:root {
    --basics-amber: #ffd166;
    --basics-cyan: #20d5ff;
    --basics-violet: #ad7dff;
    --basics-ink: #070a10;
    --basics-panel: #0d111b;
    --basics-panel-soft: #111724;
    --basics-text: #f4f7fb;
    --basics-muted: #98a3b7;
    --basics-line: rgba(255, 255, 255, 0.09);
}

/* Courses-page gateway */
.basics-gateway {
    position: relative;
    z-index: 2;
    padding: 6px 20px 46px;
}

.basics-gateway-shell {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
    overflow: hidden;
    border: 1px solid rgba(255, 209, 102, 0.24);
    border-radius: 28px;
    background:
        linear-gradient(90deg, rgba(255, 209, 102, 0.045) 1px, transparent 1px) 0 0 / 56px 56px,
        linear-gradient(rgba(255, 209, 102, 0.045) 1px, transparent 1px) 0 0 / 56px 56px,
        #090d15;
    box-shadow: 0 30px 90px rgba(0, 0, 0, 0.34), inset 0 1px rgba(255, 255, 255, 0.04);
}

.basics-gateway-shell::before {
    content: 'A   B   C   D   E   F   G   H';
    position: absolute;
    inset-inline: 34px;
    top: 11px;
    direction: ltr;
    color: rgba(255, 209, 102, 0.25);
    font: 700 0.63rem/1 'Space Grotesk', 'Cairo', sans-serif;
    letter-spacing: 0.36em;
    white-space: pre;
    pointer-events: none;
}

.basics-gateway-intro {
    display: grid;
    grid-template-columns: minmax(270px, 0.8fr) minmax(390px, 1.2fr);
    gap: 32px;
    align-items: center;
    padding: 50px 44px 34px;
    border-bottom: 1px solid var(--basics-line);
}

[dir="ltr"] .basics-gateway-intro {
    grid-template-columns: minmax(390px, 1.2fr) minmax(270px, 0.8fr);
}

[dir="ltr"] .basics-gateway-copy { order: -1; }

.basics-coach-note {
    display: flex;
    gap: 16px;
    align-items: center;
    min-height: 124px;
    padding: 18px;
    border: 1px solid rgba(32, 213, 255, 0.16);
    border-radius: 20px 20px 6px 20px;
    background: rgba(9, 15, 25, 0.82);
}

[dir="ltr"] .basics-coach-note { border-radius: 20px 20px 20px 6px; }

.basics-coach-avatar {
    position: relative;
    flex: 0 0 76px;
    width: 76px;
    height: 76px;
    padding: 3px;
    border: 1px solid rgba(32, 213, 255, 0.4);
    border-radius: 18px;
    background: #080c13;
}

.basics-coach-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 14px;
}

.basics-coach-online {
    position: absolute;
    right: -4px;
    bottom: -4px;
    width: 14px;
    height: 14px;
    border: 3px solid #090d15;
    border-radius: 50%;
    background: #36d399;
}

.basics-coach-label {
    display: block;
    margin-bottom: 5px;
    color: var(--basics-cyan);
    font-size: 0.72rem;
    font-weight: 900;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.basics-coach-note p {
    margin: 0;
    color: #dce3ef;
    font-size: 0.92rem;
    font-weight: 600;
    line-height: 1.8;
}

.basics-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--basics-amber);
    font-size: 0.78rem;
    font-weight: 900;
    letter-spacing: 0.08em;
}

.basics-gateway-copy h2 {
    margin: 8px 0 10px;
    color: var(--basics-text);
    font-size: clamp(2rem, 4vw, 3.15rem);
    font-weight: 900;
    letter-spacing: -0.045em;
    line-height: 1.1;
}

.basics-gateway-copy > p {
    max-width: 660px;
    margin: 0;
    color: var(--basics-muted);
    font-size: 0.98rem;
    line-height: 1.9;
}

.basics-gateway-actions {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-top: 22px;
}

