/* Root design tokens */
:root {
  /* Brand palette */
  --color-bg: #0b0f17;
  --color-surface: #111827;
  --color-elevated: #0f172a;
  --color-primary: #22d3ee; /* cyan-400 */
  --color-primary-600: #0891b2;
  --color-secondary: #a78bfa; /* violet-400 */
  --color-accent: #34d399; /* emerald-400 */
  --color-text: #e5e7eb;
  --color-text-dim: #9ca3af;
  --color-border: #1f2937;
  --color-danger: #ef4444;

  /* Shadows and radii */
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 10px;
  --shadow-1: 0 10px 30px rgba(0, 0, 0, 0.35);
  --shadow-2: 0 20px 50px rgba(0, 0, 0, 0.45);

  /* Layout */
  --container-max: 1300px;
  --gutter: 20px;
}

/* Base reset */
* {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  padding: 0;
  background: radial-gradient(
      1200px 600px at 80% -100px,
      rgba(34, 211, 238, 0.12),
      transparent
    ),
    radial-gradient(
      900px 500px at -20% -80px,
      rgba(167, 139, 250, 0.12),
      transparent
    ),
    var(--color-bg);
  color: var(--color-text);
  font-family: "Inter", system-ui, -apple-system, Segoe UI, Roboto, Ubuntu,
    Cantarell, "Helvetica Neue", Arial, "Apple Color Emoji", "Segoe UI Emoji";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Custom Scrollbar cho toàn bộ trang */
html::-webkit-scrollbar,
body::-webkit-scrollbar {
  width: 10px;
}

html::-webkit-scrollbar-track,
body::-webkit-scrollbar-track {
  background: var(--color-bg);
}

html::-webkit-scrollbar-thumb,
body::-webkit-scrollbar-thumb {
  background: color-mix(in srgb, var(--color-border), #fff 20%);
  border-radius: 5px;
  border: 2px solid var(--color-bg);
}

html::-webkit-scrollbar-thumb:hover,
body::-webkit-scrollbar-thumb:hover {
  background: color-mix(in srgb, var(--color-primary), transparent 60%);
}

/* Firefox scrollbar */
html,
body {
  scrollbar-width: thin;
  scrollbar-color: color-mix(in srgb, var(--color-border), #fff 20%) var(--color-bg);
}

.container {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* Buttons */
.btn {
  appearance: none;
  border: 1px solid var(--color-border);
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.02),
    rgba(255, 255, 255, 0)
  );
  color: var(--color-text);
  padding: 12px 18px;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-weight: 600;
  transition: transform 0.1s ease, border-color 0.2s ease, background 0.2s ease;
}
.btn:hover {
  transform: translateY(-1px);
}
.btn:active {
  transform: translateY(0);
}
.btn:focus-visible {
  outline: 2px solid color-mix(in srgb, var(--color-primary), transparent 60%);
  outline-offset: 2px;
}

.btn--primary {
  background: linear-gradient(
    135deg,
    color-mix(in srgb, var(--color-primary), #ffffff 10%),
    var(--color-primary-600)
  );
  border-color: color-mix(in srgb, var(--color-primary), #000 30%);
  color: #031016;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.25),
    0 10px 25px rgba(8, 145, 178, 0.35);
}

.btn--secondary {
  background: linear-gradient(
    135deg,
    color-mix(in srgb, var(--color-secondary), #ffffff 12%),
    #6d28d9
  );
  border-color: color-mix(in srgb, var(--color-secondary), #000 30%);
  color: #0f1024;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.25),
    0 10px 25px rgba(109, 40, 217, 0.35);
}

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

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

/* Links reset */
a {
  color: inherit;
  text-decoration: none;
}