 1;
  margin-bottom: 10px;
}
.feature-card h3 {
  margin: 0 0 12px;
  font-size: 20px;
  color: var(--text);
}
.feature-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.feature-card li {
  padding: 6px 0 6px 22px;
  position: relative;
  font-size: 15px;
  color: var(--text-soft);
}
.feature-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 13px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary-500);
}
.card-ttc       li::before { background: var(--accent-ttc); }
.card-pregnancy li::before { background: var(--accent-pregnancy); }
.card-parenting li::before { background: var(--accent-parenting); }
.card-ai        li::before { background: var(--accent-ai); }
.card-mom       li::before { background: var(--accent-mom); }

.feature-note {
  margin: 14px 0 0;
  font-size: 12.5px;
  font-style: italic;
  color: var(--text-soft);
  opacity: 0.85;
}

@media (min-width: 768px) {
  .features { padding: 96px 0; }
  .features-grid { grid-template-columns: repeat(3, 1fr); gap: 24px; }
  .feature-card { padding: 32px 28px; }
}

/* ---------- Screenshots gallery ---------- */
.screens { padding: 64px 0; background: var(--bg-soft); }
.screens-track {
  display: flex;
  gap: 18px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 4px 4px 16px;
  -webkit-overflow-scrolling: touch;
}
.screen-shot {
  flex: 0 0 auto;
  width: 210px;
  margin: 0;
  scroll-snap-align: start;
}
.screen-shot img {
  width: 100%;
  border-radius: 22px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  background: #fff;
}
.screen-shot figcaption {
  margin-top: 10px;
  text-align: center;
  font-size: 13.5px;
  color: var(--text-soft);
}
@media (min-width: 768px) {
  .screens { padding: 96px 0; }
  .screen-shot { width: 230px; }
}

/* ---------- FAQ ---------- */
.faq { padding: 64px 0; background: var(--bg-soft); }
.faq-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  padding: 0;
  overflow: hidden;
}
.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 18px 24px;
  font-weight: 600;
  font-size: 16px;
  position: relative;
  padding-right: 48px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 22px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 24px;
  color: var(--primary-600);
  font-weight: 400;
  transition: transform 0.2s ease;
}
.faq-item[open] summary::after { content: "−"; }
.faq-item p {
  padding: 0 24px 20px;
  margin: 0;
  color: var(--text-soft);
  font-size: 15px;
}

@media (min-width: 768px) {
  .faq { padding: 96px 0; }
}

/* ---------- Contact ---------- */
.contact { padding: 64px 0; text-align: center; }
.contact-inner p {
  color: var(--text-soft);
  max-width: 520px;
  margin: 0 auto 24px;
}
@media (min-width: 768px) {
  .contact { padding: 96px 0; }
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--text);
  color: #f4eaea;
  padding: 28px 0;
}
.site-footer .container { padding: 0 20px; }
.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: center;
  justify-content: space-between;
  font-size: 14px;
  text-align: center;
}
.site-footer a { color: var(--primary-500); }
.site-footer a:hover { color: #fff; }
.site-footer nav span { margin: 0 6px; opacity: 0.5; }

@media (min-width: 768px) {
  .footer-inner { flex-direction: row; text-align: left; }
}

/* ---------- Legal pages (privacy/terms) ---------- */
.legal { padding: 48px 0 80px; }
.legal h1 {
  color: var(--primary-600);
  font-size: 32px;
  margin: 0 0 8px;
}
.legal .updated {
  color: var(--text-soft);
  font-size: 14px;
  margin-bottom: 32px;
}
.legal h2 {
  font-size: 20px;
  margin: 28px 0 10px;
}
.legal p, .legal li {
  color: var(--text-soft);
  font-size: 15px;
}
.legal ul { padding-left: 22px; }
.legal a { color: var(--primary-600); }

@media (min-width: 768px) {
  .legal { padding: 64px 0 96px; }
  .legal h1 { font-size: 40px; }
  .legal h2 { font-size: 22px; }
}