/* Concept 7 — Bố cục theo Diamond Hill Thái Nguyên, tone màu theo brand guideline
   ruby #842319, kem #ffe1c0, nền #fef1e8, gold gradient #e6d0a1→#caaf7a→#e6d6a2 */
:root {
  --ruby: #842319;
  --ruby-deep: #691314;
  --cream: #ffe1c0;
  --page-bg: #fef1e8;
  --tint-50: #a36b6a;
  --tint-96: #f9e8e0;
  --gold: #caaf7a;
  --gold-light: #e6d0a1;
  --gold-grad: linear-gradient(160deg, #e6d0a1 0%, #caaf7a 52%, #e6d6a2 100%);
  --black: #000000;
  --white: #ffffff;
  --sans: 'Roboto', 'Segoe UI', system-ui, -apple-system, sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: var(--sans); background: var(--page-bg); color: var(--black); line-height: 1.7; }
img { max-width: 100%; }
a { color: inherit; }
button { font-family: inherit; }

.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
.container-narrow { max-width: 820px; }
.center { text-align: center; margin-top: 30px; }

/* ===== Header trắng kiểu Diamond Hill ===== */
.site-header { position: fixed; inset: 0 0 auto 0; z-index: 100; background: var(--white); border-bottom: 1px solid var(--tint-96); transition: box-shadow .3s; }
.site-header.scrolled { box-shadow: 0 4px 18px rgba(105, 19, 20, .12); }
.header-inner { display: flex; align-items: center; gap: 20px; padding: 8px 24px; }
.logo img { height: 58px; width: auto; display: block; }
.main-nav { display: flex; gap: 2px; margin-left: auto; }
.main-nav a { position: relative; color: var(--black); text-decoration: none; font-size: .78rem; font-weight: 500; letter-spacing: 1px; text-transform: uppercase; padding: 8px 10px; transition: color .2s; }
.main-nav a::after { content: ''; position: absolute; left: 10px; right: 10px; bottom: 2px; height: 2px; background: var(--gold-grad); transform: scaleX(0); transition: transform .25s; }
.main-nav a:hover, .main-nav a.active { color: var(--ruby); }
.main-nav a:hover::after, .main-nav a.active::after { transform: scaleX(1); }
.header-phone { display: inline-flex; align-items: center; gap: 7px; background: var(--ruby); color: var(--cream); font-weight: 700; font-size: .9rem; text-decoration: none; white-space: nowrap; padding: 10px 18px; border-radius: 99px; transition: background .2s; }
.header-phone:hover { background: var(--ruby-deep); }
.nav-toggle { display: none; background: none; border: none; color: var(--ruby); cursor: pointer; }

/* ===== Nút ===== */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 13px 28px; font: 700 .8rem var(--sans); letter-spacing: 1.2px; text-transform: uppercase; text-decoration: none; border: 1px solid transparent; border-radius: 4px; cursor: pointer; transition: all .25s; }
.btn-ruby { background: var(--ruby); color: var(--cream); }
.btn-ruby:hover { background: var(--ruby-deep); box-shadow: 0 6px 18px rgba(132, 35, 25, .35); }
.btn-gold { background: var(--gold-grad); color: var(--ruby-deep); }
.btn-gold:hover { filter: brightness(1.05); box-shadow: 0 6px 18px rgba(202, 175, 122, .5); }
.btn-outline { background: transparent; color: var(--ruby); border-color: var(--ruby); }
.btn-outline:hover { background: var(--ruby); color: var(--cream); }
.btn-block { width: 100%; }

/* ===== Floating call ===== */
.floating-cta { position: fixed; right: 18px; bottom: 24px; z-index: 90; display: flex; flex-direction: column; gap: 10px; }
.floating-cta a { display: flex; align-items: center; justify-content: center; width: 50px; height: 50px; border-radius: 50%; background: var(--white); color: var(--ruby); border: 1px solid rgba(132, 35, 25, .25); box-shadow: 0 6px 18px rgba(105, 19, 20, .18); text-decoration: none; transition: all .25s; }
.floating-cta a:hover { background: var(--ruby); color: var(--cream); transform: scale(1.08); }
.floating-cta .fc-call { background: var(--ruby); color: var(--cream); animation: ring-pulse 2.2s infinite; }
@keyframes ring-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(132, 35, 25, .45); }
  50% { box-shadow: 0 0 0 12px rgba(132, 35, 25, 0); }
}

