/* DIGITAL FLAGSHIP EXPERIENCE - Base Styles */

/* Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -moz-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: var(--font-size-sm);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--color-text);
  margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-2xl); }
h2 { font-size: var(--font-size-xl); }
h3 { font-size: var(--font-size-lg); }
h4 { font-size: var(--font-size-md); }
h5 { font-size: var(--font-size-sm); }
h6 { font-size: var(--font-size-xs); }

p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* Section */
.section {
  padding: var(--spacing-2xl) 0;
}

/* Images */
img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
  height: auto;
}

/* Form Base */
input, button, textarea, select {
  font: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

button:focus {
  outline: none;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

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

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

.btn-secondary {
  background-color: var(--color-surface-dark);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover {
  background-color: var(--color-gray-100);
}

/* Focus Visible */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Glass Base */
.glass {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

[data-theme="dark"] .glass {
  background: rgba(42, 42, 42, 0.8);
}

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

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.gap-xs { gap: var(--spacing-xs); }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }

.flex { display: flex; }
.grid { display: grid; }
/* Floating launchers (phone trái, trợ lý phải) không che nội dung cuối trang */
@media (max-width: 767px) {
  body {
    scroll-padding-bottom: calc(76px + env(safe-area-inset-bottom, 0px));
  }

  .site-footer {
    padding-bottom: calc(76px + env(safe-area-inset-bottom, 0px));
  }
}