/* ==========================================================================
   KAS HOTEL COLLECTION — CORE DESIGN SYSTEM
   Luxury Vietnamese hospitality: deep black, warm ivory, champagne gold.
   ========================================================================== */

:root{
  /* ---- brand palette ---- */
  --black:#24231F;
  --black-soft:#292822;
  --char:#3A3934;
  --ink:#332E27;
  --ivory:#F5F1E8;
  --ivory-2:#EAE4D8;
  --beige:#EEE9DF;
  --sand:#EAE3D8;
  --gold:#A98955;
  --gold-lt:#C5AD78;
  --gold-dk:#80643D;
  --champagne:#D9C49A;
  --brown:#6A5338;
  --brown-dk:#493A2B;

  /* ---- text ---- */
  --tx:#2E2A24;
  --tx-2:#665F55;
  --tx-3:#8E8578;
  --tx-inv:#F8F4EC;
  --tx-inv-2:#D0C6B8;

  /* ---- lines & surfaces ---- */
  --line:#CEC5B7;
  --line-2:#C3B9A9;
  --line-dk:#4A433A;
  --surface:#F8F4EC;
  --surface-2:#F0E9DE;

  /* ---- status ---- */
  --ok:#4A7A52;
  --ok-bg:#EDF3ED;
  --warn:#A8762C;
  --err:#A6442F;
  --err-bg:#FBEFEC;

  /* ---- type ---- */

  /* ---- metrics ---- */
  --container:1320px;
  --nav-h:76px;
  --r-sm:3px;
  --r:5px;
  --r-lg:8px;
  --sh-1:0 1px 2px rgba(34,31,26,.05);
  --sh-2:0 2px 10px rgba(34,31,26,.07);
  --sh-3:0 8px 30px rgba(34,31,26,.11);
  --sh-4:0 18px 55px rgba(34,31,26,.16);
  --ease:cubic-bezier(.22,.61,.36,1);
  --t:.32s var(--ease);
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;background:var(--ivory)}
/* The off-canvas drawer is translated past the right edge; without this it
   would extend scrollWidth at tablet widths. `clip` keeps position:sticky
   working, which `overflow-x:hidden` would not. */
body{
  margin:0;background:var(--ivory);color:var(--tx);min-width:320px;
  font-family:var(--sans);font-size:15px;line-height:1.65;
  font-weight:400;letter-spacing:.005em;
  -webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;cursor:pointer;border:none;background:none}
input,select,textarea{font:inherit;color:inherit}
[hidden]{display:none!important}

/* ---------- typography ---------- */
h1,h2,h3,h4,h5{font-family:var(--serif);font-weight:400;margin:0;letter-spacing:-.01em;color:var(--tx)}
h1{line-height:1.04}
h2{line-height:1.14}
h3{line-height:1.2}
h4{font-size:1.2rem;line-height:1.3}
p{margin:0 0 1em}
p:last-child{margin-bottom:0}

.eyebrow{
  font-family:var(--sans);font-size:.66rem;font-weight:600;
  letter-spacing:.24em;text-transform:uppercase;color:var(--gold-dk);
}
.eyebrow--lt{color:var(--gold-lt)}
.rule{width:56px;height:1px;background:var(--gold);border:0;margin:1.4rem 0}
.muted{color:var(--tx-2)}
.tiny{font-size:.78rem}
.nowrap{white-space:nowrap}

/* ---------- layout ---------- */
.container{width:100%;max-width:var(--container);margin:0 auto;padding-inline:28px}
.container--narrow{max-width:1060px}
.section{padding-block:clamp(3.5rem,7vw,6rem)}
.section--tight{padding-block:clamp(2.5rem,4vw,3.5rem)}
.section--alt{background:var(--ivory-2)}
.grid{display:grid;gap:22px}
.flex{display:flex}
.between{display:flex;align-items:center;justify-content:space-between;gap:16px}
.stack{display:flex;flex-direction:column}

