:root {
  --blue: #0966ff;
  --blue-2: #1f7cff;
  --cyan: #eaf5ff;
  --ink: #071126;
  --muted: #66738b;
  --line: #dbe7fb;
  --green: #20aa78;
  --orange: #ff9f32;
  --purple: #8067ff;
  --surface: #ffffff;
  --shadow: 0 18px 45px rgba(12, 63, 142, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  overflow-x: hidden;
}

body {
  margin: 0;
  color: var(--ink);
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", Arial, sans-serif;
  background: #fff;
  letter-spacing: 0;
  overflow-x: hidden;
}

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

img {
  display: block;
  max-width: 100%;
}

.icon {
  width: 1em;
  height: 1em;
  flex: 0 0 auto;
  stroke: currentColor;
  stroke-width: 2;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.icon-sprite {
  display: none;
}

.container {
  width: min(1320px, calc(100% - 64px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  height: 88px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(219, 231, 251, 0.75);
}

.nav-wrap {
  height: 100%;
  display: grid;
  grid-template-columns: 270px 1fr auto;
  gap: 28px;
  align-items: center;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 13px;
  min-width: 0;
}

.brand-mark {
  width: 58px;
  height: 58px;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.brand-mark img {
  width: 68px;
  max-width: none;
  transform: translateY(5px);
}

.brand strong {
  display: block;
  font-size: 24px;
  line-height: 1.12;
  white-space: nowrap;
}

.brand small {
  display: block;
  margin-top: 6px;
  color: #0c1a33;
  font-size: 14px;
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(20px, 3vw, 52px);
  color: #0b1830;
  font-size: 16px;
}

.nav-links a {
  position: relative;
  padding: 34px 0 31px;
  white-space: nowrap;
}

.nav-links a.active {
  color: var(--blue);
}

.nav-links a.active::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 17px;
  width: 32px;
  height: 4px;
  border-radius: 99px;
  background: var(--blue);
  transform: translateX(-50%);
}

.nav-actions,
.hero-actions,
.cta-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 23px;
  border-radius: 8px;
  border: 1px solid transparent;
  font-weight: 700;
  font-size: 15px;
  line-height: 1;
  white-space: nowrap;
  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease,
    background 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, #0b6dff, #0051e8);
  box-shadow: 0 12px 24px rgba(0, 95, 255, 0.22);
}

.btn-ghost,
.btn-outline {
  color: var(--blue);
  border-color: var(--blue);
  background: #fff;
}

.btn-large {
  min-height: 60px;
  min-width: 218px;
  font-size: 17px;
}

.btn-light {
  color: var(--blue);
  background: #fff;
}

.btn-outline-light {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.82);
  background: rgba(255, 255, 255, 0.08);
}

.hero {
  min-height: 640px;
  padding: 70px 0 54px;
  background:
    radial-gradient(circle at 78% 38%, rgba(0, 122, 255, 0.14), transparent 26%),
    radial-gradient(circle at 54% 12%, rgba(122, 191, 255, 0.14), transparent 32%),
    linear-gradient(180deg, #f7fbff 0%, #eef7ff 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(430px, 0.9fr) minmax(520px, 1.1fr);
  gap: 48px;
  align-items: center;
}

.hero-copy,
.hero-visual {
  min-width: 0;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 22px;
  color: #1264e8;
  background: #e8f2ff;
  border-radius: 999px;
  font-weight: 700;
  font-size: 16px;
}

.hero h1 {
  margin: 34px 0 24px;
  font-size: clamp(46px, 4.5vw, 60px);
  line-height: 1.24;
  letter-spacing: 0;
  word-break: keep-all;
}

.hero h1 span {
  color: var(--blue);
  white-space: nowrap;
}

.hero-subtitle {
  width: min(650px, 100%);
  margin: 0 0 40px;
  color: #41516b;
  font-size: 20px;
  line-height: 1.85;
}

.capabilities {
  display: flex;
  flex-wrap: wrap;
  gap: 24px 36px;
  margin-top: 44px;
  color: #1b335f;
  font-size: 15px;
}

.capabilities span {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  white-space: nowrap;
}

