/* ===== local fonts ===== */
@font-face { font-family: "Inter"; font-style: normal; font-weight: 400; font-display: swap; src: url("../fonts/inter-400.woff2") format("woff2"); }
@font-face { font-family: "Inter"; font-style: normal; font-weight: 500; font-display: swap; src: url("../fonts/inter-500.woff2") format("woff2"); }
@font-face { font-family: "Inter"; font-style: normal; font-weight: 600; font-display: swap; src: url("../fonts/inter-600.woff2") format("woff2"); }
@font-face { font-family: "Inter"; font-style: normal; font-weight: 700; font-display: swap; src: url("../fonts/inter-700.woff2") format("woff2"); }
@font-face { font-family: "Inter"; font-style: normal; font-weight: 800; font-display: swap; src: url("../fonts/inter-800.woff2") format("woff2"); }
@font-face { font-family: "JetBrains Mono"; font-style: normal; font-weight: 400; font-display: swap; src: url("../fonts/jetbrainsmono-400.woff2") format("woff2"); }
@font-face { font-family: "JetBrains Mono"; font-style: normal; font-weight: 500; font-display: swap; src: url("../fonts/jetbrainsmono-500.woff2") format("woff2"); }

/* ===== reset / variables ===== */
* { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #ffffff;
  --bg-soft: #fafafa;
  --text: #0a0a0a;
  --text-2: #525252;
  --text-3: #a3a3a3;
  --border: #ededed;
  --border-strong: #d4d4d4;
  --accent: #0a0a0a;
  --accent-hover: #262626;
  --green: #16a34a;

  --font-sans: "Inter", "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;

  --max: 1180px;
  --radius: 8px;
}

html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--bg);
  line-height: 1.55;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -webkit-text-size-adjust: 100%;
  font-feature-settings: "cv11", "ss01";
}
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
input { font-family: inherit; color: inherit; }
ul { list-style: none; }
em { font-style: normal; }

.container { max-width: var(--max); margin: 0 auto; padding: 0 28px; }
.hairline { border: none; border-top: 1px solid var(--border); margin: 0; }

/* ===== navbar ===== */
.navbar {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 60px; gap: 24px;
}
.logo {
  display: flex; align-items: center; gap: 8px;
  font-weight: 700; font-size: 16px; letter-spacing: -0.01em;
  font-family: var(--font-sans);
}
.logo-mark {
  width: 18px; height: 18px;
  background: var(--text);
  border-radius: 4px;
  position: relative;
}
.logo-mark::after {
  content: ""; position: absolute; inset: 4px;
  background: #fff;
  border-radius: 2px;
}
.logo-text .dot { color: var(--green); }

.nav-menu {
  display: flex; gap: 4px;
  flex: 1; justify-content: center;
}
.nav-link {
  padding: 8px 12px;
  font-size: 13.5px;
  color: var(--text-2);
  border-radius: 6px;
  transition: color .15s, background .15s;
}
.nav-link:hover { color: var(--text); background: var(--bg-soft); }
.nav-link.active { color: var(--text); }

.nav-right { display: flex; align-items: center; gap: 14px; }
.nav-secondary {
  font-size: 13.5px;
  color: var(--text-2);
  transition: color .15s;
}
.nav-secondary:hover { color: var(--text); }
.nav-toggle { display: none; font-size: 24px; color: var(--text); }

/* ===== buttons ===== */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 9px 16px;
  font-size: 13.5px; font-weight: 500;
  border-radius: 6px;
  transition: all .15s;
  white-space: nowrap;
}
.btn span { transition: transform .15s; }
.btn:hover span { transform: translateX(2px); }

.btn-dark {
  background: var(--text);
  color: #fff;
}
.btn-dark:hover { background: var(--accent-hover); }
.btn-lg { padding: 14px 22px; font-size: 14.5px; }
.btn-link {
  color: var(--text);
  border-bottom: 1px solid transparent;
  border-radius: 0;
  padding: 9px 4px;
}
.btn-link:hover { border-bottom-color: var(--text); }
.btn-line {
  border: 1px solid var(--border-strong);
  color: var(--text);
  background: transparent;
}
.btn-line:hover { background: var(--bg-soft); border-color: var(--text); }

