:root { color-scheme: light; font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; color: #18342d; background: #f6f7f2; }
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; }
.container { width: min(1120px, 100%); margin-inline: auto; padding-inline: 24px; }
header { padding-block: 28px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
a { color: inherit; }
.brand { font-weight: 750; font-size: 1.1rem; letter-spacing: -.03em; text-decoration: none; }
.badge { font-size: .75rem; padding: 7px 12px; border: 1px solid #cbd8cf; border-radius: 100px; }
.hero { padding-block: 54px 44px; }
.eyebrow { color: #39654e; text-transform: uppercase; letter-spacing: .12em; font-size: .75rem; font-weight: 750; }
h1 { font-size: clamp(2.5rem, 6vw, 4.5rem); line-height: 1.08; letter-spacing: -.055em; margin: 20px 0; }
.intro { max-width: 610px; color: #53665d; font-size: 1.1rem; line-height: 1.75; }
.notice, .small { color: #53665d; font-size: .85rem; line-height: 1.6; }
h2 { font-size: clamp(1.5rem, 4vw, 2rem); letter-spacing: -.035em; margin: 8px 0 18px; }
h3 { margin: 0 0 12px; font-size: 1.2rem; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 16px; }
.section-heading > p { color: #53665d; font-size: .85rem; }
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0 24px; }
button { font: inherit; cursor: pointer; }
.filters button { border: 1px solid #bdcbbf; border-radius: 100px; background: transparent; color: #18342d; padding: 10px 18px; }
.filters button[aria-pressed="true"], .primary { background: #183f30; color: #fff; border: 1px solid #183f30; }
.courses { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.course, .study-panel, .practice-panel { background: #fff; padding: 28px; border: 1px solid #dde5da; border-radius: 16px; }
.course h3 { font-size: 1.6rem; }
.description { color: #53665d; line-height: 1.6; }
.course ul { padding: 0; list-style: none; margin: 24px 0 0; }
.course li + li { border-top: 1px solid #e4e9e0; }
.skill-button { width: 100%; text-align: left; padding: 16px 8px; border: 0; background: transparent; color: #18342d; border-radius: 6px; line-height: 1.4; }
.skill-button > span:first-child { font-weight: 650; }
.skill-summary { display: block; font-size: .85rem; color: #53665d; margin-top: 6px; }
.skill-button:hover, .option:hover { background: #f0f5eb; }
:focus-visible { outline: 3px solid #986100; outline-offset: 4px; }
.lesson { scroll-margin-top: 24px; }
.text-button { color: #183f30; background: transparent; border: 0; padding: 12px 0; text-decoration: underline; margin-bottom: 20px; }
.lesson-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.study-panel p { line-height: 1.8; }
.example { background: #f0f5eb; border-radius: 10px; padding: 20px; margin-top: 28px; }
.example p { margin-bottom: 0; }
fieldset { padding: 0; margin: 0; border: 0; min-width: 0; }
legend { font-size: 1.1rem; font-weight: 650; line-height: 1.6; margin-bottom: 18px; }
.option { display: flex; gap: 12px; align-items: center; border: 1px solid #cdd9ce; padding: 14px; border-radius: 8px; margin-bottom: 10px; cursor: pointer; }
input { accent-color: #183f30; width: 18px; height: 18px; flex-shrink: 0; }
.primary { padding: 12px 20px; border-radius: 8px; margin-top: 12px; }
#feedback { line-height: 1.7; }
.correct { color: #205c36; }
.incorrect { color: #8b3d17; }
footer { margin-top: 64px; padding-block: 28px; color: #53665d; font-size: .85rem; line-height: 1.6; border-top: 1px solid #dce3d7; }
.skip-link { position: absolute; top: -80px; left: 16px; padding: 12px; background: white; z-index: 1; }
.skip-link:focus { top: 12px; }
@media (max-width: 700px) { .courses, .lesson-grid { grid-template-columns: 1fr; } .hero { padding-top: 30px; } header, .section-heading { flex-wrap: wrap; } .course, .study-panel, .practice-panel { padding: 22px; } }
/* Interactive demo */
html { scroll-padding-top: 20px; }
body { min-height: 100vh; }
.demo-banner { padding: 10px 20px; text-align: center; font-size: .8rem; background: #e8eedf; color: #304e3c; line-height: 1.5; }
.brand span { color: #578264; }
nav { display: flex; gap: 20px; align-items: center; flex-wrap: wrap; font-size: .9rem; }
nav a { text-decoration: none; padding-block: 10px; }
nav a[aria-current] { text-decoration: underline; text-underline-offset: 6px; font-weight: 700; }
button:disabled { cursor: default; opacity: .65; }
.secondary, .danger { border: 1px solid #b9cbbb; border-radius: 8px; padding: 10px 16px; background: #fff; color: #183f30; }
.secondary:hover { background: #edf3e8; }
.danger { color: #8b3422; border-color: #d6b3a9; }
.hero { display: grid; grid-template-columns: 1fr 260px; align-items: center; gap: 32px; }
