:root {
    --bg: #07090d;
    --surface: #0d1118;
    --surface-2: #111720;
    --surface-3: #151c27;
    --border: rgba(255, 255, 255, 0.08);
    --border-strong: rgba(255, 255, 255, 0.16);
    --text: #f2f5f9;
    --text-soft: #c1c9d4;
    --muted: #818b99;
    --muted-2: #5f6977;
    --accent: #dfe6f3;
    --accent-dark: #080a0f;
    --blue: #7aa2ff;
    --blue-soft: rgba(122, 162, 255, 0.12);
    --green: #57d39a;
    --green-soft: rgba(87, 211, 154, 0.12);
    --red: #ff7070;
    --red-soft: rgba(255, 112, 112, 0.13);
    --amber: #ffd166;
    --amber-soft: rgba(255, 209, 102, 0.12);
    --radius: 16px;
    --radius-sm: 11px;
    --container: 1180px;
}

* {
    box-sizing: border-box;
}

html {
    min-height: 100%;
    background: var(--bg);
}

body {
    margin: 0;
    min-height: 100vh;
    color: var(--text);
    font-family:
        Inter,
        ui-sans-serif,
        system-ui,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        sans-serif;
    background:
        radial-gradient(
            circle at top left,
            rgba(122, 162, 255, 0.11),
            transparent 30rem
        ),
        radial-gradient(
            circle at top right,
            rgba(255, 255, 255, 0.055),
            transparent 24rem
        ),
        linear-gradient(180deg, #07090d 0%, #090d13 100%);
}

a {
    color: inherit;
}

button,
input {
    font: inherit;
}

button {
    cursor: pointer;
}

button:disabled {
    cursor: not-allowed;
}

.icon {
    width: 18px;
    height: 18px;
    flex: 0 0 auto;
}

.app-shell {
    width: min(var(--container), calc(100% - 32px));
    margin: 0 auto;
    padding: 18px 0 48px;
}

.app-shell--trainer {
    width: min(1320px, calc(100% - 32px));
}

.site-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    margin-bottom: 22px;
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: rgba(13, 17, 24, 0.72);
    backdrop-filter: blur(16px);
}

.brand-link,
.main-nav,
.nav-link,
.btn,
.actions-row,
.category-panel__actions,
.mode-link,
.back-link,
.trainer-controls,
.listen-box {
    display: flex;
    align-items: center;
}

.brand-link {
    gap: 12px;
    text-decoration: none;
    min-width: 0;
}

.brand-mark,
.panel-icon,
.stat-line span,
.mode-tile span,
.mode-link span,
.progress-panel__main span {
    width: 42px;
    height: 42px;
    display: inline-grid;
    place-items: center;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.03);
    color: var(--text);
}

.brand-link strong {
    display: block;
    font-size: 0.96rem;
    letter-spacing: -0.02em;
}

.brand-link small {
    display: block;
    color: var(--muted);
    font-size: 0.78rem;
    margin-top: 2px;
}

.main-nav {
    gap: 8px;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.nav-link,
.btn {
    min-height: 42px;
    gap: 9px;
    border-radius: 12px;
    text-decoration: none;
    transition:
        border-color 180ms ease,
        background 180ms ease,
        transform 180ms ease,
        color 180ms ease;
}

.nav-link {
    padding: 0 13px;
    color: var(--muted);
    border: 1px solid transparent;
}

.nav-link:hover,
.nav-link.is-active {
    color: var(--text);
    border-color: var(--border);
    background: rgba(255, 255, 255, 0.035);
}

.btn {
    justify-content: center;
    padding: 0 15px;
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.025);
    color: var(--text);
    font-weight: 700;
}

.btn:hover {
    transform: translateY(-1px);
    border-color: var(--border-strong);
}

.btn-primary {
    border-color: var(--accent);
    background: var(--accent);
    color: var(--accent-dark);
}

.btn-primary:hover {
    border-color: #ffffff;
    background: #ffffff;
}

.btn-ghost {
    background: rgba(255, 255, 255, 0.025);
}

.btn-full {
    width: 100%;
}

.hero-section,
.trainer-layout,
.split-section {
    display: grid;
    gap: 18px;
}