/* ===== hero ===== */
.hero {
  padding: 110px 0 90px;
  text-align: left;
}
.hero-pill {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px;
  border: 1px solid var(--border);
  background: var(--bg-soft);
  border-radius: 50px;
  font-size: 13px;
  color: var(--text-2);
  margin-bottom: 32px;
  transition: border-color .15s;
}
.hero-pill:hover { border-color: var(--border-strong); }
.dot-green {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 3px rgba(22,163,74,0.15);
}
.hero-title {
  font-size: clamp(48px, 7.5vw, 96px);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  margin-bottom: 28px;
  max-width: 900px;
}
.hero-title em {
  color: var(--text-3);
  font-weight: 800;
}
.hero-sub {
  font-size: clamp(16px, 1.4vw, 19px);
  color: var(--text-2);
  max-width: 640px;
  line-height: 1.55;
  margin-bottom: 40px;
}
.hero-cta {
  display: flex; align-items: center; gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 90px;
}

.hero-meta {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--border);
}
.meta {
  padding: 28px 0 4px;
  display: flex; flex-direction: column; gap: 4px;
  border-right: 1px solid var(--border);
  padding-left: 24px;
}
.meta:first-child { padding-left: 0; }
.meta:last-child { border-right: none; }
.meta-key {
  font-size: 12px;
  color: var(--text-3);
  font-family: var(--font-mono);
}
.meta b {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

/* ===== generic section ===== */
.flow, .panel {
  padding: 100px 0;
}
.section-head { margin-bottom: 60px; max-width: 720px; }
.eyebrow {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-3);
  margin-bottom: 18px;
  letter-spacing: 0.02em;
}
.section-title {
  font-size: clamp(32px, 4.5vw, 56px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: 18px;
}
.section-sub {
  font-size: 16px;
  color: var(--text-2);
  max-width: 540px;
  line-height: 1.6;
}
.section-sub b { color: var(--text); font-weight: 600; }

/* ===== flow ===== */
.flow-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--border);
  border-left: 1px solid var(--border);
}
.flow-item {
  padding: 32px 28px 32px;
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  transition: background .15s;
}
.flow-item:hover { background: var(--bg-soft); }
.flow-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-3);
  margin-bottom: 32px;
}
.flow-item h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}
.flow-item p {
  font-size: 13.5px;
  color: var(--text-2);
  line-height: 1.6;
}

/* ===== price ===== */
.price-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
  margin-bottom: 28px;
}
.price-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: border-color .15s;
}
.price-card:hover { border-color: var(--border-strong); }
.price-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.02em;
  padding: 3px 9px;
  background: var(--text);
  color: #fff;
  border-radius: 4px;
  margin-bottom: 20px;
}
.price-amount {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
  margin-bottom: 6px;
}
.price-amount span {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-3);
  margin-left: 6px;
}
.price-energy {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-3);
  margin-bottom: 14px;
}
.price-desc { font-size: 13.5px; color: var(--text-2); line-height: 1.6; }

/* ===== form ===== */
.form-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
}
.form-tip {
  padding: 14px 18px;
  background: var(--bg-soft);
  border-left: 2px solid var(--text);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 13.5px;
  color: var(--text-2);
  margin-bottom: 22px;
}
.form-tip b { color: var(--text); font-weight: 600; }
.form-row {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 24px;
  padding-bottom: 24px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--border);
  align-items: start;
}
.form-row:last-of-type {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}
.form-label {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text);
  padding-top: 11px;
}
.form-input {
  width: 100%;
  padding: 11px 14px;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  font-size: 14px;
  color: var(--text);
  transition: border-color .15s, box-shadow .15s;
}
.form-input:focus {
  outline: none;
  border-color: var(--text);
  box-shadow: 0 0 0 3px rgba(0,0,0,0.06);
}
.form-input.readonly { background: var(--bg-soft); color: var(--text); cursor: default; }
.form-input::placeholder { color: var(--text-3); }

