/*
  HDT Solutions - hdts.com.vn
  Mobile-first. Breakpoints: 576px (SP lớn), 768px (tablet), 992px (PC), 1200px (PC rộng)
*/

:root {
  --c-primary: #006699;
  --c-primary-dark: #004d73;
  --c-accent: #f7941e;
  --c-navy: #0b2540;
  --c-navy-2: #12355a;
  --c-text: #33414e;
  --c-muted: #5d6b78;
  --c-line: #dfe5eb;
  --c-bg: #ffffff;
  --c-bg-soft: #f4f7fa;

  --font: "Be Vietnam Pro", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(11, 37, 64, 0.08);
  --shadow-lg: 0 20px 45px rgba(11, 37, 64, 0.16);
  --header-h: 64px;
  --gutter: 20px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-h);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, p, ul, figure {
  margin: 0;
}

ul[role="list"],
.main-nav ul {
  list-style: none;
  padding: 0;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease;
}

:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 3px;
}

.sr-only {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.icon {
  width: 1em;
  height: 1em;
  fill: currentColor;
  flex-shrink: 0;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding-left: max(var(--gutter), env(safe-area-inset-left));
  padding-right: max(var(--gutter), env(safe-area-inset-right));
}

/* ---------- Header ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  height: var(--header-h);
  color: #fff;
  transition: background-color 0.3s ease, box-shadow 0.3s ease, color 0.3s ease;
}

.site-header.is-scrolled,
.site-header.is-open {
  background: rgba(11, 37, 64, 0.96);
  box-shadow: 0 2px 18px rgba(11, 37, 64, 0.25);
  -webkit-backdrop-filter: saturate(160%) blur(8px);
  backdrop-filter: saturate(160%) blur(8px);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
}

.brand-title {
  line-height: 0;
}

.brand img {
  height: 40px;
  width: auto;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  margin-right: -8px;
  padding: 0;
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: inherit;
  font-size: 22px;
  cursor: pointer;
}

.nav-toggle .icon-close,
.nav-toggle[aria-expanded="true"] .icon-open {
  display: none;
}

.nav-toggle[aria-expanded="true"] .icon-close {
  display: block;
}

/* Menu SP: dropdown dưới header */
.main-nav {
  position: absolute;
  top: var(--header-h);
  left: 0;
  right: 0;
  background: var(--c-navy);
  box-shadow: 0 16px 30px rgba(11, 37, 64, 0.3);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  visibility: hidden;
  opacity: 0;
  transform: translateY(-8px);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
}

.site-header.is-open .main-nav {
  visibility: visible;
  opacity: 1;
  transform: none;
}

.main-nav ul {
  padding: 8px var(--gutter) 16px;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 4px;
  font-size: 1rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.main-nav li:last-child .nav-link {
  border-bottom: 0;
}

.nav-link::before {
  content: "";
  width: 10px;
  height: 10px;
  background: var(--c-accent);
  opacity: 0;
  transform: scale(0.4);
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.nav-link.is-active {
  color: #fff;
}

.nav-link.is-active::before {
  opacity: 1;
  transform: none;
}

/* ---------- Hero (Trang chủ) ---------- */
.hero {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 100vh;
  min-height: 100svh;
  padding: calc(var(--header-h) + 32px) 0 56px;
  color: #fff;
  background: var(--c-navy);
  overflow: hidden;
  isolation: isolate;
}

.hero-bg,
.hero-bg img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: 60% center;
  z-index: -2;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(180deg, rgba(11, 37, 64, 0.55) 0%, rgba(11, 37, 64, 0.82) 70%, rgba(11, 37, 64, 0.92) 100%);
}

.hero-inner {
  display: flex;
}

.hero-card {
  max-width: 620px;
}

.hero-line {
  display: block;
  width: 56px;
  height: 4px;
  margin-bottom: 22px;
  border-radius: 2px;
  background: var(--c-accent);
}

.hero-title {
  font-size: clamp(1.9rem, 7vw, 3.4rem);
  line-height: 1.2;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.01em;
  margin-bottom: 20px;
}

.hero-text {
  font-size: clamp(1rem, 2.6vw, 1.15rem);
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.88);
}

