@font-face { font-family: 'MongolianBrand'; font-style: normal; font-weight: 500; font-display: swap; src: url('/assets/fonts/yanone-kaffeesatz-medium.woff2') format('woff2'); }
* { box-sizing: border-box; }
    html { background: #bbdbfb; }
    body { margin: 0; font-family: system-ui, -apple-system, sans-serif; color: #153d48; }
    [hidden] { display: none !important; }
    .site-header { --brand-size: clamp(30px, calc(10vw - 2px), 64px); display: flex; align-items: center; justify-content: space-between; gap: 12px; width: 100%; margin-top: -20px; margin-bottom: 32px; min-height: 50px; }
    .site-brand { display: inline-flex; align-items: center; flex-shrink: 0; gap: 8px; color: inherit; text-decoration: none; }
    .site-brand:focus-visible { outline: 2px solid #153d48; outline-offset: 5px; border-radius: 4px; }
    .brand-logo { display: block; flex-shrink: 0; width: var(--brand-size); height: var(--brand-size); object-fit: contain; }
    .brand-name { margin: 0; font: 500 var(--brand-size)/1 'MongolianBrand', 'Arial Narrow', sans-serif; letter-spacing: -.02em; white-space: nowrap; }
    .footer-logo { display: block; width: 88px; height: 88px; margin: 0 auto 24px; object-fit: contain; }
    .language-switch { display: inline-flex; flex-shrink: 0; gap: 2px; padding: 3px; border: 1px solid #153d4824; border-radius: 999px; background: #eaf4f3b8; backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); box-shadow: 0 2px 12px #153d4808; }
    .language-switch a { min-width: 44px; min-height: 44px; padding: 0 12px; border: 1px solid transparent; border-radius: 999px; background: transparent; color: #55747a; font: 600 12px/1 system-ui, -apple-system, sans-serif; text-decoration: none; display: inline-flex; align-items: center; justify-content: center; letter-spacing: .06em; cursor: pointer; transition: background .18s, color .18s, box-shadow .18s; -webkit-tap-highlight-color: transparent; }
    .language-switch a:hover { background: #ffffff70; color: #153d48; }
    .language-switch a[aria-current="page"] { border-color: #153d481c; background: #fff; color: #153d48; box-shadow: 0 2px 6px #153d4812; }
    .language-switch a:focus-visible { outline: 2px solid #153d48; outline-offset: 2px; }
    .hero { position: relative; isolation: isolate; min-height: 100svh; display: flex; flex-direction: column; align-items: center; padding: max(36px, env(safe-area-inset-top)) 24px max(160px, env(safe-area-inset-bottom)); }
    .landscape { position: absolute; inset: 0; z-index: -2; width: 100%; height: 100%; object-fit: cover; object-position: center center; }
    .hero::before { content: ''; position: absolute; inset: 0; z-index: -1; opacity: .7744; background: linear-gradient(180deg, rgba(239,250,252,.94) 0%, rgba(239,250,252,.88) 85%, rgba(239,250,252,.5) 100%); }
    .intro { text-align: center; width: 100%; max-width: 820px; }
    h1, .how-title { margin: 0; font-family: Georgia, serif; font-size: clamp(34px, 5.5vw, 62px); line-height: 1.1; text-wrap: balance; letter-spacing: -.045em; font-weight: 500; }
    .brand-tagline { margin: 16px 0 0; font-size: clamp(18px, 2.5vw, 24px); line-height: 1.35; text-wrap: balance; }
    .description { margin: 24px auto; max-width: 640px; font-size: clamp(17px, 2vw, 19px); line-height: 1.6; text-wrap: pretty; }
    .how-title { margin: 48px 0 0; font-size: clamp(30.4px, 5.2vw, 60.8px); }
    .steps { list-style: none; padding: 0; margin: 40px auto 48px; max-width: 640px; display: grid; gap: 48px; }
    .step { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 6px; }
    .step-number { font-family: Georgia, serif; font-size: clamp(40.32px, 5.04vw, 55.44px); font-weight: 500; line-height: 1; letter-spacing: -.045em; color: #000; opacity: .64; }
    .step-title { margin: 14px 0 0; max-width: 100%; font-size: 22.88px; font-weight: 500; line-height: 1.3; }
    .step-description { margin: 0; max-width: 380px; font-size: 19.5px; line-height: 1.7; opacity: .7; }
    .button { display: inline-flex; align-items: center; justify-content: center; gap: 18px; min-height: 76px; padding: 20px 38px; border: 2px solid #ff6b00; border-radius: 18px; background: #ff6b00; color: #171308; font-size: clamp(21px, 2.5vw, 27px); font-weight: 800; line-height: 1.25; text-decoration: none; box-shadow: 0 8px 0 #bb4700, 0 16px 34px #73350030; transition: transform .15s, background .15s; }
    .button:hover { background: #ff8329; transform: translateY(-2px); }
    .button:focus-visible, summary:focus-visible, .installation a:focus-visible { outline: 3px solid #153d48; outline-offset: 6px; }
    .button svg { width: 25px; height: 25px; flex-shrink: 0; }
    .start-note { margin: 18px 0 0; font-size: 14px; line-height: 1.5; }
    .installation { margin: 20px auto 0; max-width: 480px; font-size: 15px; line-height: 1.55; }
    summary { cursor: pointer; font-weight: 650; list-style: none; display: flex; align-items: center; justify-content: center; gap: 10px; min-height: 48px; width: fit-content; margin: auto; padding: 10px 18px; border: 1px solid #153d4850; border-radius: 14px; background: #f4faf5e8; }
    summary::-webkit-details-marker { display: none; }
