:root {
  --web-surface: #f1f6fd;
  --ink: #171347;
  --slate: #42506d;
  --muted: #79859f;
  --green: #3cbb71;
  --green-strong: #40be73;
  --blue: #006aff;
  --blue-soft: #77c3f4;
  --yellow: #fdcc52;
  --orange: #ff9933;
  --white: #ffffff;
  --line: rgba(23, 19, 71, 0.1);
  --shadow: 0 28px 80px rgba(23, 19, 71, 0.12);
  --display-font: "Songti SC", "STSong", "Noto Serif CJK SC", serif;
  --body-font: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--web-surface);
  font-family: var(--body-font);
  overflow-x: hidden;
}

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

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

button,
a {
  -webkit-tap-highlight-color: transparent;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 20;
  width: 100%;
  height: 72px;
  padding: 0 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid transparent;
  background: rgba(241, 246, 253, 0.74);
  backdrop-filter: blur(18px);
  transition: border-color 180ms ease, background 180ms ease;
}

.site-header[data-elevated="true"] {
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.9);
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  color: var(--ink);
}

.brand-mark img {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  object-fit: cover;
}

.brand-mark span {
  font-size: 20px;
}

nav {
  display: flex;
  align-items: center;
  gap: 30px;
  color: var(--slate);
  font-size: 15px;
  font-weight: 700;
}

nav a {
  position: relative;
  padding: 10px 0;
}

nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 4px;
  width: 0;
  height: 2px;
  background: var(--green);
  transition: width 180ms ease;
}

nav a:hover::after {
  width: 100%;
}

.header-action,
.primary-action,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  border: 0;
  font-weight: 800;
}

.header-action {
  height: 42px;
  padding: 0 18px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--white);
  font-size: 14px;
}

.header-action i,
.primary-action i {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background:
    linear-gradient(45deg, transparent 45%, currentColor 46%, currentColor 54%, transparent 55%),
    linear-gradient(currentColor, currentColor);
  background-size: 11px 11px, 9px 2px;
  background-position: 5px 3px, 2px 7px;
  background-repeat: no-repeat;
}

.hero {
  position: relative;
  min-height: 88svh;
  padding: 132px 64px 72px;
  overflow: hidden;
  display: flex;
  align-items: center;
  isolation: isolate;
  background:
    radial-gradient(circle at 76% 18%, rgba(64, 190, 115, 0.22), transparent 25%),
    radial-gradient(circle at 18% 82%, rgba(253, 204, 82, 0.26), transparent 24%),
    var(--web-surface);
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(23, 19, 71, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 19, 71, 0.055) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(circle at 50% 48%, black, transparent 78%);
}

.hero-copy {
  position: relative;
  z-index: 4;
  width: min(540px, 45vw);
  padding-top: 28px;
}

.section-kicker {
  margin: 0 0 18px;
  width: fit-content;
  min-height: 34px;
  display: flex;
  align-items: center;
  padding: 0 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.72);
  color: var(--green);
  font-size: 14px;
  font-weight: 900;
}

h1,
h2,
h3,
p {
  letter-spacing: 0;
}

h1 {
  margin: 0;
  color: var(--ink);
  font-family: var(--display-font);
  font-size: 124px;
  line-height: 1;
  font-weight: 900;
}

.hero-lede {
  margin: 24px 0 0;
  max-width: 520px;
  color: var(--slate);
  font-size: 24px;
  line-height: 1.7;
  font-weight: 600;
}

.hero-actions {
  margin-top: 34px;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.primary-action {
  min-height: 54px;
  padding: 0 24px;
  border-radius: 999px;
  background: var(--green-strong);
  color: var(--white);
  box-shadow: 0 18px 36px rgba(64, 190, 115, 0.26);
}

.secondary-action {
  min-height: 54px;
  padding: 0 24px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.72);
  color: var(--ink);
}

.hero-art {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
}

.web-entry {
  position: absolute;
  right: 90px;
  top: 112px;
  width: 420px;
  height: 236px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  transform: rotate(3deg);
}

.web-entry span {
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
}

.web-entry strong {
  color: var(--ink);
  font-size: 46px;
  font-weight: 900;
}