.hero-section {
    grid-template-columns: minmax(0, 1.55fr) minmax(280px, 0.7fr);
    align-items: stretch;
}

.hero-content,
.hero-aside,
.section-block,
.category-panel,
.mode-tile,
.trainer-sidebar,
.trainer-main,
.exercise-stage {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: linear-gradient(
        180deg,
        rgba(255, 255, 255, 0.038),
        rgba(255, 255, 255, 0.015)
    );
}

.hero-content {
    min-height: 420px;
    padding: clamp(24px, 4vw, 48px);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.eyebrow {
    margin: 0 0 12px;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.16em;
    font-size: 0.73rem;
    font-weight: 800;
}

h1,
h2,
h3,
p {
    margin-top: 0;
}

h1,
h2,
h3 {
    letter-spacing: -0.055em;
}

.hero-content h1,
.page-heading h1 {
    max-width: 880px;
    margin-bottom: 18px;
    font-size: clamp(2.35rem, 7vw, 5rem);
    line-height: 0.94;
}

.lead {
    max-width: 760px;
    margin-bottom: 0;
    color: var(--text-soft);
    line-height: 1.75;
    font-size: clamp(1rem, 1.4vw, 1.08rem);
}

.lead-narrow {
    max-width: 640px;
}

.actions-row {
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 28px;
}

.hero-aside {
    padding: 18px;
    display: grid;
    gap: 12px;
    align-content: center;
}

.stat-line {
    display: grid;
    grid-template-columns: 42px 1fr;
    gap: 14px;
    align-items: center;
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: 14px;
    background: rgba(255, 255, 255, 0.025);
}

.stat-line strong {
    display: block;
    font-size: 1.75rem;
    line-height: 1;
}

.stat-line small {
    display: block;
    margin-top: 5px;
    color: var(--muted);
}

.section-block,
.page-heading {
    margin-top: 18px;
}

.section-block {
    padding: clamp(18px, 3vw, 28px);
}

.section-heading {
    margin-bottom: 18px;
}

.section-heading h2,
.trainer-topbar h2,
.sidebar-block h1 {
    margin-bottom: 0;
    font-size: clamp(1.45rem, 3vw, 2.25rem);
    line-height: 1.02;
}

.section-heading--row {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 16px;
}

.feature-grid,
.category-grid,
.mode-strip {
    display: grid;
    gap: 14px;
}

.feature-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.feature-panel {
    padding: 20px;
    border: 1px solid var(--border);
    border-radius: 14px;
    background: rgba(255, 255, 255, 0.02);
}

.feature-panel h3,
.category-panel h2,
.mode-tile strong {
    margin: 16px 0 10px;
    font-size: 1.15rem;
    letter-spacing: -0.03em;
}

.feature-panel p,
.category-panel p,
.mode-tile small,
.sidebar-block p {
    color: var(--muted);
    line-height: 1.65;
    margin-bottom: 0;
}

.compact-list {
    display: grid;
    gap: 8px;
}

.compact-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    padding: 15px;
    border: 1px solid var(--border);
    border-radius: 13px;
    text-decoration: none;
    background: rgba(255, 255, 255, 0.02);
    transition:
        border-color 180ms ease,
        background 180ms ease,
        transform 180ms ease;
}

.compact-row:hover {
    transform: translateX(2px);
    border-color: var(--border-strong);
    background: rgba(255, 255, 255, 0.035);
}

.compact-row strong,
.compact-row small {
    display: block;
}

.compact-row small {
    margin-top: 4px;
    color: var(--muted);
}

.compact-row em,
.category-panel__meta {
    color: var(--muted);
    font-style: normal;
    white-space: nowrap;
}

.page-heading {
    padding: clamp(20px, 4vw, 34px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.022);
}

.category-heading {
    display: grid;
    gap: 22px;
}

.back-link {
    width: max-content;
    gap: 8px;
    color: var(--muted);
    text-decoration: none;
    font-size: 0.92rem;
    transition: color 180ms ease;
}

.back-link:hover {
    color: var(--text);
}

.category-grid {
    margin-top: 18px;
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.category-panel {
    padding: 20px;
}