.capabilities .icon {
  width: 22px;
  height: 22px;
  color: var(--blue);
}

.hero-visual {
  position: relative;
  min-height: 475px;
}

.hero-visual::before {
  content: "";
  position: absolute;
  inset: -80px -130px -80px -180px;
  background:
    radial-gradient(circle at 72% 42%, rgba(163, 205, 255, 0.28), transparent 34%),
    radial-gradient(circle at 86% 72%, rgba(58, 137, 255, 0.14), transparent 30%);
  pointer-events: none;
}

.hero-banner-art {
  position: absolute;
  right: -86px;
  top: -8px;
  width: min(900px, 128%);
  max-width: none;
  clip-path: inset(3.5% 0 6% 0);
  filter: drop-shadow(0 26px 42px rgba(12, 67, 142, 0.18));
  -webkit-mask-image:
    linear-gradient(to right, transparent 0%, rgba(0, 0, 0, 0.08) 6%, rgba(0, 0, 0, 0.72) 16%, #000 30%, #000 100%),
    linear-gradient(to bottom, transparent 0%, rgba(0, 0, 0, 0.75) 10%, #000 22%, #000 78%, rgba(0, 0, 0, 0.75) 90%, transparent 100%);
  -webkit-mask-composite: source-in;
  mask-image:
    linear-gradient(to right, transparent 0%, rgba(0, 0, 0, 0.08) 6%, rgba(0, 0, 0, 0.72) 16%, #000 30%, #000 100%),
    linear-gradient(to bottom, transparent 0%, rgba(0, 0, 0, 0.75) 10%, #000 22%, #000 78%, rgba(0, 0, 0, 0.75) 90%, transparent 100%);
  mask-composite: intersect;
}

.phone {
  position: absolute;
  right: 0;
  top: 56px;
  width: 210px;
  aspect-ratio: 1179 / 2556;
  padding: 6px;
  border-radius: 34px;
  background: #0c1420;
  box-shadow: 0 22px 38px rgba(5, 38, 85, 0.22);
}

.phone::before {
  display: none;
}

.phone-shot-frame {
  overflow: hidden;
  border-radius: 26px;
  background: #0c1420;
}

.phone-shot {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 27px;
}

.section {
  padding: 44px 0;
}

.section-title {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  margin: 0 0 36px;
  text-align: center;
  font-size: clamp(27px, 3vw, 34px);
  line-height: 1.35;
}

.section-title span {
  width: 32px;
  height: 2px;
  background: #b9c8dc;
}

.scene-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.scene-card {
  min-height: 310px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #fff;
  box-shadow: var(--shadow);
}

.scene-head {
  display: flex;
  gap: 18px;
  align-items: center;
  margin-bottom: 28px;
}

.scene-icon {
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  color: #fff;
  border-radius: 11px;
  font-size: 28px;
  box-shadow: 0 12px 22px rgba(0, 96, 255, 0.2);
}

.scene-icon.blue {
  background: linear-gradient(135deg, #267fff, #005ff1);
}

.scene-icon.green {
  background: linear-gradient(135deg, #48caa0, #12a374);
}

.scene-head h3 {
  margin: 0;
  font-size: 22px;
}

.scene-head p {
  margin: 8px 0 0;
  color: #58677f;
  font-size: 15px;
}

.scene-preview {
  min-height: 150px;
  border-radius: 14px;
  background: linear-gradient(180deg, #f8fbff, #edf5ff);
  border: 1px solid #dce8fa;
}

.image-preview {
  overflow: hidden;
  aspect-ratio: 16 / 9;
  min-height: 0;
  padding: 0;
  background: #f6fbff;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.72);
}

.image-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  transform: scale(1.08);
}

.dual {
  padding-top: 0;
}

.dual-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.role-card {
  position: relative;
  overflow: hidden;
  min-height: 355px;
  padding: 42px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background:
    radial-gradient(circle at 84% 52%, rgba(9, 102, 255, 0.1), transparent 38%),
    linear-gradient(180deg, #f7fbff, #fff);
}

.teacher-card {
  background:
    radial-gradient(circle at 83% 48%, rgba(32, 170, 120, 0.12), transparent 38%),
    linear-gradient(180deg, #f6fffb, #fff);
}

