.dd-category-page {
    --dd-primary: #2256d8;
    --dd-primary-dark: #173f9f;
    --dd-primary-soft: #eef4ff;
    --dd-ink: #152238;
    --dd-muted: #6b778c;
    --dd-line: #dfe6ef;
    --dd-surface: #ffffff;
    --dd-surface-soft: #f7f9fc;
    --dd-success: #198754;
    --dd-warning: #b86b00;
    color: var(--dd-ink);
}

.dd-category-breadcrumb {
    margin-bottom: 1.25rem;
    font-size: 0.875rem;
}

.dd-category-breadcrumb .breadcrumb-item,
.dd-category-breadcrumb .breadcrumb-item.active {
    color: var(--dd-muted);
}

.dd-category-breadcrumb a {
    color: var(--dd-primary);
    font-weight: 700;
    text-decoration: none;
}

.dd-category-breadcrumb a:hover,
.dd-category-breadcrumb a:focus {
    color: var(--dd-primary-dark);
    text-decoration: underline;
}

.dd-category-header {
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    padding: 1.5rem 1.6rem;
    border: 1px solid #d9e4f7;
    border-radius: 1.25rem;
    background:
        radial-gradient(circle at top right, rgba(34, 86, 216, 0.12), transparent 34%),
        linear-gradient(135deg, #ffffff 0%, #f5f8ff 100%);
    box-shadow: 0 14px 36px rgba(29, 54, 96, 0.08);
}

.dd-category-header > div {
    min-width: 0;
}

.dd-category-eyebrow {
    display: inline-flex;
    align-items: center;
    margin-bottom: 0.55rem;
    padding: 0.38rem 0.72rem;
    border: 1px solid #d6e1fb;
    border-radius: 999px;
    background: #f0f5ff;
    color: var(--dd-primary);
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.dd-category-header h1 {
    margin: 0;
    color: var(--dd-ink);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 900;
    line-height: 1.08;
    letter-spacing: -0.035em;
}

.dd-category-header p {
    max-width: 760px;
    margin: 0.7rem 0 0;
    color: var(--dd-muted);
    font-size: 0.96rem;
    line-height: 1.7;
}

.dd-category-header__count {
    flex: 0 0 auto;
    padding: 0.6rem 0.9rem;
    border: 1px solid #cad8f5;
    border-radius: 0.8rem;
    background: #ffffff;
    color: var(--dd-primary);
    font-size: 0.82rem;
    font-weight: 800;
    white-space: nowrap;
    box-shadow: 0 6px 18px rgba(34, 86, 216, 0.08);
}

.dd-section-accordion {
    display: grid;
    gap: 0.95rem;
}

.dd-section-item {
    --section-color: #2563eb;
    --section-soft: rgba(37, 99, 235, 0.10);
    --section-border: rgba(37, 99, 235, 0.28);
    --section-shadow: rgba(37, 99, 235, 0.15);

    overflow: hidden;
    border: 1px solid var(--dd-line);
    border-radius: 1rem;
    background: var(--dd-surface);
    box-shadow: 0 8px 24px rgba(31, 49, 85, 0.06);
    transition:
        border-color 0.2s ease,
        box-shadow 0.2s ease,
        transform 0.2s ease;
}


