/* ============================================================
   喇叭花 · 销售落地页（/）
   六块结构：① 首屏 ② 痛点 ③ 演示 ④ 功能 ⑤ 信任 ⑥ 价格
   铁律：全页仅「开通」一个行动按钮，重复 3 次，无导航栏。
   依赖 base.css 的变量（--b1 --b2 --ink --ink2 --line）。
   ============================================================ */

.lb-landing {
  --hot: #f97316;
  --hot-soft: #fff7ed;
  background: linear-gradient(170deg, #f7f3ff 0%, #eaf2fe 48%, #f4f0ff 100%);
  background-attachment: fixed;
}

/* ---------------- 顶栏：只有品牌 + 一个登录文字链 ---------------- */
.lb-top {
  max-width: 1080px; margin: 0 auto; padding: 14px 20px;
  display: flex; align-items: center; justify-content: space-between;
}
.lb-logo { font-size: 1.16rem; color: var(--ink); text-decoration: none; letter-spacing: .5px; }
.lb-login { color: var(--ink2); text-decoration: none; font-size: .92rem; padding: 7px 14px; border-radius: 999px; }
.lb-login:hover { color: var(--b1); background: #fff; }

.lb-main { max-width: 1080px; margin: 0 auto; padding: 0 20px 24px; }

/* ---------------- ① 首屏 ----------------
   桌面端排成双栏：左列文案逐行落位，右列演示（手机→大屏）跨满整列。
   这样做的目的是把「产品长什么样」提到折叠线以上——纯文案撑满一屏是最贵的浪费。
   刻意不改 HTML 结构（该文件由设计工具托管），全部用 grid 定位实现。 */
.lb-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.02fr);
  column-gap: 36px; row-gap: 0;
  align-items: start;
  text-align: left;
  padding: 30px 0 10px;
}
.lb-badge { grid-column: 1; grid-row: 1; justify-self: start; }
.lb-h1    { grid-column: 1; grid-row: 2; }
.lb-lead  { grid-column: 1; grid-row: 3; }
.lb-trust { grid-column: 1; grid-row: 4; }
.lb-cta   { grid-column: 1; grid-row: 5; justify-content: flex-start; }
.lb-micro { grid-column: 1; grid-row: 6; }
.lb-demo  { grid-column: 2; grid-row: 1 / 7; align-self: center; margin-top: 0; }

.lb-badge {
  display: inline-block; font-size: .8rem; font-weight: 600; color: var(--b1);
  background: #fff; border: 1px solid #dbe6fb; border-radius: 999px; padding: 6px 14px;
  box-shadow: 0 6px 18px -12px rgba(37, 99, 235, .8);
}
.lb-h1 {
  margin-top: 16px; font-size: clamp(1.62rem, 3.1vw, 2.3rem); line-height: 1.24;
  color: var(--ink); letter-spacing: -.5px;
}
.lb-h1 em {
  font-style: normal; position: relative; white-space: nowrap;
  background: linear-gradient(120deg, var(--b1), var(--b2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.lb-lead { margin-top: 13px; font-size: clamp(.96rem, 1.2vw, 1.06rem); line-height: 1.7; color: var(--ink2); }
.lb-lead b { color: var(--ink); }
.lb-trust { margin-top: 11px; font-size: .86rem; color: var(--ink2); letter-spacing: .2px; }
.lb-trust b { color: var(--hot); font-size: 1rem; }
.lb-cta { margin-top: 18px; display: flex; }
.lb-micro { margin-top: 11px; font-size: .79rem; color: var(--ink2); line-height: 1.65; }
.lb-micro b { color: var(--ink); }

/* 主按钮 */
.lb-btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 52px; padding: 0 34px; border-radius: 999px;
  background: #fff; border: 1.5px solid var(--line); color: var(--ink);
  font-size: 1.06rem; font-weight: 700; text-decoration: none;
  transition: transform .16s, box-shadow .16s, border-color .16s, color .16s;
}
.lb-btn:hover { border-color: var(--b1); color: var(--b1); transform: translateY(-1px); }
.lb-btn-primary {
  background: linear-gradient(120deg, var(--b1), var(--b2));
  border: none; color: #fff; padding: 0 42px;
  box-shadow: 0 16px 34px -14px rgba(37, 99, 235, .75);
  animation: lbPulse 3.4s ease-in-out infinite;
}
.lb-btn-primary:hover { color: #fff; filter: brightness(1.06); box-shadow: 0 20px 40px -14px rgba(37, 99, 235, .85); }
.lb-btn-lg { min-height: 58px; font-size: 1.16rem; padding: 0 54px; }
@keyframes lbPulse {
  0%, 100% { box-shadow: 0 16px 34px -14px rgba(37, 99, 235, .75); }
  50%      { box-shadow: 0 18px 40px -12px rgba(124, 58, 237, .80); }
}
@media (prefers-reduced-motion: reduce) {
  .lb-btn-primary { animation: none; }
}