/* ===== Hero ===== */
.hero { min-height: 100vh; display: flex; align-items: center; background-size: cover; background-position: center; position: relative; }
.hero-overlay { position: absolute; inset: 0; background: linear-gradient(rgba(20, 5, 4, .35), rgba(105, 19, 20, .55)); }
.hero-content { position: relative; z-index: 1; display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); gap: 60px; align-items: center; width: 100%; padding-top: 110px; padding-bottom: 70px; }
.hero-tagline { color: var(--gold-light); font-size: .85rem; letter-spacing: 5px; text-transform: uppercase; margin-bottom: 12px; }
.hero-title { color: var(--white); font-size: clamp(2.6rem, 5.6vw, 4.4rem); font-weight: 800; text-transform: uppercase; letter-spacing: 4px; line-height: 1.1; text-shadow: 0 4px 24px rgba(0, 0, 0, .4); }
.hero-slogan { color: var(--cream); font-size: clamp(1rem, 1.9vw, 1.35rem); letter-spacing: 2px; text-transform: uppercase; margin-top: 16px; }
.hero-form { background: rgba(255, 255, 255, .96); border-top: 4px solid var(--ruby); border-radius: 8px; padding: 28px 26px; max-width: 350px; justify-self: end; width: 100%; box-shadow: 0 20px 50px rgba(0, 0, 0, .38); display: grid; gap: 12px; }
.hero-form h3 { color: var(--ruby); font-size: 1.1rem; text-transform: uppercase; letter-spacing: 1.5px; text-align: center; }

/* ===== Section + tiêu đề in hoa có gạch trang trí (kiểu Diamond Hill) ===== */
.section { padding: 80px 0; }
.section-tint { background: var(--tint-96); }
.sec-head { text-align: center; margin-bottom: 18px; }
.sec-head h2 { display: inline-block; position: relative; color: var(--ruby); font-size: clamp(1.5rem, 3vw, 2.15rem); font-weight: 800; text-transform: uppercase; letter-spacing: 2px; padding-bottom: 16px; }
.sec-head h2::after { content: ''; position: absolute; left: 50%; bottom: 0; transform: translateX(-50%); width: 120px; height: 2px; background: var(--gold-grad); }
.sec-head h2::before { content: ''; position: absolute; left: 50%; bottom: -3.5px; transform: translateX(-50%) rotate(45deg); width: 9px; height: 9px; background: var(--gold); }
.sec-lead { text-align: center; max-width: 760px; margin: 0 auto 40px; color: #4a3a33; }

/* ===== Khối ảnh trái - chữ phải ===== */
.split-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); gap: 46px; align-items: center; margin-top: 34px; }
.split-media img { display: block; border-radius: 8px; border: 1px solid var(--gold-light); box-shadow: 14px 14px 0 var(--tint-96), 0 16px 40px rgba(105, 19, 20, .14); }
.split-text h3 { color: var(--ruby); font-size: 1.25rem; margin-bottom: 12px; }
.split-text > p { color: #4a3a33; margin-bottom: 18px; }
.overview-list { list-style: none; display: grid; gap: 9px; margin-bottom: 22px; }
.overview-list li { display: flex; align-items: center; gap: 10px; font-size: .93rem; }
.ov-icon { color: var(--ruby); display: flex; flex-shrink: 0; }
.overview-list strong { color: var(--ruby-deep); }

/* ===== Ảnh đôi (kiến trúc) ===== */
.story-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; margin-bottom: 30px; }
.story-grid img { display: block; width: 100%; aspect-ratio: 16/10; object-fit: cover; border-radius: 8px; border: 1px solid var(--gold-light); box-shadow: 0 14px 36px rgba(105, 19, 20, .13); }

/* ===== Vị trí: danh sách kết nối ===== */
.travel-list { list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 6px 0 22px; }
.travel-list li { display: flex; align-items: center; gap: 12px; background: var(--white); border: 1px solid var(--gold-light); border-radius: 8px; padding: 12px 14px; }
.tv-icon { display: flex; align-items: center; justify-content: center; width: 38px; height: 38px; flex-shrink: 0; background: var(--tint-96); color: var(--ruby); border-radius: 50%; }
.travel-list strong { display: block; color: var(--ruby); font-size: 1rem; line-height: 1.2; }
.travel-list li span:not(.tv-icon) { font-size: .82rem; color: #4a3a33; }
.travel-list li div span { display: block; font-size: .82rem; color: #4a3a33; }

