/* ==========================================================================
   NAM NGUYỄN TECH — Components
   ========================================================================== */

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  border: 1px solid transparent;
  transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
  white-space: nowrap;
}

.btn:active {
  transform: translateY(1px);
}

.btn--primary {
  background: var(--primary);
  color: #fff;
}

.btn--primary:hover {
  background: var(--primary-dark);
}

.btn--ghost {
  background: transparent;
  color: var(--primary);
  border-color: var(--border);
}

.btn--ghost:hover {
  border-color: var(--primary);
  background: var(--primary-soft);
}

.btn--on-dark {
  background: #fff;
  color: var(--primary-dark);
}

.btn--on-dark:hover {
  background: var(--text-inverse);
}

.btn--ghost-on-dark {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.35);
}

.btn--ghost-on-dark:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.btn--block {
  width: 100%;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border);
}

/* Hiệu ứng nền mờ kính được tách ra pseudo-element thay vì đặt trực tiếp
   trên .site-header. Lý do: backdrop-filter/filter trên .site-header sẽ
   biến nó thành "containing block" cho .main-nav (position: fixed) bên
   trong — khiến menu mobile bị ép gọn trong khung header thay vì phủ toàn
   màn hình (bug đặc biệt rõ trên Safari/iOS). Tách blur ra pseudo-element
   (không phải ancestor của .main-nav) để tránh lỗi này. */
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: rgba(247, 249, 252, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: 76px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--primary-dark);
}

.brand__logo {
  display: block;
  width: 36px;
  height: 36px;
  object-fit: contain;
  flex-shrink: 0;
}

.footer-brand .brand__logo {
  width: 32px;
  height: 32px;
}

.brand__mark {
  color: var(--primary);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.main-nav a {
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.main-nav a:hover,
.main-nav a[aria-current="page"] {
  color: var(--primary);
  background: var(--primary-soft);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
}

.nav-toggle__bars,
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.nav-toggle__bars::before {
  transform: translateY(-6px);
}

.nav-toggle__bars::after {
  transform: translateY(4px);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before {
  transform: translateY(0) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after {
  transform: translateY(-2px) rotate(-45deg);
}

/* ---------- Hero ---------- */
.hero {
  padding-top: 72px;
  padding-bottom: 72px;
  background:
    radial-gradient(600px 320px at 88% -10%, rgba(31, 78, 121, 0.10), transparent 60%),
    var(--background);
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  padding: 7px 16px;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.hero__headline {
  margin-top: 22px;
  max-width: 16ch;
}

.hero__sub {
  margin-top: 18px;
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--primary-dark);
}

.hero__desc {
  margin-top: 16px;
  max-width: 56ch;
  font-size: 1.0625rem;
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.hero__meta {
  margin-top: 40px;
  font-size: 0.875rem;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

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

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

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.problem-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 28px;
}

.problem-card__index {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0.05em;
}

.problem-card h3 {
  margin-top: 12px;
}

.problem-card p {
  margin-top: 10px;
  font-size: 0.975rem;
}

.section-note {
  margin-top: 36px;
  padding: 18px 22px;
  border-left: 3px solid var(--primary);
  background: var(--primary-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.975rem;
  color: var(--primary-dark);
}

.section-note--center {
  text-align: center;
  border-left: none;
  border-top: 3px solid var(--primary);
  border-radius: var(--radius-sm);
}

/* ---------- Service card ---------- */
.service-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: box-shadow var(--transition-base), border-color var(--transition-base), transform var(--transition-base);
}

.service-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.service-card__num {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.06em;
}

.service-card__link {
  margin-top: auto;
  font-weight: 600;
  color: var(--primary);
  font-size: 0.95rem;
}

/* ---------- Solution card ---------- */
.solution-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 26px;
}

.solution-card h3 {
  margin-bottom: 14px;
}

.solution-card__row {
  display: flex;
  gap: 10px;
  font-size: 0.925rem;
  padding-block: 8px;
  border-top: 1px solid var(--border);
}

.solution-card__row:first-of-type {
  border-top: none;
}

.solution-card__row-label {
  flex: 0 0 88px;
  font-weight: 600;
  color: var(--text);
}

.solution-card__row-value {
  color: var(--text-muted);
}

/* ---------- Process steps ---------- */
.process-list {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
}

.process-step {
  position: relative;
  padding-top: 20px;
  border-top: 2px solid var(--border);
}

.process-step__num {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.process-step h3 {
  margin-top: 10px;
}

.process-step p {
  margin-top: 8px;
  font-size: 0.95rem;
}

/* ---------- Project card ---------- */
.project-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 32px;
}

.filter-btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  padding: 9px 18px;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 500;
  transition: background var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}

.filter-btn[aria-pressed="true"] {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.project-card__media {
  aspect-ratio: 16 / 10;
  background: var(--primary-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 600;
}

.project-card__body {
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
}

.project-card__tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.tag {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-soft);
  padding: 4px 10px;
  border-radius: 999px;
}

.project-card__link {
  margin-top: auto;
  font-weight: 600;
  color: var(--primary);
  font-size: 0.9rem;
}

.empty-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: 64px 24px;
  border: 1px dashed var(--border);
  border-radius: var(--radius-md);
  color: var(--text-muted);
}

/* ---------- Article card ---------- */
.article-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 26px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.article-card__cat {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.article-card__link {
  margin-top: auto;
  font-weight: 600;
  color: var(--primary);
  font-size: 0.9rem;
}