.basics-primary-action {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    min-height: 46px;
    padding: 0 20px;
    border: 1px solid rgba(32, 213, 255, 0.35);
    border-radius: 12px;
    background: rgba(32, 213, 255, 0.1);
    color: var(--basics-cyan);
    font-size: 0.86rem;
    font-weight: 900;
    text-decoration: none;
    transition: transform 180ms ease, background 180ms ease, border-color 180ms ease;
}

.basics-primary-action:hover {
    transform: translateY(-2px);
    border-color: var(--basics-cyan);
    background: rgba(32, 213, 255, 0.16);
}

[dir="ltr"] .basics-primary-action i { transform: rotate(180deg); }

.basics-progress-label {
    color: var(--basics-muted);
    font: 800 0.78rem/1 'Space Grotesk', 'Cairo', sans-serif;
}

.basics-piece-courses {
    display: grid;
    grid-template-columns: repeat(6, minmax(0, 1fr));
}

.basics-piece-card {
    position: relative;
    display: grid;
    min-height: 194px;
    padding: 22px 18px 18px;
    border-inline-start: 1px solid var(--basics-line);
    color: inherit;
    text-align: center;
    text-decoration: none;
    transition: background 180ms ease, transform 180ms ease;
}

.basics-piece-card:first-child { border-inline-start: 0; }

.basics-piece-card:hover,
.basics-piece-card:focus-visible {
    z-index: 1;
    outline: none;
    background: rgba(255, 209, 102, 0.065);
    transform: translateY(-4px);
}

.basics-card-order {
    position: absolute;
    top: 12px;
    inset-inline-start: 14px;
    color: rgba(255, 255, 255, 0.24);
    font: 700 0.64rem/1 'Space Grotesk', 'Cairo', sans-serif;
}

.basics-piece-mark {
    position: relative;
    display: grid;
    place-items: center;
    width: 72px;
    height: 72px;
    margin: 4px auto 12px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    background:
        conic-gradient(from 90deg, #141a26 25%, #0b1019 0 50%, #141a26 0 75%, #0b1019 0) 0 0 / 28px 28px;
}

.basics-piece-mark b {
    position: relative;
    z-index: 2;
    color: #fff;
    font: 400 2.65rem/1 Georgia, serif;
    filter: drop-shadow(0 3px 8px rgba(0, 0, 0, 0.55));
}

/* Real board piece art (pises set) on the six piece-lesson cards. */
.basics-piece-mark .basics-piece-art {
    position: relative;
    z-index: 2;
    width: 52px;
    height: 52px;
    object-fit: contain;
    filter: drop-shadow(0 3px 8px rgba(0, 0, 0, 0.55));
}

.basics-piece-mark i {
    position: absolute;
    top: 3px;
    right: 6px;
    color: var(--basics-amber);
    font: 800 1rem/1 'Space Grotesk', sans-serif;
    opacity: 0.82;
}

.basics-piece-name {
    color: var(--basics-text);
    font-size: 0.95rem;
    font-weight: 900;
}

.basics-piece-topic {
    margin-top: 3px;
    color: var(--basics-muted);
    font-size: 0.71rem;
    font-weight: 600;
    line-height: 1.55;
}

.basics-card-state {
    position: absolute;
    top: 11px;
    inset-inline-end: 13px;
    color: rgba(255, 255, 255, 0.24);
    font-size: 0.7rem;
}

.basics-piece-card.is-complete .basics-card-state { color: #36d399; }
.basics-piece-card.is-complete .basics-piece-mark { border-color: rgba(54, 211, 153, 0.45); }

.basics-curriculum {
    display: grid;
    gap: 28px;
    padding: 28px 30px 34px;
}

.basics-curriculum-section {
    display: grid;
    gap: 14px;
}

.basics-curriculum-section + .basics-curriculum-section {
    padding-top: 26px;
    border-top: 1px solid var(--basics-line);
}

.basics-curriculum-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 18px;
    padding-inline: 2px;
    text-align: start;
}

