/* ==========================================================================
   dy赞自助下单 - 全站样式
   深藏青底 + 电光蓝/青柠（区别于站1黑青粉、站3墨绿、站4暖米白、站5酒红）
   纯静态、零依赖、移动优先
   ========================================================================== */

:root {
  --bg: #060d1f;
  --bg-deep: #040915;
  --panel: rgba(140, 180, 255, 0.07);
  --panel-2: rgba(140, 180, 255, 0.12);
  --edge: rgba(120, 170, 255, 0.22);
  --edge-strong: rgba(120, 170, 255, 0.45);
  --ink: #eaf1ff;
  --ink-dim: #a9b9d8;
  --ink-mute: #7488ab;
  --blue: #3da5ff;
  --lime: #c8f542;
  --grad: linear-gradient(118deg, #3da5ff 0%, #4ec9ff 50%, #c8f542 100%);
  --radius: 16px;
  --radius-sm: 10px;
  --max: 1100px;
  --shadow: 0 20px 60px rgba(0, 0, 0, .55);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.85;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(620px 400px at 16% -10%, rgba(61, 165, 255, .18), transparent 60%),
    radial-gradient(700px 440px at 86% 4%, rgba(200, 245, 66, .08), transparent 62%),
    radial-gradient(880px 620px at 50% 112%, rgba(78, 201, 255, .12), transparent 66%);
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
details summary { cursor: pointer; list-style: none; }
details summary::-webkit-details-marker { display: none; }

.row { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 22px; }

/* ===================== 顶栏 ===================== */
.bar {
  position: sticky; top: 0; z-index: 60;
  background: rgba(6, 13, 31, .85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--edge);
}
.bar-row { display: flex; align-items: center; justify-content: space-between; height: 64px; }

.wordmark { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; font-size: 17px; }
.wordmark-bolt {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px;
  border-radius: 9px;
  background: var(--grad);
  font-size: 15px;
}

.bar-nav { display: flex; gap: 24px; font-size: 14.5px; color: var(--ink-dim); }
.bar-nav a { transition: color .25s; }
.bar-nav a:hover { color: var(--lime); }

/* ===================== 首屏 ===================== */
.front { padding: 80px 0 72px; text-align: center; }
.front-inner { max-width: 820px; }

.front-tag {
  display: inline-block;
  padding: 7px 18px;
  border-radius: 999px;
  border: 1px solid var(--edge-strong);
  background: var(--panel);
  color: var(--lime);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .05em;
  margin-bottom: 22px;
}

.front h1 { font-size: clamp(32px, 5vw, 54px); font-weight: 900; line-height: 1.24; }
.front h1 span {
  display: block;
  font-size: .55em;
  margin-top: 12px;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.front-text { margin: 22px auto 0; max-width: 620px; color: var(--ink-dim); font-size: 16.5px; }

.jump {
  display: inline-flex; align-items: center; justify-content: center;
  margin-top: 34px;
  padding: 15px 40px;
  border-radius: 999px;
  font-size: 16.5px;
  font-weight: 900;
  color: #04121f;
  background: var(--grad);
  box-shadow: 0 12px 34px rgba(61, 165, 255, .4);
  transition: transform .22s, box-shadow .22s;
}
.jump:hover { transform: translateY(-3px); box-shadow: 0 18px 44px rgba(61, 165, 255, .5); }

/* 首屏数据板 */
.board {
  margin-top: 56px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  text-align: center;
}
.board-cell {
  background: var(--panel);
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  padding: 22px 14px;
  transition: transform .25s, border-color .25s;
}
.board-cell:hover { transform: translateY(-4px); border-color: var(--edge-strong); }
.board-cell b {
  display: block;
  font-size: 21px;
  font-weight: 900;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.board-cell span { display: block; margin-top: 4px; font-size: 13px; color: var(--ink-mute); }

/* ===================== 通用区块 ===================== */
.slice { padding: 74px 0; }
.slice-deep { background: var(--bg-deep); }

.slice-head { max-width: 680px; margin-bottom: 44px; }
.slice-head h2 { font-size: clamp(24px, 3.2vw, 33px); font-weight: 900; }
.slice-head p { margin-top: 10px; color: var(--ink-dim); }

/* ===================== 点赞方案 ===================== */
.plan-list { display: grid; gap: 14px; }