/* ---------- header ---------- */
.hdr{
  position:sticky;top:0;z-index:900;background:var(--black);
  border-bottom:1px solid rgba(194,162,92,.16);
  transition:background-color .4s ease,backdrop-filter .4s ease,box-shadow .4s ease,border-color .4s ease;
}
.hdr--float{position:fixed;left:0;right:0;background:transparent;border-bottom-color:rgba(194,162,92,.12);
  backdrop-filter:none;-webkit-backdrop-filter:none}
/* Homepage header states have one source of truth. JS toggles these classes on scroll. */
.hdr--float.header--transparent{background:transparent;border-bottom-color:rgba(194,162,92,.12);
  box-shadow:none;backdrop-filter:none;-webkit-backdrop-filter:none}
.hdr--float.header--scrolled{background:#0d0d0d;border-bottom-color:rgba(194,162,92,.16);
  box-shadow:0 2px 24px rgba(0,0,0,.32);backdrop-filter:none;-webkit-backdrop-filter:none}
.header--transparent{background:transparent}
.header--scrolled{background:#0d0d0d}
.hdr--solid{background:#0d0d0d;border-bottom-color:rgba(194,162,92,.16);box-shadow:0 2px 24px rgba(0,0,0,.32)}
.hdr__in{display:flex;align-items:center;justify-content:space-between;gap:24px;height:var(--nav-h)}
/* Reserve the header's space before app.js renders it, so page content does not jump down (CLS). */
#hdr:empty{display:block;min-height:calc(var(--nav-h) + 1px);background:var(--black)}
.home-redesign #hdr:empty{min-height:0;background:transparent}
/* Inner pages are rendered by JS right after the header. Keep the static skeleton
   invisible until then, so it neither jumps (CLS) nor flashes untranslated text.
   Failsafe: content is revealed after 3s even if a script fails. */
body:not(.home-redesign) #hdr:empty ~ *{visibility:hidden;animation:kas-boot-failsafe 0s linear 3s forwards}
@keyframes kas-boot-failsafe{to{visibility:visible}}

.logo{display:flex;align-items:center;gap:11px;flex-shrink:0}
.logo__mark{width:34px;height:34px;flex-shrink:0}

.nav{display:flex;align-items:center;gap:26px}
.nav a{
  font-size:.71rem;font-weight:500;letter-spacing:.15em;text-transform:uppercase;
  color:var(--tx-inv-2);padding:6px 0;position:relative;transition:color var(--t);
}
.nav a::after{
  content:'';position:absolute;left:0;right:100%;bottom:0;height:1px;
  background:var(--gold);transition:right var(--t);
}
.nav a:hover{color:var(--ivory)}
.nav a:hover::after,.nav a.is-active::after{right:0}
.nav a.is-active{color:var(--gold-lt)}

.hdr__right{display:flex;align-items:center;gap:16px;flex-shrink:0}
.lang-wrap{
  display:flex;align-items:center;justify-content:center;
  position:relative;margin:0;
}
.lang-select{
  appearance:none;-webkit-appearance:none;
  min-width:64px;height:36px;padding:0 26px 0 10px;
  border:1px solid rgba(194,162,92,.48);border-radius:var(--r-sm);
  background:var(--black-soft);
  color:var(--ivory);font-family:var(--sans);
  font-size:.72rem;font-weight:600;letter-spacing:.1em;
  cursor:pointer;outline:none;
  background-image:linear-gradient(45deg,transparent 50%,var(--gold-lt) 50%),linear-gradient(135deg,var(--gold-lt) 50%,transparent 50%);
  background-position:calc(100% - 11px) 15px,calc(100% - 7px) 15px;
  background-size:4px 4px,4px 4px;background-repeat:no-repeat;
}
.lang-select:hover,.lang-select:focus{
  border-color:var(--gold);background-color:var(--char);
}
.lang-select option{
  background:#1a1815;color:#fbf9f5;font-family:var(--sans);
  font-size:.78rem;letter-spacing:.04em;
}
.burger{display:none;color:var(--ivory);padding:8px;margin-right:-8px}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  padding:13px 28px;border-radius:var(--r-sm);cursor:pointer;
  font-size:.72rem;font-weight:600;letter-spacing:.15em;text-transform:uppercase;
  transition:all var(--t);border:1px solid transparent;white-space:nowrap;
  line-height:1.3;text-align:center;
}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn--gold{background:linear-gradient(160deg,var(--gold-lt),var(--gold));color:var(--black);box-shadow:var(--sh-1)}
.btn--gold:not(:disabled):hover{background:linear-gradient(160deg,var(--gold),var(--gold-dk));box-shadow:var(--sh-3);transform:translateY(-1px)}
.btn--dark{background:var(--black);color:var(--ivory)}
.btn--dark:not(:disabled):hover{background:var(--char);transform:translateY(-1px);box-shadow:var(--sh-3)}
.btn--ghost{background:transparent;border-color:var(--line-2);color:var(--tx)}
.btn--ghost:not(:disabled):hover{border-color:var(--gold);color:var(--gold-dk);background:rgba(194,162,92,.06)}
.btn--ghost-lt{background:transparent;border-color:rgba(232,215,180,.4);color:var(--champagne)}
.btn--ghost-lt:hover{border-color:var(--gold-lt);background:rgba(194,162,92,.14);color:var(--ivory)}
.btn--lg{padding:16px 38px;font-size:.76rem}
.btn--sm{padding:9px 18px;font-size:.66rem}
.btn--block{width:100%}
.btn--link{padding:0;color:var(--gold-dk);text-transform:none;letter-spacing:.01em;font-size:.85rem;font-weight:500}
.btn--link:hover{color:var(--brown);text-decoration:underline;text-underline-offset:3px}