    summary svg { width: 21px; height: 21px; flex-shrink: 0; }
    .disclosure { transition: transform .15s; }
    details[open] .disclosure { transform: rotate(180deg); }
    .install-guide { margin-top: 14px; padding: 24px; border-radius: 20px; background: #f8fcf7; text-align: left; box-shadow: 0 8px 30px #153d4820; }
    .install-guide h2 { margin: 0 0 8px; font-size: 23px; line-height: 1.2; letter-spacing: -.02em; }
    .install-intro { margin: 0; color: #385a60; }
    .install-steps { margin: 22px 0; padding: 0; list-style: none; counter-reset: install-step; }
    .install-steps li { counter-increment: install-step; display: grid; grid-template-columns: 30px minmax(0, 1fr); gap: 12px; margin-top: 18px; }
    .install-steps li::before { content: counter(install-step); display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; background: #dcebdc; color: #153d48; font-weight: 750; }
    .install-steps strong { display: block; font-size: 16px; }
    .install-steps p { margin: 4px 0 0; color: #385a60; }
    .install-guide a { color: #124b60; text-underline-offset: 3px; font-weight: 650; }
    .share-icon { display: inline-block; width: 22px; height: 25px; vertical-align: -.3em; margin-left: 3px; }
    .install-tip { border-top: 1px solid #153d4820; padding-top: 16px; margin: 0; font-size: 14px; color: #385a60; }
    .install-tip + .install-tip { border: 0; padding-top: 10px; }
    .install-finish { margin: 20px 0 0; padding: 12px 14px; border-radius: 12px; background: #e5eee2; font-weight: 600; }
    @media (max-width: 600px) {
      .language-switch { gap: 0; padding: 2px; }
      .language-switch a { min-width: 32px; padding: 0 6px; letter-spacing: .02em; }
      .hero { padding-top: max(40px, env(safe-area-inset-top)); }
      .landscape { object-position: 55% center; }
      .hero::before { background: linear-gradient(180deg, rgba(239,250,252,.96), rgba(239,250,252,.9) 85%, rgba(239,250,252,.55) 100%); }
      .button { width: 100%; padding: 20px 22px; }
      .description { max-width: 440px; }
    }
    @media (prefers-reduced-motion: reduce) { .button, .disclosure, .language-switch a { transition: none; } }
    .site-footer { background: #262626; color: #dedede; padding: 36px 24px max(36px, env(safe-area-inset-bottom)); text-align: center; font-size: 14px; line-height: 1.7; }
    .site-footer p { margin: 0 0 12px; }
    .site-footer nav { display: flex; flex-direction: column; align-items: center; gap: 0; }
    .site-footer a { color: #dedede; text-underline-offset: 4px; padding: 0; }
    .site-footer a:hover { color: #fff; }
    .site-footer a:focus-visible { outline: 2px solid #fff; outline-offset: 5px; }
  
    .course-facts { margin: 24px 0; font-size: 16px; line-height: 1.6; font-weight: 600; }
    .hero-cta { margin: 0 auto 10px; }
    .course-content { background: #effafc; padding: 0 24px 80px; }
    .content-section { width: 100%; max-width: 920px; margin: 0 auto; padding: 56px 0; text-align: center; }
    .content-section + .content-section { border-top: 1px solid #153d4820; }
    .section-title { margin: 0 0 20px; font: 500 clamp(28px, 4vw, 42px)/1.2 Georgia, serif; letter-spacing: -.025em; text-wrap: balance; }
    .section-lead { max-width: 680px; margin: 0 auto 24px; font-size: 18px; line-height: 1.65; }
    .topic-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px 28px; max-width: 680px; padding: 0; margin: 24px auto; list-style: none; }
    .topic-list li { padding: 12px 0; border-bottom: 1px solid #153d4818; line-height: 1.5; }
    .text-link { color: #124b60; font-weight: 650; text-underline-offset: 4px; }
    .phrase-examples { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; margin-top: 28px; }
    .phrase-example { padding: 24px 16px; border: 1px solid #153d4824; border-radius: 18px; background: #ffffff90; }
    .phrase-example h3 { margin: 0 0 8px; font-size: 22px; font-weight: 600; }
    .phrase-example p { margin: 0 0 20px; line-height: 1.6; }
    .phrase-example audio { width: 100%; height: 44px; }
    .faq { max-width: 760px; margin: 28px auto 0; text-align: left; }
    .faq details { border-bottom: 1px solid #153d4824; padding: 16px 0; }
    .faq summary { display: block; width: 100%; margin: 0; padding: 8px 28px 8px 0; border: 0; border-radius: 0; background: none; font-size: 18px; line-height: 1.5; position: relative; }
    .faq summary::after { content: '+'; position: absolute; right: 0; top: 8px; font-size: 24px; font-weight: 400; }
    .faq details[open] summary::after { content: '−'; }
    .faq p { margin: 8px 0; line-height: 1.75; }
    @media (max-width: 600px) { .topic-list, .phrase-examples { grid-template-columns: 1fr; } .content-section { padding: 40px 0; } }

    .intro-divider { display: flex; align-items: center; justify-content: center; gap: 12px; max-width: 180px; margin: 28px auto; }
    .intro-divider::before, .intro-divider::after { content: ''; flex: 1; height: 1px; background: linear-gradient(to right, transparent, #b5172560); }
    .intro-divider::after { transform: scaleX(-1); }
    .intro-divider img { display: block; width: 24px; height: 24px; }