.web-entry em {
  width: 120px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: var(--yellow);
  color: var(--ink);
  font-style: normal;
  font-size: 14px;
  font-weight: 900;
}

.study-phone {
  position: absolute;
  right: 170px;
  top: 220px;
  width: 386px;
  min-height: 614px;
  padding: 26px;
  border: 10px solid var(--ink);
  border-radius: 46px;
  background: var(--white);
  box-shadow: 0 36px 100px rgba(23, 19, 71, 0.22);
  transform: rotate(-4deg);
}

.phone-head,
.course-panel,
.progress-panel {
  display: flex;
}

.phone-head {
  align-items: center;
  justify-content: space-between;
}

.phone-head div {
  display: grid;
  gap: 4px;
}

.phone-head span {
  color: var(--muted);
  font-size: 15px;
  font-weight: 700;
}

.phone-head strong {
  color: var(--ink);
  font-size: 24px;
  font-weight: 900;
}

.phone-head b {
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--green);
  color: var(--white);
}

.course-panel {
  margin-top: 22px;
  min-height: 150px;
  padding: 20px;
  border-radius: 8px;
  background: var(--green);
  color: var(--white);
  justify-content: space-between;
  overflow: hidden;
}

.course-panel div {
  display: grid;
  gap: 8px;
}

.course-panel span {
  font-size: 14px;
  opacity: 0.86;
}

.course-panel strong {
  width: 148px;
  font-size: 22px;
  line-height: 1.25;
}

.course-panel em {
  width: 86px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: 999px;
  background: var(--white);
  color: var(--green);
  font-size: 13px;
  font-style: normal;
  font-weight: 900;
}

.course-panel img {
  width: 98px;
  object-fit: contain;
}

.progress-panel {
  margin-top: 20px;
  padding: 20px;
  align-items: center;
  gap: 18px;
  border-radius: 8px;
  background: #f4f8ff;
}

.progress-ring {
  width: 116px;
  height: 116px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: conic-gradient(var(--blue) 0 82%, #d3e5ff 82% 100%);
}

.progress-ring span {
  width: 88px;
  height: 88px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--white);
  color: var(--blue);
  font-size: 28px;
  font-weight: 900;
}

.progress-panel strong {
  display: block;
  color: var(--ink);
  font-size: 36px;
}

.progress-panel span,
.progress-panel small {
  display: block;
  color: var(--slate);
  font-size: 14px;
  line-height: 1.8;
}

.hero-students {
  position: absolute;
  right: 315px;
  bottom: 42px;
  width: 330px;
  filter: drop-shadow(0 26px 42px rgba(23, 19, 71, 0.18));
}

.path-card {
  position: absolute;
  width: 270px;
  border-radius: 8px;
  box-shadow: 0 22px 60px rgba(23, 19, 71, 0.16);
}

.path-card-blue {
  right: 95px;
  bottom: 178px;
  transform: rotate(5deg);
}

.path-card-green {
  right: 310px;
  bottom: 126px;
  transform: rotate(-6deg);
}

.feature-strip {
  min-height: 96px;
  padding: 18px 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  background: var(--ink);
  color: var(--white);
}

.feature-strip span {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  padding: 0 18px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  font-weight: 800;
}

.section {
  padding: 118px 64px;
}

.section-heading {
  max-width: 850px;
  margin: 0 auto 56px;
  text-align: center;
}

.section-heading .section-kicker {
  margin-left: auto;
  margin-right: auto;
}

h2 {
  margin: 0;
  color: var(--ink);
  font-family: var(--display-font);
  font-size: 58px;
  line-height: 1.14;
}

.section-heading p:not(.section-kicker),
.audience-copy p:not(.section-kicker),
.contact-panel p {
  margin: 18px 0 0;
  color: var(--slate);
  font-size: 20px;
  line-height: 1.8;
}

.feature-layout {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  gap: 26px;
}

.learning-path {
  min-height: 330px;
  padding: 34px;
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 28px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(119, 195, 244, 0.22), transparent 45%),
    var(--white);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.path-copy span,
.report-card span,
.chart-card span,
.audience-card span {
  color: var(--green);
  font-size: 15px;
  font-weight: 900;
}