/* ---------- forms ---------- */
.field{display:flex;flex-direction:column;gap:7px;min-width:0}
.label{
  font-size:.63rem;font-weight:600;letter-spacing:.15em;
  text-transform:uppercase;color:var(--tx-3);
}
.label .req{color:var(--err)}
.input,.select,.textarea{
  width:100%;padding:12px 14px;background:var(--surface);
  border:1px solid var(--line);border-radius:var(--r-sm);
  font-size:.92rem;color:var(--tx);transition:border-color var(--t),box-shadow var(--t);
}
.input:hover,.select:hover,.textarea:hover{border-color:var(--line-2)}
.input:focus,.select:focus,.textarea:focus{
  outline:none;border-color:var(--gold);box-shadow:0 0 0 3px rgba(194,162,92,.14);
}
.input::placeholder,.textarea::placeholder{color:var(--tx-3)}
.textarea{resize:vertical;min-height:90px;font-family:var(--sans)}
.select{
  appearance:none;cursor:pointer;padding-right:38px;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%238B8275' stroke-width='1.4' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat:no-repeat;background-position:right 14px center;
}
.input.is-err,.select.is-err,.textarea.is-err{border-color:var(--err);background:var(--err-bg)}
.err-msg{
  font-size:.76rem;color:var(--err);display:none;align-items:center;gap:5px;margin-top:-2px;
}
.err-msg.show{display:flex}
.hint{font-size:.75rem;color:var(--tx-3)}

/* radio / checkbox */
.opt{display:flex;align-items:flex-start;gap:10px;cursor:pointer;font-size:.88rem;line-height:1.5}
.opt input{
  appearance:none;width:17px;height:17px;flex-shrink:0;margin-top:2px;
  border:1.5px solid var(--line-2);background:var(--surface);
  transition:all var(--t);cursor:pointer;position:relative;
}
.opt input[type=radio]{border-radius:50%}
.opt input[type=checkbox]{border-radius:2px}
.opt input:checked{border-color:var(--gold);background:var(--gold)}
.opt input[type=radio]:checked::after{
  content:'';position:absolute;inset:3.5px;border-radius:50%;background:var(--black);
}
.opt input[type=checkbox]:checked::after{
  content:'';position:absolute;left:5px;top:1.5px;width:4px;height:8px;
  border:solid var(--black);border-width:0 1.8px 1.8px 0;transform:rotate(42deg);
}
.opt input:focus-visible{outline:2px solid var(--gold);outline-offset:2px}
.opt:hover input{border-color:var(--gold)}

