/* ==========================================================================
   FB Contact Pro — site-01 (phong cách tối giản, cảm hứng danieltriendl.com)
   ========================================================================== */

:root {
  --bg: #fafafa;
  --bg-tint: #f2f1ee;
  --bg-dark: #131313;
  --text: #141414;
  --text-muted: #6b6b66;
  --border: #e4e2dd;
  --accent: #8a6a4c;
  --accent-soft: #efe8e0;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-display: "Inter Tight", "Inter", -apple-system, sans-serif;
  --wrap-max: 1160px;

  /* Override buy-modal palette để hợp tông sáng/tối giản */
  --buy-modal-accent: #8a6a4c;
  --buy-modal-accent-text: #ffffff;
  --buy-modal-bg: #ffffff;
  --buy-modal-text: #141414;
  --buy-modal-muted: #6b6b66;
  --buy-modal-border: #e4e2dd;
  --buy-modal-radius: 4px;
  --buy-modal-font: "Inter", -apple-system, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--wrap-max);
  margin: 0 auto;
  padding: 0 32px;
}

a { color: inherit; }

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

/* ---------- Fade-in on scroll ---------- */
[data-fade] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
[data-fade].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  text-decoration: none;
  letter-spacing: -0.01em;
}

.nav {
  display: flex;
  gap: 32px;
}

.nav a {
  font-size: 14.5px;
  text-decoration: none;
  color: var(--text-muted);
  position: relative;
  padding-bottom: 2px;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: -2px;
  height: 1px;
  background: var(--text);
  transition: right 0.25s ease;
}

.nav a:hover {
  color: var(--text);
}

.nav a:hover::after {
  right: 0;
}

/* ---------- Buttons ---------- */
.btn-cta {
  appearance: none;
  border: none;
  cursor: pointer;
  background: var(--text);
  color: var(--bg);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 14.5px;
  padding: 13px 26px;
  border-radius: 100px;
  transition: transform 0.2s ease, background 0.2s ease;
}

.btn-cta:hover {
  background: var(--accent);
  transform: translateY(-2px);
}

.btn-cta--small {
  padding: 10px 20px;
  font-size: 13.5px;
}

.btn-cta--large {
  padding: 17px 38px;
  font-size: 16px;
}

.btn-cta--onlight {
  background: #fff;
  color: var(--bg-dark);
}

.btn-cta--onlight:hover {
  background: var(--accent);
  color: #fff;
}

.btn-ghost {
  text-decoration: none;
  font-weight: 600;
  font-size: 14.5px;
  color: var(--text);
  padding: 13px 6px;
  position: relative;
}

.btn-ghost::after {
  content: "";
  position: absolute;
  left: 6px;
  right: 100%;
  bottom: 10px;
  height: 1px;
  background: var(--text);
  transition: right 0.25s ease;
}

.btn-ghost:hover::after {
  right: 6px;
}

/* ---------- Hero ---------- */
.hero {
  padding: 96px 0 72px;
}

.hero-inner {
  max-width: 880px;
}

.eyebrow {
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 20px;
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 0.98;
  margin: 0 0 28px;
  font-size: clamp(2.6rem, 7vw, 5.6rem);
}

.hero-tagline {
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 0 40px;
  font-weight: 400;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.hero-price {
  font-size: 14px;
  color: var(--text-muted);
}

/* ---------- Mockup (thuần CSS) ---------- */
.mockup {
  margin-top: 56px;
}

.mockup-browser {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 30px 70px -30px rgba(20, 20, 20, 0.25);
}

.mockup-browser-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-tint);
}

.mockup-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #d8d5cd;
  display: inline-block;
}

.mockup-url {
  margin-left: 12px;
  font-size: 12.5px;
  color: var(--text-muted);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 5px 14px;
  flex: 1;
  max-width: 340px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.mockup-browser-body {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 0;
  min-height: 320px;
}

.mockup-feed {
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  border-right: 1px solid var(--border);
}

.mockup-post {
  height: 76px;
  border-radius: 8px;
  background: linear-gradient(90deg, var(--bg-tint) 0%, #ecebe6 50%, var(--bg-tint) 100%);
}

.mockup-post.short {
  height: 44px;
  width: 70%;
}

.mockup-popup {
  padding: 24px;
  background: var(--bg-tint);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.mockup-popup-head {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 14px;
}

.mockup-popup-row {
  display: flex;
  justify-content: space-between;
  font-size: 12.5px;
  color: var(--text-muted);
}

.mockup-popup-bar {
  height: 6px;
  border-radius: 100px;
  background: var(--border);
  overflow: hidden;
}

.mockup-popup-bar span {
  display: block;
  width: 62%;
  height: 100%;
  background: var(--accent);
  animation: mockup-progress 3.2s ease-in-out infinite alternate;
}

@keyframes mockup-progress {
  from { width: 30%; }
  to { width: 82%; }
}

.mockup-popup-table {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.mockup-popup-tr {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
}

.mockup-popup-tr:last-child {
  border-bottom: none;
}

/* ---------- Sections ---------- */
.section {
  padding: 108px 0;
}

.section--tinted {
  background: var(--bg-tint);
}

.section--dark {
  background: var(--bg-dark);
  color: #fafafa;
  padding: 120px 0;
}

.section-title {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.08;
  font-size: clamp(1.9rem, 4vw, 3.1rem);
  margin: 0 0 20px;
}

