:root {
  color-scheme: light;
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  color: #271d18;
  background: #f7eee2;
  font-synthesis: none;
  --red: #bd3227;
  --red-dark: #8f211a;
  --ink: #271d18;
  --muted: #705f55;
  --line: rgba(103, 67, 45, .19);
  --paper: rgba(255, 252, 247, .91);
  --shadow: 0 18px 52px rgba(70, 38, 20, .16);
}

* { box-sizing: border-box; }
html, body { min-height: 100%; margin: 0; }
body { min-height: 100svh; letter-spacing: 0; background: #f7eee2 url("hero-oil-desktop.jpg") center / cover fixed no-repeat; }
body::before { content: ""; position: fixed; inset: 0; z-index: -1; background: rgba(255, 248, 238, .28); }
button { font: inherit; letter-spacing: 0; cursor: pointer; }
.hidden { display: none !important; }

.storefront { width: min(1440px, 100%); min-height: 100svh; margin: 0 auto; padding: clamp(28px, 5vw, 74px); display: grid; grid-template-columns: minmax(300px, .82fr) minmax(610px, 1.18fr); align-items: center; gap: clamp(42px, 6vw, 94px); }
.brand-panel { align-self: center; text-shadow: 0 2px 16px rgba(255,255,255,.95); }
.brand-lockup { display: flex; align-items: center; gap: 12px; margin-bottom: clamp(34px, 7vh, 76px); color: #632a1d; font: 900 24px/1 "STKaiti", "KaiTi", "Songti SC", serif; }
.brand-lockup img { width: 58px; height: 58px; object-fit: contain; filter: drop-shadow(0 5px 14px rgba(91,43,25,.14)); }
h1 { margin: 0; color: var(--ink); font-family: "STKaiti", "KaiTi", "Songti SC", serif; }
h1 span, h1 strong { display: block; letter-spacing: 0; }
h1 span { font-size: clamp(52px, 5.3vw, 82px); font-weight: 900; }
h1 strong { margin-top: 12px; color: var(--red); font-size: clamp(38px, 4vw, 62px); }
.brand-panel > p { max-width: 430px; margin: 30px 0 0; color: #574338; font-size: 17px; line-height: 1.8; font-weight: 700; }

.plans { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.plan-card { min-width: 0; padding: 28px; border: 1px solid rgba(118,72,46,.23); border-radius: 8px; background: var(--paper); box-shadow: var(--shadow); backdrop-filter: blur(18px); }
.plan-card.featured { border-top: 4px solid var(--red); padding-top: 25px; }
.plan-card header { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; padding-bottom: 22px; border-bottom: 1px solid var(--line); }
.plan-card header p { margin: 0 0 7px; color: var(--red); font-size: 13px; font-weight: 900; }
.plan-card h2 { margin: 0; font-size: 25px; }
.price { display: flex; align-items: flex-start; color: var(--red); white-space: nowrap; }
.price span { margin-top: 8px; font-size: 18px; font-weight: 900; }
.price strong { font-size: 46px; line-height: 1; }
.plan-card ul { min-height: 236px; margin: 24px 0; padding: 0; list-style: none; display: grid; align-content: start; gap: 16px; }
.plan-card li { display: grid; grid-template-columns: 23px minmax(0, 1fr); gap: 10px; color: #493931; font-size: 15px; line-height: 1.55; font-weight: 700; }
.plan-card li svg { width: 20px; height: 20px; margin-top: 2px; color: var(--red); stroke-width: 2.2; }
.buy-button { width: 100%; min-height: 50px; border: 0; border-radius: 6px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; color: white; background: var(--red); font-weight: 900; transition: transform .18s ease, background .18s ease; }
.buy-button:hover { background: var(--red-dark); transform: translateY(-2px); }
.buy-button svg { width: 19px; }

dialog { width: min(450px, calc(100% - 28px)); padding: 0; border: 1px solid var(--line); border-radius: 8px; background: #fffdf9; box-shadow: var(--shadow); }
dialog::backdrop { background: rgba(34,24,19,.48); backdrop-filter: blur(5px); }
.checkout-panel { padding: 26px; }
.checkout-panel > header { display: flex; justify-content: space-between; gap: 18px; }
.checkout-panel header p { margin: 0 0 5px; color: var(--muted); font-size: 13px; font-weight: 800; }
.checkout-panel h2 { margin: 0; font-size: 24px; }
.icon-button { width: 38px; height: 38px; padding: 0; border: 1px solid var(--line); border-radius: 6px; display: grid; place-items: center; color: var(--ink); background: white; }
.icon-button svg { width: 19px; }
.checkout-summary { margin: 24px 0 18px; padding: 18px 0; border-block: 1px solid var(--line); display: flex; align-items: center; justify-content: space-between; }
.checkout-summary span { color: var(--muted); font-weight: 700; }
.checkout-summary strong { color: var(--red); font-size: 30px; }
.channel-view { display: grid; grid-template-columns: 1fr; gap: 10px; }
.channel-button { min-height: 52px; border: 0; border-radius: 6px; display: flex; align-items: center; justify-content: center; gap: 8px; color: white; font-weight: 900; }
.channel-button svg { width: 20px; }
.channel-button.wechat { background: #149546; }
.channel-button:disabled { cursor: wait; opacity: .55; }
.checkout-message { min-height: 24px; margin: 17px 0 0; color: var(--muted); font-size: 14px; text-align: center; }
.qr-view { display: grid; justify-items: center; gap: 9px; }
.qr-view img { width: 220px; height: 220px; border: 1px solid var(--line); }
.qr-view strong { font-size: 16px; }
.qr-view span { color: var(--muted); font-size: 12px; overflow-wrap: anywhere; }
.toast { position: fixed; right: 22px; bottom: 22px; z-index: 30; max-width: min(360px, calc(100% - 44px)); padding: 12px 15px; border-radius: 6px; color: white; background: #271d18; box-shadow: var(--shadow); opacity: 0; transform: translateY(10px); pointer-events: none; transition: .2s ease; }
.toast.visible { opacity: 1; transform: translateY(0); }

@media (max-width: 1050px) {
  .storefront { grid-template-columns: 1fr; align-content: center; gap: 34px; }
  .brand-lockup { margin-bottom: 24px; }
  h1 span, h1 strong { display: inline; font-size: 46px; }
  h1 strong { margin-left: 16px; }
  .brand-panel > p { margin-top: 16px; }
}

@media (max-width: 680px) {
  body { background-image: url("hero-oil-mobile.jpg"); background-attachment: scroll; }
  body::before { background: rgba(255,249,241,.55); }
  .storefront { padding: 22px 16px 34px; align-content: start; gap: 26px; }
  .brand-lockup { margin-bottom: 22px; font-size: 20px; }
  .brand-lockup img { width: 48px; height: 48px; }
  h1 span, h1 strong { display: block; font-size: 42px; }
  h1 strong { margin: 5px 0 0; font-size: 34px; }
  .brand-panel > p { margin-top: 12px; font-size: 14px; line-height: 1.65; }
  .plans { grid-template-columns: 1fr; gap: 14px; }
  .plan-card { padding: 22px; }
  .plan-card.featured { padding-top: 19px; }
  .plan-card ul { min-height: 0; margin: 20px 0; gap: 12px; }
  .price strong { font-size: 40px; }
  .channel-view { grid-template-columns: 1fr; }
}