:root {
  --bg: #f5f5f2;
  --paper: #ffffff;
  --ink: #101114;
  --muted: #62666d;
  --soft: #e7e5dc;
  --line: rgba(16, 17, 20, 0.1);
  --accent: #176b5f;
  --accent-soft: #dceee9;
  --blue-soft: #e7eef8;
  --shadow: 0 28px 90px rgba(24, 30, 38, 0.1);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% 8%, rgba(23, 107, 95, 0.08), transparent 26%),
    linear-gradient(180deg, #fbfbf8 0%, var(--bg) 44%, #ffffff 100%);
  font-size: 15px;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px clamp(20px, 5vw, 72px);
  border-bottom: 1px solid rgba(16, 17, 20, 0.06);
  background: rgba(250, 250, 247, 0.82);
  backdrop-filter: blur(24px) saturate(160%);
}

.brand {
  display: inline-flex;
  align-items: center;
}

.brand img {
  width: 126px;
  height: 40px;
  object-fit: contain;
}

.nav-links {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.7);
}

.nav-links a,
.nav-action {
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 15px;
  border-radius: 999px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
  white-space: nowrap;
}

.nav-links a.is-active {
  color: var(--ink);
  background: var(--paper);
  box-shadow: 0 10px 26px rgba(24, 30, 38, 0.08);
}

.nav-action {
  color: var(--ink);
  border: 1px solid var(--line);
  background: #fff;
}

main {
  width: min(1240px, calc(100% - 40px));
  margin: 0 auto;
}

.hero {
  min-height: calc(100vh - 140px);
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(480px, 1.1fr);
  gap: clamp(48px, 7vw, 104px);
  align-items: center;
  padding: clamp(28px, 4.8vw, 58px) 0 clamp(42px, 6vw, 64px);
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 720px;
  margin-bottom: 22px;
  font-size: clamp(40px, 5.3vw, 70px);
  line-height: 0.98;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 14px;
  font-size: clamp(28px, 3.4vw, 44px);
  line-height: 1.05;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 20px;
  letter-spacing: 0;
}

.lead {
  max-width: 660px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: clamp(15px, 1.55vw, 19px);
  line-height: 1.58;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.button {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid var(--line);
  font-weight: 650;
  white-space: nowrap;
}

.button.primary {
  color: #fff;
  border-color: #101114;
  background: #101114;
  box-shadow: 0 18px 48px rgba(16, 17, 20, 0.18);
}

.button.secondary {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.74);
}

.hero-product {
  order: 2;
  min-width: 0;
  align-self: center;
}

.hero-copy {
  order: 1;
}

.promo-video-shell {
  position: relative;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 1px solid rgba(16, 17, 20, 0.08);
  border-radius: 34px;
  background:
    radial-gradient(circle at 20% 12%, rgba(255, 255, 255, 0.94), transparent 34%),
    linear-gradient(145deg, rgba(255, 255, 255, 0.92), rgba(229, 239, 244, 0.74));
  box-shadow: var(--shadow);
}

.promo-video-shell::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  border-radius: inherit;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.72);
}

.promo-video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.screen-shell {
  position: relative;
  overflow: hidden;
  min-height: 560px;
  border: 1px solid rgba(16, 17, 20, 0.1);
  border-radius: 34px;
  background:
    linear-gradient(145deg, rgba(255,255,255,0.92), rgba(239, 242, 238, 0.7)),
    #ffffff;
  box-shadow: var(--shadow);
}

.screen-top {
  height: 56px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 22px;
  border-bottom: 1px solid rgba(16, 17, 20, 0.08);
}

.screen-top span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #cfd3d1;
}

.lesson-canvas {
  position: relative;
  min-height: 504px;
  padding: 30px;
  background:
    linear-gradient(rgba(16,17,20,0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16,17,20,0.035) 1px, transparent 1px),
    radial-gradient(circle at 78% 24%, rgba(23, 107, 95, 0.14), transparent 24%),
    radial-gradient(circle at 18% 74%, rgba(99, 132, 178, 0.14), transparent 22%);
  background-size: 34px 34px, 34px 34px, auto, auto;
}