.role-copy {
  position: relative;
  z-index: 2;
  width: 52%;
}

.role-copy h2 {
  margin: 0 0 8px;
  color: var(--blue);
  font-size: 30px;
}

.teacher-card .role-copy h2 {
  color: #0b875d;
}

.role-copy p {
  margin: 0 0 34px;
  color: #1264e8;
  font-size: 18px;
  font-weight: 700;
}

.teacher-card .role-copy p {
  color: #0b875d;
}

.check-items {
  display: grid;
  gap: 23px;
  margin: 0;
  padding: 0;
  list-style: none;
  color: #273b5d;
  font-size: 17px;
}

.check-items li {
  position: relative;
  padding-left: 34px;
}

.check-items li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: -2px;
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  color: var(--blue);
  border: 2px solid currentColor;
  border-radius: 3px;
  font-size: 14px;
  font-weight: 900;
}

.check-items.green li::before {
  color: var(--green);
}

.role-phone {
  position: absolute;
  top: 26px;
  right: 56px;
  transform: scale(1.03);
}

.switch-badge {
  position: absolute;
  left: 50%;
  top: 50%;
  z-index: 4;
  width: 56px;
  height: 56px;
  display: grid;
  place-items: center;
  color: var(--blue);
  border: 1px solid var(--line);
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 12px 28px rgba(15, 86, 180, 0.14);
  transform: translate(-50%, -50%);
  font-size: 26px;
  font-weight: 900;
}

.teacher-workspace-art {
  position: absolute;
  right: 28px;
  top: 44px;
  width: 50%;
  min-width: 340px;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border-radius: 18px;
  background: #f7fbf8;
  box-shadow: 0 20px 34px rgba(19, 72, 54, 0.16);
}

.teacher-workspace-art img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  transform: scale(1.05);
}

.loop {
  padding-top: 6px;
}

.section-title.compact {
  margin-bottom: 26px;
}

.loop-flow {
  display: grid;
  grid-template-columns: 1fr 42px 1fr 42px 1fr 42px 1fr 42px 1fr;
  gap: 6px;
  align-items: center;
  margin: 0 auto 32px;
}

.loop-flow > i {
  height: 2px;
  background: var(--blue);
  position: relative;
}

.loop-flow > i::after {
  content: "";
  position: absolute;
  right: -1px;
  top: -4px;
  border-left: 8px solid var(--blue);
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
}

.flow-step {
  min-height: 88px;
  display: grid;
  grid-template-columns: 42px 1fr;
  grid-template-rows: auto auto;
  column-gap: 12px;
  align-items: center;
  padding: 15px 18px;
  border: 1px solid #cfe0f7;
  border-radius: 12px;
  background: #fff;
}

.flow-step span {
  grid-row: 1 / 3;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  color: var(--blue);
  border: 2px solid #d8e7fb;
  border-radius: 50%;
  font-size: 22px;
}

.flow-step b {
  font-size: 16px;
}

.flow-step small {
  color: #607189;
  font-size: 13px;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1px;
  overflow: hidden;
  padding: 22px 28px;
  border-radius: 16px;
  background: linear-gradient(180deg, #f6fbff, #edf5ff);
}

.metrics div {
  display: grid;
  grid-template-columns: 50px 1fr;
  grid-template-rows: auto auto;
  column-gap: 14px;
  align-items: center;
  padding: 0 22px;
  border-right: 1px solid #d7e4f5;
}

.metrics div:last-child {
  border-right: 0;
}

.metrics span {
  grid-row: 1 / 3;
  color: var(--blue);
  font-size: 40px;
  line-height: 1;
}

.metrics b {
  color: var(--blue);
  font-size: 30px;
  line-height: 1.1;
}

.metrics small {
  color: #4f6078;
  font-size: 14px;
}

.final-cta {
  padding: 0 0 36px;
}

.cta-panel {
  position: relative;
  min-height: 120px;
  display: grid;
  grid-template-columns: 150px 1fr auto;
  gap: 26px;
  align-items: center;
  overflow: hidden;
  padding: 0 52px 0 28px;
  color: #fff;
  border-radius: 16px;
  background:
    radial-gradient(circle at 12% 30%, rgba(255, 255, 255, 0.34), transparent 16%),
    linear-gradient(135deg, #0a72ff, #0053e8);
}

