.grammar-v3 {
    --grammar-blue: #155bd7;
    --grammar-blue-dark: #0b3ea8;
    --grammar-cyan: #0ea5c6;
    --grammar-orange: #f59e0b;
    --grammar-green: #159b67;
    --grammar-red: #dc3545;
    --grammar-ink: #172033;
    --grammar-muted: #667085;
    --grammar-line: #e5eaf2;
    --grammar-soft: #f6f9ff;
    max-width: 1240px;
    margin: 0 auto;
    padding: 24px 18px 64px;
    color: var(--grammar-ink);
}

.grammar-v3 a { text-decoration: none; }
.grammar-v3__hero {
    position: relative;
    overflow: hidden;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 32px;
    align-items: center;
    padding: 34px 38px;
    border: 1px solid #dce7fb;
    border-radius: 24px;
    background:
        radial-gradient(circle at 88% 22%, rgba(14,165,198,.13), transparent 34%),
        linear-gradient(135deg, #f7fbff 0%, #eef5ff 57%, #fff8e9 100%);
    box-shadow: 0 18px 50px rgba(35, 66, 120, .08);
}
.grammar-v3__hero::after {
    content: "";
    position: absolute;
    right: -60px;
    bottom: -90px;
    width: 240px;
    height: 240px;
    border: 34px solid rgba(21,91,215,.07);
    border-radius: 50%;
}
.grammar-v3__hero-copy { position: relative; z-index: 1; max-width: 760px; }
.grammar-v3__eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 10px;
    color: var(--grammar-blue-dark);
    font-size: .82rem;
    font-weight: 800;
    letter-spacing: .08em;
    text-transform: uppercase;
}
.grammar-v3__hero h1,
.grammar-v3__topic-hero h1,
.grammar-v3__lesson-header h1 {
    margin: 0;
    color: #102044;
    font-weight: 850;
    letter-spacing: -.035em;
}
.grammar-v3__hero h1 { max-width: 720px; font-size: clamp(2rem, 4vw, 3.35rem); line-height: 1.06; }
.grammar-v3__hero p { max-width: 760px; margin: 16px 0 0; color: #526078; font-size: 1.02rem; line-height: 1.7; }
.grammar-v3__hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.grammar-v3__hero-stats {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: repeat(3, minmax(92px, 1fr));
    overflow: hidden;
    min-width: 330px;
    border: 1px solid rgba(21,91,215,.12);
    border-radius: 18px;
    background: rgba(255,255,255,.84);
    box-shadow: 0 12px 35px rgba(18,60,120,.08);
    backdrop-filter: blur(8px);
}
.grammar-v3__hero-stats > div { padding: 20px 14px; text-align: center; }
.grammar-v3__hero-stats > div + div { border-left: 1px solid var(--grammar-line); }
.grammar-v3__hero-stats strong { display: block; color: var(--grammar-blue-dark); font-size: 1.8rem; line-height: 1; }
.grammar-v3__hero-stats span { display: block; margin-top: 7px; color: var(--grammar-muted); font-size: .78rem; font-weight: 700; }

.grammar-v3__toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 18px;
    margin: 22px 0 30px;
    padding: 16px 18px;
    border: 1px solid var(--grammar-line);
    border-radius: 16px;
    background: #fff;
}
.grammar-v3__toolbar strong { display: block; color: #1f2b44; }
.grammar-v3__toolbar span { display: block; margin-top: 3px; color: var(--grammar-muted); font-size: .86rem; }
.grammar-v3__toolbar--compact { margin-top: 18px; }
.grammar-v3__level-pills { display: flex; flex-wrap: wrap; gap: 7px; }
.grammar-v3__level-pills a {
    min-width: 42px;
    padding: 8px 12px;
    border: 1px solid #d8e1ef;
    border-radius: 999px;
    color: #40506a;
    background: #fff;
    font-size: .82rem;
    font-weight: 800;
    text-align: center;
}
.grammar-v3__level-pills a:hover,
.grammar-v3__level-pills a.is-active { border-color: var(--grammar-blue); color: #fff; background: var(--grammar-blue); }