/* ---------- FAQ ---------- */
.faq-list {
  max-width: 760px;
  margin-inline: auto;
}

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

.faq-item__question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 22px 4px;
  background: transparent;
  border: none;
  text-align: left;
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--text);
}

.faq-item__icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  position: relative;
}

.faq-item__icon::before,
.faq-item__icon::after {
  content: "";
  position: absolute;
  background: var(--primary);
  border-radius: 2px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.faq-item__icon::before {
  width: 14px;
  height: 2px;
}

.faq-item__icon::after {
  width: 2px;
  height: 14px;
  transition: transform var(--transition-fast);
}

.faq-item__question[aria-expanded="true"] .faq-item__icon::after {
  transform: translate(-50%, -50%) rotate(90deg) scale(0);
}

.faq-item__answer {
  overflow: hidden;
  max-height: 0;
  transition: max-height var(--transition-base);
}

.faq-item__answer p {
  padding: 0 4px 22px;
  font-size: 0.975rem;
}

/* ---------- CTA band ---------- */
.cta-band {
  text-align: center;
  padding: 72px 24px;
  border-radius: var(--radius-lg);
  background: var(--primary-dark);
  color: #fff;
}

.cta-band h2 {
  color: #fff;
}

.cta-band p {
  margin-top: 14px;
  color: rgba(247, 249, 252, 0.78);
  max-width: 52ch;
  margin-inline: auto;
}

.cta-band__actions {
  margin-top: 30px;
  display: flex;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

/* ---------- Local strip ---------- */
.local-strip {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 28px;
}

.local-pill {
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-weight: 600;
  font-size: 0.925rem;
  color: var(--primary-dark);
}

/* ---------- Why-us list ---------- */
.why-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.why-item {
  display: flex;
  gap: 16px;
}

.why-item__mark {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: var(--primary-soft);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

.why-item h3 {
  margin-bottom: 6px;
}

.why-item p {
  font-size: 0.975rem;
}

/* ---------- AI application grid ---------- */
.ai-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.ai-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
}

.ai-card__icon {
  width: 44px;
  height: 44px;
  margin-inline: auto;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

.ai-card h3 {
  margin-top: 14px;
  font-size: 1.02rem;
}

/* ---------- Forms ---------- */
.form-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-field--full {
  grid-column: 1 / -1;
}

.form-field label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
}

.form-field input,
.form-field textarea,
.form-field select {
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  transition: border-color var(--transition-fast);
}

.form-field input:focus,
.form-field textarea:focus,
.form-field select:focus {
  border-color: var(--primary);
}

.checkbox-group {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.checkbox-pill {
  position: relative;
}

.checkbox-pill input {
  position: absolute;
  opacity: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
  margin: 0;
}

.checkbox-pill span {
  display: inline-flex;
  padding: 9px 16px;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-size: 0.9rem;
  font-weight: 500;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.checkbox-pill input:checked + span {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

.checkbox-pill input:focus-visible + span {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.form-status {
  margin-top: 16px;
  font-size: 0.925rem;
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  display: none;
}

.form-status--success {
  display: block;
  background: #E7F3EC;
  color: #1E6B3F;
}

.form-status--error {
  display: block;
  background: #FBEAEA;
  color: #A02A2A;
}

.contact-side {
  background: var(--primary-dark);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 36px;
}

.contact-side h3 {
  color: #fff;
}

.contact-side__list {
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.contact-side__item-label {
  font-size: 0.8rem;
  color: rgba(247, 249, 252, 0.6);
}

.contact-side__item-value {
  font-size: 1rem;
  font-weight: 600;
  margin-top: 4px;
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--primary-dark);
  color: rgba(247, 249, 252, 0.85);
  padding-block: 56px 28px;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  gap: 32px;
  flex-wrap: wrap;
  padding-bottom: 36px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.footer-brand .brand {
  color: #fff;
}

.footer-brand p {
  margin-top: 10px;
  color: rgba(247, 249, 252, 0.65);
  max-width: 34ch;
}

.footer-tagline {
  margin-top: 14px;
  font-weight: 600;
  color: #fff;
}

.footer-links {
  display: flex;
  gap: 56px;
  flex-wrap: wrap;
}

.footer-links h4 {
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: rgba(247, 249, 252, 0.55);
  margin-bottom: 14px;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 0.925rem;
  color: rgba(247, 249, 252, 0.85);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: #fff;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding-top: 24px;
  font-size: 0.825rem;
  color: rgba(247, 249, 252, 0.5);
}

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  font-size: 0.875rem;
  color: var(--text-muted);
  padding-top: 28px;
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: var(--primary);
}

.breadcrumb__sep {
  margin: 0 8px;
}

/* ---------- Page hero (inner pages) ---------- */
.page-hero {
  padding-block: 40px var(--section-spacing-sm);
}

.page-hero h1 {
  margin-top: 12px;
  max-width: 24ch;
}

.page-hero p {
  margin-top: 16px;
  max-width: 60ch;
  font-size: 1.05rem;
}

/* ---------- Detail page blocks ---------- */
.detail-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.detail-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 20px;
}

.detail-list li {
  display: flex;
  gap: 12px;
  font-size: 0.975rem;
  color: var(--text-muted);
}

.detail-list li::before {
  content: "";
  flex-shrink: 0;
  width: 8px;
  height: 8px;
  margin-top: 8px;
  border-radius: 999px;
  background: var(--primary);
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
}