.section-sub {
  color: var(--text-muted);
  font-size: clamp(1rem, 1.6vw, 1.15rem);
  max-width: 560px;
  margin: 0 0 64px;
}

/* ---------- Feature list (dạng dòng văn bản lớn, KHÔNG card box) ---------- */
.feature-list {
  display: flex;
  flex-direction: column;
}

.feature-row {
  display: grid;
  grid-template-columns: 64px 1fr 1.4fr;
  gap: 32px;
  align-items: baseline;
  padding: 34px 0;
  border-top: 1px solid var(--border);
  transition: padding-left 0.3s ease;
}

.feature-list .feature-row:last-child {
  border-bottom: 1px solid var(--border);
}

.feature-row:hover {
  padding-left: 12px;
}

.feature-icon {
  font-size: 26px;
  line-height: 1;
}

.feature-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.15rem, 2vw, 1.5rem);
  letter-spacing: -0.01em;
}

.feature-desc {
  color: var(--text-muted);
  font-size: 15.5px;
  max-width: 620px;
}

/* ---------- Steps (cách hoạt động) ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 40px;
}

.step {
  border-top: 1px solid var(--border);
  padding-top: 24px;
}

.step-num {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 14px;
  color: var(--accent);
  margin-bottom: 18px;
}

.step h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  margin: 0 0 10px;
  letter-spacing: -0.01em;
}

.step p {
  color: var(--text-muted);
  font-size: 14.5px;
  margin: 0;
}

/* ---------- Use cases ---------- */
.usecase-list {
  display: flex;
  flex-direction: column;
}

.usecase-row {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: 32px;
  padding: 30px 0;
  border-top: 1px solid var(--border);
  transition: padding-left 0.3s ease;
}

.usecase-list .usecase-row:last-child {
  border-bottom: 1px solid var(--border);
}

.usecase-row:hover {
  padding-left: 12px;
}

.usecase-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.05rem, 1.8vw, 1.3rem);
  letter-spacing: -0.01em;
}

.usecase-desc {
  color: var(--text-muted);
  font-size: 15px;
}

/* ---------- Pricing ---------- */
.pricing-wrap {
  text-align: center;
}

.pricing-wrap .section-sub {
  margin-left: auto;
  margin-right: auto;
}

.pricing-box {
  max-width: 480px;
  margin: 0 auto;
  padding: 56px 40px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
}

.pricing-amount {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  font-size: clamp(2rem, 5vw, 2.8rem);
  margin-bottom: 12px;
}

.pricing-note {
  color: var(--text-muted);
  font-size: 14px;
  margin: 0 0 32px;
}

/* ---------- FAQ ---------- */
.faq-list {
  display: flex;
  flex-direction: column;
}

.faq-item {
  border-top: 1px solid var(--border);
  padding: 26px 0;
}

.faq-list .faq-item:last-child {
  border-bottom: 1px solid var(--border);
}

.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.02rem, 1.8vw, 1.2rem);
  color: var(--text);
  padding: 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}

.faq-question-plus {
  font-size: 22px;
  font-weight: 400;
  color: var(--accent);
  transition: transform 0.25s ease;
  flex-shrink: 0;
}

.faq-item.is-open .faq-question-plus {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, margin-top 0.3s ease;
}

.faq-item.is-open .faq-answer {
  max-height: 520px;
  margin-top: 16px;
}

.faq-answer p {
  color: var(--text-muted);
  font-size: 15px;
  margin: 0;
  max-width: 700px;
}

/* ---------- Final CTA ---------- */
.cta-final-inner {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.cta-final-title {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
  font-size: clamp(1.8rem, 4.5vw, 3rem);
  max-width: 760px;
  margin: 0 0 40px;
}

.contact-channels {
  margin-top: 36px;
  display: flex;
  gap: 28px;
}

.contact-channels a {
  text-decoration: none;
  font-size: 14.5px;
  font-weight: 600;
  color: #d8d5cd;
  position: relative;
  padding-bottom: 2px;
}

.contact-channels a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 100%;
  bottom: -2px;
  height: 1px;
  background: #fff;
  transition: right 0.25s ease;
}

.contact-channels a:hover {
  color: #fff;
}

.contact-channels a:hover::after {
  right: 0;
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--bg-dark);
  color: #a3a39c;
  padding: 32px 0 48px;
}

.footer-disclaimer {
  font-size: 12px;
  line-height: 1.7;
  max-width: 760px;
  color: #82827b;
  margin: 0 0 20px;
}

.footer-copy {
  font-size: 12px;
  margin: 0;
  color: #6b6b66;
}

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .nav { display: none; }

  .mockup-browser-body { grid-template-columns: 1fr; }
  .mockup-feed { border-right: none; border-bottom: 1px solid var(--border); }

  .feature-row {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .feature-icon { font-size: 22px; }

  .steps { grid-template-columns: 1fr 1fr; }

  .usecase-row { grid-template-columns: 1fr; gap: 8px; }
}

@media (max-width: 560px) {
  .wrap { padding: 0 20px; }
  .hero { padding: 64px 0 48px; }
  .section { padding: 72px 0; }
  .section--dark { padding: 84px 0; }
  .steps { grid-template-columns: 1fr; gap: 32px; }
  .pricing-box { padding: 40px 24px; }
  .contact-channels { flex-direction: column; gap: 14px; }
  .hero-actions { gap: 14px; }
}