:root{--bg-navy:#F8F6F0;--gold:#1A1A1A;}
  *{box-sizing:border-box;}
  body{margin:0;padding:0;background:var(--bg-navy);color:var(--gold);font-family:"Roboto","Sarabun",Arial,sans-serif;font-weight:300;-webkit-tap-highlight-color:transparent;}
  .page{max-width:640px;margin:0 auto;padding-bottom:40px;}
  .banner-wrap{width:100%;overflow:hidden;height:clamp(120px,26vw,260px);position:relative;}
  .banner-wrap img{width:100%;height:100%;object-fit:cover;object-position:center center;display:block;}
  .banner-title-overlay{position:absolute;top:0;left:0;right:0;bottom:0;display:flex;align-items:center;justify-content:center;text-align:center;padding:0 12%;pointer-events:none;}
  .banner-title-overlay h1{margin:0;font-weight:400;font-size:clamp(22px,4.6vw,38px);color:#d1d5db;text-shadow:-1px -1px 0 #33060e,1px -1px 0 #33060e,-1px 1px 0 #33060e,1px 1px 0 #33060e,0 2px 6px rgba(0,0,0,0.6);}
  .container{padding:24px 20px;}
  .step-title{font-size:15px;opacity:0.75;margin:0 0 14px;letter-spacing:0.4px;}
  .step-title b{color:var(--gold);opacity:1;}
  .goi-banner{width:100%;border-radius:10px;overflow:hidden;margin-bottom:12px;}
  .goi-banner img{width:100%;display:block;}
  .huong-dan-text{font-size:14px;line-height:1.6;opacity:0.85;text-align:center;margin:0 0 20px;}
  .step-guide-list{margin:0 0 20px;padding:0;list-style:none;font-size:14px;line-height:1.7;opacity:0.9;text-align:left;}
  .step-guide-list li{position:relative;padding-left:18px;margin-bottom:8px;}
  .step-guide-list li::before{content:"•";position:absolute;left:0;color:var(--gold);}
  .step-guide-list li:last-child{margin-bottom:0;}
  .goi-list{display:flex;flex-direction:column;gap:10px;}
  .goi-item{display:flex;justify-content:space-between;align-items:center;gap:12px;border:1px solid rgba(26,26,26,0.35);border-radius:8px;padding:14px 16px;cursor:pointer;background:transparent;color:var(--gold);font-family:inherit;text-align:left;width:100%;transition:background 0.15s ease,border-color 0.15s ease;}
  .goi-item:hover{background:rgba(26,26,26,0.06);}
  .goi-item.selected{border-color:var(--gold);background:rgba(26,26,26,0.12);}
  .goi-item-ten{font-size:16px;font-weight:400;}
  .goi-item-gia{font-size:15px;opacity:0.9;white-space:nowrap;}
  .goi-item-mota{font-size:13px;opacity:0.8;text-align:right;}
  .empty-msg{opacity:0.7;font-size:15px;}
  .form-wrap{display:none;margin-top:28px;padding-top:20px;border-top:1px solid rgba(26,26,26,0.25);}
  .form-wrap.show{display:block;}
  .form-field{margin-bottom:14px;}
  .form-field label{display:block;font-size:13px;opacity:0.8;margin-bottom:6px;}
  .form-field input{width:100%;padding:12px 14px;background:rgba(26,26,26,0.08);border:1px solid rgba(26,26,26,0.4);border-radius:6px;color:var(--gold);font-family:inherit;font-weight:300;font-size:15px;outline:none;}
  .form-field input::placeholder{color:rgba(26,26,26,0.45);}
  .goi-dang-chon{font-size:14px;opacity:0.85;margin-bottom:16px;}
  .goi-dang-chon-ten{color:var(--gold);opacity:1;font-size:20px;font-weight:400;}
  .goi-dang-chon-phu{font-size:14px;opacity:0.8;margin-left:2px;}
  .submit-btn{width:100%;padding:14px;background:var(--gold);color:var(--bg-navy);border:none;border-radius:8px;font-family:inherit;font-weight:400;font-size:16px;cursor:pointer;}
  .submit-btn:disabled{opacity:0.5;cursor:default;}
  .form-error{color:#33060e;font-size:13px;margin-top:10px;display:none;}
  .form-error.show{display:block;}
  .result-wrap{display:none;margin-top:28px;padding-top:20px;border-top:1px solid rgba(26,26,26,0.25);text-align:center;}
  .result-wrap.show{display:block;}
  .result-title{font-size:19px;font-weight:400;margin:0 0 12px;}
  .qr-img{max-width:280px;width:100%;border-radius:8px;background:#fff;padding:12px;}
  .qr-info{margin-top:16px;font-size:15px;line-height:1.7;text-align:left;background:rgba(26,26,26,0.08);border-radius:8px;padding:14px 16px;}
  .qr-info b{color:var(--gold);}
  .ma-thanh-toan{font-size:22px;font-weight:700;color:var(--gold);letter-spacing:1px;}
  .luu-y-box{margin-top:14px;background:rgba(255,138,138,0.1);border-left:3px solid #33060e;padding:12px 14px;font-size:13px;text-align:left;line-height:1.6;border-radius:4px;}
  .result-error{color:#33060e;font-size:15px;line-height:1.6;}
  .thu-lai-btn{margin-top:16px;padding:10px 20px;background:transparent;border:1px solid var(--gold);color:var(--gold);border-radius:6px;font-family:inherit;cursor:pointer;font-size:14px;}
  .faint-divider{width:100%;height:1px;background-color:var(--gold);opacity:0.4;}
  .back-button-wrap{display:flex;justify-content:center;padding:24px 20px 8px 20px;}
  .back-button-inner{position:relative;display:inline-block;width:60%;max-width:260px;}
  .back-button-inner img{width:100%;display:block;}
  
  .chat-fab{position:fixed;right:16px;bottom:16px;width:56px;height:56px;border-radius:50%;background:#fff;display:flex;align-items:center;justify-content:center;box-shadow:0 3px 10px rgba(0,0,0,0.35);z-index:999;text-decoration:none;}
  .chat-fab svg{width:28px;height:28px;fill:#33060e;}
  .chat-fab:hover{filter:brightness(1.08);}
  @media (max-width:600px){.chat-fab{right:12px;bottom:12px;width:50px;height:50px;}.chat-fab svg{width:25px;height:25px;}}