/* ===== Tiện ích: danh sách đánh số + gallery ===== */
.utilities-board { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr); gap: 36px; align-items: start; }
.utility-index { list-style: none; display: grid; gap: 0; background: var(--white); border: 1px solid var(--gold-light); border-radius: 10px; overflow: hidden; }
.utility-index li { display: flex; gap: 14px; align-items: center; padding: 14px 18px; border-bottom: 1px solid var(--tint-96); }
.utility-index li:last-child { border-bottom: none; }
.ui-num { font-size: 1.15rem; font-weight: 800; color: var(--gold); min-width: 34px; }
.utility-index strong { display: block; color: var(--ruby); font-size: .95rem; }
.utility-index li div span { font-size: .8rem; color: #4a3a33; }
.utility-slider { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.us-item { position: relative; display: block; border-radius: 8px; overflow: hidden; border: 1px solid var(--gold-light); text-decoration: none; }
.us-item img { width: 100%; aspect-ratio: 16/10; object-fit: cover; display: block; transition: transform .35s; }
.us-item:hover img { transform: scale(1.06); }
.us-item span { position: absolute; inset: auto 0 0 0; padding: 22px 12px 10px; background: linear-gradient(transparent, rgba(105, 19, 20, .9)); color: var(--cream); font-size: .8rem; }

/* ===== Mặt bằng ===== */
.masterplan a { display: block; }
.masterplan img { display: block; width: 100%; max-height: 620px; object-fit: cover; border-radius: 8px; border: 1px solid var(--gold-light); box-shadow: 0 16px 44px rgba(105, 19, 20, .15); }
.doc-row { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 26px; justify-content: center; }
.doc-item { display: inline-flex; align-items: center; gap: 10px; padding: 12px 22px; background: var(--white); border: 1px solid var(--ruby); border-radius: 4px; color: var(--ruby); text-decoration: none; font-size: .88rem; font-weight: 600; transition: all .2s; }
.doc-item:hover { background: var(--ruby); color: var(--cream); }
.doc-soon { opacity: .5; border-color: var(--tint-50); color: var(--tint-50); cursor: default; }
.doc-soon:hover { background: transparent; color: var(--tint-50); }
.doc-item small { font-size: .68rem; letter-spacing: 1px; text-transform: uppercase; }

/* ===== Sản phẩm điển hình: khối tuần tự ===== */
.unit-row { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 40px; align-items: center; margin-top: 38px; }
.unit-row-flip .unit-media { order: 2; }
.unit-media img { display: block; width: 100%; aspect-ratio: 16/10; object-fit: cover; border-radius: 8px; border: 1px solid var(--gold-light); box-shadow: 0 14px 36px rgba(105, 19, 20, .14); }
.unit-badge { display: inline-block; background: var(--gold-grad); color: var(--ruby-deep); font-size: .72rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; padding: 6px 16px; border-radius: 99px; margin-bottom: 12px; }
.unit-info h3 { color: var(--ruby); font-size: 1.3rem; margin-bottom: 14px; }
.unit-specs { width: 100%; border-collapse: collapse; margin-bottom: 14px; }
.unit-specs td { padding: 9px 12px; border-bottom: 1px solid var(--tint-96); font-size: .92rem; }
.unit-specs td:first-child { color: #4a3a33; width: 45%; }
.unit-specs td:last-child { color: var(--ruby-deep); font-weight: 700; }
.unit-info > p { font-size: .88rem; color: #4a3a33; margin-bottom: 16px; }

/* ===== Tiến độ & pháp lý ===== */
.progress-legal { display: grid; grid-template-columns: 1.2fr 1fr; gap: 60px; margin-top: 30px; }
.timeline { list-style: none; position: relative; padding-left: 26px; }
.timeline::before { content: ''; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 1px; background: var(--tint-50); }
.timeline li { position: relative; padding: 0 0 24px 18px; }
.timeline li::before { content: ''; position: absolute; left: -26px; top: 5px; width: 15px; height: 15px; border-radius: 50%; border: 2px solid var(--tint-50); background: var(--page-bg); }
.timeline li.tl-done::before { background: var(--ruby); border-color: var(--ruby); }
.timeline li.tl-doing::before { background: var(--gold); border-color: var(--gold); box-shadow: 0 0 0 5px rgba(202, 175, 122, .35); }
.tl-year { font-size: 1.2rem; font-weight: 800; color: var(--ruby); display: inline-block; margin-right: 12px; }
.tl-desc { display: block; font-size: .85rem; color: #4a3a33; margin-top: 2px; }
.legal-list { list-style: none; display: grid; gap: 14px; }
.legal-list li { display: flex; gap: 14px; align-items: flex-start; padding: 16px; background: var(--white); border: 1px solid var(--gold-light); border-radius: 8px; }
.legal-icon { color: var(--ruby); flex-shrink: 0; }
.legal-list strong { display: block; color: var(--ruby); font-size: .95rem; }
.legal-list li div span { font-size: .84rem; color: #4a3a33; }