.category-panel__top,
.category-panel__meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.level-badge {
    padding: 7px 9px;
    border-radius: 10px;
    border: 1px solid var(--border);
    color: var(--muted);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.09em;
    text-transform: uppercase;
}

.category-panel__meta {
    margin-top: 18px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
    font-size: 0.9rem;
}

.category-panel__actions {
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 18px;
}

.mode-strip {
    margin-top: 18px;
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.mode-tile {
    display: block;
    padding: 18px;
    text-decoration: none;
    transition:
        border-color 180ms ease,
        background 180ms ease,
        transform 180ms ease;
}

.mode-tile:hover {
    transform: translateY(-2px);
    border-color: var(--border-strong);
    background: rgba(255, 255, 255, 0.035);
}

.mode-tile strong,
.mode-tile small {
    display: block;
}

.learning-table {
    width: 100%;
    overflow-x: auto;
    border: 1px solid var(--border);
    border-radius: 14px;
}

.learning-table__head,
.learning-row {
    min-width: 720px;
    display: grid;
    grid-template-columns: 1.1fr 1.1fr 0.8fr;
    gap: 16px;
    align-items: center;
    padding: 14px 16px;
}

.learning-table__head {
    color: var(--muted);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    background: rgba(255, 255, 255, 0.025);
}

.learning-row + .learning-row {
    border-top: 1px solid var(--border);
}

.learning-row strong {
    font-weight: 750;
}

.learning-row span {
    color: var(--text-soft);
}

.learning-row em {
    color: var(--amber);
    font-style: normal;
}

.trainer-layout {
    grid-template-columns: 320px minmax(0, 1fr);
    align-items: start;
}

.trainer-sidebar,
.trainer-main {
    padding: 18px;
}

.trainer-sidebar {
    position: sticky;
    top: 18px;
    display: grid;
    gap: 16px;
}

.sidebar-block {
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

.mode-nav {
    display: grid;
    gap: 8px;
}

.mode-link {
    gap: 11px;
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 13px;
    background: rgba(255, 255, 255, 0.02);
    color: var(--muted);
    text-decoration: none;
    transition:
        border-color 180ms ease,
        background 180ms ease,
        color 180ms ease;
}

.mode-link span {
    width: 36px;
    height: 36px;
    border-radius: 10px;
}

.mode-link.is-active,
.mode-link:hover {
    color: var(--text);
    border-color: var(--border-strong);
    background: rgba(255, 255, 255, 0.045);
}

.progress-panel {
    display: grid;
    gap: 12px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
}

.progress-panel__main {
    display: grid;
    grid-template-columns: 42px 1fr;
    gap: 12px;
    align-items: center;
}

.progress-panel__main strong {
    display: block;
    font-size: 2rem;
    line-height: 1;
}

.progress-panel__main small {
    display: block;
    color: var(--muted);
    margin-top: 4px;
}

.progress-mini-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
}

.progress-mini-grid span {
    padding: 10px;
    border: 1px solid var(--border);
    border-radius: 11px;
    color: var(--muted);
    font-size: 0.8rem;
    background: rgba(255, 255, 255, 0.02);
}

.progress-mini-grid strong {
    display: block;
    margin-top: 3px;
    color: var(--text);
    font-size: 1rem;
}

.trainer-main {
    min-height: 680px;
}

.trainer-topbar {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 16px;
}

.exercise-stage {
    min-height: 500px;
    display: grid;
    align-items: center;
    padding: clamp(18px, 4vw, 38px);
}

.exercise-card {
    max-width: 780px;
}

.exercise-kicker {
    margin-bottom: 16px;
    color: var(--muted);
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    font-size: 0.75rem;
}

.exercise-card h3 {
    margin-bottom: 16px;
    font-size: clamp(2.1rem, 6vw, 4.4rem);
    line-height: 0.98;
}

.exercise-card h3.sentence-title {
    font-size: clamp(1.8rem, 5vw, 3.2rem);
    line-height: 1.08;
}

.pronunciation {
    display: inline-flex;
    margin: 0 0 20px;
    padding: 9px 11px;
    border: 1px solid rgba(255, 209, 102, 0.23);
    border-radius: 10px;
    background: var(--amber-soft);
    color: var(--amber);
    font-weight: 800;
}

