:root {
  --ink: #102a2f;
  --muted: #5f7072;
  --paper: #f7f8f4;
  --white: #ffffff;
  --teal: #075f56;
  --teal-dark: #053f3a;
  --mint: #d7eee7;
  --gold: #f3b936;
  --coral: #ee725c;
  --line: #dbe2df;
  --header-height: 72px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  letter-spacing: 0;
  line-height: 1.65;
}

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

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

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 max(24px, calc((100vw - 1180px) / 2));
  background: rgba(247, 248, 244, 0.96);
  border-bottom: 1px solid rgba(16, 42, 47, 0.12);
  backdrop-filter: blur(16px);
}

.brand,
.footer-brand {
  display: flex;
  align-items: center;
  gap: 11px;
}

.brand img,
.footer-brand img {
  border-radius: 8px;
}

.brand span {
  font-size: 18px;
  font-weight: 800;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 30px;
  font-size: 14px;
  font-weight: 700;
}

.site-nav a:not(.nav-action):hover {
  color: var(--teal);
}

.nav-action {
  padding: 10px 17px;
  color: var(--white);
  background: var(--teal);
  border-radius: 6px;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 10px;
  border: 0;
  background: transparent;
}

.nav-toggle span {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--ink);
}

.hero {
  position: relative;
  min-height: min(760px, calc(100svh - var(--header-height) - 24px));
  display: flex;
  align-items: center;
  isolation: isolate;
  overflow: hidden;
  color: var(--white);
  background-color: #102b2b;
  background-image: url("assets/scholar-thinking-cover.png");
  background-size: cover;
  background-position: center 36%;
}

.hero-shade {
  position: absolute;
  z-index: -1;
  inset: 0;
  background: rgba(3, 22, 23, 0.64);
}

.hero-content {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
  padding: 64px 0 90px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 14px;
  color: var(--teal);
  font-size: 14px;
  font-weight: 800;
  text-transform: uppercase;
}

.eyebrow {
  display: inline-block;
  padding: 7px 11px;
  color: #183535;
  background: var(--gold);
  border-radius: 4px;
}

.hero h1 {
  max-width: 760px;
  margin: 16px 0 8px;
  font-size: 88px;
  line-height: 1.02;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 690px;
  margin: 0;
  color: rgba(255, 255, 255, 0.9);
  font-size: 28px;
  font-weight: 600;
  line-height: 1.5;
}

.hero-actions,
.download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  min-height: 52px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 13px 21px;
  border: 1px solid transparent;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 800;
  transition: transform 160ms ease, background-color 160ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary,
.button-gold {
  color: #143132;
  background: var(--gold);
}

.button-secondary {
  color: var(--white);
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.44);
  backdrop-filter: blur(10px);
}

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  margin: 36px 0 0;
  padding: 0;
  list-style: none;
  color: rgba(255, 255, 255, 0.78);
  font-size: 14px;
}

.hero-points li::before {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  margin-right: 9px;
  background: var(--coral);
  border-radius: 50%;
}

.hero-next {
  position: absolute;
  right: max(24px, calc((100vw - 1180px) / 2));
  bottom: 24px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 13px;
  font-weight: 700;
}

.section {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
  padding: 110px 0;
}

.section-heading {
  max-width: 760px;
}

.section-heading h2,
.feature-copy h2,
.download-copy h2 {
  margin: 0;
  font-size: 52px;
  line-height: 1.18;
  letter-spacing: 0;
}

.section-heading > p:last-child,
.feature-copy > p,
.download-copy > p {
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.learning-flow {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: 64px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.learning-flow article {
  min-height: 300px;
  padding: 34px 28px 34px 0;
  border-right: 1px solid var(--line);
}

.learning-flow article:not(:first-child) {
  padding-left: 28px;
}

.learning-flow article:last-child {
  border-right: 0;
}

.flow-number {
  color: var(--coral);
  font-size: 14px;
  font-weight: 900;
}

.learning-flow h3,
.result-list h3 {
  margin: 36px 0 12px;
  font-size: 22px;
  line-height: 1.35;
}

.learning-flow p,
.result-list p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