/* ---------------- 首屏演示动图（纯 CSS）---------------- */
.lb-demo { margin-top: 0; }
.lb-demo-stage {
  display: grid; grid-template-columns: 1fr auto 1.12fr;
  align-items: center; gap: 11px;
  background: rgba(255, 255, 255, .62);
  border: 1px solid var(--line); border-radius: 22px;
  padding: 18px; backdrop-filter: blur(6px);
}

/* 手机 */
.lb-phone {
  background: #fff; border: 1px solid var(--line); border-radius: 15px;
  padding: 8px; box-shadow: 0 18px 40px -28px rgba(11, 42, 74, .7); text-align: left;
}
.lb-phone-bar {
  display: flex; align-items: center; gap: 5px;
  font-size: .6rem; color: var(--ink2); padding: 2px 3px 7px;
  border-bottom: 1px solid #eef2f8;
}
.lb-phone-body { padding-top: 7px; display: flex; flex-direction: column; gap: 5px; }
.lb-chip {
  font-size: .65rem; color: var(--ink2); background: #f4f7fc;
  border-radius: 8px; padding: 5px 8px; line-height: 1.35;
}
.lb-chip-send {
  display: flex; align-items: center; justify-content: space-between; gap: 4px;
  font-weight: 700; color: var(--ink);
  animation: lbSend 5s ease-in-out infinite;
}
.lb-chip-send i {
  flex: none; font-style: normal; font-size: .55rem; font-weight: 600;
  background: #fff; color: var(--b1); border-radius: 999px; padding: 2px 6px;
}
@keyframes lbSend {
  0%, 5%   { background: #f4f7fc; color: var(--ink); transform: scale(1); box-shadow: none; }
  9%, 24%  { background: linear-gradient(120deg, var(--b1), var(--b2)); color: #fff;
             transform: scale(1.05); box-shadow: 0 10px 22px -10px rgba(37, 99, 235, .9); }
  32%, 100%{ background: #f4f7fc; color: var(--ink); transform: scale(1); box-shadow: none; }
}

/* 中间信号 */
.lb-link { display: flex; align-items: center; gap: 5px; }
.lb-link i {
  width: 7px; height: 7px; border-radius: 50%; display: block;
  background: var(--b1); opacity: .22;
  animation: lbDot 5s ease-in-out infinite;
}
.lb-link i:nth-child(1) { animation-delay: 0s; }
.lb-link i:nth-child(2) { animation-delay: .16s; }
.lb-link i:nth-child(3) { animation-delay: .32s; }
@keyframes lbDot {
  0%, 8%   { opacity: .22; transform: scale(.8); }
  13%, 25% { opacity: 1; transform: scale(1.3); }
  34%, 100%{ opacity: .22; transform: scale(.8); }
}

/* 教室大屏 */
.lb-screen {
  position: relative; background: #fff; border: 1.5px solid var(--line);
  border-radius: 15px; padding: 12px 14px 14px; min-height: 124px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  overflow: hidden;
  animation: lbGlow 5s ease-in-out infinite;
}
@keyframes lbGlow {
  0%, 32%  { border-color: var(--line); box-shadow: 0 18px 40px -28px rgba(11, 42, 74, .7); }
  42%, 86% { border-color: rgba(37, 99, 235, .5);
             box-shadow: 0 0 0 3px rgba(37, 99, 235, .12), 0 22px 46px -24px rgba(37, 99, 235, .85); }
  96%, 100%{ border-color: var(--line); box-shadow: 0 18px 40px -28px rgba(11, 42, 74, .7); }
}
.lb-screen-bar {
  position: absolute; top: 8px; left: 11px;
  display: flex; align-items: center; gap: 5px;
  font-size: .6rem; color: var(--ink2);
}
.lb-dot { width: 5px; height: 5px; border-radius: 50%; background: #34d399; display: block; }
.lb-screen-clock {
  position: absolute; top: 8px; right: 11px;
  font-size: .6rem; color: var(--ink2); font-variant-numeric: tabular-nums;
}
.lb-screen-msg {
  font-size: clamp(1.25rem, 2.4vw, 1.85rem); font-weight: 800; letter-spacing: .12em;
  color: var(--ink); line-height: 1.2; margin-top: 10px; white-space: nowrap;
  animation: lbMsg 5s ease-in-out infinite;
}
@keyframes lbMsg {
  0%, 32%  { opacity: 0; transform: scale(.8); }
  40%, 88% { opacity: 1; transform: scale(1); }
  97%, 100%{ opacity: 0; transform: scale(.92); }
}
.lb-wave { display: flex; align-items: center; gap: 4px; height: 17px; margin-top: 9px; }
.lb-wave i {
  width: 4px; height: 100%; border-radius: 2px; display: block;
  background: linear-gradient(180deg, var(--b1), var(--b2));
  transform-origin: center; animation: lbWave 5s ease-in-out infinite;
}
.lb-wave i:nth-child(1) { animation-delay: 0s; }
.lb-wave i:nth-child(2) { animation-delay: .11s; }
.lb-wave i:nth-child(3) { animation-delay: .22s; }
.lb-wave i:nth-child(4) { animation-delay: .33s; }
.lb-wave i:nth-child(5) { animation-delay: .44s; }
@keyframes lbWave {
  0%, 40%  { transform: scaleY(.22); opacity: .3; }
  52%      { transform: scaleY(1);   opacity: 1; }
  66%, 100%{ transform: scaleY(.22); opacity: .3; }
}
.lb-demo-cap { margin-top: 10px; text-align: center; font-size: .76rem; color: var(--ink2); }