.basics-curriculum-heading h3 {
    margin: 0;
    color: var(--basics-text);
    font-size: 1.05rem;
    font-weight: 900;
}

.basics-curriculum-heading p {
    margin: 3px 0 0;
    color: var(--basics-muted);
    font-size: 0.72rem;
    font-weight: 600;
}

.basics-curriculum-heading > span {
    flex: 0 0 auto;
    color: rgba(255, 209, 102, 0.78);
    font: 800 0.67rem/1 'Space Grotesk', 'Cairo', sans-serif;
}

.basics-curriculum .basics-curriculum-grid {
    display: grid;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 10px;
}

.basics-curriculum .section-rules .basics-curriculum-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.basics-curriculum .section-advanced .basics-curriculum-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.basics-curriculum .basics-curriculum-card,
.basics-curriculum .basics-curriculum-card:first-child {
    min-height: 182px;
    padding: 20px 12px 30px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 15px;
    background: rgba(255, 255, 255, 0.025);
}

.basics-curriculum .basics-curriculum-card:hover,
.basics-curriculum .basics-curriculum-card:focus-visible {
    border-color: rgba(255, 209, 102, 0.28);
    background: rgba(255, 209, 102, 0.055);
}

.basics-curriculum .basics-piece-mark {
    width: 64px;
    height: 64px;
    margin-bottom: 9px;
}

.basics-curriculum .basics-piece-mark b { font-size: 2.25rem; }

.basics-curriculum .basics-piece-mark .basics-piece-art { width: 46px; height: 46px; }

.basics-curriculum .basics-piece-mark.is-concept b {
    font-family: 'Space Grotesk', 'Cairo', sans-serif;
    font-size: 2rem;
    font-weight: 800;
}

.basics-curriculum .basics-piece-mark.is-notation b {
    font-size: 1.1rem;
    letter-spacing: -0.06em;
}

.basics-curriculum .basics-piece-mark i {
    font-size: 0.6rem;
    font-style: normal;
    letter-spacing: -0.03em;
}

.basics-card-exercises {
    position: absolute;
    bottom: 10px;
    inset-inline-start: 12px;
    direction: ltr;
    color: rgba(255, 255, 255, 0.3);
    font: 800 0.61rem/1 'Space Grotesk', 'Cairo', sans-serif;
}

.basics-curriculum-card.is-complete .basics-card-exercises { color: #36d399; }

.advanced-course-divider {
    display: flex;
    align-items: center;
    gap: 18px;
    max-width: 1200px;
    margin: 0 auto 22px;
    padding: 0 20px;
    color: var(--basics-muted);
    font-size: 0.78rem;
    font-weight: 800;
}

.advanced-course-divider::before,
.advanced-course-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: rgba(255, 255, 255, 0.08);
}

/* Dedicated piece-movement course */
body.basics-course-page {
    min-height: 100vh;
    background:
        radial-gradient(circle at 78% 14%, rgba(32, 213, 255, 0.07), transparent 28%),
        #05070c;
    color: var(--basics-text);
}

.basics-course-topbar {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 72px;
    padding: 0 max(20px, calc((100vw - 1280px) / 2));
    border-bottom: 1px solid var(--basics-line);
    background: rgba(5, 7, 12, 0.88);
    backdrop-filter: blur(18px);
}

.basics-course-brand,
.basics-back-link {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--basics-text);
    font-weight: 900;
    text-decoration: none;
}

.basics-course-brand img { width: 34px; height: 34px; border-radius: 50%; }

.basics-back-link {
    color: var(--basics-muted);
    font-size: 0.82rem;
}

.basics-back-link:hover { color: var(--basics-cyan); }
[dir="ltr"] .basics-back-link i { transform: rotate(180deg); }

.basics-course-top-actions { display: flex; align-items: center; gap: 12px; }

.basics-lang-button {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    border: 1px solid var(--basics-line);
    border-radius: 11px;
    background: rgba(255, 255, 255, 0.035);
    color: var(--basics-text);
    cursor: pointer;
}

