:root {
  --sky: #dceeff;
  --cloud: #f7fbff;
  --white: #fff;
  --cobalt: #1557d5;
  --cobalt-dark: #123f91;
  --ink: #10284a;
  --muted: #607b9f;
  --line: #d8e6f3;
  --cyan: #20a7d8;
  --shadow: 0 22px 64px rgba(56, 104, 157, .15);
  --font: "SF Pro Display", "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
}

* { box-sizing: border-box; }
html, body { max-width: 100%; overflow-x: clip; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--cloud); font-family: var(--font); -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button { color: inherit; font: inherit; }
img { display: block; max-width: 100%; }
.skip-link { position: fixed; top: 8px; left: 8px; z-index: 100; padding: 10px 14px; color: white; background: var(--ink); transform: translateY(-150%); }
.skip-link:focus { transform: none; }
:focus-visible { outline: 3px solid #0876d1; outline-offset: 3px; }

.course-header { position: absolute; z-index: 20; top: 0; left: 0; right: 0; height: 76px; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 32px; padding: 0 max(28px, calc((100vw - 1450px) / 2)); }
.course-brand { color: #1461cf; font-size: 25px; font-weight: 950; letter-spacing: -.03em; white-space: nowrap; }
.course-header nav { display: flex; justify-content: center; gap: 42px; font-size: 14px; font-weight: 650; }
.course-header nav a { position: relative; padding: 28px 0 24px; }
.course-header nav a.active::after { content: ""; position: absolute; left: 0; right: 0; bottom: 18px; height: 2px; background: var(--cobalt); }
.consult-button { min-height: 42px; display: inline-flex; align-items: center; justify-content: center; padding: 0 20px; border-radius: 999px; background: var(--cobalt); color: white; font-size: 13px; font-weight: 800; box-shadow: 0 10px 25px rgba(21, 87, 213, .24); transition: transform .2s ease, background .2s ease; }
.consult-button:hover { background: var(--cobalt-dark); transform: translateY(-2px); }

.course-hero { position: relative; min-height: 410px; display: grid; grid-template-columns: minmax(0, 1fr) minmax(440px, .9fr); align-items: center; overflow: hidden; padding: 110px max(40px, calc((100vw - 1450px) / 2)) 54px; background: linear-gradient(100deg, #fff 0 42%, #dceeff 100%); }
.course-hero::before { content: ""; position: absolute; z-index: 1; inset: 0; background: linear-gradient(90deg, rgba(255,255,255,.98) 0%, rgba(255,255,255,.9) 34%, rgba(255,255,255,.18) 51%, transparent 64%); pointer-events: none; }
.course-hero::after { content: ""; position: absolute; z-index: 3; left: -5%; right: -5%; bottom: -58px; height: 76px; border-radius: 50% 50% 0 0; background: var(--cloud); }
.hero-copy { position: relative; z-index: 2; }
.hero-copy h1 { margin: 0; max-width: 720px; font-size: clamp(56px, 5.2vw, 84px); line-height: 1.03; letter-spacing: -.03em; }
.hero-copy > p { margin: 20px 0 0; color: #263850; font-family: "Songti SC", STSong, serif; font-size: clamp(22px, 2vw, 31px); letter-spacing: .14em; }
.course-record { display: flex; flex-wrap: wrap; gap: 0; margin-top: 42px; color: var(--muted); }
.course-record span { padding: 0 26px; border-right: 1px solid rgba(18, 63, 145, .18); font-size: 14px; }
.course-record span:first-child { padding-left: 0; }
.course-record span:last-child { border-right: 0; }
.course-record strong { color: var(--cobalt); font-size: 27px; margin-right: 4px; }
.hero-world { position: absolute; z-index: 0; top: 76px; right: 0; bottom: 0; left: 40%; background: url("assets/course-hero-world.webp") center center / cover no-repeat; }

