:root {
  color-scheme: dark;
  --bg: #040816;
  --panel: rgba(10, 16, 40, 0.72);
  --panel-border: rgba(124, 180, 255, 0.22);
  --text: #f3f7ff;
  --muted: #b5c3ea;
  --accent: #65d9ff;
  --accent-2: #8a7dff;
  --shadow: 0 28px 90px rgba(0, 0, 0, 0.46);
  --display-font: "PingFang SC", "Microsoft YaHei", "Heiti SC", system-ui, sans-serif;
  --section-title-size: clamp(2.6rem, 4.4vw, 4.6rem);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-snap-type: y proximity;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  color: var(--text);
  background:
    linear-gradient(rgba(3, 5, 16, 0.62), rgba(3, 5, 16, 0.72)),
    url("./assets/page-background.png") center / cover fixed no-repeat;
  overflow-x: hidden;
}

.page-shell {
  width: min(1840px, calc(100vw - 10px));
  margin: 0 auto;
  padding: 0px 0 10px;
  position: relative;
  z-index: 1;
}

.topbar {
  position: sticky;
  top: 0px;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px 20px;
  border: 1px solid rgba(151, 214, 255, 0.42);
  /*border-radius: 26px;*/
  background: linear-gradient(180deg, rgba(179, 228, 255, 0.96) 0%, rgba(154, 214, 245, 0.92) 100%);
  backdrop-filter: blur(14px);
  box-shadow: 0 16px 38px rgba(37, 99, 235, 0.14);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  margin: 0;
  padding: 0;
  border: 1px solid rgba(4, 24, 56, 0.18);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.42);
  color: #0a1a33;
  cursor: pointer;
  flex-shrink: 0;
  transition: background 0.18s ease, border-color 0.18s ease;
}

.nav-toggle:hover,
.nav-toggle:focus-visible {
  background: rgba(255, 255, 255, 0.72);
  border-color: rgba(4, 24, 56, 0.28);
  outline: none;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: 999px;
  background: currentColor;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.topbar.is-nav-open .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.topbar.is-nav-open .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.topbar.is-nav-open .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: inherit;
  text-decoration: none;
}

.brand-mark {
  display: block;
  width: clamp(126px, 18vw, 220px);
  height: 42px;
}

.brand-logo {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.deck {
  display: grid;
  gap: 20px;
  padding: 24px 0 26px;
}

.panel {
  min-height: calc(100vh - 120px);
  display: grid;
  grid-template-rows: auto minmax(330px, 1fr) auto;
  justify-items: center;
  text-align: center;
  padding: 16px 80px 10px 16px;
  scroll-snap-align: start;
  scroll-margin-top: 14px;
  position: relative;
}

.hero-panel {
  padding-top: calc(114px - 1cm);
}

.nav {
  display: flex;
  flex-wrap: nowrap;
  justify-content: flex-end;
  gap: 12px 16px;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 48px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid rgba(126, 214, 255, 0.18);
  background: linear-gradient(180deg, rgba(112, 215, 255, 0.14) 0%, rgba(137, 126, 255, 0.12) 100%);
  color: #ecf5ff;
  text-decoration: none;
  font-family: var(--display-font);
  font-size: 1.06rem;
  font-weight: 900;
  white-space: nowrap;
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

.nav-btn:hover,
.nav-btn:focus-visible {
  transform: translateY(-1px);
  color: #ffffff;
  border-color: rgba(125, 228, 255, 0.44);
  background: linear-gradient(180deg, rgba(86, 211, 255, 0.22) 0%, rgba(129, 112, 255, 0.2) 100%);
}

.nav-btn-accent {
  background: linear-gradient(180deg, #6fe7ff 0%, #6d7cff 100%);
  border-color: rgba(125, 228, 255, 0.3);
  color: #04111f;
}

.nav-btn-accent:hover,
.nav-btn-accent:focus-visible {
  color: #03101a;
}

.eyebrow {
  margin: 0 0 2px;
  color: rgba(120, 213, 255, 0.94);
  font-size: 0.88rem;
  font-weight: 800;
  letter-spacing: 0.18em;
}

