/* ==========================================================================
   Trang nội dung (Giới thiệu, Chính sách, Điều khoản, DMCA, Liên hệ) + 404
   ========================================================================== */

/* ---------- Đầu trang: nền tối trơn + quầng sáng nhẹ, không ảnh để chữ dễ đọc ---------- */
.page-head { position: relative; isolation: isolate; overflow: hidden; padding: clamp(112px, 11vw, 150px) 0 clamp(36px, 4vw, 52px); text-align: center; border-bottom: 1px solid rgb(255 255 255 / .06); }
.page-head__glow { position: absolute; inset: 0; z-index: -1; pointer-events: none;
  background:
    radial-gradient(600px 260px at 50% 0%, rgb(168 85 247 / .28), transparent 70%),
    radial-gradient(420px 220px at 78% 20%, rgb(255 79 216 / .12), transparent 70%),
    radial-gradient(420px 220px at 22% 30%, rgb(34 211 238 / .08), transparent 70%); }
.page-head__inner { display: grid; justify-items: center; gap: 12px; }
.page-head__title { font-size: clamp(2rem, 1.4rem + 2.4vw, 3rem); letter-spacing: -0.005em; line-height: 1.15; max-width: 22ch; text-wrap: balance; }
.page-head__lead { max-width: 600px; margin: 0; color: var(--text-secondary); font-size: 1rem; line-height: 1.65; text-wrap: pretty; }
.page-head__meta { margin: 2px 0 0; font-size: var(--fs-xs); color: var(--text-tertiary); letter-spacing: .01em; }
.breadcrumb { display: inline-flex; align-items: center; gap: 6px; font-size: var(--fs-xs); color: var(--text-tertiary); }
.breadcrumb a { color: var(--text-secondary); }
.breadcrumb a:hover { color: var(--text-primary); }
.breadcrumb span { color: var(--text-body); }

/* ---------- Thân trang ---------- */
.page-body { padding-top: clamp(36px, 4.5vw, 64px) !important; }
.page-body__grid { display: grid; gap: clamp(32px, 5vw, 72px); align-items: start; max-width: 1080px; }
.page-body--plain .page-body__grid { max-width: 760px; }
.page-body--toc .page-body__grid { grid-template-columns: 220px minmax(0, 720px); justify-content: center; }
.page-body--contact .page-body__grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr); }

/* Mục lục: danh sách mảnh, vạch trái chỉ mục đang đọc */
.toc { position: sticky; top: 104px; }
.toc__box { padding: 0; }
.toc__box summary { padding: 0 0 12px; font-size: .75rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--text-tertiary); cursor: pointer; list-style: none; }
.toc__box summary::-webkit-details-marker { display: none; }
.toc ol { list-style: none; margin: 0; padding: 0; border-left: 1px solid rgb(255 255 255 / .08); max-height: calc(100vh - 180px); overflow: auto; }
.toc a { display: block; margin-left: -1px; padding: 6px 0 6px 14px; border-left: 2px solid transparent; font-size: .8125rem; line-height: 1.45; color: var(--text-tertiary); transition: color .2s, border-color .2s; }
.toc a:hover { color: var(--text-primary); }
.toc a.is-active { color: var(--text-primary); border-left-color: var(--pink); }