.dd-section-item--tone-1  { --section-color: #2563eb; --section-soft: rgba(37, 99, 235, 0.10); --section-border: rgba(37, 99, 235, 0.28); --section-shadow: rgba(37, 99, 235, 0.15); }
.dd-section-item--tone-2  { --section-color: #16a34a; --section-soft: rgba(22, 163, 74, 0.10); --section-border: rgba(22, 163, 74, 0.28); --section-shadow: rgba(22, 163, 74, 0.15); }
.dd-section-item--tone-3  { --section-color: #0284c7; --section-soft: rgba(2, 132, 199, 0.10); --section-border: rgba(2, 132, 199, 0.28); --section-shadow: rgba(2, 132, 199, 0.15); }
.dd-section-item--tone-4  { --section-color: #dc2626; --section-soft: rgba(220, 38, 38, 0.10); --section-border: rgba(220, 38, 38, 0.28); --section-shadow: rgba(220, 38, 38, 0.15); }
.dd-section-item--tone-5  { --section-color: #d97706; --section-soft: rgba(217, 119, 6, 0.11); --section-border: rgba(217, 119, 6, 0.30); --section-shadow: rgba(217, 119, 6, 0.16); }
.dd-section-item--tone-6  { --section-color: #0891b2; --section-soft: rgba(8, 145, 178, 0.10); --section-border: rgba(8, 145, 178, 0.28); --section-shadow: rgba(8, 145, 178, 0.15); }
.dd-section-item--tone-7  { --section-color: #7c3aed; --section-soft: rgba(124, 58, 237, 0.10); --section-border: rgba(124, 58, 237, 0.28); --section-shadow: rgba(124, 58, 237, 0.15); }
.dd-section-item--tone-8  { --section-color: #db2777; --section-soft: rgba(219, 39, 119, 0.10); --section-border: rgba(219, 39, 119, 0.28); --section-shadow: rgba(219, 39, 119, 0.15); }
.dd-section-item--tone-9  { --section-color: #0f766e; --section-soft: rgba(15, 118, 110, 0.10); --section-border: rgba(15, 118, 110, 0.28); --section-shadow: rgba(15, 118, 110, 0.15); }
.dd-section-item--tone-10 { --section-color: #ea580c; --section-soft: rgba(234, 88, 12, 0.10); --section-border: rgba(234, 88, 12, 0.28); --section-shadow: rgba(234, 88, 12, 0.15); }
.dd-section-item--tone-11 { --section-color: #4d7c0f; --section-soft: rgba(77, 124, 15, 0.10); --section-border: rgba(77, 124, 15, 0.28); --section-shadow: rgba(77, 124, 15, 0.15); }
.dd-section-item--tone-12 { --section-color: #ca8a04; --section-soft: rgba(202, 138, 4, 0.11); --section-border: rgba(202, 138, 4, 0.30); --section-shadow: rgba(202, 138, 4, 0.16); }
.dd-section-item--tone-13 { --section-color: #9333ea; --section-soft: rgba(147, 51, 234, 0.10); --section-border: rgba(147, 51, 234, 0.28); --section-shadow: rgba(147, 51, 234, 0.15); }
.dd-section-item--tone-14 { --section-color: #15803d; --section-soft: rgba(21, 128, 61, 0.10); --section-border: rgba(21, 128, 61, 0.28); --section-shadow: rgba(21, 128, 61, 0.15); }
.dd-section-item--tone-15 { --section-color: #b45309; --section-soft: rgba(180, 83, 9, 0.10); --section-border: rgba(180, 83, 9, 0.28); --section-shadow: rgba(180, 83, 9, 0.15); }
.dd-section-item--tone-16 { --section-color: #1d4ed8; --section-soft: rgba(29, 78, 216, 0.10); --section-border: rgba(29, 78, 216, 0.28); --section-shadow: rgba(29, 78, 216, 0.15); }
.dd-section-item--tone-17 { --section-color: #047857; --section-soft: rgba(4, 120, 87, 0.10); --section-border: rgba(4, 120, 87, 0.28); --section-shadow: rgba(4, 120, 87, 0.15); }
.dd-section-item--tone-18 { --section-color: #4f46e5; --section-soft: rgba(79, 70, 229, 0.10); --section-border: rgba(79, 70, 229, 0.28); --section-shadow: rgba(79, 70, 229, 0.15); }
.dd-section-item--tone-19 { --section-color: #475569; --section-soft: rgba(71, 85, 105, 0.10); --section-border: rgba(71, 85, 105, 0.28); --section-shadow: rgba(71, 85, 105, 0.15); }
.dd-section-item--tone-20 { --section-color: #be123c; --section-soft: rgba(190, 18, 60, 0.10); --section-border: rgba(190, 18, 60, 0.28); --section-shadow: rgba(190, 18, 60, 0.15); }

.dd-section-item:hover {
    border-color: var(--section-border);
    box-shadow: 0 12px 30px rgba(31, 49, 85, 0.09);
}

.dd-section-item.is-open {
    border-color: var(--section-border);
    box-shadow: 0 14px 34px var(--section-shadow);
}