.hero-head {
  display: grid;
  justify-items: center;
  gap: 4px;
  align-self: start;
  margin-top: 28px;
}

.hero-panel h1 {
  margin: 0;
  display: inline-block;
  padding-bottom: 0;
  font-family: var(--display-font);
  font-size: var(--section-title-size);
  line-height: 1;
  letter-spacing: 0;
  font-weight: 900;
  background: linear-gradient(180deg, #ffffff 0%, #8cf1ff 40%, #7784ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-stroke: 0.5px rgba(255, 255, 255, 0.14);
  text-shadow: 0 16px 38px rgba(72, 123, 255, 0.22);
}

.hero-stage {
  align-self: center;
  position: relative;
  width: min(76vw, 1080px);
  max-width: 100%;
  min-height: 360px;
  margin-top: calc(48px + 2cm);
}

.hero-figure {
  position: absolute;
  display: block;
  max-width: 100%;
  object-fit: contain;
}

.hero-figure-left {
  left: 1%;
  bottom:11%;
  width: min(30vw, 360px);
  transform: translateX(-4%) scale(0.86) rotate(-4deg);
  opacity: 0.92;
  z-index: 1;
  filter: saturate(0.96) brightness(0.98);
}

.hero-figure-center {
  left: 47%;
  bottom: 0;
  width: min(39vw, 520px);
  transform: translateX(-50%);
  z-index: 3;
}

.hero-figure-right {
  right: 0%;
  bottom: 11%;
  width: min(30vw, 360px);
  transform: translateX(4%) scale(0.86) rotate(4deg);
  opacity: 0.92;
  z-index: 1;
  filter: saturate(0.96) brightness(0.98);
}

.lead {
  width: min(820px, 100%);
  margin: 2cm auto 0;
  color: var(--muted);
  font-size: clamp(1rem, 1.8vw, 1.18rem);
  line-height: 1.65;
  align-self: end;
  padding-bottom: 72px;
}

.section-copy {
  display: grid;
  justify-items: center;
  gap: 12px;
  width: min(980px, 100%);
}

.section-copy h2 {
  margin: 0;
  font-size: var(--section-title-size);
  line-height: 1;
  font-family: var(--display-font);
  font-weight: 900;
  background: linear-gradient(180deg, #ffffff 0%, #8feaff 42%, #7f84ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 14px 34px rgba(72, 123, 255, 0.18);
}

.section-copy p {
  margin: 0;
  color: var(--muted);
  line-height: 1.8;
  font-size: clamp(1rem, 1.7vw, 1.12rem);
}

.about-panel {
  grid-template-rows: auto auto auto;
  gap: 18px;
  padding-top: calc(34px + 0.5cm + 2.2rem);
}

.about-hero {
  display: grid;
  justify-items: center;
  gap: 14px;
  width: min(1140px, 100%);
}

.about-hero h2 {
  margin: 0;
  font-family: var(--display-font);
  font-size: clamp(2.3rem, 4vw, 4.4rem);
  line-height: 1.05;
  font-weight: 900;
  text-align: center;
  background: linear-gradient(180deg, #ffffff 0%, #8feaff 42%, #7f84ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 14px 34px rgba(72, 123, 255, 0.18);
}

.about-lead {
  width: min(1020px, 100%);
  margin: 0;
  color: #d9e6ff;
  line-height: 1.9;
  font-size: clamp(1.02rem, 1.8vw, 1.16rem);
}

.about-grid-four {
  width: min(1180px, 100%);
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.about-card {
  min-height: 210px;
}

.about-card h3 {
  font-size: 1.1rem;
}

.about-footer {
  width: min(1180px, 100%);
  display: grid;
  justify-items: center;
  gap: 10px;
  margin-top: -3.6rem;
  text-align: center;
  color: var(--muted);
  line-height: 1.8;
}

.mission-line {
  margin: 0;
  color: #f5fbff;
  font-family: var(--display-font);
  font-size: clamp(1.2rem, 2vw, 1.6rem);
  font-weight: 900;
}

.footer-address {
  margin: 0;
  margin-top: 4.4rem;
  color: #d9e6ff;
  font-size: clamp(1rem, 1.6vw, 1.12rem);
  font-weight: 700;
}