.path-copy h3,
.audience-card h3 {
  margin: 12px 0 0;
  color: var(--ink);
  font-size: 32px;
  line-height: 1.28;
}

.path-copy p,
.module-grid p,
.loop-steps p,
.audience-card p {
  margin: 12px 0 0;
  color: var(--slate);
  font-size: 16px;
  line-height: 1.75;
}

.path-stack {
  position: relative;
  min-height: 230px;
}

.path-stack img {
  position: absolute;
  width: 440px;
  border-radius: 8px;
  box-shadow: 0 20px 50px rgba(23, 19, 71, 0.12);
}

.path-stack img:first-child {
  top: 0;
  right: 78px;
  transform: rotate(-3deg);
}

.path-stack img:last-child {
  top: 118px;
  right: 0;
  transform: rotate(4deg);
}

.module-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.module-grid article {
  min-height: 218px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: 0 16px 42px rgba(23, 19, 71, 0.07);
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.module-grid article:hover {
  transform: translateY(-6px);
  box-shadow: 0 24px 60px rgba(23, 19, 71, 0.12);
}

.module-grid img {
  width: 62px;
  height: 62px;
  object-fit: contain;
}

.module-grid h3 {
  margin: 18px 0 0;
  color: var(--ink);
  font-size: 22px;
}

.module-grid .accent-module {
  background: var(--ink);
}

.module-grid .accent-module h3,
.module-grid .accent-module p {
  color: var(--white);
}

.loop-section {
  background:
    radial-gradient(circle at 16% 20%, rgba(253, 204, 82, 0.22), transparent 24%),
    radial-gradient(circle at 82% 78%, rgba(0, 106, 255, 0.15), transparent 30%),
    #fbfdff;
}

.loop-layout {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 36px;
  align-items: center;
}

.loop-steps {
  display: grid;
  gap: 14px;
}

.loop-steps article {
  padding: 24px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.76);
}

.loop-steps article.active {
  background: var(--ink);
}

.loop-steps span {
  color: var(--orange);
  font-size: 14px;
  font-weight: 900;
}

.loop-steps h3 {
  margin: 8px 0 0;
  font-size: 24px;
}

.loop-steps article.active h3,
.loop-steps article.active p {
  color: var(--white);
}

.report-wall {
  position: relative;
  min-height: 560px;
}

.report-blue {
  position: absolute;
  top: 20px;
  left: 0;
  width: 470px;
  border-radius: 8px;
  box-shadow: var(--shadow);
  transform: rotate(-5deg);
}

.report-card {
  position: absolute;
  left: 80px;
  bottom: 58px;
  width: 245px;
  min-height: 188px;
  padding: 24px;
  border-radius: 8px;
  background: var(--ink);
  color: var(--white);
  box-shadow: var(--shadow);
}

.report-card strong {
  display: block;
  margin-top: 16px;
  color: var(--yellow);
  font-size: 64px;
}

.report-card em {
  font-style: normal;
  color: rgba(255, 255, 255, 0.8);
}

.chart-card {
  position: absolute;
  right: 0;
  bottom: 20px;
  width: 430px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
  transform: rotate(3deg);
}

.chart-card img {
  margin-top: 14px;
  border-radius: 8px;
  background: #f6fbfe;
}

.audience-section {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 48px;
  align-items: center;
  max-width: 1180px;
  margin: 0 auto;
}

.audience-copy h2 {
  max-width: 560px;
}

.audience-panel {
  padding: 10px;
  border-radius: 8px;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.audience-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  padding: 8px;
  border-radius: 8px;
  background: #f4f8ff;
}

.audience-tabs button {
  height: 54px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--slate);
  font-family: var(--body-font);
  font-size: 17px;
  font-weight: 900;
  cursor: pointer;
}

.audience-tabs button.active {
  color: var(--white);
  background: var(--green);
}

.audience-card {
  min-height: 270px;
  padding: 38px;
}

.contact-section {
  padding: 40px 64px 104px;
}

.contact-panel {
  max-width: 1180px;
  min-height: 330px;
  margin: 0 auto;
  padding: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(64, 190, 115, 0.9), rgba(0, 106, 255, 0.78)),
    var(--green);
  color: var(--white);
  overflow: hidden;
}