.dd-section-toggle {
    display: grid;
    width: 100%;
    grid-template-columns: 64px minmax(0, 1fr) auto 18px;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.1rem;
    border: 0;
    background: linear-gradient(180deg, #ffffff 0%, #fbfcff 100%);
    color: inherit;
    text-align: left;
    cursor: pointer;
    transition:
        background 0.2s ease,
        color 0.2s ease;
}

.dd-section-toggle:hover {
    background: #f6f9ff;
}

.dd-section-toggle:focus-visible {
    outline: 3px solid rgba(34, 86, 216, 0.2);
    outline-offset: -3px;
}

.dd-section-item.is-open .dd-section-toggle {
    background:
        linear-gradient(90deg, var(--section-soft), transparent 48%),
        #ffffff;
}

.dd-section-toggle__visual {
    position: relative;
    overflow: visible;
    display: grid;
    width: 54px;
    height: 54px;
    place-items: center;
    border: 1px solid var(--section-border);
    border-radius: 0.95rem;
    background: var(--section-soft);
    color: var(--section-color);
    box-shadow: 0 5px 14px var(--section-shadow);
    transition:
        background 0.2s ease,
        color 0.2s ease,
        border-color 0.2s ease,
        transform 0.2s ease,
        box-shadow 0.2s ease;
}

.dd-section-toggle__icon {
    display: block;
    font-family: "Segoe UI Emoji", "Apple Color Emoji", "Noto Color Emoji", sans-serif;
    font-size: 1.28rem;
    line-height: 1;
}

.dd-section-toggle__number {
    position: absolute;
    right: 2px;
    bottom: 2px;
    z-index: 5;
    display: flex !important;
    width: 23px;
    height: 23px;
    align-items: center;
    justify-content: center;
    padding: 0;
    border: 2px solid #ffffff;
    border-radius: 50%;
    background-color: var(--section-color) !important;
    color: #ffffff !important;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 10px;
    font-weight: 900;
    line-height: 1;
    letter-spacing: 0;
    visibility: visible !important;
    opacity: 1 !important;
    box-shadow: 0 3px 8px rgba(15, 23, 42, 0.22);
}

.dd-section-item.is-open .dd-section-toggle__visual {
    background: var(--section-color);
    color: #ffffff;
    border-color: var(--section-color);
    box-shadow: 0 9px 20px var(--section-shadow);
    transform: translateY(-1px);
}

.dd-section-item.is-open .dd-section-toggle__number {
    background-color: #ffffff !important;
    color: var(--section-color) !important;
    border-color: var(--section-color) !important;
}

.dd-section-toggle__content {
    display: flex;
    min-width: 0;
    flex-direction: column;
    gap: 0.2rem;
}

.dd-section-toggle__content strong {
    display: flex;
    overflow: hidden;
    align-items: baseline;
    gap: 0.4rem;
    color: var(--dd-ink);
    font-size: 1rem;
    font-weight: 850;
    line-height: 1.3;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.dd-section-toggle__content small {
    display: -webkit-box;
    overflow: hidden;
    color: var(--dd-muted);
    font-size: 0.82rem;
    line-height: 1.45;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 2;
}

.dd-section-toggle__meta {
    padding: 0.42rem 0.65rem;
    border: 1px solid #d9e3f6;
    border-radius: 999px;
    background: #f8faff;
    color: var(--section-color);
    font-size: 0.75rem;
    font-weight: 800;
    white-space: nowrap;
}

.dd-section-toggle__chevron {
    position: relative;
    width: 14px;
    height: 14px;
    transition: transform 0.25s ease;
}

.dd-section-toggle__chevron::before,
.dd-section-toggle__chevron::after {
    position: absolute;
    top: 6px;
    width: 8px;
    height: 2px;
    border-radius: 2px;
    background: #77849a;
    content: "";
    transition: background 0.2s ease;
}

.dd-section-toggle__chevron::before {
    left: 0;
    transform: rotate(45deg);
}

.dd-section-toggle__chevron::after {
    right: 0;
    transform: rotate(-45deg);
}

.dd-section-item.is-open .dd-section-toggle__chevron {
    transform: rotate(180deg);
}