.canvas-label {
  position: absolute;
  left: 30px;
  top: 28px;
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.72);
  font-size: 13px;
  font-weight: 760;
}

.motion-track {
  position: absolute;
  left: 11%;
  right: 10%;
  top: 45%;
  height: 10px;
  border-radius: 999px;
  background: rgba(16, 17, 20, 0.08);
}

.motion-line {
  position: absolute;
  left: 0;
  top: 4px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, rgba(23, 107, 95, 0.55), transparent);
}

.motion-dot {
  position: absolute;
  left: 10%;
  top: 50%;
  width: 74px;
  height: 74px;
  border-radius: 50%;
  transform: translate(-50%, -50%);
  background:
    radial-gradient(circle at 36% 30%, #ffffff, rgba(255,255,255,0.5) 18%, transparent 19%),
    linear-gradient(145deg, #1e8676, #103f3a);
  box-shadow: 0 26px 60px rgba(23, 107, 95, 0.28);
  animation: glide 5.8s ease-in-out infinite;
}

.lesson-panel {
  position: absolute;
  width: min(220px, 34%);
  padding: 18px;
  border: 1px solid rgba(16, 17, 20, 0.09);
  border-radius: 22px;
  background: rgba(255,255,255,0.82);
  box-shadow: 0 18px 44px rgba(24, 30, 38, 0.08);
}

.lesson-panel strong,
.lesson-panel span {
  display: block;
}

.lesson-panel strong {
  margin-bottom: 6px;
  font-size: 20px;
}

.lesson-panel span {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

.primary-panel {
  right: 7%;
  top: 19%;
}

.secondary-panel {
  left: 9%;
  bottom: 18%;
}

.third-panel {
  right: 10%;
  bottom: 10%;
  background: rgba(220, 238, 233, 0.9);
}

.section,
.showcase-section,
.flow-section,
.pricing-slice,
.final-cta {
  margin: 0 auto 26px;
  border: 1px solid rgba(16, 17, 20, 0.08);
  border-radius: 34px;
  background: rgba(255,255,255,0.76);
  box-shadow: 0 18px 60px rgba(24, 30, 38, 0.05);
}

.section {
  padding: clamp(30px, 5vw, 58px);
}

.showcase-section {
  padding: clamp(30px, 5vw, 58px);
  background:
    radial-gradient(circle at 20% 10%, rgba(23,107,95,0.1), transparent 24%),
    radial-gradient(circle at 84% 72%, rgba(82, 116, 160, 0.1), transparent 24%),
    rgba(255,255,255,0.76);
}

.section-head {
  max-width: 760px;
  margin-bottom: 34px;
}

.section-head p {
  color: var(--muted);
  line-height: 1.7;
}

.advantage-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.advantage-grid article,
.price-row article,
.flow-line article {
  min-width: 0;
  border: 1px solid rgba(16,17,20,0.08);
  border-radius: 24px;
  background: #fff;
}

.advantage-grid article {
  padding: 24px;
}

.advantage-grid span {
  display: inline-flex;
  margin-bottom: 28px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 850;
}

.advantage-grid p,
.flow-copy p,
.pricing-slice p,
.final-cta p {
  color: var(--muted);
  line-height: 1.7;
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.showcase-card {
  min-width: 0;
  overflow: hidden;
  min-height: 330px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 18px;
  border: 1px solid rgba(16,17,20,0.08);
  border-radius: 28px;
  background: #fff;
  box-shadow: 0 18px 50px rgba(24, 30, 38, 0.06);
}

.showcase-visual {
  position: relative;
  min-height: 190px;
  overflow: hidden;
  margin-bottom: 22px;
  border-radius: 22px;
  background:
    linear-gradient(rgba(16,17,20,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16,17,20,0.04) 1px, transparent 1px),
    #f4f3ee;
  background-size: 28px 28px;
}