.pill-group { display: flex; flex-wrap: wrap; gap: 8px; }
.pill {
  padding: 8px 16px;
  background: var(--bg);
  border: 1px solid var(--border-strong);
  border-radius: 50px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-2);
  transition: all .15s;
}
.pill:hover { border-color: var(--text); color: var(--text); }
.pill.active {
  background: var(--text);
  color: #fff;
  border-color: var(--text);
}
.pill-custom { color: var(--text); }
.pill-custom.active { background: var(--text); }

/* ===== pay summary ===== */
.pay-summary {
  margin-top: 32px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}
.pay-line {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--border);
  gap: 16px; flex-wrap: wrap;
}
.pay-line:last-of-type { border-bottom: none; }
.pay-label {
  font-size: 13.5px;
  color: var(--text-2);
}
.pay-line b { font-size: 14.5px; font-weight: 600; }
.pay-amount {
  font-size: 22px !important;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.pay-addr {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  background: var(--bg-soft);
  padding: 8px 12px;
  border-radius: 6px;
  border: 1px solid var(--border);
  color: var(--text-2);
  word-break: break-all;
}
.copy-btn {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  padding: 4px 10px;
  background: var(--text);
  color: #fff;
  border-radius: 4px;
  transition: background .15s;
  flex-shrink: 0;
}
.copy-btn:hover { background: var(--accent-hover); }

.pay-qr {
  display: flex; align-items: center; gap: 20px;
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px dashed var(--border);
}
.pay-qr img {
  width: 90px; height: 90px;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px;
  background: #fff;
  flex-shrink: 0;
}
.pay-qr-text h4 {
  font-size: 14.5px;
  font-weight: 600;
  margin-bottom: 4px;
}
.pay-qr-text p {
  font-size: 13px;
  color: var(--text-2);
  line-height: 1.6;
}
.pay-qr-text code {
  font-family: var(--font-mono);
  font-size: 12px;
  background: var(--bg-soft);
  padding: 1px 6px;
  border-radius: 3px;
}

/* ===== bullets ===== */
.bullets {
  border-top: 1px solid var(--border);
  margin-bottom: 36px;
}
.bullets li {
  display: flex; align-items: baseline; gap: 24px;
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
  font-size: 16px;
  color: var(--text);
}
.bullets li span {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-3);
  flex-shrink: 0;
  width: 24px;
}

/* ===== rate ===== */
.rate-grid {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 24px;
}
.rate-cell {
  padding: 24px 22px;
  border-right: 1px solid var(--border);
}
.rate-cell:last-child { border-right: none; }
.rate-cell span {
  display: block;
  font-size: 12px;
  color: var(--text-3);
  font-family: var(--font-mono);
  margin-bottom: 8px;
}
.rate-cell b {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

/* ===== swap ===== */
.swap-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: end;
  gap: 18px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 24px;
}
.swap-col .form-label { padding-top: 0; margin-bottom: 8px; display: block; }
.swap-divider {
  font-size: 22px; color: var(--text-3);
  padding-bottom: 11px;
}
.swap-input { position: relative; }
.swap-input input { padding-right: 60px; font-size: 18px; padding: 14px 60px 14px 16px; font-weight: 600; }
.swap-suffix {
  position: absolute; right: 16px; top: 50%; transform: translateY(-50%);
  font-size: 13px; font-weight: 600; color: var(--text-3);
  font-family: var(--font-mono);
}