.hero-note { padding: 32px; border-radius: 80px 16px 16px 16px; background: #e4eddc; line-height: 1.6; }
.hero-note strong { display: block; }.hero-note p, .hero-note a { font-size: .85rem; }
.big-number { font-size: 5rem; font-weight: 750; line-height: 1.2; letter-spacing: -.08em; }
.view:not(#library) { padding-top: 32px; min-height: 55vh; }
.view:not(#library) h1 { font-size: clamp(2rem, 5vw, 3.25rem); }
.catalogue-controls { display: flex; justify-content: space-between; gap: 24px; align-items: center; }
.search-label { font-size: .8rem; color: #53665d; min-width: 250px; }
input:not([type=radio]), select { width: 100%; height: auto; padding: 12px; border: 1px solid #bac9bb; border-radius: 8px; font: inherit; color: #18342d; background: #fff; margin: 6px 0 12px; }
.skill-button { display: block; text-decoration: none; }
.skill-tag { display: inline-block; font-size: .72rem; padding: 4px 8px; margin-top: 10px; background: #edf3e7; border-radius: 5px; color: #38533e; }
.panel { padding: 28px; border-radius: 16px; border: 1px solid #dde5da; background: #fff; line-height: 1.7; }
.study-panel h2 { font-size: 1.2rem; letter-spacing: 0; }
.back-link { display: inline-block; margin: 10px 0 20px; }
.button-row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.button-row .text-button { margin: 0; }
figure { margin: 24px 0; }figure img { width: 100%; height: auto; border: 1px solid #dde5da; border-radius: 12px; }figcaption { font-size: .8rem; color: #53665d; line-height: 1.6; margin-top: 8px; }
.video-placeholder { margin-top: 24px; padding-top: 20px; border-top: 1px solid #dde5da; font-size: .85rem; }summary { cursor: pointer; font-weight: 650; }
.stats { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; }
.stat { padding: 24px; border-radius: 14px; background: #e6eedf; display: grid; gap: 8px; }
.stat strong { font-size: 2rem; }.stat span { color: #46604d; font-size: .9rem; }
.history-panel { margin-top: 24px; }.progress-row { padding: 14px 0; border-bottom: 1px solid #e4e9e0; display: flex; justify-content: space-between; gap: 20px; }.progress-row:last-child { border: 0; }
.link-button { text-decoration: none; display: inline-block; }.stack { display: grid; gap: 12px; margin-block: 20px; }
.price { font-size: 1.8rem; font-weight: 750; letter-spacing: -.04em; }.plan-card h2 { margin-top: 24px; }.plan-card ul { padding-left: 20px; }
.subscription-state { font-weight: 700; }#subscription-details { display: grid; gap: 12px; }
.notification:not(:empty), .warning:not(:empty) { padding: 12px 16px; border-radius: 8px; background: #e6efdf; font-size: .9rem; line-height: 1.6; }.warning:not(:empty) { background: #fff0db; color: #763d13; }
#notification:empty { margin: 0; }
footer { display: flex; justify-content: space-between; gap: 20px; align-items: center; }footer > div { display: flex; gap: 24px; align-items: center; }footer .text-button { font-size: .85rem; margin: 0; }
dialog { color: #18342d; width: min(560px, calc(100% - 32px)); max-height: 88vh; border: 1px solid #c7d3c2; border-radius: 18px; padding: 28px; background: #f9faf6; box-shadow: 0 20px 80px #18342d30; }dialog::backdrop { background: #10281fcc; }dialog p { line-height: 1.65; }.dialog-heading { display: flex; justify-content: space-between; align-items: start; gap: 16px; }.dialog-heading h2 { font-size: 1.5rem; }dialog h3 { margin-top: 24px; }dialog form { margin-block: 20px; }#profile-list { display: flex; gap: 10px; flex-wrap: wrap; }#current-account > button { margin: 0 10px 10px 0; }#account-error { color: #8b3422; }.file-label { font-size: .9rem; }
@media (max-width: 800px) { .hero { grid-template-columns: 1fr; }.hero-note { display: none; }header { flex-wrap: wrap; }nav { gap: 14px; }.catalogue-controls { flex-direction: column; align-items: stretch; gap: 0; }.filters { margin-bottom: 10px; }footer, footer > div { flex-wrap: wrap; }.progress-row { flex-direction: column; gap: 4px; } }
@media (max-width: 480px) { .container { padding-inline: 18px; }.stats { grid-template-columns: 1fr; gap: 10px; }.stat { display: flex; justify-content: space-between; align-items: center; }.stat strong { font-size: 1.6rem; }nav { width: 100%; font-size: .8rem; }#account-button { max-width: 100%; overflow-wrap: anywhere; }.panel { padding: 22px; }dialog { padding: 22px; } }
@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; } }
.unit-group { border-top: 1px solid #dde5da; padding-block: 12px; }
.unit-group summary { padding: 6px 0; line-height: 1.5; font-size: .95rem; }
.unit-group ul { margin-top: 8px; }
.lesson-selector { max-width: 640px; margin-bottom: 24px; }
.lesson-selector label { font-size: .85rem; }
#explanation, #example { white-space: pre-line; }
.skill-summary { overflow-wrap: anywhere; }