.showcase-card strong {
  display: block;
  margin-bottom: 8px;
  font-size: 21px;
}

.showcase-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}

.showcase-card .orb {
  position: absolute;
  left: 24%;
  top: 50%;
  width: 62px;
  height: 62px;
  border-radius: 50%;
  transform: translateY(-50%);
  background:
    radial-gradient(circle at 32% 28%, #fff, rgba(255,255,255,0.4) 18%, transparent 19%),
    linear-gradient(145deg, #176b5f, #0c3934);
  box-shadow: 0 22px 48px rgba(23,107,95,0.26);
  animation: showcaseFloat 4s ease-in-out infinite;
}

.showcase-card .showcase-visual i {
  position: absolute;
  left: 16%;
  right: 14%;
  top: 50%;
  height: 5px;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(23,107,95,0.1), rgba(23,107,95,0.44), rgba(23,107,95,0.1));
}

.showcase-visual svg {
  position: absolute;
  inset: 22px;
  width: calc(100% - 44px);
  height: calc(100% - 44px);
}

.showcase-visual svg path,
.showcase-visual svg line {
  fill: none;
  stroke: #176b5f;
  stroke-width: 7;
  stroke-linecap: round;
}

.showcase-visual svg line {
  stroke: rgba(16,17,20,0.18);
  stroke-width: 4;
}

.paper-line {
  position: absolute;
  left: 26px;
  right: 26px;
  top: 62px;
  height: 14px;
  border-radius: 999px;
  background: rgba(16,17,20,0.16);
}

.paper-line.short {
  right: 70px;
  top: 98px;
  background: rgba(23,107,95,0.28);
}

.paper-dot {
  position: absolute;
  right: 32px;
  bottom: 34px;
  width: 62px;
  height: 62px;
  border-radius: 20px;
  background: var(--accent-soft);
}

.map-ring {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 130px;
  height: 130px;
  border: 2px solid rgba(23,107,95,0.26);
  border-radius: 50%;
  transform: translate(-50%, -50%);
  box-shadow: inset 0 0 0 28px rgba(23,107,95,0.08);
}

.map-pin {
  position: absolute;
  left: 52%;
  top: 42%;
  width: 28px;
  height: 28px;
  border-radius: 50% 50% 50% 6px;
  transform: rotate(-45deg);
  background: #176b5f;
  box-shadow: 0 16px 32px rgba(23,107,95,0.28);
}

.flow-section {
  display: grid;
  grid-template-columns: minmax(330px, 0.7fr) minmax(470px, 0.98fr);
  gap: clamp(16px, 1.8vw, 26px);
  align-items: center;
  padding: clamp(30px, 4vw, 46px) clamp(52px, 5.8vw, 76px) clamp(30px, 4vw, 46px) clamp(70px, 7vw, 92px);
  overflow: hidden;
}

.flow-copy {
  max-width: 450px;
  padding-left: clamp(10px, 1vw, 16px);
}

.flow-copy h2 {
  max-width: 440px;
  font-size: clamp(28px, 2.45vw, 34px);
  line-height: 1.08;
}

.flow-line {
  display: grid;
  grid-template-columns: minmax(116px, 1fr) 8px minmax(116px, 1fr) 8px minmax(116px, 1fr);
  align-items: center;
  gap: 4px;
  min-width: 0;
}

.flow-line article {
  min-height: 108px;
  min-width: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(12px, 1.1vw, 16px);
}

.flow-line strong {
  margin-bottom: 6px;
  font-size: 17px;
}

.flow-line span {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.45;
  overflow-wrap: anywhere;
}

.flow-line i {
  display: block;
  height: 1px;
  background: var(--line);
}

.pricing-slice {
  display: grid;
  grid-template-columns: minmax(0, 0.7fr) minmax(560px, 1.3fr);
  gap: 30px;
  align-items: center;
  padding: clamp(30px, 5vw, 54px);
  background:
    linear-gradient(135deg, rgba(220, 238, 233, 0.7), rgba(255,255,255,0.8)),
    #fff;
}