/* ===== feature grid ===== */
.feature-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--border);
  border-left: 1px solid var(--border);
  margin-bottom: 40px;
}
.feature-item {
  padding: 32px 28px;
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  transition: background .15s;
}
.feature-item:hover { background: var(--bg-soft); }
.feature-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-3);
  margin-bottom: 32px;
}
.feature-item h3 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
}
.feature-item p {
  font-size: 13.5px;
  color: var(--text-2);
  line-height: 1.6;
}

.cta-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }

/* ===== about ===== */
.about-content { max-width: 720px; }
.about-content p {
  font-size: 18px;
  color: var(--text-2);
  line-height: 1.7;
  margin-bottom: 18px;
}
.meta-list {
  margin-top: 56px;
  border-top: 1px solid var(--border);
}
.meta-list > div {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 24px;
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
}
.meta-list dt {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-3);
}
.meta-list dd {
  font-size: 15.5px;
  color: var(--text);
  font-weight: 500;
}

/* ===== contact ===== */
.contact-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
}
.contact-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  background: var(--bg);
  transition: border-color .15s;
}
.contact-card:hover { border-color: var(--border-strong); }
.contact-key {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-3);
  margin-bottom: 16px;
}
.contact-card h3 {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
  font-family: var(--font-mono);
}
.contact-card p {
  font-size: 13.5px;
  color: var(--text-2);
  margin-bottom: 20px;
}

/* ===== footer ===== */
.footer {
  padding: 80px 0 36px;
  background: var(--bg);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 50px;
  border-bottom: 1px solid var(--border);
}
.footer-brand p {
  margin-top: 16px;
  font-size: 14px;
  color: var(--text-2);
  line-height: 1.6;
}
.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-3);
  letter-spacing: 0.02em;
  margin-bottom: 16px;
  font-weight: 500;
}
.footer-col li {
  padding: 5px 0;
  font-size: 13.5px;
  color: var(--text-2);
}
.footer-col a { transition: color .15s; }
.footer-col a:hover { color: var(--text); }
.footer-bottom {
  margin-top: 28px;
  display: flex; justify-content: space-between;
  font-size: 13px;
  color: var(--text-3);
  flex-wrap: wrap; gap: 12px;
}
.status { display: inline-flex; align-items: center; gap: 8px; color: var(--text-2); }

/* ===== toast ===== */
.toast {
  position: fixed; bottom: 32px; left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--text); color: #fff;
  padding: 10px 22px; border-radius: 6px;
  font-size: 13.5px;
  opacity: 0; pointer-events: none;
  transition: all .2s;
  z-index: 200;
  box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ===== responsive ===== */
.hide-sm { display: inline; }
@media (max-width: 980px) {
  .nav-menu {
    position: absolute; top: 60px; left: 0; right: 0;
    flex-direction: column; gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 10px 24px; display: none;
  }
  .nav-menu.open { display: flex; }
  .nav-link { padding: 12px 14px; }
  .nav-toggle { display: block; }
  .nav-right .btn-dark, .nav-secondary { display: none; }
  .hero-meta { grid-template-columns: repeat(2, 1fr); }
  .meta { border-bottom: 1px solid var(--border); }
  .meta:nth-child(2) { border-right: none; }
  .price-grid, .contact-grid { grid-template-columns: 1fr; }
  .flow-grid, .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .rate-grid { grid-template-columns: repeat(2, 1fr); }
  .rate-cell:nth-child(2) { border-right: none; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .form-row { grid-template-columns: 1fr; gap: 10px; }
  .form-label { padding-top: 0; }
  .meta-list > div { grid-template-columns: 1fr; gap: 4px; }
  .hide-sm { display: none; }
}
@media (max-width: 560px) {
  .container { padding: 0 20px; }
  .flow, .panel { padding: 70px 0; }
  .flow-grid, .feature-grid, .rate-grid, .footer-grid { grid-template-columns: 1fr; }
  .swap-row { grid-template-columns: 1fr; }
  .swap-divider { transform: rotate(90deg); padding: 0; text-align: center; }
  .pay-qr { flex-direction: column; align-items: flex-start; }
  .form-card { padding: 24px; }
}