.feature-band {
  color: var(--white);
  background: var(--teal-dark);
}

.feature-inner {
  width: min(1180px, calc(100% - 48px));
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(480px, 1.1fr);
  gap: 80px;
  align-items: center;
  margin: 0 auto;
  padding: 110px 0;
}

.section-kicker.light {
  color: #76d2bd;
}

.feature-copy > p,
.download-copy > p {
  color: rgba(255, 255, 255, 0.72);
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin-top: 30px;
}

.feature-tags span {
  padding: 7px 12px;
  color: #d5f2eb;
  border: 1px solid rgba(213, 242, 235, 0.3);
  border-radius: 4px;
  font-size: 13px;
}

.game-board {
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.23);
  border-radius: 8px;
  background: #0a4e48;
  box-shadow: 24px 24px 0 rgba(238, 114, 92, 0.18);
}

.board-head,
.game-row {
  display: grid;
  align-items: center;
}

.board-head {
  grid-template-columns: 1fr auto;
  padding: 17px 20px;
  color: rgba(255, 255, 255, 0.64);
  border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  font-size: 13px;
}

.board-head strong {
  color: var(--gold);
}

.game-row {
  grid-template-columns: 44px 1fr auto;
  gap: 14px;
  min-height: 96px;
  padding: 16px 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.13);
}

.game-row:last-child {
  border-bottom: 0;
}

.game-index {
  color: #75cfbb;
  font-size: 14px;
  font-weight: 800;
}

.game-row strong,
.game-row small {
  display: block;
}

.game-row strong {
  font-size: 18px;
}

.game-row small {
  margin-top: 3px;
  color: rgba(255, 255, 255, 0.58);
  font-size: 13px;
}

.game-status {
  padding: 5px 9px;
  color: #173232;
  background: var(--gold);
  border-radius: 4px;
  font-size: 12px;
  font-weight: 800;
}

.section-heading.compact {
  max-width: 820px;
}

.result-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 44px;
  margin-top: 62px;
}

.result-list article {
  padding-top: 24px;
  border-top: 3px solid var(--teal);
}

.result-list article:nth-child(2) {
  border-color: var(--gold);
}

.result-list article:nth-child(3) {
  border-color: var(--coral);
}

.result-list span {
  color: var(--teal);
  font-size: 14px;
  font-weight: 900;
}

.result-list h3 {
  margin-top: 26px;
}

.grade-note {
  display: grid;
  grid-template-columns: minmax(260px, 0.7fr) 1.3fr;
  gap: 44px;
  align-items: center;
  margin-top: 74px;
  padding: 34px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.grade-note strong {
  font-size: 23px;
}

.grade-note p {
  margin: 0;
  color: var(--muted);
}

.download-section {
  width: min(1180px, calc(100% - 48px));
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 90px;
  align-items: center;
  margin: 0 auto 60px;
  padding: 80px;
  color: var(--white);
  background: var(--teal);
  border-radius: 8px;
}

.button-outline {
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.55);
}

.direct-link {
  max-width: 560px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 12px;
  margin-top: 34px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.22);
  font-size: 13px;
}

.direct-link code {
  min-width: 0;
  overflow: hidden;
  color: #cbede5;
  text-overflow: ellipsis;
}

.direct-link button {
  padding: 6px 10px;
  color: var(--white);
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 4px;
  cursor: pointer;
}

.qr-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 26px;
  color: var(--ink);
  background: var(--white);
  border-radius: 8px;
  text-align: center;
}

.qr-panel img {
  width: min(100%, 280px);
  height: auto;
}

.qr-panel strong {
  margin-top: 14px;
  font-size: 18px;
}

.qr-panel span {
  color: var(--muted);
  font-size: 13px;
}

.site-footer {
  width: min(1180px, calc(100% - 48px));
  display: grid;
  grid-template-columns: 1fr auto auto;
  gap: 36px;
  align-items: center;
  margin: 0 auto;
  padding: 34px 0 48px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 13px;
}

