@import url('https://cdn.jsdelivr.net/npm/@tabler/icons-webfont@3.31.0/dist/tabler-icons.min.css');

:root {
  --color-bg:          #171717;
  --color-bg-card:     #1f1f1f;
  --color-bg-subtle:   #242424;
  --color-text:        #f5f5f5;
  --color-text-muted:  #a3a3a3;
  --color-accent:      #ffffff;
  --color-cta:         #2563eb;
  --color-cta-hover:   #1d4ed8;
  --color-zalo:        #0068ff;
  --color-messenger:   #0084ff;
  --color-border:      #2a2a2a;
  --color-success:     #22c55e;
  --color-error:       #ef4444;
}

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

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: 'Be Vietnam Pro', sans-serif;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Be Vietnam Pro', sans-serif;
}

/* Icon boxes — Tabler Icons */
.icon-box {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  background: rgba(37, 99, 235, 0.1);
  border-radius: 14px;
  color: var(--color-cta);
  flex-shrink: 0;
}
.icon-box .ti { font-size: 26px; line-height: 1; }

.icon-box-sm {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: rgba(37, 99, 235, 0.1);
  border-radius: 10px;
  color: var(--color-cta);
  flex-shrink: 0;
}
.icon-box-sm .ti { font-size: 20px; line-height: 1; }

.icon-contact {
  font-size: 18px;
  color: var(--color-cta);
  flex-shrink: 0;
  line-height: 1;
  margin-top: 2px;
}

/* Scroll animation classes */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.animate-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.animate-delay-100 { transition-delay: 0.1s; }
.animate-delay-200 { transition-delay: 0.2s; }
.animate-delay-300 { transition-delay: 0.3s; }
.animate-delay-400 { transition-delay: 0.4s; }

/* Navbar */
.navbar {
  background: rgba(23, 23, 23, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

/* Hero overlay */
.hero-overlay {
  background: rgba(0, 0, 0, 0.55);
}

/* CTA Button */
.btn-cta {
  background-color: var(--color-cta);
  color: #fff;
  font-weight: 600;
  padding: 0.75rem 1.75rem;
  border-radius: 0.5rem;
  transition: background-color 0.2s ease, transform 0.2s ease;
  display: inline-block;
  text-decoration: none;
}
.btn-cta:hover {
  background-color: var(--color-cta-hover);
  transform: translateY(-1px);
}
.btn-cta-sm {
  padding: 0.4rem 0.85rem;
}

.btn-outline {
  border: 2px solid rgba(255, 255, 255, 0.5);
  color: #fff;
  font-weight: 600;
  padding: 0.75rem 1.75rem;
  border-radius: 0.5rem;
  transition: border-color 0.2s ease, background-color 0.2s ease, transform 0.2s ease;
  display: inline-block;
  text-decoration: none;
}
.btn-outline:hover {
  border-color: #fff;
  background-color: rgba(255, 255, 255, 0.1);
  transform: translateY(-1px);
}

/* Card */
.card {
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 1rem;
  overflow: hidden;
  transition: transform 0.3s ease, border-color 0.3s ease;
}
.card:hover {
  transform: translateY(-4px);
  border-color: #3a3a3a;
}

/* Badge */
.badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background-color: var(--color-cta);
  color: #fff;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
}

/* Highlight box */
.highlight-box {
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: 0.75rem;
  padding: 1.5rem;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}
.highlight-box:hover {
  border-color: #3a3a3a;
  background-color: var(--color-bg-subtle);
}

/* Specs table */
.specs-table {
  width: 100%;
  border-collapse: collapse;
}
.specs-table tr {
  border-bottom: 1px solid var(--color-border);
}
.specs-table tr:last-child {
  border-bottom: none;
}
.specs-table td {
  padding: 0.875rem 1rem;
  vertical-align: top;
}
.specs-table td:first-child {
  color: var(--color-text-muted);
  font-weight: 500;
  width: 40%;
  white-space: nowrap;
}

/* FAQ Accordion */
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: 0.75rem;
  overflow: hidden;
  margin-bottom: 0.75rem;
}
.faq-question {
  width: 100%;
  text-align: left;
  padding: 1.25rem 1.5rem;
  background: var(--color-bg-card);
  color: var(--color-text);
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: none;
  transition: background-color 0.2s ease;
}
.faq-question:hover {
  background-color: var(--color-bg-subtle);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  background-color: var(--color-bg);
  padding: 0 1.5rem;
  color: var(--color-text-muted);
}
.faq-answer.open {
  max-height: 300px;
  padding: 1rem 1.5rem;
}
.faq-chevron {
  transition: transform 0.3s ease;
  flex-shrink: 0;
}
.faq-question.active .faq-chevron {
  transform: rotate(180deg);
}

/* Contact form */
.form-input {
  width: 100%;
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  color: var(--color-text);
  padding: 0.75rem 1rem;
  outline: none;
  transition: border-color 0.2s ease;
  font-family: 'DM Sans', sans-serif;
}
.form-input:focus {
  border-color: var(--color-cta);
}
.form-input::placeholder {
  color: var(--color-text-muted);
}
.form-label {
  display: block;
  color: var(--color-text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.375rem;
}

/* Footer */
.footer {
  background-color: #111111;
  border-top: 1px solid var(--color-border);
}

/* Mobile menu */
#mobileMenu {
  display: none;
}
#mobileMenu.open {
  display: block;
}

/* Floating buttons */
.float-btn {
  position: fixed;
  right: 1.25rem;
  z-index: 50;
  border-radius: 9999px;
  padding: 0.75rem;
  box-shadow: 0 4px 16px rgba(0,0,0,0.4);
  transition: transform 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}
.float-btn:hover {
  transform: scale(1.1);
}