.footer-note {
  margin: 0 0 0;
  color: var(--muted);
  font-size: clamp(0.95rem, 1.45vw, 1.05rem);
  line-height: 1.8;
}

.about-grid,
.course-grid,
.course-module-grid {
  width: min(1120px, 100%);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  align-self: center;
}

.info-card {
  border: 1px solid var(--panel-border);
  background: linear-gradient(180deg, rgba(15, 20, 48, 0.84) 0%, rgba(9, 14, 34, 0.8) 100%);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
  border-radius: 22px;
  padding: 24px;
  text-align: left;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease;
}

.info-card:hover,
.info-card:focus-within,
.lesson-card:hover,
.lesson-card:focus-within,
.page-next-group:hover,
.page-next-group:focus-within {
  transform: translateY(-3px);
  border-color: rgba(153, 226, 255, 0.42);
  background: linear-gradient(180deg, rgba(18, 25, 58, 0.94) 0%, rgba(12, 18, 42, 0.9) 100%);
  box-shadow: 0 22px 48px rgba(0, 0, 0, 0.36), 0 0 0 1px rgba(126, 214, 255, 0.08) inset;
}

.info-card h3 {
  margin: 0 0 10px;
  font-family: var(--display-font);
  font-size: 1.22rem;
  font-weight: 900;
  color: #f5fbff;
}

.info-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.course-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 52px;
  margin-top: 18px;
  padding: 0 22px;
  border-radius: 999px;
  background: linear-gradient(180deg, #6fe7ff 0%, #7a79ff 100%);
  color: #06111d;
  text-decoration: none;
  font-weight: 900;
  box-shadow: 0 16px 44px rgba(109, 174, 255, 0.28);
}

.curriculum-panel {
  grid-template-rows: auto auto;
  align-content: start;
  gap: 24px;
  padding-top: 34px;
  transform: translateY(-2.4rem);
}

.course-panel .section-copy {
  margin-top: calc(2rem + 3.4rem);
}

.curriculum-copy {
  display: grid;
  justify-items: center;
  gap: 12px;
  width: min(1180px, 100%);
}

.curriculum-copy h2 {
  margin: 0;
  font-family: var(--display-font);
  font-size: clamp(2.2rem, 3.8vw, 4.2rem);
  line-height: 1.02;
  font-weight: 900;
  background: linear-gradient(180deg, #ffffff 0%, #8feaff 42%, #7f84ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 14px 34px rgba(72, 123, 255, 0.18);
}

.curriculum-copy > .eyebrow,
.curriculum-copy > h2 {
  transform: translateY(5.5rem);
}

.curriculum-intro {
  width: min(980px, 100%);
  margin: calc(2rem + 4.5rem) 0 0;
  color: var(--muted);
  line-height: 1.8;
  font-size: clamp(1rem, 1.7vw, 1.08rem);
}

.curriculum-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.meta-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 0 14px;
  border-radius: 999px;
  border: 1px solid rgba(126, 214, 255, 0.2);
  background: linear-gradient(180deg, rgba(112, 215, 255, 0.14) 0%, rgba(137, 126, 255, 0.12) 100%);
  color: #eaf5ff;
  font-size: 0.95rem;
  font-weight: 800;
}

.lesson-grid {
  width: min(1180px, 100%);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  align-self: start;
}

.lesson-card {
  border: 1px solid rgba(126, 214, 255, 0.16);
  background: linear-gradient(180deg, rgba(15, 20, 48, 0.84) 0%, rgba(9, 14, 34, 0.82) 100%);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
  border-radius: 18px;
  padding: 18px 18px 16px;
  text-align: left;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease;
}

.lesson-time {
  margin: 0 0 8px;
  color: rgba(120, 213, 255, 0.94);
  font-size: 0.88rem;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.lesson-card h3 {
  margin: 0 0 8px;
  font-family: var(--display-font);
  font-size: 1.08rem;
  line-height: 1.35;
  font-weight: 900;
  color: #f5fbff;
}

.lesson-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.65;
  font-size: 0.96rem;
}

.curriculum-foot {
  width: min(1180px, 100%);
  display: grid;
  gap: 6px;
  justify-items: center;
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.7;
  text-align: center;
}