.grammar-v3__section { margin-top: 30px; }
.grammar-v3__section-heading { display: flex; align-items: end; justify-content: space-between; gap: 16px; margin-bottom: 16px; }
.grammar-v3__section-heading span { display: block; color: var(--grammar-blue); font-size: .76rem; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.grammar-v3__section-heading h2 { margin: 3px 0 0; font-size: 1.55rem; font-weight: 830; }
.grammar-v3__section-heading > a,
.grammar-v3__section-links a,
.grammar-v3__text-link { color: var(--grammar-blue); font-weight: 750; }
.grammar-v3__section-links { display: flex; flex-wrap: wrap; gap: 14px; }

.grammar-v3__topic-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.grammar-v3__topic-card {
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    min-height: 270px;
    padding: 20px;
    border: 1px solid var(--grammar-line);
    border-top: 4px solid var(--grammar-topic-accent, var(--grammar-blue));
    border-radius: 18px;
    background: #fff;
    box-shadow: 0 10px 30px rgba(30, 55, 95, .055);
    transition: transform .18s ease, box-shadow .18s ease;
}
.grammar-v3__topic-card:hover { transform: translateY(-3px); box-shadow: 0 18px 40px rgba(30,55,95,.10); }
.grammar-v3__topic-card-top { display: flex; align-items: center; justify-content: space-between; }
.grammar-v3__topic-number { color: #a9b5c8; font-size: .76rem; font-weight: 800; }
.grammar-v3__topic-icon { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 12px; color: var(--grammar-topic-accent, var(--grammar-blue)); background: color-mix(in srgb, var(--grammar-topic-accent, var(--grammar-blue)) 11%, white); font-size: 1.15rem; }
.grammar-v3__topic-card h3 { margin: 15px 0 8px; font-size: 1.18rem; font-weight: 820; }
.grammar-v3__topic-card h3 a { color: #1c2942; }
.grammar-v3__topic-card p { flex: 1; margin: 0; color: var(--grammar-muted); font-size: .9rem; line-height: 1.58; }
.grammar-v3__topic-meta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 16px; color: #6b7890; font-size: .78rem; }
.grammar-v3__topic-meta span { display: inline-flex; gap: 5px; align-items: center; }
.grammar-v3__topic-cta { display: inline-flex; align-items: center; gap: 6px; margin-top: 14px; color: var(--grammar-topic-accent, var(--grammar-blue)); font-weight: 800; font-size: .88rem; }

.grammar-v3__breadcrumb { display: flex; flex-wrap: wrap; align-items: center; gap: 7px; margin: 0 0 14px; color: #7b879a; font-size: .82rem; }
.grammar-v3__breadcrumb a { color: #52627c; }
.grammar-v3__breadcrumb i { font-size: .65rem; }
.grammar-v3__topic-hero {
    display: flex;
    justify-content: space-between;
    gap: 26px;
    align-items: center;
    padding: 28px 30px;
    border: 1px solid color-mix(in srgb, var(--grammar-topic-accent, #155bd7) 20%, white);
    border-left: 5px solid var(--grammar-topic-accent, #155bd7);
    border-radius: 20px;
    background: linear-gradient(135deg, color-mix(in srgb, var(--grammar-topic-accent, #155bd7) 7%, white), #fff);
}
.grammar-v3__topic-hero h1 { font-size: clamp(1.9rem, 3vw, 2.65rem); }
.grammar-v3__topic-hero p { max-width: 760px; margin: 12px 0 0; color: var(--grammar-muted); line-height: 1.65; }
.grammar-v3__topic-hero-actions { display: grid; gap: 9px; min-width: 180px; }