.basics-course-layout {
    display: grid;
    grid-template-columns: 248px minmax(0, 1fr);
    gap: 30px;
    width: min(1280px, calc(100% - 40px));
    margin: 0 auto;
    padding: 38px 0 80px;
}

[dir="rtl"] .basics-course-layout { grid-template-columns: minmax(0, 1fr) 248px; }
[dir="rtl"] .basics-lesson-rail { grid-column: 2; }
[dir="rtl"] .basics-lesson-content { grid-column: 1; grid-row: 1; }

.basics-lesson-rail {
    position: sticky;
    top: 102px;
    align-self: start;
    overflow: hidden;
    border: 1px solid var(--basics-line);
    border-radius: 20px;
    background: rgba(13, 17, 27, 0.88);
}

.basics-rail-heading { padding: 20px 20px 15px; border-bottom: 1px solid var(--basics-line); }
.basics-rail-heading span { color: var(--basics-amber); font-size: 0.7rem; font-weight: 900; letter-spacing: 0.09em; }
.basics-rail-heading strong { display: block; margin-top: 4px; font-size: 1.05rem; }

.basics-lesson-nav { display: grid; padding: 8px; }

.basics-lesson-link {
    display: grid;
    grid-template-columns: 38px 1fr auto;
    gap: 10px;
    align-items: center;
    min-height: 56px;
    padding: 6px 10px;
    border: 1px solid transparent;
    border-radius: 12px;
    color: var(--basics-muted);
    text-decoration: none;
}

.basics-lesson-link:hover { color: var(--basics-text); background: rgba(255, 255, 255, 0.035); }
.basics-lesson-link.is-active { border-color: rgba(32, 213, 255, 0.2); background: rgba(32, 213, 255, 0.07); color: var(--basics-text); }
.basics-lesson-link.is-complete .basics-nav-state { color: #36d399; }
.basics-nav-piece { color: #fff; font: 400 1.85rem/1 Georgia, serif; text-align: center; }
.basics-nav-copy small { display: block; color: var(--basics-muted); font-size: 0.66rem; }
.basics-nav-copy strong { font-size: 0.8rem; }
.basics-nav-state { color: rgba(255, 255, 255, 0.18); font-size: 0.68rem; }

.basics-lesson-content { min-width: 0; }

.basics-lesson-hero {
    position: relative;
    overflow: hidden;
    padding: clamp(26px, 5vw, 54px);
    border: 1px solid var(--basics-line);
    border-radius: 26px;
    background: #0b1019;
}

.basics-lesson-hero::after {
    content: attr(data-piece);
    position: absolute;
    inset-inline-end: 30px;
    top: -34px;
    color: rgba(255, 255, 255, 0.035);
    font: 400 14rem/1 Georgia, serif;
    pointer-events: none;
}

.basics-lesson-kicker { color: var(--basics-amber); font-size: 0.74rem; font-weight: 900; letter-spacing: 0.1em; }
.basics-lesson-hero h1 { position: relative; z-index: 1; margin: 8px 0 10px; font-size: clamp(2.2rem, 6vw, 4.8rem); line-height: 1; letter-spacing: -0.055em; }
.basics-lesson-hero p { position: relative; z-index: 1; max-width: 700px; margin: 0; color: var(--basics-muted); line-height: 1.9; }

.basics-practice-grid {
    display: grid;
    grid-template-columns: minmax(320px, 560px) minmax(260px, 1fr);
    gap: 24px;
    margin-top: 24px;
}

.basics-board-panel,
.basics-rule-panel,
.basics-course-coach {
    border: 1px solid var(--basics-line);
    border-radius: 22px;
    background: rgba(13, 17, 27, 0.9);
}

.basics-board-panel { padding: clamp(14px, 2vw, 22px); }

.basics-board-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 14px;
}

.basics-board-toolbar strong { font-size: 0.9rem; }
.basics-board-progress { color: var(--basics-cyan); font: 800 0.76rem/1 'Space Grotesk', sans-serif; }