.exercise-help,
.result-text,
.empty-state {
    color: var(--muted);
    line-height: 1.65;
}

.answer-panel {
    margin-top: 18px;
    padding: 18px;
    border: 1px solid var(--border);
    border-radius: 13px;
    background: rgba(255, 255, 255, 0.02);
}

.answer-panel span,
.answer-panel small,
.result-text {
    display: block;
}

.answer-panel span {
    color: var(--muted);
    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.answer-panel strong {
    display: block;
    margin-top: 8px;
    font-size: 1.35rem;
}

.answer-panel small {
    margin-top: 10px;
    color: var(--muted);
    line-height: 1.6;
}

.exercise-actions,
.choice-list {
    display: grid;
    gap: 10px;
    margin-top: 22px;
}

.exercise-actions {
    grid-template-columns: repeat(auto-fit, minmax(180px, max-content));
}

.choice-list {
    max-width: 760px;
}

.choice-btn {
    width: 100%;
    min-height: 50px;
    padding: 0 15px;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.025);
    color: var(--text);
    text-align: left;
    transition:
        border-color 180ms ease,
        background 180ms ease,
        transform 180ms ease,
        opacity 180ms ease;
}

.choice-btn:hover:not(:disabled) {
    transform: translateX(2px);
    border-color: var(--border-strong);
}

.choice-btn.is-correct {
    border-color: rgba(87, 211, 154, 0.42);
    background: var(--green-soft);
}

.choice-btn.is-wrong {
    border-color: rgba(255, 112, 112, 0.42);
    background: var(--red-soft);
}

.choice-btn.is-muted {
    opacity: 0.62;
}

.blank-line {
    color: var(--text);
}

.listen-box {
    gap: 10px;
    margin-top: 22px;
}

.answer-input {
    width: min(520px, 100%);
    min-height: 48px;
    padding: 0 15px;
    border: 1px solid var(--border);
    border-radius: 12px;
    outline: none;
    background: rgba(255, 255, 255, 0.025);
    color: var(--text);
}

.answer-input:focus {
    border-color: var(--border-strong);
    background: rgba(255, 255, 255, 0.04);
}

.trainer-controls {
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 16px;
}

.exercise-count {
    color: var(--muted);
    font-weight: 700;
}

.exercise-count strong {
    color: var(--text);
}

@media (max-width: 1080px) {
    .hero-section,
    .trainer-layout {
        grid-template-columns: 1fr;
    }

    .trainer-sidebar {
        position: static;
    }

    .mode-strip,
    .category-grid,
    .feature-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 720px) {
    .app-shell,
    .app-shell--trainer {
        width: min(100% - 18px, var(--container));
        padding-top: 9px;
        padding-bottom: 28px;
    }

    .site-header {
        align-items: stretch;
        flex-direction: column;
    }

    .main-nav,
    .nav-link {
        width: 100%;
    }

    .nav-link {
        justify-content: center;
    }

    .hero-content {
        min-height: auto;
    }

    .mode-strip,
    .category-grid,
    .feature-grid,
    .progress-mini-grid {
        grid-template-columns: 1fr;
    }

    .section-heading--row,
    .trainer-topbar {
        align-items: stretch;
        flex-direction: column;
    }

    .compact-row,
    .listen-box {
        align-items: stretch;
        flex-direction: column;
    }

    .compact-row em {
        white-space: normal;
    }

    .trainer-main,
    .exercise-stage {
        min-height: auto;
    }

    .exercise-stage {
        padding: 18px;
    }

    .exercise-actions {
        grid-template-columns: 1fr;
    }

    .answer-input {
        width: 100%;
    }
}

/* Final UX polish */
.mobile-menu-btn {
    display: none;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-height: 42px;
    padding: 0 13px;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.025);
    color: var(--text);
    font-weight: 750;
}

.compact-list--grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.section-block--featured,
.category-panel--featured {
    border-color: rgba(122, 162, 255, 0.22);
    background:
        radial-gradient(
            circle at top right,
            rgba(122, 162, 255, 0.13),
            transparent 18rem
        ),
        linear-gradient(
            180deg,
            rgba(255, 255, 255, 0.045),
            rgba(255, 255, 255, 0.018)
        );
}