/* ---------- Sections ---------- */
.section {
  padding: 64px 0;
}

.section-light {
  background: var(--c-bg-soft);
}

.section-title {
  position: relative;
  font-size: clamp(1.6rem, 5vw, 2.2rem);
  font-weight: 700;
  line-height: 1.3;
  color: var(--c-primary);
  margin-bottom: 32px;
  padding-bottom: 14px;
}

.section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 48px;
  height: 4px;
  border-radius: 2px;
  background: var(--c-accent);
}

.section-title-light {
  color: #fff;
}

.card {
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

/* ---------- Giới thiệu ---------- */
.about-grid {
  display: grid;
  gap: 20px;
}

.about-card {
  padding: 28px 24px;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 72px;
  margin-bottom: 20px;
  border-radius: 18px;
  font-size: 34px;
  color: var(--c-accent);
  background: rgba(247, 148, 30, 0.12);
}

.card-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--c-primary);
  margin-bottom: 16px;
}

.about-card p + p {
  margin-top: 16px;
}

/* ---------- Dịch vụ ---------- */
/* SP: vuốt ngang (scroll-snap) */
.services {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: min(68vw, 260px);
  gap: 16px;
  margin: 0 calc(-1 * var(--gutter));
  padding: 4px var(--gutter) 20px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x mandatory;
  scroll-padding: 0 var(--gutter);
  scrollbar-width: thin;
  scrollbar-color: var(--c-line) transparent;
}

.service {
  scroll-snap-align: start;
}

.service-card {
  position: relative;
  aspect-ratio: 2 / 3;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--c-primary);
  box-shadow: var(--shadow);
  color: #fff;
}

.service-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s var(--ease), opacity 0.35s ease;
}

.service-card figcaption {
  position: absolute;
  inset: auto 0 0 0;
  padding: 64px 18px 20px;
  text-align: center;
  background: linear-gradient(180deg, rgba(0, 51, 77, 0) 0%, rgba(0, 51, 77, 0.78) 40%, rgba(0, 40, 61, 0.95) 100%);
}

/* Khung viền trắng (hiệu ứng Bubba của bản cũ) */
.service-card::before,
.service-card::after {
  content: "";
  position: absolute;
  inset: 14px;
  z-index: 1;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.35s ease, transform 0.35s ease;
}

.service-card::before {
  border-top: 1px solid #fff;
  border-bottom: 1px solid #fff;
  transform: scale(0, 1);
}

.service-card::after {
  border-left: 1px solid #fff;
  border-right: 1px solid #fff;
  transform: scale(1, 0);
}

.service-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  line-height: 1.3;
  margin-bottom: 6px;
}

.service-card p {
  font-size: 0.875rem;
  line-height: 1.5;
  color: rgba(255, 255, 255, 0.9);
}

/* ---------- Liên hệ ---------- */
.contact-grid {
  display: grid;
  gap: 20px;
}

.contact-info {
  padding: 32px 24px;
  border-radius: var(--radius);
  color: rgba(255, 255, 255, 0.9);
  background:
    radial-gradient(circle at 100% 0%, rgba(0, 102, 153, 0.55), transparent 60%),
    linear-gradient(160deg, var(--c-navy-2), var(--c-navy));
  box-shadow: var(--shadow-lg);
}

.contact-list {
  display: grid;
  gap: 16px;
  margin-bottom: 24px;
}

.contact-list li {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  line-height: 1.6;
}

.contact-list .icon {
  font-size: 24px;
  margin-top: 1px;
  color: var(--c-accent);
}

.contact-list a {
  word-break: break-word;
}

.contact-list a:hover {
  color: var(--c-accent);
}

.contact-meta {
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.75);
}

.contact-form-card {
  padding: 28px 24px;
}

.field {
  margin-bottom: 24px;
}

.field input,
.field textarea {
  width: 100%;
  padding: 12px 2px;
  border: 0;
  border-bottom: 1px solid #c9d2db;
  border-radius: 0;
  background: transparent;
  font: inherit;
  font-size: 16px; /* >=16px để iOS Safari không tự zoom khi focus */
  color: var(--c-text);
  transition: border-color 0.2s ease;
  -webkit-appearance: none;
  appearance: none;
}