/* ---------- footer ---------- */
.ftr{background:var(--ivory-2);border-top:1px solid var(--line);padding-top:3.5rem}
.ftr__main{display:grid;grid-template-columns:1.45fr repeat(5,minmax(0,1fr)) 1.25fr 1.25fr;gap:24px;padding-bottom:3rem;align-items:start}
.ftr__brand p{font-size:.83rem;color:var(--tx-2);margin:1.1rem 0 1.4rem;max-width:230px}
.ftr__col h5{
  font-size:.64rem;font-weight:600;letter-spacing:.16em;text-transform:uppercase;
  color:var(--tx);margin-bottom:1rem;font-family:var(--sans);
}
.ftr__col a{display:block;font-size:.82rem;color:var(--tx-2);padding:4px 0;transition:color var(--t)}
.ftr__col a:hover{color:var(--gold-dk)}
.social{display:flex;gap:9px}
.social a{
  width:32px;height:32px;display:grid;place-items:center;border-radius:50%;
  border:1px solid var(--line-2);color:var(--tx-2);transition:all var(--t);
}
.social a:hover{background:var(--gold);border-color:var(--gold);color:var(--black)}
.news{display:flex;margin-top:12px;border:1px solid var(--line-2);border-radius:var(--r-sm);overflow:hidden;background:var(--surface)}
.news input{flex:1;border:none;padding:11px 13px;font-size:.83rem;min-width:0;background:transparent}
.news input:focus{outline:none}
.news button{
  padding:0 15px;background:var(--gold);color:var(--black);
  display:grid;place-items:center;transition:background var(--t);
}
.news button:hover{background:var(--gold-dk)}
.ftr__btm{
  border-top:1px solid var(--line);padding-block:1.3rem;
  display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;
  font-size:.76rem;color:var(--tx-3);
}
.ftr__btm a{transition:color var(--t)}
.ftr__btm a:hover{color:var(--gold-dk)}
.ftr__legal{display:flex;gap:20px}

/* ---------- accessibility ---------- */
.sr{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
:focus-visible{outline:2px solid var(--gold);outline-offset:2px}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important;scroll-behavior:auto!important}
}

/* The header is sticky, so anything we scrollIntoView() must reserve room for
   it or its first lines end up hidden underneath. */
[id]{scroll-margin-top:calc(var(--nav-h) + 20px)}

/* ==========================================================================
   KAS HOMEPAGE — HERITAGE SECTION
   A tighter, more editorial luxury-hotel composition.
   ========================================================================== */

/* KAS typography — editorial luxury pairing */
:root{
  --serif:"Cormorant Garamond", Georgia, "Times New Roman", serif;
  --sans:"Inter", "Helvetica Neue", Arial, sans-serif;
}
html,body,button,input,select,textarea{
  font-family:var(--sans);
}
h1,h2,h3,h4,h5,h6,.hero h1{
  font-family:var(--serif);
  font-weight:400;
}
.eyebrow,.btn,.nav,.trust,.lang-select{
  font-family:var(--sans);
}

/* ---------- custom EN / VI language picker ---------- */
.lang-wrap--custom{position:relative}
.lang-wrap--custom .lang-select{position:absolute;opacity:0;pointer-events:none;width:1px;height:1px;overflow:hidden}
.lang-button{
  min-width:72px;height:38px;padding:0 10px;display:inline-flex;align-items:center;justify-content:center;gap:7px;
  border:1px solid rgba(194,162,92,.58);border-radius:var(--r-sm);background:rgba(14,13,11,.72);
  color:var(--ivory);font-family:var(--sans);font-size:.72rem;font-weight:600;letter-spacing:.08em;
  transition:border-color var(--t),background var(--t),box-shadow var(--t)
}
.lang-button:hover,.lang-wrap--custom.is-open .lang-button{border-color:var(--gold);background:rgba(42,38,33,.94);box-shadow:0 0 0 2px rgba(194,162,92,.12)}
.lang-current-flag{width:18px;height:12px;display:inline-flex;align-items:center;justify-content:center;flex:0 0 18px}.lang-flag-svg{display:block;width:18px;height:12px;border-radius:2px;overflow:hidden;box-shadow:0 0 0 1px rgba(255,255,255,.14)}
.lang-current-code{min-width:24px;text-align:left}
.lang-chevron{font-size:.9rem;line-height:1;color:var(--gold-lt);transform:translateY(-1px)}
.lang-menu{
  position:absolute;right:0;top:calc(100% + 7px);min-width:116px;padding:6px;
  display:none;z-index:1200;background:rgba(24,21,18,.98);border:1px solid rgba(194,162,92,.45);
  border-radius:6px;box-shadow:0 12px 30px rgba(0,0,0,.35);backdrop-filter:blur(10px)
}
.lang-wrap--custom.is-open .lang-menu{display:block}
.lang-option{width:100%;display:flex;align-items:center;gap:9px;padding:9px 10px;border-radius:4px;color:var(--ivory);font-size:.72rem;font-weight:600;letter-spacing:.08em;text-align:left}
.lang-option:hover,.lang-option:focus{background:rgba(194,162,92,.14);outline:none}
.lang-option-flag{width:20px;height:13px;display:inline-flex;align-items:center;justify-content:center;flex:0 0 20px}.lang-option-flag .lang-flag-svg{width:20px;height:13px}

