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

:root{
  /* ---- brand palette ---- */
  --black:#0E0D0B;
  --black-soft:#1A1815;
  --char:#2A2621;
  --ink:#221F1A;
  --ivory:#FBF9F5;
  --ivory-2:#F5F1E9;
  --beige:#EDE6D9;
  --sand:#E3D9C6;
  --gold:#C2A25C;
  --gold-lt:#D9BE85;
  --gold-dk:#9C7F3E;
  --champagne:#E8D7B4;
  --brown:#6B553A;
  --brown-dk:#4A3A26;

  /* ---- text ---- */
  --tx:#221F1A;
  --tx-2:#5D564C;
  --tx-3:#8B8275;
  --tx-inv:#FBF9F5;
  --tx-inv-2:#C9C1B3;

  /* ---- lines & surfaces ---- */
  --line:#E4DCCC;
  --line-2:#D2C7B2;
  --line-dk:#3A342C;
  --surface:#FFFFFF;
  --surface-2:#FBF9F5;

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

  /* ---- type ---- */
  --serif:'Cormorant Garamond',Georgia,'Times New Roman',serif;
  --sans:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;

  /* ---- 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;overflow-x:clip}
/* 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);
  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{font-size:clamp(2.6rem,5.2vw,4.3rem);line-height:1.04}
h2{font-size:clamp(1.9rem,3.2vw,2.75rem);line-height:1.14}
h3{font-size:clamp(1.35rem,2vw,1.85rem);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)}
.section-title{text-align:center;margin-bottom:.5rem}
.section-sub{text-align:center;color:var(--tx-2);font-size:.95rem;margin-bottom:3rem}
.rule{width:56px;height:1px;background:var(--gold);border:0;margin:1.4rem 0}
.rule--c{margin-left:auto;margin-right:auto}
.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--dark{background:var(--black);color:var(--tx-inv)}
.section--dark h1,.section--dark h2,.section--dark h3{color:var(--tx-inv)}
.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:box-shadow var(--t),background var(--t);
}
.hdr--float{position:fixed;left:0;right:0;background:transparent;border-bottom-color:transparent}
.hdr--solid{background:var(--black);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)}

.logo{display:flex;align-items:center;gap:11px;flex-shrink:0}
.logo__mark{width:34px;height:34px;flex-shrink:0}
.logo__tx{display:flex;flex-direction:column;line-height:1}
.logo__name{font-family:var(--serif);font-size:1.62rem;letter-spacing:.18em;color:var(--ivory);font-weight:500}
.logo__sub{font-size:.5rem;letter-spacing:.34em;color:var(--gold);text-transform:uppercase;margin-top:3px}

.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{
  display:flex;align-items:center;gap:6px;color:var(--tx-inv-2);
  font-size:.72rem;letter-spacing:.1em;padding:7px 9px;border-radius:var(--r-sm);
  transition:color var(--t),background var(--t);
}
.lang:hover{color:var(--ivory);background:rgba(255,255,255,.06)}
.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__strip{
  border-bottom:1px solid var(--line);padding-bottom:2.2rem;margin-bottom:2.8rem;
  display:grid;grid-template-columns:repeat(4,1fr);gap:24px;
}
.ftr__ct{display:flex;align-items:center;gap:12px}
.ftr__ct svg{color:var(--gold-dk);flex-shrink:0}
.ftr__ct b{display:block;font-size:.82rem;font-weight:600}
.ftr__ct span{font-size:.8rem;color:var(--tx-2)}
.ftr__main{display:grid;grid-template-columns:1.7fr repeat(4,1fr) 1.5fr;gap:32px;padding-bottom:3rem}
.ftr__brand .logo__name{color:var(--tx)}
.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)}