.category-intro {
    padding-top: 22px;
    padding-bottom: 22px;
}

.trainer-main,
.trainer-sidebar,
.exercise-stage,
.category-panel,
.section-block,
.hero-content,
.hero-aside {
    box-shadow: 0 18px 60px rgba(0, 0, 0, 0.22);
}

@media (min-width: 1081px) {
    .category-panel--featured {
        grid-column: span 1;
    }
}

@media (max-width: 900px) {
    .site-header {
        position: sticky;
        top: 10px;
        z-index: 50;
    }

    .trainer-sidebar {
        gap: 14px;
    }

    .mode-nav {
        grid-template-columns: repeat(4, minmax(145px, 1fr));
        overflow-x: auto;
        padding-bottom: 4px;
        scrollbar-width: thin;
    }

    .mode-link {
        min-width: 145px;
    }

    .progress-panel {
        grid-template-columns: 1fr auto;
        align-items: center;
    }

    .progress-mini-grid,
    .progress-panel .btn-full {
        grid-column: 1 / -1;
    }

    .trainer-main {
        min-height: auto;
        width: 100%;
    }
}

@media (max-width: 720px) {
    body {
        background:
            radial-gradient(
                circle at top left,
                rgba(122, 162, 255, 0.1),
                transparent 22rem
            ),
            linear-gradient(180deg, #07090d 0%, #090d13 100%);
    }

    .site-header {
        display: grid;
        grid-template-columns: minmax(0, 1fr) auto;
        align-items: center;
        gap: 10px;
        margin-bottom: 14px;
        padding: 8px;
    }

    .mobile-menu-btn {
        display: inline-flex;
    }

    .main-nav {
        display: none;
        grid-column: 1 / -1;
        grid-template-columns: 1fr;
        gap: 8px;
        padding-top: 8px;
        border-top: 1px solid var(--border);
    }

    .site-header.is-menu-open .main-nav {
        display: grid;
    }

    .nav-link {
        justify-content: flex-start;
        min-height: 48px;
        padding: 0 12px;
        border-color: var(--border);
        background: rgba(255, 255, 255, 0.02);
    }

    .brand-link small {
        display: none;
    }

    .brand-mark,
    .panel-icon,
    .stat-line span,
    .mode-tile span,
    .mode-link span,
    .progress-panel__main span {
        width: 38px;
        height: 38px;
    }

    .hero-section,
    .split-section,
    .trainer-layout {
        gap: 12px;
    }

    .hero-content,
    .hero-aside,
    .section-block,
    .category-panel,
    .trainer-sidebar,
    .trainer-main {
        border-radius: 14px;
    }

    .hero-content {
        padding: 22px;
    }

    .hero-content h1,
    .page-heading h1 {
        font-size: clamp(2.1rem, 12vw, 3.2rem);
        line-height: 0.96;
    }

    .lead {
        font-size: 0.98rem;
        line-height: 1.65;
    }

    .actions-row,
    .category-panel__actions {
        display: grid;
        grid-template-columns: 1fr;
        width: 100%;
    }

    .btn {
        min-height: 48px;
        padding-inline: 14px;
    }

    .compact-list--grid,
    .category-grid,
    .feature-grid,
    .mode-strip {
        grid-template-columns: 1fr;
    }

    .compact-row {
        gap: 10px;
        padding: 14px;
    }

    .compact-row em {
        color: var(--text-soft);
        font-size: 0.9rem;
    }

    .category-panel {
        padding: 18px;
    }

    .category-panel h2 {
        font-size: 1.3rem;
    }

    .trainer-sidebar {
        padding: 14px;
    }

    .mode-nav {
        display: flex;
        gap: 8px;
        margin-inline: -2px;
        overflow-x: auto;
        scroll-snap-type: x proximity;
    }

    .mode-link {
        flex: 0 0 168px;
        scroll-snap-align: start;
    }

    .progress-panel {
        grid-template-columns: 1fr;
    }

    .progress-panel__main strong {
        font-size: 1.65rem;
    }

    .trainer-topbar {
        gap: 12px;
    }

    .trainer-topbar .btn {
        width: 100%;
    }

    .exercise-card {
        max-width: none;
        width: 100%;
    }

    .exercise-card h3 {
        font-size: clamp(2rem, 12vw, 3.1rem);
        line-height: 1;
        overflow-wrap: anywhere;
    }