.price-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.price-row article {
  padding: 22px;
}

.price-row span {
  display: block;
  margin-bottom: 16px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 760;
}

.price-row strong {
  display: block;
  margin-bottom: 8px;
  font-size: clamp(27px, 3vw, 38px);
}

.price-row p {
  margin-bottom: 0;
}

.final-cta {
  min-height: 260px;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 44px 24px;
  background: #fff;
  color: var(--ink);
}

.final-cta h2 {
  max-width: 720px;
  margin-bottom: 12px;
}

.final-cta p {
  max-width: 620px;
  margin: 0 auto 24px;
  color: var(--muted);
  font-size: 17px;
}

.final-cta .button.primary {
  color: #fff;
  border-color: #101114;
  background: #101114;
}

.site-footer {
  width: min(1240px, calc(100% - 40px));
  min-height: 86px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin: 0 auto;
  color: var(--muted);
  font-size: 14px;
}

.site-footer a {
  color: inherit;
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--ink);
}

.footer-line {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}

.footer-line a {
  position: relative;
}

.footer-line a::before {
  content: "·";
  margin-right: 10px;
  color: rgba(98, 102, 109, 0.72);
}

@keyframes glide {
  0%, 100% {
    left: 10%;
  }
  50% {
    left: 88%;
  }
}

@keyframes showcaseFloat {
  0%, 100% {
    left: 24%;
  }
  50% {
    left: 70%;
  }
}

@media (max-width: 980px) {
  .site-header {
    position: static;
    flex-wrap: wrap;
  }

  .nav-links {
    order: 3;
    width: 100%;
    justify-content: space-between;
    overflow-x: auto;
  }

  .hero,
  .flow-section,
  .pricing-slice {
    grid-template-columns: 1fr;
  }

  .hero {
    gap: 34px;
  }

  .screen-shell {
    min-height: 460px;
  }

  .lesson-canvas {
    min-height: 404px;
  }

  .advantage-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .showcase-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .flow-line {
    grid-template-columns: 1fr;
  }

  .flow-line i {
    width: 1px;
    height: 22px;
    margin: 0 auto;
  }

  .price-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  main,
  .site-footer {
    width: min(100% - 28px, 1240px);
  }