.page-next-group {
  display: grid;
  justify-items: start;
  align-content: start;
  gap: 12px;
  min-height: 150px;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease;
}

.page-next {
  width: 58px;
  height: 58px;
  border: 1px solid rgba(126, 214, 255, 0.24);
  border-radius: 999px;
  background: linear-gradient(180deg, rgba(112, 215, 255, 0.18) 0%, rgba(137, 126, 255, 0.16) 100%);
  color: #edf6ff;
  box-shadow: 0 12px 30px rgba(37, 99, 235, 0.16);
  cursor: pointer;
  font: inherit;
  font-size: 1.3rem;
  font-weight: 900;
  line-height: 1;
  display: grid;
  place-items: center;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.page-next:hover,
.page-next:focus-visible {
  transform: translateY(-2px);
  border-color: rgba(153, 226, 255, 0.48);
  background: linear-gradient(180deg, rgba(126, 232, 255, 0.26) 0%, rgba(136, 132, 255, 0.24) 100%);
}

.page-next-arrow {
  font-size: 1.3rem;
  line-height: 0.8;
  transform: scaleY(1.15);
}

.page-rail {
  position: fixed;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 35;
  display: grid;
  gap: 10px;
}

.page-dot {
  width: 56px;
  height: 56px;
  border-radius: 999px;
  border: 1px solid rgba(191, 201, 255, 0.28);
  background: rgba(7, 12, 28, 0.68);
  color: rgba(238, 242, 255, 0.88);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  backdrop-filter: blur(10px);
}

.page-dot span {
  display: block;
  font-size: 0.92rem;
}

.page-dot.is-active {
  background: linear-gradient(180deg, #9cefff 0%, #7e86ff 100%);
  color: #07111c;
  border-color: rgba(255, 255, 255, 0.5);
}

@media (max-width: 1100px) {
  .page-shell {
    width: 100%;
    margin: 0;
    padding: 0 0 10px;
  }

  .topbar {
    flex-wrap: wrap;
    justify-content: flex-start;
    gap: 12px 14px;
    padding: 12px 14px;
    border-radius: 0;
    border-top: none;
    top: 0;
  }

  .nav-toggle {
    display: inline-flex;
    order: 1;
    margin-left: auto;
  }

  .brand {
    order: 0;
  }

  .brand-mark {
    width: clamp(110px, 36vw, 180px);
    height: 36px;
  }

  .nav {
    display: none;
    order: 2;
    flex-direction: column;
    flex-wrap: nowrap;
    align-items: stretch;
    justify-content: flex-start;
    gap: 10px;
    width: 100%;
    padding: 4px 0 2px;
  }

  .topbar.is-nav-open .nav {
    display: flex;
  }

  .nav-btn {
    width: 100%;
    justify-content: center;
  }

  .hero-panel {
    grid-template-rows: auto auto auto;
  }

  .hero-stage {
    align-self: start;
    margin-top: calc(48px + 2cm);
  }
}

@media (max-width: 900px) {
  .deck {
    gap: 14px;
    padding: 12px 0 18px;
  }

  .panel {
    min-height: auto;
    padding: 14px 16px 12px;
  }

  .hero-panel {
    padding-top: calc(114px - 1cm);
  }

  .hero-stage {
    min-height: min(52vw, 340px);
  }

  .lead {
    margin-top: 2cm;
    padding-bottom: 52px;
  }

  .hero-figure-left,
  .hero-figure-right {
    width: min(38vw, 220px);
    bottom: 14%;
  }

  .hero-figure-center {
    width: min(52vw, 340px);
  }

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

  .about-grid-four {
    grid-template-columns: 1fr;
  }

  .about-panel {
    padding-top: calc(24px + 0.5cm + 1.8rem);
  }

  .about-footer {
    margin-top: -2.4rem;
  }

  .curriculum-panel {
    gap: 14px;
    padding-top: 24px;
  }

  .course-panel .section-copy {
    margin-top: calc(1.2rem + 3.4rem);
  }

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

  .page-rail {
    right: 8px;
    gap: 8px;
  }

  .page-dot {
    width: 46px;
    height: 46px;
  }
}