/* ---------------- 区块通用 ---------------- */
.lb-sec { margin-top: 76px; }
.lb-sec-t { text-align: center; font-size: clamp(1.3rem, 3vw, 1.62rem); color: var(--ink); letter-spacing: -.3px; }
.lb-sec-s { text-align: center; margin-top: 10px; font-size: .92rem; color: var(--ink2); line-height: 1.7; }

/* ---------------- ② 痛点 ---------------- */
.lb-pains { list-style: none; padding: 0; margin: 30px 0 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.lb-pain {
  background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 20px 18px;
  display: flex; flex-direction: column; gap: 8px;
}
.lb-pain-ic { font-size: 1.5rem; line-height: 1; }
.lb-pain b { font-size: 1rem; color: var(--ink); }
.lb-pain span { font-size: .85rem; color: var(--ink2); line-height: 1.7; }

/* ---------------- ③ 演示三步 ---------------- */
.lb-flow { list-style: none; padding: 0; margin: 30px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; counter-reset: none; }
.lb-flow li { position: relative; background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 22px 18px; }
.lb-flow li::after {
  content: "→"; position: absolute; right: -13px; top: 50%; transform: translateY(-50%);
  color: var(--b1); opacity: .35; font-weight: 700;
}
.lb-flow li:last-child::after { content: none; }
.lb-flow i {
  font-style: normal; display: inline-flex; width: 30px; height: 30px; border-radius: 50%;
  background: linear-gradient(120deg, var(--b1), var(--b2)); color: #fff;
  align-items: center; justify-content: center; font-weight: 700; font-size: .9rem;
}
.lb-flow b { display: block; margin: 11px 0 6px; font-size: 1.04rem; color: var(--ink); }
.lb-flow span { font-size: .86rem; color: var(--ink2); line-height: 1.7; }

/* ---------------- ④ 功能四宫格 ---------------- */
.lb-feats { list-style: none; padding: 0; margin: 30px 0 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.lb-feat { background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 22px 18px; transition: .18s; }
.lb-feat:hover { border-color: #c9d9f5; transform: translateY(-2px); box-shadow: 0 18px 36px -26px rgba(11, 42, 74, .8); }
.lb-feat-ic { font-size: 1.5rem; line-height: 1; }
.lb-feat b { display: block; margin: 10px 0 7px; font-size: 1.04rem; color: var(--ink); }
.lb-feat span { font-size: .85rem; color: var(--ink2); line-height: 1.7; }
.lb-more { margin-top: 16px; text-align: center; font-size: .84rem; color: var(--ink2); }

/* ---------------- CTA 中段 / 末段 ---------------- */
.lb-cta-mid { margin-top: 56px; text-align: center; }
.lb-cta-final { margin-top: 76px; text-align: center; }

/* ---------------- ⑤ 信任 ---------------- */
.lb-proof {
  margin: 16px auto 0; text-align: center; display: inline-block;
  position: relative; left: 50%; transform: translateX(-50%);
  font-size: .9rem; color: var(--ink2); background: #fff;
  border: 1px solid var(--line); border-radius: 999px; padding: 8px 20px;
}
.lb-proof b { color: var(--hot); font-size: 1.08rem; }
.lb-promises { list-style: none; padding: 0; margin: 30px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.lb-promise { background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 22px 20px; }
.lb-promise b { display: block; font-size: 1.02rem; color: var(--ink); margin-bottom: 8px; }
.lb-promise span { font-size: .86rem; color: var(--ink2); line-height: 1.75; }

/* 真实反馈（注释块解开即用） */
.lb-quotes { list-style: none; padding: 0; margin: 22px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.lb-quotes li { background: var(--hot-soft); border: 1px solid #fed7aa; border-radius: 18px; padding: 18px 20px; }
.lb-quotes p { font-size: .9rem; color: var(--ink); line-height: 1.75; }
.lb-quotes span { display: block; margin-top: 10px; font-size: .8rem; color: var(--ink2); }