.grammar-v3__section-stack { display: grid; gap: 15px; }
.grammar-v3__section-card { overflow: hidden; border: 1px solid var(--grammar-line); border-radius: 18px; background: #fff; }
.grammar-v3__section-card > header { display: flex; justify-content: space-between; align-items: center; gap: 20px; padding: 20px; background: #fbfcff; }
.grammar-v3__section-card > header span { color: var(--grammar-blue); font-size: .76rem; font-weight: 800; text-transform: uppercase; letter-spacing: .06em; }
.grammar-v3__section-card > header h3 { margin: 3px 0 4px; font-size: 1.18rem; font-weight: 820; }
.grammar-v3__section-card > header p { margin: 0; color: var(--grammar-muted); font-size: .87rem; }
.grammar-v3__section-card > header > a { white-space: nowrap; color: var(--grammar-blue); font-weight: 800; font-size: .84rem; }
.grammar-v3__lesson-list { border-top: 1px solid var(--grammar-line); }
.grammar-v3__lesson-list--standalone { overflow: hidden; border: 1px solid var(--grammar-line); border-radius: 18px; background: #fff; }
.grammar-v3__lesson-row { display: grid; grid-template-columns: 38px minmax(0, 1fr) auto; gap: 12px; align-items: center; padding: 14px 17px; color: inherit; }
.grammar-v3__lesson-row + .grammar-v3__lesson-row { border-top: 1px solid #edf0f5; }
.grammar-v3__lesson-row:hover { background: #f7faff; }
.grammar-v3__lesson-status,
.grammar-v3__lesson-index { display: grid; place-items: center; width: 31px; height: 31px; border: 1px solid #dce4ef; border-radius: 50%; color: #9aa7ba; background: #fff; font-size: .8rem; font-weight: 800; }
.grammar-v3__lesson-row.is-completed .grammar-v3__lesson-status,
.grammar-v3__lesson-row.is-completed .grammar-v3__lesson-index { border-color: #bce8d6; color: var(--grammar-green); background: #eaf9f2; }
.grammar-v3__lesson-copy { min-width: 0; }
.grammar-v3__lesson-copy strong { display: block; color: #24314b; font-size: .94rem; }
.grammar-v3__lesson-copy small { display: block; overflow: hidden; margin-top: 3px; color: #7b8799; text-overflow: ellipsis; white-space: nowrap; }
.grammar-v3__lesson-meta { display: flex; align-items: center; gap: 10px; color: #7a879a; font-size: .75rem; }
.grammar-v3__lesson-meta b { padding: 4px 7px; border-radius: 999px; color: #0f55c8; background: #eaf2ff; }
.grammar-v3__section-empty { padding: 16px 20px; border-top: 1px solid var(--grammar-line); color: var(--grammar-muted); font-size: .86rem; }

.grammar-v3__empty { padding: 26px; border: 1px dashed #cfd8e6; border-radius: 16px; color: var(--grammar-muted); background: #fbfcfe; text-align: center; }
.grammar-v3__empty--small { padding: 18px; font-size: .87rem; }