/* V18.6 RESTORE — dark editorial footer matching the approved KAS reference */
.ftr--dark{
  background:#292822;
  color:#f5efe3;
  border-top:1px solid rgba(194,162,92,.08);
  padding-top:3.5rem;
}
.ftr--dark .ftr__brand p{
  color:rgba(245,239,227,.72);
  max-width:230px;
  line-height:1.65;
}
.ftr--dark .ftr__col h5{
  color:#f5efe3;
  font-size:.61rem;
  letter-spacing:.15em;
  margin-bottom:1rem;
}
.ftr--dark .ftr__col a{
  color:rgba(245,239,227,.76);
  font-size:.76rem;
  padding:4px 0;
}
.ftr--dark .ftr__col a:hover{color:#c2a25c}
.ftr--dark .social a{
  border-color:rgba(194,162,92,.25);
  color:#c2a25c;
  border-radius:0;
}
.ftr--dark .social a:hover{
  background:#c2a25c;
  border-color:#c2a25c;
  color:#0b0a09;
}
.ftr--dark .ftr__contact .ftr-contact-row{
  display:flex;
  align-items:center;
  gap:10px;
  padding:7px 0;
  white-space:nowrap;
}
.ftr--dark .ftr-contact-row svg{color:#c2a25c;flex:0 0 auto}
.ftr--dark .ftr-contact-address{display:flex;align-items:flex-start;gap:10px;margin:12px 0 0;color:rgba(245,239,227,.72);font-size:.76rem;line-height:1.55;white-space:normal}.ftr--dark .ftr-contact-address svg{color:#c2a25c;flex:0 0 auto;margin-top:2px}
.ftr--dark .ftr__news p{
  margin:0;
  color:rgba(245,239,227,.72);
  font-size:.76rem;
  line-height:1.5;
}
.ftr--dark .news{
  margin-top:12px;
  border-color:rgba(194,162,92,.22);
  border-radius:0;
  background:#11100f;
}
.ftr--dark .news input{
  color:#f5efe3;
  font-size:.76rem;
}
.ftr--dark .news input::placeholder{color:rgba(245,239,227,.7)}
.ftr--dark .news button{background:#c2a25c}
.ftr--dark .ftr__btm{
  border-top-color:rgba(194,162,92,.12);
  color:rgba(194,162,92,.65);
}
.ftr--dark .ftr__btm a{color:rgba(194,162,92,.65)}
.ftr--dark .ftr__btm a:hover{color:#f5efe3}

/* Booking-flow pages: keep the shared navigation in document flow so it cannot
   cover the breadcrumb or the five-step booking progress bar. Other pages retain
   their existing transparent/overlay navigation behaviour. */
body:has(#steps) #hdr.hdr--float {
  position: relative;
  inset: auto;
  width: 100%;
  z-index: 900;
  background: #0d0d0d;
  border-bottom-color: rgba(194,162,92,.16);
  box-shadow: 0 2px 24px rgba(0,0,0,.18);
}
body:has(#steps) #hdr.hdr--float.header--transparent {
  background: #0d0d0d;
}


/* Booking flow: keep the five-step progress bar accessible while scrolling.
   The main site navigation stays in normal flow on booking pages, so this
   sticky bar takes over only after the navigation/breadcrumb scroll away. */
body:has(#steps) #steps.steps {
  position: sticky;
  top: 0;
  z-index: 850;
  background: var(--surface, #f5f0e7);
  box-shadow: 0 5px 16px rgba(25, 22, 16, .07);
}

/* Plain text back link, matching the hotel detail breadcrumb treatment. */
.booking-back-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  margin: 0 0 16px;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--tx-2);
  font-size: .92rem;
  line-height: 1.5;
  text-decoration: none;
  transition: color var(--t);
}
.booking-back-link:hover {
  color: var(--gold-dk);
}
.booking-back-link svg {
  flex: 0 0 auto;
}