/* Reset nhẹ, chữ, nút, form, tiện ích. */

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

html { -webkit-text-size-adjust: 100%; scroll-padding-top: calc(var(--header-h) + 16px); }

body {
  margin: 0;
  font: 400 var(--fs-body)/1.45 var(--font-body);
  color: var(--c8);
  background: var(--c1);
  overflow-x: hidden;
}
body.is-locked { overflow: hidden; }

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

h1, h2, h3, h4, h5 { font-weight: 600; line-height: 1.3; color: var(--c8); margin: 0 0 .5em; }
h1 { font-size: var(--fs-title); text-transform: uppercase; letter-spacing: -.015em; }
h2 { font-size: calc(var(--fs-title) * .9); }
h3 { font-size: max(2rem, 15px); }
h4, h5 { font-size: max(1.6rem, 13px); }

p { margin: 0 0 1em; }

a { color: var(--c5); text-decoration: none; }
a:hover { color: var(--c5-hover); }

:focus-visible { outline: 3px solid var(--c5); outline-offset: 2px; }
.u-on-dark :focus-visible { outline-color: var(--c1); }

hr { border: 0; border-top: 1px solid var(--line); margin: 1.5em 0; }

/* Nút pill (doc §1.4) */
.c-btn {
  display: inline-block;
  padding: 1.3rem 2.9rem;
  border: 0;
  border-radius: var(--radius-pill);
  background: var(--c5);
  color: var(--c1);
  font: 700 max(1.4rem, 12px)/1.2 var(--font-body);
  letter-spacing: .015em;
  text-transform: uppercase;
  text-align: center;
  cursor: pointer;
  transition: background-color .2s, color .2s;
}
.c-btn:hover { background: var(--c5-hover); color: var(--c1); }
.c-btn--sm { padding: .9rem 2rem; font-size: max(1.2rem, 11px); }
.c-btn--light { background: var(--c1); color: var(--c5); }
.c-btn--light:hover { background: var(--c6); color: var(--c5); }
.c-btn--block { display: block; width: 100%; }
.c-btn--ghost { background: transparent; color: var(--c5); box-shadow: inset 0 0 0 2px var(--c5); }
.c-btn--ghost:hover { background: var(--c5); color: var(--c1); }
.c-btn:disabled { opacity: .55; cursor: not-allowed; }

/* Form (custom CSS 930: ô cao 44px bo 24px) */
input, textarea, select {
  width: 100%;
  height: max(4.4rem, 38px);
  padding: 0 2rem;
  border: 1px solid #ccc;
  border-radius: 2.4rem;
  background: var(--c1);
  color: var(--c8);
  font: inherit;
  font-size: var(--fs-small);
}
textarea { height: auto; min-height: 10rem; padding: 1.4rem 2rem; resize: vertical; }
input:focus, textarea:focus { border-color: var(--c8); }
::placeholder { color: #777; }

/* Tiện ích */
.u-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;
}
.u-center { text-align: center; }
.u-on-dark, .u-on-dark h1, .u-on-dark h2, .u-on-dark h3, .u-on-dark h4 { color: var(--c1); }

.c-skip-link {
  position: absolute;
  left: 16px; top: -60px;
  z-index: 1000;
  padding: 10px 16px;
  background: var(--c5);
  color: var(--c1);
  border-radius: 4px;
}
.c-skip-link:focus { top: 12px; color: var(--c1); }

[hidden] { display: none !important; }

/* Ẩn/hiện theo mốc của theme gốc: small ≤970px · medium 971–1024px · large ≥1025px */
@media (max-width: 970px) { .u-hide-sm { display: none !important; } }
@media (min-width: 971px) and (max-width: 1024px) { .u-hide-md { display: none !important; } }
@media (min-width: 1025px) { .u-hide-lg { display: none !important; } }