.cta-panel img {
  width: 145px;
  align-self: end;
  margin-bottom: -20px;
  filter: drop-shadow(0 10px 16px rgba(0, 34, 97, 0.26));
}

.cta-panel h2 {
  margin: 0;
  font-size: clamp(24px, 2.6vw, 32px);
  line-height: 1.35;
}

@media (max-width: 1180px) {
  .nav-wrap {
    grid-template-columns: auto 1fr auto;
  }

  .nav-links {
    gap: 22px;
    font-size: 14px;
  }

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

  .hero-visual {
    min-height: 500px;
  }

  .hero-banner-art {
    right: 50%;
    width: min(980px, 118%);
    transform: translateX(50%);
  }

  .scene-grid,
  .dual-grid {
    grid-template-columns: 1fr;
  }

  .switch-badge {
    display: none;
  }

  .loop-flow {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .loop-flow > i {
    width: 2px;
    height: 22px;
    justify-self: center;
  }

  .loop-flow > i::after {
    left: -4px;
    right: auto;
    top: auto;
    bottom: -1px;
    border-top: 8px solid var(--blue);
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-bottom: 0;
  }

  .metrics {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
  }

  .metrics div {
    border-right: 0;
  }
}

@media (max-width: 900px) {
  .container {
    width: min(100% - 36px, 720px);
  }

  .site-header {
    height: auto;
  }

  .nav-wrap {
    grid-template-columns: 1fr auto;
    padding: 14px 0;
  }

  .nav-links {
    grid-column: 1 / -1;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .nav-links a {
    padding: 10px 0;
  }

  .nav-links a.active::after {
    bottom: 0;
  }

  .hero {
    padding-top: 42px;
  }

  .hero h1 {
    font-size: clamp(36px, 7.6vw, 46px);
  }

  .hero-actions {
    flex-wrap: wrap;
  }

  .btn-large {
    min-width: min(100%, 260px);
  }

  .hero-visual {
    min-height: 430px;
  }

  .hero-banner-art {
    top: 8px;
    width: min(820px, 132%);
  }

  .role-copy {
    width: 100%;
  }

  .role-card {
    padding: 32px;
    min-height: 620px;
  }

  .role-phone {
    top: auto;
    right: 50%;
    bottom: 30px;
    transform: translateX(50%) scale(1);
  }

  .teacher-workspace-art {
    top: auto;
    right: 24px;
    left: 24px;
    bottom: 32px;
    width: auto;
    min-width: 0;
    aspect-ratio: 16 / 10;
  }

  .cta-panel {
    grid-template-columns: 100px 1fr;
    padding: 18px 22px 0;
  }

  .cta-panel img {
    width: 105px;
  }

  .cta-actions {
    grid-column: 1 / -1;
    flex-wrap: wrap;
    padding-bottom: 22px;
  }
}

@media (max-width: 560px) {
  .nav-wrap {
    grid-template-columns: 1fr;
  }

  .brand strong {
    font-size: 21px;
  }

  .nav-actions {
    display: none;
  }

  .hero-subtitle {
    font-size: 17px;
  }

  .hero h1 {
    font-size: 34px;
    line-height: 1.32;
    word-break: normal;
    overflow-wrap: anywhere;
  }

  .hero h1 span {
    white-space: normal;
  }

  .section-title {
    display: block;
    max-width: 330px;
    margin-left: auto;
    margin-right: auto;
    font-size: 25px;
    line-height: 1.35;
  }

  .section-title span {
    display: none;
  }

  .capabilities {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px 20px;
  }

  .capabilities span {
    white-space: normal;
  }

  .hero-visual {
    min-height: 360px;
    overflow: hidden;
  }

  .hero-banner-art {
    top: 32px;
    width: 150%;
  }

  .scene-card {
    padding: 22px;
  }

  .role-card {
    padding: 26px;
  }

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

  .metrics div {
    padding: 0;
  }

  .cta-panel {
    display: block;
    padding: 22px;
    text-align: center;
  }

  .cta-panel img {
    width: 120px;
    margin: 0 auto 10px;
  }

  .cta-actions {
    justify-content: center;
    margin-top: 18px;
    padding-bottom: 0;
  }
}