.basics-board {
    direction: ltr;
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    width: 100%;
    aspect-ratio: 1;
    overflow: hidden;
    border: 3px solid #202838;
    border-radius: 12px;
    background: #111827;
    box-shadow: 0 18px 48px rgba(0, 0, 0, 0.32);
}

.basics-square {
    position: relative;
    display: grid;
    place-items: center;
    min-width: 0;
    padding: 0;
    border: 0;
    background: #d9e2ea;
    color: #17202d;
    cursor: pointer;
}

.basics-square.is-dark { background: #526579; }
.basics-square:focus-visible { z-index: 5; outline: 3px solid var(--basics-cyan); outline-offset: -3px; }
.basics-square-piece { position: relative; z-index: 2; font: 400 clamp(1.7rem, 5vw, 4rem)/1 Georgia, serif; filter: drop-shadow(0 3px 2px rgba(0, 0, 0, 0.3)); }
.basics-square-piece.is-white { color: #fff; -webkit-text-stroke: 1px rgba(0, 0, 0, 0.75); }
.basics-square-piece.is-black { color: #111827; -webkit-text-stroke: 1px rgba(255, 255, 255, 0.3); }

.basics-square.is-legal::after,
.basics-square.is-found::after {
    content: '';
    position: absolute;
    z-index: 1;
    width: 24%;
    aspect-ratio: 1;
    border-radius: 50%;
    background: rgba(17, 24, 39, 0.38);
}

.basics-board:not(.show-hints) .basics-square.is-legal:not(.is-found)::after { display: none; }
.basics-square.is-found::after { width: 52%; border: 3px solid rgba(54, 211, 153, 0.9); background: rgba(54, 211, 153, 0.22); }
.basics-square.has-capture.is-legal::after { width: 74%; border: 4px solid rgba(255, 209, 102, 0.8); background: transparent; }
.basics-square.is-wrong { animation: basicsWrong 320ms ease; box-shadow: inset 0 0 0 4px rgba(255, 92, 120, 0.8); }

.basics-square-coordinate {
    position: absolute;
    right: 3px;
    bottom: 2px;
    color: currentColor;
    font: 800 clamp(0.42rem, 1vw, 0.62rem)/1 'Space Grotesk', sans-serif;
    opacity: 0.58;
}

.basics-board-actions { display: flex; gap: 10px; margin-top: 14px; }
.basics-board-button {
    min-height: 40px;
    padding: 0 14px;
    border: 1px solid var(--basics-line);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.035);
    color: var(--basics-text);
    font-family: inherit;
    font-size: 0.75rem;
    font-weight: 800;
    cursor: pointer;
}
.basics-board-button:hover { border-color: rgba(32, 213, 255, 0.4); color: var(--basics-cyan); }

.basics-rule-column { display: grid; align-content: start; gap: 18px; }
.basics-course-coach { display: flex; gap: 14px; align-items: center; padding: 16px; }
.basics-course-coach img { width: 64px; height: 64px; border-radius: 15px; object-fit: cover; border: 1px solid rgba(32, 213, 255, 0.3); }
.basics-course-coach span { color: var(--basics-cyan); font-size: 0.67rem; font-weight: 900; }
.basics-course-coach p { margin: 4px 0 0; color: #dce3ef; font-size: 0.82rem; line-height: 1.75; }

.basics-rule-panel { padding: 20px; }
.basics-rule-panel h2 { margin: 0 0 14px; font-size: 1rem; }
.basics-rule-list { display: grid; gap: 12px; margin: 0; padding: 0; list-style: none; }
.basics-rule-list li { display: grid; grid-template-columns: 24px 1fr; gap: 9px; color: var(--basics-muted); font-size: 0.79rem; line-height: 1.75; }
.basics-rule-list li i { color: var(--basics-amber); margin-top: 6px; font-size: 0.55rem; }