.footer-brand {
  color: var(--ink);
  font-size: 16px;
}

.footer-meta {
  display: flex;
  align-items: center;
  gap: 14px;
}

.footer-meta a:hover {
  color: var(--teal);
}

.toast {
  position: fixed;
  z-index: 50;
  left: 50%;
  bottom: 28px;
  padding: 10px 16px;
  color: var(--white);
  background: var(--ink);
  border-radius: 5px;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 12px);
  transition: opacity 180ms ease, transform 180ms ease;
}

.toast.visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

@media (max-width: 900px) {
  .hero h1 {
    font-size: 70px;
  }

  .hero-lead {
    font-size: 23px;
  }

  .section-heading h2,
  .feature-copy h2,
  .download-copy h2 {
    font-size: 44px;
  }

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

  .learning-flow article:nth-child(2) {
    border-right: 0;
  }

  .learning-flow article:nth-child(n + 3) {
    border-top: 1px solid var(--line);
  }

  .feature-inner,
  .download-section {
    grid-template-columns: 1fr;
  }

  .feature-inner {
    gap: 56px;
  }

  .download-section {
    gap: 52px;
    padding: 60px;
  }

  .qr-panel {
    max-width: 360px;
  }

  .site-footer {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .site-footer p {
    margin: 0;
  }

  .footer-meta {
    align-items: flex-start;
    flex-direction: column;
    gap: 2px;
  }
}

@media (max-width: 720px) {
  :root {
    --header-height: 64px;
  }

  .site-header {
    padding: 0 18px;
  }

  .brand img {
    width: 36px;
    height: 36px;
  }

  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: var(--header-height);
    right: 0;
    left: 0;
    display: none;
    align-items: stretch;
    gap: 0;
    padding: 12px 18px 18px;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
  }

  .site-nav.open {
    display: grid;
  }

  .site-nav a {
    padding: 12px 4px;
  }

  .site-nav .nav-action {
    margin-top: 6px;
    padding: 11px 14px;
    text-align: center;
  }

  .hero {
    min-height: min(720px, calc(100svh - var(--header-height) - 16px));
    align-items: flex-end;
    background-position: 56% center;
  }

  .hero-shade {
    background: rgba(2, 18, 19, 0.7);
  }

  .hero-content {
    width: calc(100% - 36px);
    padding: 54px 0 74px;
  }

  .hero h1 {
    font-size: 42px;
    white-space: nowrap;
  }

  .hero-lead {
    font-size: 19px;
  }

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

  .hero-actions .button,
  .download-actions .button {
    width: 100%;
  }

  .hero-points {
    gap: 7px 17px;
    margin-top: 24px;
    font-size: 12px;
  }

  .hero-next {
    right: 18px;
    bottom: 13px;
  }

  .section,
  .feature-inner,
  .download-section,
  .site-footer {
    width: calc(100% - 36px);
  }

  .section,
  .feature-inner {
    padding: 76px 0;
  }

  .section-heading h2,
  .feature-copy h2,
  .download-copy h2 {
    font-size: 35px;
  }

  .section-heading > p:last-child,
  .feature-copy > p,
  .download-copy > p {
    font-size: 16px;
  }

  .learning-flow {
    grid-template-columns: 1fr;
    margin-top: 44px;
  }

  .learning-flow article,
  .learning-flow article:not(:first-child) {
    min-height: 0;
    padding: 28px 0;
    border-top: 1px solid var(--line);
    border-right: 0;
  }

  .learning-flow article:first-child {
    border-top: 0;
  }

  .learning-flow h3 {
    margin-top: 20px;
  }

  .game-board {
    box-shadow: 10px 12px 0 rgba(238, 114, 92, 0.18);
  }

  .game-row {
    grid-template-columns: 31px 1fr;
    gap: 9px;
    padding: 15px 13px;
  }

  .game-status {
    display: none;
  }

  .result-list {
    grid-template-columns: 1fr;
    gap: 36px;
    margin-top: 46px;
  }

  .grade-note {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .download-section {
    margin-bottom: 36px;
    padding: 48px 22px;
  }

  .direct-link {
    grid-template-columns: 1fr auto;
  }

  .direct-link span {
    grid-column: 1 / -1;
  }

  .qr-panel {
    padding: 18px;
  }
}

@media (max-width: 350px) {
  .hero h1 {
    font-size: 36px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}