.dd-section-item.is-open .dd-section-toggle__chevron::before,
.dd-section-item.is-open .dd-section-toggle__chevron::after {
    background: var(--section-color);
}

.dd-section-panel {
    border-top: 1px solid #e4e9f2;
    background: #ffffff;
}

.dd-section-panel[hidden] {
    display: none !important;
}

.dd-section-lessons {
    display: grid;
}

.dd-lesson-row {
    --lesson-color: var(--section-color);
    --lesson-soft: var(--section-soft);
    --lesson-border: var(--section-border);
    --lesson-shadow: var(--section-shadow);
    display: grid;
    min-width: 0;
    grid-template-columns: 42px minmax(0, 1fr) auto 20px;
    align-items: center;
    gap: 0.9rem;
    padding: 0.9rem 1.1rem;
    border-bottom: 1px solid #edf0f5;
    border-left: 3px solid var(--lesson-color);
    color: inherit;
    text-decoration: none;
    transition:
        background 0.18s ease,
        color 0.18s ease,
        transform 0.18s ease;
}

.dd-lesson-row:last-child {
    border-bottom: 0;
}

.dd-lesson-row:hover {
    background: #f7faff;
    color: inherit;
}

.dd-lesson-row:focus-visible {
    outline: 3px solid rgba(34, 86, 216, 0.2);
    outline-offset: -3px;
}

.dd-lesson-row__position {
    display: grid;
    width: 34px;
    height: 34px;
    place-items: center;
    border: 1px solid var(--lesson-color);
    border-radius: 0.7rem;
    background: var(--lesson-color);
    color: #ffffff;
    box-shadow: 0 4px 10px var(--lesson-shadow);
    font-size: 0.78rem;
    font-weight: 850;
    transition:
        background 0.18s ease,
        color 0.18s ease;
}

.dd-lesson-row__content {
    display: flex;
    min-width: 0;
    flex-direction: column;
    gap: 0.18rem;
}

.dd-lesson-row__content strong {
    overflow: hidden;
    color: var(--dd-ink);
    font-size: 0.92rem;
    font-weight: 800;
    line-height: 1.35;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.dd-lesson-row__content small {
    overflow: hidden;
    color: var(--dd-muted);
    font-size: 0.76rem;
    line-height: 1.35;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.dd-lesson-row__status {
    display: flex;
    justify-content: flex-end;
}

.dd-lesson-status {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 76px;
    padding: 0.38rem 0.62rem;
    border-radius: 999px;
    font-size: 0.7rem;
    font-weight: 800;
    line-height: 1;
    white-space: nowrap;
}

.dd-lesson-status.is-available {
    border: 1px solid #bfe4ce;
    background: #edf9f2;
    color: var(--dd-success);
}

.dd-lesson-status.is-locked {
    border: 1px solid #e4d4ba;
    background: #fff8ec;
    color: var(--dd-warning);
}

.dd-lesson-row__arrow {
    color: #8a96a8;
    font-size: 1rem;
    font-weight: 800;
    transition:
        color 0.18s ease,
        transform 0.18s ease;
}

.dd-lesson-row:hover .dd-lesson-row__arrow {
    color: var(--lesson-color);
    transform: translateX(3px);
}

@media (max-width: 991.98px) {
    .dd-category-header {
        align-items: flex-start;
    }

    .dd-section-toggle {
        grid-template-columns: 52px minmax(0, 1fr) auto 18px;
    }
}

@media (max-width: 767.98px) {
    .dd-category-page {
        padding-top: 1rem !important;
        padding-bottom: 1.5rem !important;
    }

    .dd-category-header {
        align-items: flex-start;
        flex-direction: column;
        padding: 1.25rem;
    }

    .dd-category-header__count {
        align-self: flex-start;
    }

    .dd-section-toggle {
        grid-template-columns: 44px minmax(0, 1fr) 16px;
        gap: 0.75rem;
        padding: 0.9rem;
    }

    .dd-section-toggle__icon {
        width: 40px;
        height: 40px;
    }

    .dd-section-toggle__meta {
        display: none;
    }

    .dd-lesson-row {
        grid-template-columns: 38px minmax(0, 1fr) 18px;
        gap: 0.7rem;
        padding: 0.82rem 0.9rem;
    }