.field textarea {
  resize: vertical;
  min-height: 120px;
}

.field input::placeholder,
.field textarea::placeholder {
  color: #8a96a2;
}

.field input:focus,
.field textarea:focus {
  outline: none;
  border-bottom-color: var(--c-primary);
  box-shadow: 0 1px 0 0 var(--c-primary);
}

.form-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 16px;
}

.form-status {
  flex: 1;
  font-size: 0.9rem;
  line-height: 1.5;
}

.form-status.is-success {
  color: #1e7a46;
}

.form-status.is-error {
  color: #b42318;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 120px;
  min-height: 46px;
  padding: 10px 28px;
  border: 0;
  border-radius: 999px;
  font: inherit;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background-color 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
}

.btn-primary {
  color: #fff;
  background: var(--c-primary);
  box-shadow: 0 8px 18px rgba(0, 102, 153, 0.25);
}

.btn-primary:hover {
  background: var(--c-primary-dark);
  transform: translateY(-1px);
}

.btn[disabled] {
  opacity: 0.6;
  cursor: progress;
}

/* ---------- Footer ---------- */
.site-footer {
  padding: 22px 0 max(22px, env(safe-area-inset-bottom));
  background: var(--c-navy);
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
  text-align: center;
}

/* ---------- Reveal on scroll (bật bởi JS) ---------- */
.js .reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}

.js .reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- Hover (chỉ thiết bị có chuột) ---------- */
@media (hover: hover) and (pointer: fine) {
  .about-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
  }

  .service-card:hover img {
    transform: scale(1.06);
    opacity: 0.55;
  }

  .service-card:hover::before,
  .service-card:hover::after {
    opacity: 1;
    transform: scale(1);
  }

  .main-nav .nav-link:hover {
    color: #fff;
  }
}

/* ---------- >= 576px ---------- */
@media (min-width: 576px) {
  :root {
    --gutter: 28px;
  }

  .about-card,
  .contact-form-card {
    padding: 36px;
  }

  .contact-info {
    padding: 40px 36px;
  }
}

/* ---------- >= 768px: tablet ---------- */
@media (min-width: 768px) {
  .section {
    padding: 88px 0;
  }

  .hero::after {
    background: linear-gradient(90deg, rgba(11, 37, 64, 0.92) 0%, rgba(11, 37, 64, 0.72) 50%, rgba(11, 37, 64, 0.3) 100%);
  }

  /* Dịch vụ: 3 cột, hàng cuối căn giữa */
  .services {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin: 0;
    padding: 0;
    overflow: visible;
  }

  .service {
    flex: 0 0 calc((100% - 2 * 20px) / 3);
  }

  .about-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
  }
}

/* ---------- >= 992px: PC ---------- */
@media (min-width: 992px) {
  :root {
    --header-h: 80px;
    --gutter: 40px;
  }

  body {
    font-size: 17px;
  }

  .brand img {
    height: 48px;
  }

  .nav-toggle {
    display: none;
  }

  .main-nav {
    position: static;
    visibility: visible;
    opacity: 1;
    transform: none;
    background: none;
    box-shadow: none;
    border: 0;
  }

  .main-nav ul {
    display: flex;
    gap: 8px;
    padding: 0;
  }

  .nav-link {
    position: relative;
    padding: 10px 14px;
    border: 0;
    font-size: 0.9rem;
    color: inherit;
  }

  .nav-link::before {
    display: none;
  }

  .nav-link::after {
    content: "";
    position: absolute;
    left: 14px;
    right: 14px;
    bottom: 4px;
    height: 2px;
    background: var(--c-accent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s var(--ease);
  }

  .nav-link.is-active::after,
  .nav-link:hover::after {
    transform: scaleX(1);
  }

  .hero-card {
    padding: 8px 0;
  }

  .contact-grid {
    grid-template-columns: 5fr 7fr;
    gap: 32px;
    align-items: stretch;
  }

  .contact-info,
  .contact-form-card {
    padding: 48px;
  }
}

/* ---------- >= 1200px: PC rộng - Dịch vụ 5 cột ---------- */
@media (min-width: 1200px) {
  .service {
    flex-basis: calc((100% - 4 * 20px) / 5);
  }

  .section {
    padding: 104px 0;
  }
}

/* ---------- Giảm chuyển động ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  .js .reveal {
    opacity: 1;
    transform: none;
  }
}