.curriculum-section, .benefit-section { padding: 88px max(28px, calc((100vw - 1450px) / 2)); }
.section-intro { max-width: 860px; margin-bottom: 38px; }
.section-intro h2 { margin: 0; font-size: clamp(36px, 3.4vw, 54px); line-height: 1.08; letter-spacing: -.03em; }
.section-intro p { max-width: 760px; margin: 18px 0 0; color: var(--muted); font-size: 16px; line-height: 1.85; }
.curriculum-explorer { min-height: 690px; display: grid; grid-template-columns: 360px 1fr; overflow: hidden; border-radius: 16px; background: white; box-shadow: var(--shadow); }
.chapter-navigation { padding: 28px 18px; background: #f5f9fd; border-right: 1px solid var(--line); }
.chapter-navigation > p { margin: 0 14px 18px; color: var(--muted); font-size: 12px; }
#chapterNav { display: grid; gap: 3px; }
.chapter-tab { width: 100%; min-height: 42px; display: grid; grid-template-columns: 38px 1fr; align-items: center; gap: 8px; padding: 8px 14px; border: 0; border-radius: 10px; background: transparent; text-align: left; cursor: pointer; transition: color .2s ease, background .2s ease; }
.chapter-tab:hover { background: #eaf3fc; }
.chapter-tab[aria-selected="true"] { color: white; background: var(--cobalt); }
.chapter-tab small { color: #2d79da; font-size: 12px; font-weight: 850; }
.chapter-tab[aria-selected="true"] small { color: white; }
.chapter-tab strong { font-size: 14px; font-weight: 750; }
.chapter-panel { min-width: 0; padding: 48px 52px; background: linear-gradient(135deg,#fff 0 45%,#f4f9ff 100%); }
.chapter-heading { position: relative; z-index: 2; }
.chapter-number { display: inline-flex; min-width: 44px; min-height: 44px; align-items: center; justify-content: center; border-radius: 11px; background: var(--cobalt); color: white; font-size: 18px; font-weight: 900; }
.chapter-heading h2 { margin: 18px 0 0; font-size: clamp(32px,3vw,48px); letter-spacing: -.025em; }
.chapter-heading > p { max-width: 720px; margin: 14px 0 0; color: var(--muted); font-size: 16px; line-height: 1.75; }
.chapter-content { display: grid; grid-template-columns: minmax(340px,.82fr) minmax(420px,1.18fr); gap: 38px; align-items: center; margin-top: 24px; }
.chapter-copy h3 { margin: 0 0 12px; font-size: 17px; }
.chapter-points { display: grid; gap: 0; margin: 0; padding: 0; list-style: none; }
.chapter-points li { position: relative; padding: 12px 0 12px 28px; border-bottom: 1px solid var(--line); color: #365471; font-size: 14px; line-height: 1.55; }
.chapter-points li::before { content: ""; position: absolute; left: 2px; top: 18px; width: 8px; height: 8px; border-radius: 50%; background: var(--cobalt); box-shadow: 0 0 0 4px #e7f1ff; }
.chapter-extra { margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--line); }
.chapter-extra h3 { margin: 0 0 9px; color: var(--cobalt-dark); font-size: 16px; }
.chapter-extra p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
.chapter-meta { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 22px; }
.chapter-meta span { padding: 7px 10px; border-radius: 999px; background: #eaf3ff; color: var(--cobalt-dark); font-size: 11px; font-weight: 750; }
.chapter-figure { align-self: stretch; display: grid; place-items: center; min-height: 400px; }
.chapter-figure img { width: 100%; height: 100%; max-height: 470px; object-fit: contain; mix-blend-mode: multiply; transition: opacity .24s ease, transform .36s cubic-bezier(.16,1,.3,1); }
.chapter-panel.is-changing .chapter-figure img { opacity: .25; transform: translateX(16px); }

.learning-section { padding: 90px max(28px, calc((100vw - 1450px) / 2)); color: white; background: #123f91; }
.light-intro p { color: #c9dbef; }
.info-switcher { display: grid; grid-template-columns: 320px 1fr; min-height: 390px; margin-top: 36px; border-top: 1px solid rgba(255,255,255,.18); }
.info-nav { display: grid; align-content: start; padding: 28px 28px 28px 0; border-right: 1px solid rgba(255,255,255,.18); }
.info-tab { min-height: 56px; display: flex; align-items: center; justify-content: space-between; border: 0; border-bottom: 1px solid rgba(255,255,255,.13); background: transparent; color: #c9dbef; text-align: left; cursor: pointer; }
.info-tab[aria-selected="true"] { color: white; font-weight: 800; }
.info-tab::after { content: ""; width: 8px; height: 8px; border-top: 2px solid currentColor; border-right: 2px solid currentColor; transform: rotate(45deg); }
.info-panel { padding: 44px 52px; }
.info-panel h3 { margin: 0; font-size: 35px; }
.info-panel > p { max-width: 720px; margin: 14px 0 26px; color: #c9dbef; line-height: 1.8; }
.info-list { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px 36px; margin: 0; padding: 0; list-style: none; }
.info-list li { padding: 12px 0; border-bottom: 1px solid rgba(255,255,255,.14); line-height: 1.55; }
.info-list strong { font-weight: 600; }

.benefit-catalog { margin-top: 36px; }
.benefit-core-list { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); column-gap: 64px; background: white; padding: 20px 42px; border-radius: 16px; box-shadow: var(--shadow); }
.benefit-core-list article { min-height: 116px; display: grid; align-content: center; grid-template-columns: 150px 1fr; gap: 24px; border-bottom: 1px solid var(--line); }
.benefit-core-list article:nth-last-child(-n+2) { border-bottom: 0; }
.benefit-core-list h3, .benefit-media-card h3 { margin: 0; color: var(--ink); font-size: 19px; font-weight: 850; }
.benefit-core-list p, .benefit-media-card p { margin: 0; color: #4d6c90; font-size: 15px; line-height: 1.7; }
.benefit-media-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 22px; margin-top: 22px; }
.benefit-media-card { min-width: 0; overflow: hidden; border-radius: 16px; background: white; box-shadow: var(--shadow); }
.benefit-media-card > div:last-child { min-height: 116px; padding: 24px 26px; }
.benefit-media-card p { margin-top: 8px; }
.benefit-media { position: relative; height: 279px; overflow: hidden; background: #edf4fc; }
.benefit-media img { width: 100%; height: 100%; object-fit: cover; }
.ace-media img { object-position: center; }
.hardware-media img, .merch-media img { object-position: center; }
.benefit-note { margin: 20px 0 0; color: var(--muted); font-size: 12px; line-height: 1.7; }