    .dd-lesson-row__status {
        display: none;
    }
}

@media (max-width: 575.98px) {
    .dd-category-header {
        border-radius: 1rem;
    }

    .dd-category-header h1 {
        font-size: 1.85rem;
    }

    .dd-category-header p {
        font-size: 0.9rem;
    }

    .dd-section-item {
        border-radius: 0.9rem;
    }

    .dd-section-toggle__content strong {
        font-size: 0.94rem;
    }

    .dd-section-toggle__content small {
        font-size: 0.78rem;
        -webkit-line-clamp: 1;
    }

    .dd-lesson-row__content strong {
        font-size: 0.88rem;
    }

    .dd-lesson-row__content small {
        font-size: 0.72rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    .dd-section-item,
    .dd-section-toggle,
    .dd-section-toggle__visual,
    .dd-section-toggle__chevron,
    .dd-lesson-row,
    .dd-lesson-row__position,
    .dd-lesson-row__arrow {
        transition: none;
    }
}


/* Section number visibility fallback */
.dd-section-item .dd-section-toggle__number {
    display: flex !important;
    visibility: visible !important;
    opacity: 1 !important;
}

/* Section lesson layout: 1-8 lessons = one column, 9-16 lessons = two columns. */
.dd-section-lessons--one-column {
    grid-template-columns: minmax(0, 1fr);
}

.dd-section-lessons--two-columns {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.dd-section-lessons__column {
    min-width: 0;
}

.dd-section-lessons--two-columns .dd-section-lessons__column + .dd-section-lessons__column {
    border-left: 1px solid #edf0f5;
}

.dd-section-lessons__column .dd-lesson-row:last-child {
    border-bottom: 0;
}

.dd-section-toggle__content strong small {
    color: var(--dd-muted);
    font-size: 0.8rem;
    font-weight: 700;
}

.dd-lesson-status--sentences {
    min-width: 0;
    border: 0;
    background: transparent;
    color: var(--lesson-color);
}

@media (max-width: 991.98px) {
    .dd-section-lessons--two-columns {
        grid-template-columns: minmax(0, 1fr);
    }

    .dd-section-lessons--two-columns .dd-section-lessons__column + .dd-section-lessons__column {
        border-left: 0;
    }

    .dd-section-lessons--two-columns .dd-section-lessons__column:first-child .dd-lesson-row:last-child {
        border-bottom: 1px solid #edf0f5;
    }
}

@media (max-width: 575.98px) {
    .dd-section-toggle__content strong {
        align-items: flex-start;
        flex-direction: column;
        gap: 0.1rem;
        white-space: normal;
    }
}

/* Disabled lesson state: lesson has no MP3 file. */
.dd-lesson-row--coming-soon,
.dd-lesson-row--locked {
    cursor: default;
}

.dd-lesson-row--coming-soon:hover,
.dd-lesson-row--locked:hover {
    background: #fbfcfe;
    transform: none;
}

.dd-lesson-row--coming-soon .dd-lesson-row__position,
.dd-lesson-row--locked .dd-lesson-row__position,
.dd-lesson-row--coming-soon:hover .dd-lesson-row__position,
.dd-lesson-row--locked:hover .dd-lesson-row__position {
    border-color: #a9b4c4;
    background: #a9b4c4;
    box-shadow: none;
    color: #ffffff;
}

.dd-lesson-row--coming-soon .dd-lesson-row__content strong,
.dd-lesson-row--locked .dd-lesson-row__content strong {
    color: #5f6b7a;
}

.dd-lesson-row--coming-soon .dd-lesson-row__content small,
.dd-lesson-row--locked .dd-lesson-row__content small {
    color: #94a3b8;
}

.dd-lesson-row--coming-soon .dd-lesson-row__arrow,
.dd-lesson-row--locked .dd-lesson-row__arrow,
.dd-lesson-row--coming-soon:hover .dd-lesson-row__arrow,
.dd-lesson-row--locked:hover .dd-lesson-row__arrow {
    color: #a5afbd;
    transform: none;
}