.grammar-v3__lesson-layout { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 22px; align-items: start; }
.grammar-v3__lesson-article { overflow: hidden; border: 1px solid var(--grammar-line); border-radius: 20px; background: #fff; box-shadow: 0 12px 35px rgba(32,55,90,.055); }
.grammar-v3__lesson-header { padding: 28px 32px; border-bottom: 1px solid var(--grammar-line); background: linear-gradient(145deg, #f8fbff, #fff); }
.grammar-v3__lesson-header h1 { margin-top: 11px; font-size: clamp(1.8rem, 3vw, 2.55rem); }
.grammar-v3__lesson-header p { margin: 11px 0 0; color: var(--grammar-muted); font-size: .98rem; line-height: 1.65; }
.grammar-v3__lesson-badges { display: flex; flex-wrap: wrap; gap: 8px; }
.grammar-v3__lesson-badges span { display: inline-flex; gap: 5px; align-items: center; padding: 6px 9px; border-radius: 999px; color: #345071; background: #edf4ff; font-size: .74rem; font-weight: 800; }
.grammar-v3__rich-content { padding: 30px 32px; color: #2c374d; font-size: 1rem; line-height: 1.78; }
.grammar-v3__rich-content h2,
.grammar-v3__rich-content h3 { margin-top: 1.6em; color: #152443; font-weight: 820; }
.grammar-v3__rich-content h2:first-child,
.grammar-v3__rich-content h3:first-child { margin-top: 0; }
.grammar-v3__rich-content table { width: 100%; margin: 18px 0; border-collapse: collapse; }
.grammar-v3__rich-content th,
.grammar-v3__rich-content td { padding: 10px 12px; border: 1px solid #dfe5ee; vertical-align: top; }
.grammar-v3__rich-content th { background: #f4f7fb; }
.grammar-v3__rich-content blockquote { margin: 18px 0; padding: 14px 18px; border-left: 4px solid var(--grammar-orange); border-radius: 0 10px 10px 0; background: #fff8e8; }
.grammar-v3__lesson-complete { display: flex; align-items: center; justify-content: space-between; gap: 20px; margin: 0 32px 26px; padding: 18px; border: 1px solid #dfe8f4; border-radius: 15px; background: #f8fbff; }
.grammar-v3__lesson-complete strong { display: block; }
.grammar-v3__lesson-complete span { display: block; margin-top: 3px; color: var(--grammar-muted); font-size: .84rem; }
.grammar-v3__lesson-nav { display: grid; grid-template-columns: 1fr 1fr; border-top: 1px solid var(--grammar-line); }
.grammar-v3__lesson-nav > a { display: flex; flex-direction: column; gap: 4px; padding: 18px 24px; color: #27364f; }
.grammar-v3__lesson-nav > a + a { border-left: 1px solid var(--grammar-line); }
.grammar-v3__lesson-nav > a.is-next { align-items: end; text-align: right; }
.grammar-v3__lesson-nav small { color: var(--grammar-blue); font-weight: 800; }
.grammar-v3__lesson-sidebar { position: sticky; top: 90px; display: grid; gap: 14px; }
.grammar-v3__sidebar-card { padding: 20px; border: 1px solid var(--grammar-line); border-radius: 17px; background: #fff; }
.grammar-v3__sidebar-card--practice { background: linear-gradient(160deg, #f2f7ff, #fff); }
.grammar-v3__sidebar-card > span { color: var(--grammar-blue); font-size: .74rem; font-weight: 800; text-transform: uppercase; }
.grammar-v3__sidebar-card h2 { margin: 5px 0 8px; font-size: 1.12rem; font-weight: 820; }
.grammar-v3__sidebar-card p { margin: 0 0 14px; color: var(--grammar-muted); font-size: .86rem; line-height: 1.55; }
.grammar-v3__sidebar-card .btn + .btn { margin-top: 8px; }