    .exercise-card h3.sentence-title {
        font-size: clamp(1.65rem, 9vw, 2.55rem);
    }

    .pronunciation {
        display: flex;
        width: fit-content;
        max-width: 100%;
        line-height: 1.45;
    }

    .choice-btn,
    .answer-input {
        min-height: 52px;
        font-size: 1rem;
    }

    .trainer-controls {
        display: grid;
        grid-template-columns: 1fr 1fr;
        align-items: center;
    }

    .exercise-count {
        grid-column: 1 / -1;
        grid-row: 1;
        text-align: center;
        padding: 4px 0;
    }

    .trainer-controls .btn:first-child {
        grid-column: 1;
        grid-row: 2;
    }

    .trainer-controls .btn:last-child {
        grid-column: 2;
        grid-row: 2;
    }
}

@media (max-width: 430px) {
    .app-shell,
    .app-shell--trainer {
        width: min(100% - 12px, var(--container));
    }

    .site-header {
        top: 6px;
    }

    .brand-link {
        gap: 9px;
    }

    .brand-link strong {
        font-size: 0.92rem;
    }

    .mobile-menu-btn span {
        display: none;
    }

    .hero-content,
    .section-block,
    .category-panel,
    .trainer-main,
    .trainer-sidebar,
    .exercise-stage {
        padding: 14px;
    }

    .hero-aside {
        padding: 12px;
    }

    .section-heading--row .btn {
        width: 100%;
    }

    .stat-line {
        padding: 13px;
    }

    .mode-link {
        flex-basis: 156px;
    }

    .trainer-controls {
        grid-template-columns: 1fr;
    }

    .trainer-controls .btn:first-child,
    .trainer-controls .btn:last-child {
        grid-column: 1;
    }

    .trainer-controls .btn:first-child {
        grid-row: 2;
    }

    .trainer-controls .btn:last-child {
        grid-row: 3;
    }
}

/* Mobile-first trainer flow: exercice avant le panneau de session */
@media (max-width: 720px) {
    .trainer-layout {
        display: flex;
        flex-direction: column;
    }

    .trainer-main {
        order: 1;
    }

    .trainer-sidebar {
        order: 2;
        padding: 12px;
        gap: 12px;
    }

    .trainer-sidebar .back-link {
        min-height: 42px;
    }

    .trainer-sidebar .sidebar-block {
        padding-bottom: 12px;
    }

    .trainer-sidebar .sidebar-block p:not(.eyebrow) {
        display: none;
    }

    .trainer-sidebar .sidebar-block h1 {
        font-size: 1.45rem;
        margin-bottom: 0;
    }

    .trainer-sidebar .mode-nav {
        margin-top: 0;
    }

    .trainer-sidebar .progress-panel {
        padding-top: 12px;
    }
}

.mobile-reset-action {
    display: none;
}

/* Mobile trainer: modes au-dessus de l’exercice, sans bloc de suivi */
@media (max-width: 720px) {
    .trainer-layout {
        display: flex;
        flex-direction: column;
        gap: 10px;
    }

    .trainer-sidebar {
        order: 1;
        position: static;
        display: grid;
        grid-template-columns: minmax(0, 1fr) 48px;
        align-items: center;
        gap: 8px;
        padding: 8px;
        border-radius: 16px;
        background: rgba(255, 255, 255, 0.025);
    }

    .trainer-main {
        order: 2;
    }

    .trainer-sidebar .back-link,
    .trainer-sidebar .sidebar-block,
    .trainer-sidebar .progress-panel {
        display: none;
    }

    .trainer-sidebar .mode-nav {
        grid-column: 1;
        display: flex;
        gap: 8px;
        margin: 0;
        padding: 0;
        overflow-x: auto;
        scroll-snap-type: x mandatory;
        scrollbar-width: none;
        -webkit-overflow-scrolling: touch;
    }

    .trainer-sidebar .mode-nav::-webkit-scrollbar {
        display: none;
    }

    .trainer-sidebar .mode-link {
        flex: 0 0 auto;
        min-width: 142px;
        min-height: 48px;
        padding: 7px 9px;
        scroll-snap-align: start;
    }