.contact-panel .section-kicker {
  color: var(--ink);
  background: var(--yellow);
  border-color: transparent;
}

.contact-panel h2 {
  max-width: 720px;
  color: var(--white);
}

.contact-panel p {
  max-width: 620px;
  color: rgba(255, 255, 255, 0.88);
}

.contact-panel .primary-action {
  flex: 0 0 auto;
  color: var(--ink);
  background: var(--white);
  box-shadow: 0 18px 38px rgba(23, 19, 71, 0.18);
}

footer {
  min-height: 112px;
  padding: 28px 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-top: 1px solid var(--line);
  background: #ffffff;
}

.footer-links {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  justify-content: flex-end;
  color: var(--slate);
  font-size: 14px;
}

.footer-links a {
  font-weight: 800;
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 520ms ease, transform 520ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1200px) {
  .site-header {
    padding: 0 24px;
  }

  nav {
    display: none;
  }

  .hero {
    min-height: auto;
    padding: 118px 24px 36px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
  }

  .hero-copy {
    order: 1;
    width: 100%;
    padding-top: 0;
  }

  h1 {
    font-size: 82px;
  }

  .hero-lede {
    font-size: 20px;
  }

  .hero-art {
    order: 2;
    position: relative;
    height: 580px;
    margin-top: 34px;
  }

  .web-entry {
    right: 24px;
    top: 0;
    width: 300px;
    height: 170px;
  }

  .study-phone {
    right: 120px;
    top: 80px;
    width: 330px;
    min-height: 540px;
  }

  .hero-students {
    right: 20px;
    bottom: 0;
    width: 260px;
  }

  .path-card-blue {
    right: auto;
    left: 0;
    bottom: 130px;
  }

  .path-card-green {
    right: 0;
    bottom: 58px;
  }

  .section {
    padding: 86px 24px;
  }

  h2 {
    font-size: 42px;
  }

  .learning-path,
  .loop-layout,
  .audience-section {
    grid-template-columns: 1fr;
  }

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

  .contact-section {
    padding: 24px 24px 72px;
  }

  .contact-panel {
    align-items: flex-start;
    flex-direction: column;
    padding: 34px;
  }

  footer {
    padding: 28px 24px;
    align-items: flex-start;
    flex-direction: column;
  }

  .footer-links {
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  .site-header {
    height: 64px;
  }

  .brand-mark span {
    font-size: 18px;
  }

  .header-action {
    height: 38px;
    padding: 0 14px;
  }

  .hero {
    padding-top: 100px;
  }

  h1 {
    font-size: 64px;
  }

  .hero-lede,
  .section-heading p:not(.section-kicker),
  .audience-copy p:not(.section-kicker),
  .contact-panel p {
    font-size: 17px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .primary-action,
  .secondary-action {
    width: 100%;
  }

  .hero-art {
    height: 520px;
  }

  .web-entry {
    display: none;
  }

  .study-phone {
    left: 24px;
    right: auto;
    top: 24px;
    width: 300px;
    min-height: 500px;
    border-width: 8px;
  }

  .hero-students {
    width: 210px;
    right: 0;
  }

  .path-card {
    width: 210px;
  }

  .path-card-blue {
    bottom: 110px;
  }

  .path-card-green {
    bottom: 22px;
  }

  .feature-strip {
    padding: 16px 18px;
    justify-content: flex-start;
  }

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

  .learning-path {
    padding: 24px;
  }

  .path-stack {
    min-height: 250px;
  }

  .path-stack img {
    width: 300px;
  }

  .path-stack img:first-child {
    right: 30px;
  }

  .report-wall {
    min-height: 520px;
  }

  .report-blue {
    width: 320px;
  }

  .report-card {
    left: 18px;
    bottom: 104px;
  }

  .chart-card {
    width: 310px;
    right: 0;
  }

  .audience-tabs button {
    font-size: 15px;
  }

  .audience-card {
    padding: 28px 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition: none !important;
    animation: none !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}