/* Văn bản */
.prose { min-width: 0; color: var(--text-body); font-size: 1rem; line-height: 1.75; }
.prose > * + * { margin-top: 1em; }
.prose > :first-child { margin-top: 0; }
.prose > p:first-child { font-size: 1.0625rem; color: var(--text-primary); }
.prose h2 { margin-top: 2.4em; font-size: 1.375rem; line-height: 1.3; letter-spacing: -0.005em; color: var(--text-primary); scroll-margin-top: 110px; }
.prose h3 { margin-top: 1.8em; font-size: 1.0625rem; letter-spacing: -0.005em; color: var(--text-primary); scroll-margin-top: 110px; }
.prose h2 + *, .prose h3 + * { margin-top: .55em; }
.prose a { color: var(--cyan-soft); text-decoration: underline; text-decoration-color: rgb(103 232 249 / .35); text-underline-offset: 3px; }
.prose a:hover { text-decoration-color: currentColor; }
.prose strong { color: var(--text-primary); font-weight: 600; }
.prose ul, .prose ol { padding-left: 1.25em; }
.prose li + li { margin-top: .35em; }
.prose li::marker { color: var(--text-tertiary); }
.prose blockquote { margin-inline: 0; padding: 12px 16px; border-left: 2px solid var(--pink); background: rgb(255 255 255 / .03); border-radius: 0 10px 10px 0; }
.prose hr { border: 0; border-top: 1px solid rgb(255 255 255 / .08); margin-block: 2em; }
.prose table { width: 100%; border-collapse: collapse; font-size: .9375rem; }
.prose th, .prose td { padding: 10px 12px; border-bottom: 1px solid rgb(255 255 255 / .08); text-align: left; }

/* ---------- Liên hệ ---------- */
.contact-box { display: grid; gap: 16px; }
.contact-box__info { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 14px; padding: 16px 18px; border-radius: var(--r-md); background: rgb(255 255 255 / .04); border: 1px solid var(--glass-border-soft); }
.contact-box__info small { display: block; color: var(--text-tertiary); font-size: var(--fs-xs); }
.contact-box__info a { font-weight: 700; color: var(--text-primary); word-break: break-all; }
.contact-box__time { display: inline-flex; align-items: center; gap: 6px; margin-left: auto; font-size: var(--fs-sm); color: var(--text-secondary); }
.contact-form { display: grid; gap: 16px; }
.contact-form__title { font-size: 1.375rem; letter-spacing: -0.005em; }
.contact-form__row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.contact-form__privacy { margin: 0; font-size: var(--fs-sm); color: var(--text-tertiary); }
.contact-form__privacy a { color: var(--cyan-soft); }
.contact-form__send { justify-self: start; }
.hp-field { position: absolute !important; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.notice-box { display: flex; gap: 10px; align-items: flex-start; margin: 0; padding: 12px 14px; border-radius: 12px; font-size: .9375rem; line-height: 1.5; }
.notice-box svg { flex: none; margin-top: 2px; }
.notice-box--success { background: rgb(34 197 94 / .12); border: 1px solid rgb(34 197 94 / .35); color: #BBF7D0; }
.notice-box--error { background: rgb(251 113 133 / .12); border: 1px solid rgb(251 113 133 / .35); color: #FECDD3; }

/* ---------- Khối tải video cuối trang ---------- */
.page-cta { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr); gap: 24px 40px; align-items: center;
  padding: clamp(24px, 3.5vw, 40px); border-radius: var(--r-lg); background: var(--grad-card); border: 1px solid var(--glass-border-soft); box-shadow: var(--shadow-card); }
.page-cta__title { font-size: clamp(1.375rem, 1.1rem + 1vw, 1.875rem); letter-spacing: -0.005em; }
.page-cta p { margin: 8px 0 0; color: var(--text-secondary); }

/* ---------- 404 ---------- */
.page-hero__404 { font-size: clamp(6rem, 20vw, 16rem); line-height: 1; font-weight: 900; letter-spacing: -0.005em; margin: 0; }
.page-hero--404 .page-hero__title { font-size: clamp(1.75rem, 1.2rem + 2vw, 2.5rem); }

@media (max-width: 1024px) {
  .page-body--toc .page-body__grid, .page-body--contact .page-body__grid { grid-template-columns: 1fr; }
  .toc { position: static; }
  .toc { padding: 14px 16px; border-radius: var(--r-md); background: rgb(255 255 255 / .03); border: 1px solid var(--glass-border-soft); }
  .toc__box:not([open]) summary { padding-bottom: 0; }
  .page-cta { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .contact-form__row { grid-template-columns: 1fr; }
  .contact-box__time { margin-left: 0; }
  .prose { font-size: 1rem; }
}