.plan {
  display: grid;
  grid-template-columns: 74px 1fr auto;
  align-items: center;
  gap: 20px;
  background: var(--panel);
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  padding: 20px 24px;
  transition: transform .25s, border-color .25s;
}
.plan:hover { transform: translateX(6px); border-color: var(--edge-strong); }

.plan-side {
  display: inline-flex; align-items: center; justify-content: center;
  height: 52px;
  border-radius: var(--radius-sm);
  background: var(--grad);
  color: #04121f;
  font-size: 15px;
  font-weight: 900;
  writing-mode: horizontal-tb;
}

.plan-body h3 { font-size: 18px; font-weight: 800; }
.plan-body p { margin-top: 4px; font-size: 14.5px; color: var(--ink-dim); }

.plan-speed {
  font-size: 13px; font-weight: 700;
  color: var(--lime);
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px dashed var(--edge-strong);
  white-space: nowrap;
}

.plan-note { margin-top: 18px; font-size: 13.5px; color: var(--ink-mute); text-align: center; }

/* ===================== 通道特性 ===================== */
.feat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }

.feat {
  background: var(--panel);
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  padding: 24px 20px;
  transition: transform .25s, box-shadow .25s;
}
.feat:hover { transform: translateY(-5px); box-shadow: var(--shadow); }

.feat-no {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px;
  border-radius: 10px;
  background: var(--panel-2);
  border: 1px solid var(--edge-strong);
  color: var(--lime);
  font-size: 14px;
  font-weight: 900;
  margin-bottom: 14px;
}
.feat h3 { font-size: 16.5px; font-weight: 800; }
.feat p { margin-top: 6px; font-size: 13.5px; color: var(--ink-dim); }

/* ===================== 三步 ===================== */
.trio { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }

.trio li {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  padding: 30px 24px 24px;
  overflow: hidden;
  transition: transform .25s, border-color .25s;
}
.trio li:hover { transform: translateY(-5px); border-color: var(--edge-strong); }

.trio-key {
  position: absolute;
  top: 10px; right: 16px;
  font-size: 52px;
  font-weight: 900;
  color: rgba(140, 180, 255, .12);
  line-height: 1;
}
.trio h3 { font-size: 18px; font-weight: 800; position: relative; }
.trio p { margin-top: 8px; font-size: 14.5px; color: var(--ink-dim); position: relative; }

/* ===================== 问答 ===================== */
.qa-box { display: grid; gap: 12px; max-width: 820px; }
.qa-box details {
  background: var(--panel);
  border: 1px solid var(--edge);
  border-radius: var(--radius-sm);
  padding: 16px 22px;
  transition: border-color .25s;
}
.qa-box details[open] { border-color: var(--blue); }
.qa-box summary { display: flex; justify-content: space-between; align-items: center; font-size: 15.5px; font-weight: 800; }
.qa-box summary::after { content: "→"; color: var(--lime); transition: transform .3s; }
.qa-box details[open] summary::after { transform: rotate(90deg); }
.qa-box details p { margin-top: 10px; font-size: 14.5px; color: var(--ink-dim); }

/* ===================== 收尾 ===================== */
.last { padding: 84px 0; background: var(--bg-deep); border-top: 1px solid var(--edge); }
.last-inner { text-align: center; max-width: 640px; }
.last h2 { font-size: clamp(26px, 3.4vw, 36px); font-weight: 900; }
.last p { margin: 14px 0 30px; color: var(--ink-dim); }

/* ===================== 页脚 ===================== */
.foot { padding: 30px 0 36px; }
.foot-row { text-align: center; font-size: 14px; color: var(--ink-dim); }
.foot-tiny { margin-top: 4px; font-size: 12.5px; color: var(--ink-mute); }

/* ===================== 入场动画 ===================== */
.up { opacity: 0; transform: translateY(24px); transition: opacity .65s ease, transform .65s ease; }
.up.ok { opacity: 1; transform: none; }

/* ===================== 响应式 ===================== */
@media (max-width: 880px) {
  .board { grid-template-columns: repeat(2, 1fr); }
  .feat-grid { grid-template-columns: repeat(2, 1fr); }
  .trio { grid-template-columns: 1fr; }
  .plan { grid-template-columns: 58px 1fr; }
  .plan-speed { grid-column: 1 / -1; justify-self: center; }
}
@media (max-width: 560px) {
  .bar-nav { display: none; }
  .feat-grid { grid-template-columns: 1fr; }
  .board { grid-template-columns: 1fr 1fr; }
  .front { padding-top: 60px; }
  .slice { padding: 56px 0; }
}