.course-cta { display: flex; align-items: center; justify-content: space-between; gap: 40px; padding: 70px max(28px, calc((100vw - 1240px) / 2)); background: linear-gradient(120deg,#dbeeff,#f8fbff); }
.course-cta h2 { margin: 0; font-size: clamp(34px,3vw,48px); letter-spacing: -.025em; }
.course-cta p { max-width: 680px; margin: 14px 0 0; color: var(--muted); line-height: 1.75; }
.consult-button.large { min-height: 52px; padding: 0 28px; font-size: 15px; }
.course-footer { display: flex; align-items: center; justify-content: space-between; padding: 34px max(28px, calc((100vw - 1240px) / 2)); background: white; }
.course-footer p { margin: 0; color: var(--muted); font-size: 13px; }

@media (max-width: 980px) {
  .course-header nav { gap: 18px; }
  .course-hero { grid-template-columns: 1fr; min-height: 560px; }
  .hero-world { top: 86px; right: 0; bottom: 0; left: 34%; width: auto; opacity: .82; background-position: center; }
  .curriculum-explorer { grid-template-columns: 270px 1fr; }
  .chapter-panel { padding: 38px 32px; }
  .chapter-content { grid-template-columns: 1fr; }
  .chapter-figure { min-height: 280px; }
}

@media (max-width: 760px) {
  .course-header { height: 66px; padding: 0 16px; grid-template-columns: 1fr auto; }
  .course-header nav { display: none; }
  .consult-button { min-height: 38px; padding: 0 14px; font-size: 11px; }
  .course-hero { min-height: 590px; padding: 120px 18px 64px; }
  .hero-copy h1 { font-size: 50px; }
  .hero-copy > p { font-size: 18px; letter-spacing: .08em; }
  .course-record { display: grid; grid-template-columns: repeat(2,1fr); gap: 16px 0; margin-top: 34px; }
  .course-record span { padding: 0 12px; }
  .course-record span:nth-child(odd) { padding-left: 0; }
  .course-record span:nth-child(2) { border-right: 0; }
  .course-hero::before { background: linear-gradient(180deg, rgba(255,255,255,.98) 0%, rgba(255,255,255,.92) 47%, rgba(255,255,255,.34) 70%, transparent 100%); }
  .hero-world { top: 240px; right: -34%; bottom: 0; left: -12%; width: auto; opacity: .68; background-position: center; }
  .curriculum-section, .benefit-section, .learning-section { padding: 68px 16px; }
  .section-intro h2 { font-size: 38px; }
  .curriculum-explorer { display: block; min-height: 0; overflow: visible; background: transparent; box-shadow: none; }
  .chapter-navigation { position: sticky; z-index: 10; top: 0; padding: 12px 0; border: 0; background: rgba(247,251,255,.96); box-shadow: 0 8px 24px rgba(54,104,157,.12); }
  .chapter-navigation > p { display: none; }
  #chapterNav { display: flex; gap: 7px; padding: 0 12px; overflow-x: auto; scrollbar-width: none; }
  .chapter-tab { width: auto; min-width: max-content; min-height: 40px; grid-template-columns: auto 1fr; padding: 7px 12px; border: 1px solid var(--line); background: white; }
  .chapter-panel { margin-top: 14px; padding: 30px 20px; border-radius: 14px; }
  .chapter-heading h2 { font-size: 34px; }
  .chapter-content { display: flex; flex-direction: column-reverse; gap: 20px; }
  .chapter-figure { min-height: 230px; width: 100%; }
  .chapter-figure img { max-height: 280px; }
  .info-switcher { display: block; min-height: 0; }
  .info-nav { display: flex; gap: 8px; overflow-x: auto; padding: 14px 0; border: 0; scrollbar-width: none; }
  .info-tab { min-width: max-content; min-height: 42px; padding: 0 14px; border: 1px solid rgba(255,255,255,.2); border-radius: 999px; }
  .info-tab::after { display: none; }
  .info-tab[aria-selected="true"] { color: var(--cobalt-dark); background: white; }
  .info-panel { padding: 30px 20px; }
  .info-panel h3 { font-size: 30px; }
  .info-list { grid-template-columns: 1fr; }
  .benefit-core-list { grid-template-columns: 1fr; padding: 10px 20px; }
  .benefit-core-list article { min-height: 112px; grid-template-columns: 1fr; align-content: center; gap: 6px; }
  .benefit-core-list article:nth-last-child(2) { border-bottom: 1px solid var(--line); }
  .benefit-media-grid { grid-template-columns: 1fr; }
  .benefit-media { height: 224px; }
  .course-cta { align-items: flex-start; flex-direction: column; }
  .course-footer { align-items: flex-start; flex-direction: column; gap: 12px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}