/* ---------------- ⑥ 价格三档 ---------------- */
.lb-prices { list-style: none; padding: 8px 0 0; margin: 30px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; align-items: stretch; }
.lb-tier {
  position: relative; background: #fff; border: 1.5px solid var(--line); border-radius: 22px;
  padding: 26px 22px; display: flex; flex-direction: column; text-align: center;
}
.lb-tier-hot {
  border-color: transparent; background: linear-gradient(180deg, #ffffff, #f4f8ff);
  box-shadow: 0 0 0 2px var(--b1), 0 26px 54px -30px rgba(37, 99, 235, .9);
  transform: translateY(-6px);
}
.lb-ribbon {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: linear-gradient(120deg, var(--hot), #fb923c); color: #fff;
  font-size: .74rem; font-weight: 700; letter-spacing: .5px;
  border-radius: 999px; padding: 5px 16px; white-space: nowrap;
}
.lb-tier-name { font-size: 1.02rem; color: var(--ink2); font-weight: 600; }
.lb-tier-price { margin: 10px 0 6px; color: var(--ink); font-size: 2.5rem; font-weight: 800; letter-spacing: -1px; }
.lb-tier-price i { font-style: normal; font-size: 1.1rem; font-weight: 700; margin-right: 2px; }
.lb-tier-hot .lb-tier-price { color: var(--b1); }
.lb-tier-desc { font-size: .82rem; color: var(--ink2); line-height: 1.6; }
.lb-tier-list { list-style: none; padding: 0; margin: 20px 0 0; flex: 1; }
.lb-tier-list li { font-size: .88rem; color: var(--ink2); padding: 7px 0; border-top: 1px dashed #edf2f9; }
.lb-tier-list li:first-child { border-top: none; }
.lb-tier-list li b { color: var(--ink); }
.lb-pay { margin-top: 24px; text-align: center; font-size: .84rem; color: var(--ink2); line-height: 1.75; }

/* ---------------- 页脚 ---------------- */
.lb-foot { text-align: center; padding: 46px 20px 40px; color: var(--ink2); font-size: .82rem; line-height: 1.9; }
.lb-foot b { color: var(--ink); }
.lb-foot-links { margin-top: 6px; }
.lb-foot-links a { color: var(--ink2); text-decoration: none; }
.lb-foot-links a:hover { color: var(--b1); }
.lb-foot-links span { margin: 0 8px; opacity: .5; }
.lb-copy { margin-top: 6px; opacity: .8; font-size: .78rem; }

/* ---------------- 响应式 ---------------- */

/* 窄屏首屏回落到单列居中：必须把双栏定位整套复位，否则会错位 */
@media (max-width: 900px) {
  .lb-hero {
    grid-template-columns: minmax(0, 1fr);
    text-align: center;
    padding-top: 26px;
    row-gap: 0; column-gap: 0;
  }
  .lb-badge, .lb-h1, .lb-lead, .lb-trust, .lb-cta, .lb-micro, .lb-demo {
    grid-column: 1; grid-row: auto;
  }
  .lb-badge { justify-self: center; font-size: .82rem; }
  .lb-cta { justify-content: center; }
  .lb-h1 { font-size: clamp(1.75rem, 6.2vw, 2.45rem); }
  .lb-lead { font-size: clamp(1rem, 3.4vw, 1.14rem); }
  .lb-demo { justify-self: center; width: 100%; max-width: 520px; margin-top: 24px; }

  .lb-pains, .lb-feats { grid-template-columns: repeat(2, 1fr); }
  .lb-flow, .lb-promises, .lb-prices, .lb-quotes { grid-template-columns: 1fr; }
  .lb-prices { gap: 22px; }
  .lb-tier-hot { transform: none; }
  .lb-flow li::after { content: none; }
}
@media (max-width: 640px) {
  .lb-sec { margin-top: 56px; }
  .lb-br { display: none; }
  .lb-pains, .lb-feats { grid-template-columns: 1fr; }
  .lb-cta .lb-btn, .lb-cta-mid .lb-btn, .lb-cta-final .lb-btn { width: 100%; max-width: 340px; }
  .lb-btn-primary { padding: 0 22px; }
  .lb-demo-stage { padding: 15px; gap: 9px; }
  .lb-demo-cap { font-size: .72rem; }
}
/* 极窄屏才把演示堆成一列，避免手机/大屏被压得太小 */
@media (max-width: 420px) {
  .lb-demo-stage { grid-template-columns: 1fr; gap: 10px; }
  .lb-link { justify-content: center; }
  .lb-screen { min-height: 112px; }
}