    .trainer-sidebar .mode-link span {
        width: 34px;
        height: 34px;
        border-radius: 10px;
    }

    .trainer-sidebar .mode-link strong {
        font-size: 0.9rem;
        white-space: nowrap;
    }

    .mobile-reset-action {
        grid-column: 2;
        display: inline-flex;
        width: 48px;
        min-width: 48px;
        min-height: 48px;
        justify-content: center;
        padding: 0;
    }

    .mobile-reset-action span {
        display: none;
    }

    .mobile-reset-action .icon,
    .mobile-reset-action svg {
        width: 18px;
        height: 18px;
    }

    .trainer-topbar {
        margin-bottom: 10px;
    }

    .trainer-topbar h2 {
        font-size: clamp(1.55rem, 8vw, 2.05rem);
    }
}

@media (max-width: 430px) {
    .trainer-sidebar .mode-link {
        min-width: 132px;
    }

    .trainer-sidebar .mode-link strong {
        font-size: 0.84rem;
    }
}

/* Flashcards retournables + swipe mobile */
.exercise-card--flashcard {
    width: min(780px, 100%);
}

.flashcard-scene {
    min-height: 390px;
    perspective: 1200px;
    cursor: pointer;
    touch-action: pan-y;
    user-select: none;
    transition: transform 180ms ease;
}

.flashcard-scene:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 4px;
    border-radius: var(--radius);
}

.flashcard-scene.is-swiping {
    transition: none;
}

.flashcard-flip {
    position: relative;
    min-height: 390px;
    transform-style: preserve-3d;
    transition: transform 520ms cubic-bezier(0.2, 0.78, 0.18, 1);
}

.flashcard-flip.is-flipped {
    transform: rotateY(180deg);
}

.flashcard-face {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: clamp(24px, 5vw, 44px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background:
        radial-gradient(
            circle at top right,
            rgba(255, 255, 255, 0.08),
            transparent 18rem
        ),
        linear-gradient(
            180deg,
            rgba(255, 255, 255, 0.052),
            rgba(255, 255, 255, 0.018)
        );
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.flashcard-face--back {
    transform: rotateY(180deg);
    background:
        radial-gradient(
            circle at top right,
            rgba(87, 211, 154, 0.12),
            transparent 18rem
        ),
        linear-gradient(
            180deg,
            rgba(255, 255, 255, 0.052),
            rgba(255, 255, 255, 0.018)
        );
}

.flashcard-label {
    margin-bottom: 16px;
    color: var(--muted);
    font-size: 0.74rem;
    font-weight: 800;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.exercise-card .flashcard-word {
    margin-bottom: 14px;
}

.flashcard-answer {
    display: block;
    margin-bottom: 16px;
    font-size: clamp(2.2rem, 6vw, 4.2rem);
    line-height: 0.98;
    letter-spacing: -0.055em;
}

.flashcard-example,
.flashcard-hint,
.flashcard-mobile-hint {
    color: var(--muted);
    line-height: 1.65;
}

.flashcard-example {
    max-width: 620px;
    margin-bottom: 22px;
    font-size: 0.98rem;
}

.flashcard-hint {
    margin-top: 8px;
    font-size: 0.86rem;
}

.flashcard-mobile-hint {
    display: none;
    margin: 12px 0 0;
    text-align: center;
    font-size: 0.86rem;
}

.exercise-actions--flashcard {
    margin-top: 16px;
}

@media (max-width: 720px) {
    .flashcard-scene,
    .flashcard-flip {
        min-height: 410px;
    }

    .flashcard-face {
        padding: 24px;
    }

    .flashcard-mobile-hint {
        display: block;
    }

    .exercise-actions--flashcard {
        grid-template-columns: 1fr;
    }

    .exercise-actions--flashcard .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 430px) {
    .flashcard-scene,
    .flashcard-flip {
        min-height: 380px;
    }

    .flashcard-face {
        padding: 20px;
    }

    .flashcard-answer {
        font-size: clamp(2rem, 12vw, 3.4rem);
    }
}

@media (prefers-reduced-motion: reduce) {
    .flashcard-flip,
    .flashcard-scene {
        transition: none;
    }
}