/* ===== Đối tác: 4 cột ===== */
.partners-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.partner-item { display: grid; gap: 6px; align-content: center; justify-items: center; text-align: center; background: var(--white); border: 1px solid var(--gold-light); border-radius: 8px; padding: 26px 16px; min-height: 118px; }
.partner-item img { max-height: 52px; width: auto; }
.partner-name { font-weight: 700; color: var(--ruby); font-size: 1rem; }
.partner-item small { color: var(--tint-50); font-size: .74rem; letter-spacing: .5px; text-transform: uppercase; }

/* ===== Thư viện: 3 card lớn + grid ===== */
.library-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-bottom: 26px; }
.library-card { position: relative; display: block; border-radius: 8px; overflow: hidden; border: 1px solid var(--gold-light); text-decoration: none; }
.library-card img { width: 100%; aspect-ratio: 16/9; object-fit: cover; display: block; transition: transform .35s; }
.library-card:hover img { transform: scale(1.05); }
.library-card span { position: absolute; inset: auto 0 0 0; padding: 30px 14px 13px; background: linear-gradient(transparent, rgba(105, 19, 20, .92)); color: var(--cream); font-weight: 700; letter-spacing: 1px; text-transform: uppercase; font-size: .82rem; }
.gallery-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
.gallery-item { position: relative; display: block; aspect-ratio: 4/3; overflow: hidden; border-radius: 8px; border: 1px solid var(--gold-light); text-decoration: none; }
.gallery-item img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s; }
.gallery-item:hover img { transform: scale(1.06); }
.gallery-caption { position: absolute; inset: auto 0 0 0; padding: 24px 12px 10px; background: linear-gradient(transparent, rgba(105, 19, 20, .92)); color: var(--cream); font-size: .8rem; display: flex; align-items: center; gap: 7px; }

/* ===== Lightbox ===== */
.lightbox { position: fixed; inset: 0; z-index: 200; background: rgba(20, 5, 4, .94); display: none; align-items: center; justify-content: center; padding: 4vh 4vw; }
.lightbox.open { display: flex; }
.lightbox img, .lightbox iframe { max-width: 100%; max-height: 88vh; border-radius: 8px; }
.lightbox iframe { width: min(1100px, 92vw); aspect-ratio: 16/9; }
.lightbox-close { position: absolute; top: 18px; right: 24px; background: none; border: none; color: var(--cream); cursor: pointer; }

/* ===== Tin tức ===== */
.news-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; margin-top: 30px; }
.news-card { display: block; text-decoration: none; color: inherit; background: var(--white); border: 1px solid var(--gold-light); border-radius: 8px; overflow: hidden; transition: box-shadow .25s, transform .25s; }
.news-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(132, 35, 25, .13); }
.news-card img { width: 100%; aspect-ratio: 16/9; object-fit: cover; display: block; }
.news-body { padding: 18px 20px 20px; }
.news-body time { font-size: .74rem; color: var(--tint-50); letter-spacing: 1px; text-transform: uppercase; }
.news-body h3 { font-size: 1.02rem; margin: 8px 0; color: var(--ruby); }
.news-body p { font-size: .86rem; color: #4a3a33; margin-bottom: 10px; }
.news-more { display: inline-flex; align-items: center; gap: 6px; color: var(--ruby); font-size: .8rem; font-weight: 700; letter-spacing: 1px; text-transform: uppercase; }
.article-thumb { margin: 10px 0 26px; border-radius: 8px; border: 1px solid var(--gold-light); }
.article-content { font-size: 1.02rem; }
.article-content p { margin-bottom: 16px; }
.article-content h2, .article-content h3 { color: var(--ruby); margin: 26px 0 12px; }
.page-head { padding: 140px 0 50px; }
.section-ruby { background: linear-gradient(150deg, var(--ruby) 0%, var(--ruby-deep) 100%); color: var(--cream); }
.section-ruby .section-title, .section-title { color: var(--ruby); font-size: clamp(1.5rem, 3vw, 2.1rem); font-weight: 800; margin-bottom: 12px; }
.section-ruby .section-title { color: var(--cream); }
.eyebrow { color: var(--ruby); font-size: .78rem; font-weight: 700; letter-spacing: 3px; text-transform: uppercase; margin-bottom: 8px; }
.section-ruby .eyebrow { color: var(--gold-light); }
.eyebrow a { text-decoration: none; }
.eyebrow-line { display: none; }