.grammar-v3__guest-note { display: inline-flex; gap: 7px; align-items: center; margin-top: 16px; padding: 9px 12px; border-radius: 10px; color: #745112; background: #fff2cf; font-size: .82rem; }
.grammar-v3__progress-grid { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 12px; margin: 20px 0; }
.grammar-v3__progress-grid > div { padding: 17px; border: 1px solid var(--grammar-line); border-radius: 15px; background: #fff; }
.grammar-v3__progress-grid span { display: block; color: var(--grammar-muted); font-size: .77rem; font-weight: 700; }
.grammar-v3__progress-grid strong { display: inline-block; margin-top: 8px; color: var(--grammar-blue-dark); font-size: 1.7rem; }
.grammar-v3__progress-grid small { display: block; margin-top: 3px; color: #8a95a5; font-size: .72rem; }
.grammar-v3__progress-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.grammar-v3__progress-panel { padding: 20px; border: 1px solid var(--grammar-line); border-radius: 18px; background: #fff; }
.grammar-v3__progress-panel--wide { margin-top: 16px; }
.grammar-v3__weak-list,
.grammar-v3__attempt-list { display: grid; gap: 9px; }
.grammar-v3__weak-item,
.grammar-v3__attempt-item { display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 12px 13px; border: 1px solid #edf0f5; border-radius: 12px; background: #fbfcfe; }
.grammar-v3__weak-item strong,
.grammar-v3__attempt-item strong { display: block; color: #27364e; font-size: .88rem; }
.grammar-v3__weak-item span,
.grammar-v3__attempt-item span { display: block; margin-top: 2px; color: #8a95a5; font-size: .73rem; }
.grammar-v3__weak-item > div:last-child { text-align: right; }
.grammar-v3__weak-item b { color: var(--grammar-red); font-size: 1rem; }
.grammar-v3__weak-item small { display: block; color: #8a95a5; font-size: .7rem; }
.grammar-v3__attempt-item > b { color: var(--grammar-blue); font-size: 1.1rem; }
.grammar-v3__completed-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }
.grammar-v3__completed-grid > a { display: flex; gap: 10px; align-items: center; padding: 12px; border: 1px solid #e7ecf3; border-radius: 12px; color: inherit; background: #fff; }
.grammar-v3__completed-grid > a:hover { border-color: #c8d9f5; background: #f8fbff; }
.grammar-v3__completed-grid > a > span { color: var(--grammar-green); font-size: 1.15rem; }
.grammar-v3__completed-grid strong { display: block; color: #27364e; font-size: .84rem; }
.grammar-v3__completed-grid small { display: block; margin-top: 2px; color: #8a95a5; font-size: .7rem; }

@media (max-width: 991.98px) {
    .grammar-v3__hero { grid-template-columns: 1fr; padding: 28px; }
    .grammar-v3__hero-stats { min-width: 0; width: 100%; }
    .grammar-v3__topic-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .grammar-v3__lesson-layout { grid-template-columns: 1fr; }
    .grammar-v3__lesson-sidebar { position: static; grid-template-columns: 1fr 1fr; }
    .grammar-v3__progress-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 767.98px) {
    .grammar-v3 { padding: 14px 11px 44px; }
    .grammar-v3__hero { padding: 23px 19px; border-radius: 18px; }
    .grammar-v3__hero h1 { font-size: 2rem; }
    .grammar-v3__toolbar,
    .grammar-v3__topic-hero,
    .grammar-v3__section-card > header,
    .grammar-v3__lesson-complete { align-items: stretch; flex-direction: column; }
    .grammar-v3__toolbar { display: grid; }
    .grammar-v3__topic-hero { display: grid; padding: 22px 19px; }
    .grammar-v3__topic-hero-actions { min-width: 0; }
    .grammar-v3__topic-grid { grid-template-columns: 1fr; }
    .grammar-v3__section-heading { align-items: start; flex-direction: column; }
    .grammar-v3__lesson-row { grid-template-columns: 34px minmax(0,1fr); padding: 13px 12px; }
    .grammar-v3__lesson-meta { grid-column: 2; justify-content: flex-start; }
    .grammar-v3__lesson-copy small { white-space: normal; }
    .grammar-v3__lesson-header,
    .grammar-v3__rich-content { padding: 22px 18px; }
    .grammar-v3__lesson-complete { margin: 0 18px 20px; }
    .grammar-v3__lesson-nav { grid-template-columns: 1fr; }
    .grammar-v3__lesson-nav > a + a { border-top: 1px solid var(--grammar-line); border-left: 0; }
    .grammar-v3__lesson-sidebar { grid-template-columns: 1fr; }
    .grammar-v3__progress-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
    .grammar-v3__progress-layout { grid-template-columns: 1fr; }
    .grammar-v3__completed-grid { grid-template-columns: 1fr; }
}

@media (max-width: 440px) {
    .grammar-v3__hero-stats { grid-template-columns: 1fr; }
    .grammar-v3__hero-stats > div + div { border-top: 1px solid var(--grammar-line); border-left: 0; }
    .grammar-v3__progress-grid { grid-template-columns: 1fr; }
}