  .hero {
    padding-top: 34px;
  }

  h1 {
    font-size: clamp(44px, 15vw, 62px);
  }

  h2 {
    font-size: 34px;
  }

  .advantage-grid {
    grid-template-columns: 1fr;
  }

  .showcase-grid {
    grid-template-columns: 1fr;
  }

  .lesson-panel {
    width: 44%;
    padding: 14px;
  }

  .lesson-panel strong {
    font-size: 17px;
  }

  .site-footer {
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
  }
}

/* Login modal, 2026-06-14 */
.login-sheet {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: grid;
  place-items: center;
  padding: 20px;
  background: rgba(14, 16, 20, 0.28);
  backdrop-filter: blur(14px);
}
.login-card {
  position: relative;
  width: min(356px, calc(100vw - 28px));
  max-height: none;
  overflow: visible;
  padding: 18px;
  border: 1px solid rgba(17, 19, 24, 0.08);
  border-radius: 24px;
  color: #111318;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 22px 70px rgba(17, 19, 24, 0.16);
}
.login-card .sheet-close {
  position: absolute;
  right: 14px;
  top: 14px;
  width: 30px;
  height: 30px;
  border: 1px solid rgba(17, 19, 24, 0.1);
  border-radius: 50%;
  color: #111318;
  background: #fff;
  font-size: 20px;
  line-height: 1;
}
.login-sheet.is-required .sheet-close { display: none; }
.login-bind-lock {
  margin-bottom: 16px;
  padding: 11px 14px;
  border: 1px solid rgba(28, 126, 214, 0.16);
  border-radius: 16px;
  color: #1c3f63;
  background: rgba(231, 245, 255, 0.88);
  font-size: 14px;
  font-weight: 650;
}
.bind-logout { width: 100%; }
.login-head { padding-right: 42px; }
.login-head h2 { margin: 0 0 8px; font-size: 26px; line-height: 1.14; font-weight: 640; }
.login-head p:not(.eyebrow) { margin: 0 0 16px; color: #667085; font-size: 14px; line-height: 1.55; }
.login-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  padding: 5px;
  margin: 4px 42px 12px 0;
  border: 1px solid rgba(17, 19, 24, 0.08);
  border-radius: 999px;
  background: #f4f5f3;
}
.login-tabs button { min-height: 32px; border: 0; border-radius: 999px; color: #667085; background: transparent; font-size: 13px; font-weight: 650; }
.login-tabs button.is-active { color: #111318; background: #fff; box-shadow: 0 10px 24px rgba(17, 19, 24, 0.08); }
.login-pane { display: none; }
.login-pane.is-active { display: block; }
.wechat-login-box { position: relative; overflow: hidden; overscroll-behavior: none; touch-action: none; display: grid; place-items: center; height: 296px; border: 1px solid rgba(17, 19, 24, 0.07); border-radius: 16px; background: #fff; }
.wechat-login-qr { display: grid; place-items: center; width: 286px; height: 286px; overflow: hidden; }
.wechat-login-qr iframe { display: block; width: 286px !important; height: 286px !important; border: 0; margin: 0; overflow: hidden; }
.wechat-login-loading { display: grid; place-items: center; width: 100%; height: 100%; color: #667085; font-size: 13px; text-align: center; }
.wechat-login-loading.is-error { color: #b42318; }
.login-agreement {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 9px;
  align-items: start;
  margin: 0 0 12px;
  color: #667085;
  font-size: 12px;
  line-height: 1.55;
}
.login-agreement input { width: 15px; height: 15px; margin-top: 2px; accent-color: #111318; }
.login-agreement a { color: #111318; text-decoration: underline; text-underline-offset: 3px; }
.login-agreement-mask {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 22px;
  color: #475467;
  background: rgba(247, 248, 251, 0.94);
  text-align: center;
  font-size: 14px;
  font-weight: 650;
  pointer-events: auto;
}
.login-agreement-mask[hidden] { display: none; }
.login-hint,
.login-fallback,
.login-message,
.phone-login-form small { color: #667085; font-size: 12px; line-height: 1.55; }
.login-fallback { display: inline-flex; margin-top: 4px; text-decoration: underline; }
.phone-login-form { display: grid; gap: 10px; }
.phone-login-form label { display: grid; gap: 7px; color: #111318; font-size: 13px; font-weight: 620; }
.phone-login-form input { width: 100%; min-height: 38px; padding: 0 12px; border: 1px solid rgba(17, 19, 24, 0.12); border-radius: 12px; outline: none; background: #fff; }
.phone-login-form input:focus { border-color: #111318; box-shadow: 0 0 0 4px rgba(17, 19, 24, 0.08); }
.captcha-row,
.code-row { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 8px; }
.captcha-row button,
.code-row button { min-height: 38px; padding: 0 12px; border: 1px solid rgba(17, 19, 24, 0.1); border-radius: 12px; color: #111318; background: #fff; font-size: 13px; font-weight: 650; white-space: nowrap; }
.captcha-row button:disabled,
.code-row button:disabled,
.phone-login-form button[type="submit"]:disabled { cursor: not-allowed; opacity: 0.45; }
.login-message { min-height: 22px; margin: 0; }
@media (max-width: 640px) {
  .login-sheet { padding: 14px; align-items: end; }
  .login-card { max-height: calc(100dvh - 28px); overflow: auto; padding: 16px; border-radius: 20px; }
  .wechat-login-box { height: 276px; }
  .wechat-login-qr,
  .wechat-login-qr iframe { width: 268px !important; height: 268px !important; }
}