/* ===== Form chung ===== */
.contact-form input, .contact-form textarea { width: 100%; padding: 12px 14px; background: var(--white); border: 1px solid var(--gold-light); border-radius: 4px; color: var(--black); font: inherit; }
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--ruby); }
.contact-form textarea { min-height: 84px; resize: vertical; }
.hp-field { position: absolute !important; left: -9999px !important; width: 1px; height: 1px; opacity: 0; }
.form-message { font-size: .86rem; min-height: 1.2em; }
.form-message.ok { color: #2c7a1e; }
.form-message.err { color: #a3271a; }
.footer-form .form-message.ok { color: #9fd48a; }
.footer-form .form-message.err { color: #ffb3a6; }

/* ===== Footer ===== */
.site-footer { background: var(--ruby-deep); color: var(--cream); padding: 64px 0 28px; }
.footer-grid { display: grid; grid-template-columns: 1.1fr 1fr 1.1fr; gap: 44px; }
.footer-logo { width: 150px; margin-bottom: 12px; }
.footer-slogan { color: var(--gold-light); font-size: .9rem; margin-bottom: 8px; }
.footer-col h4 { color: var(--gold-light); font-size: .76rem; letter-spacing: 2.5px; text-transform: uppercase; margin: 14px 0 6px; }
.footer-col h4:first-child { margin-top: 0; }
.footer-col p { font-size: .9rem; display: flex; align-items: flex-start; gap: 8px; margin-bottom: 6px; }
.footer-col a { color: var(--gold-light); text-decoration: none; }
.footer-social { display: flex; gap: 16px; margin-top: 14px; }
.footer-social a { font-size: .8rem; letter-spacing: 1px; text-transform: uppercase; border-bottom: 1px solid var(--gold); padding-bottom: 2px; }
.footer-form { display: grid; gap: 11px; align-content: start; background: rgba(254, 241, 232, .07); border: 1px solid rgba(230, 208, 161, .35); border-radius: 8px; padding: 24px 22px; }
.footer-form h4 { color: var(--gold-light); font-size: .82rem; letter-spacing: 2px; text-transform: uppercase; }
.footer-note { margin-top: 44px; padding-top: 22px; border-top: 1px solid rgba(230, 208, 161, .25); color: var(--gold-light); font-size: .8rem; opacity: .85; display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap; }

/* ===== Reveal ===== */
[data-reveal] { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
[data-reveal].revealed { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { [data-reveal] { opacity: 1; transform: none; transition: none; } }

/* ===== Responsive ===== */
@media (max-width: 1180px) {
  .header-phone { display: none; }
  .hero-content { grid-template-columns: 1fr; gap: 36px; }
  .hero-form { justify-self: start; }
  .utilities-board { grid-template-columns: 1fr; }
}
@media (max-width: 1024px) {
  .split-grid, .progress-legal { grid-template-columns: 1fr; gap: 36px; }
  .partners-row { grid-template-columns: 1fr 1fr; }
  .library-cards { grid-template-columns: 1fr; }
}
@media (max-width: 860px) {
  .main-nav { position: fixed; inset: 0 0 0 28%; background: var(--white); box-shadow: -8px 0 30px rgba(105, 19, 20, .2); flex-direction: column; padding: 90px 30px; gap: 8px; transform: translateX(105%); transition: transform .3s; z-index: 99; margin-left: 0; }
  .main-nav.open { transform: none; }
  .nav-toggle { display: block; margin-left: auto; z-index: 100; }
  .travel-list, .story-grid, .utility-slider { grid-template-columns: 1fr; }
  .unit-row { grid-template-columns: 1fr; gap: 22px; }
  .unit-row-flip .unit-media { order: 0; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .section { padding: 54px 0; }
  .floating-cta { right: 12px; bottom: 14px; }
  .floating-cta a { width: 44px; height: 44px; }
}
@media (max-width: 560px) {
  .partners-row { grid-template-columns: 1fr; }
  .hero-form { max-width: none; }
}

/* Anchor không bị header cố định che */
section[id] { scroll-margin-top: 86px; }