.basics-lesson-complete {
    display: none;
    padding: 18px;
    border: 1px solid rgba(54, 211, 153, 0.28);
    border-radius: 18px;
    background: rgba(54, 211, 153, 0.07);
}
.basics-lesson-complete.is-visible { display: block; }
.basics-lesson-complete strong { display: block; color: #70e0af; }
.basics-lesson-complete p { margin: 5px 0 13px; color: var(--basics-muted); font-size: 0.78rem; }
.basics-next-link { display: inline-flex; align-items: center; gap: 8px; color: var(--basics-cyan); font-size: 0.78rem; font-weight: 900; text-decoration: none; }

@keyframes basicsWrong {
    0%, 100% { transform: translateX(0); }
    35% { transform: translateX(-5px); }
    70% { transform: translateX(5px); }
}

@media (max-width: 1050px) {
    .basics-piece-courses { grid-template-columns: repeat(3, 1fr); }
    .basics-piece-card:nth-child(4) { border-inline-start: 0; }
    .basics-piece-card:nth-child(n + 4) { border-top: 1px solid var(--basics-line); }
    .basics-curriculum .basics-curriculum-grid,
    .basics-curriculum .section-rules .basics-curriculum-grid,
    .basics-curriculum .section-advanced .basics-curriculum-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
    .basics-curriculum .basics-curriculum-card,
    .basics-curriculum .basics-curriculum-card:first-child {
        border: 1px solid rgba(255, 255, 255, 0.08);
    }
    .basics-course-layout,
    [dir="rtl"] .basics-course-layout { grid-template-columns: 1fr; }
    [dir="rtl"] .basics-lesson-rail,
    [dir="rtl"] .basics-lesson-content { grid-column: 1; grid-row: auto; }
    .basics-lesson-rail { position: static; }
    .basics-lesson-nav { grid-template-columns: repeat(6, minmax(120px, 1fr)); overflow-x: auto; }
    .basics-rail-heading { display: none; }
}

@media (max-width: 820px) {
    .basics-gateway-intro,
    [dir="ltr"] .basics-gateway-intro { grid-template-columns: 1fr; padding: 44px 24px 26px; }
    [dir="ltr"] .basics-gateway-copy { order: 0; }
    .basics-coach-note { order: 2; }
    .basics-practice-grid { grid-template-columns: 1fr; }
    .basics-course-topbar { padding-inline: 16px; }
    .basics-course-brand span { display: none; }
}

@media (max-width: 560px) {
    .basics-gateway { padding-inline: 14px; }
    .basics-gateway-shell { border-radius: 22px; }
    .basics-piece-courses { grid-template-columns: repeat(2, 1fr); }
    .basics-piece-card:nth-child(odd) { border-inline-start: 0; }
    .basics-piece-card:nth-child(n + 3) { border-top: 1px solid var(--basics-line); }
    .basics-piece-card:nth-child(4) { border-inline-start: 1px solid var(--basics-line); }
    .basics-curriculum { gap: 22px; padding: 22px 16px 26px; }
    .basics-curriculum-heading { align-items: start; flex-direction: column; gap: 8px; }
    .basics-curriculum .basics-curriculum-grid,
    .basics-curriculum .section-rules .basics-curriculum-grid,
    .basics-curriculum .section-advanced .basics-curriculum-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    .basics-curriculum .basics-curriculum-card,
    .basics-curriculum .basics-curriculum-card:first-child {
        border: 1px solid rgba(255, 255, 255, 0.08);
    }
    .basics-gateway-actions { align-items: flex-start; flex-direction: column; }
    .basics-course-layout { width: min(100% - 24px, 1280px); padding-top: 20px; }
    .basics-lesson-hero { border-radius: 20px; }
    .basics-lesson-hero::after { font-size: 9rem; }
    .basics-board-panel { border-radius: 16px; }
    .basics-back-link span { display: none; }
}

@media (prefers-reduced-motion: reduce) {
    .basics-piece-card,
    .basics-primary-action,
    .basics-square { transition: none; }
    .basics-square.is-wrong { animation: none; }
}