.must-know-page {
    color: #111827;
    max-width: 1120px;
    margin: 0 auto;
    padding: 12px 0 48px;
}

.must-know-page * {
    box-sizing: border-box;
}

.must-know-hero,
.must-know-toolbar,
.must-know-language-summary,
.must-know-section {
    border: 1px solid rgba(15, 23, 42, 0.12);
    background: #ffffff;
    box-shadow: 0 18px 48px rgba(15, 23, 42, 0.08);
}

.must-know-hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 18px 20px;
    border-radius: 18px;
}

.must-know-kicker {
    margin: 0 0 4px;
    color: #0f766e;
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0;
    text-transform: uppercase;
}

.must-know-hero h1 {
    margin: 0;
    color: #0f172a;
    font-size: clamp(1.75rem, 3vw, 2.55rem);
    line-height: 1.05;
    letter-spacing: 0;
}

.must-know-player-link,
.must-know-search button,
.must-know-category-chip,
.must-know-card-actions a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 40px;
    border-radius: 999px;
    font-weight: 800;
    text-decoration: none;
    white-space: nowrap;
}

.must-know-player-link,
.must-know-search button {
    border: 0;
    background: #111827;
    color: #ffffff;
    padding: 0 18px;
}

.must-know-toolbar {
    position: sticky;
    top: 0;
    z-index: 5;
    margin-top: 14px;
    padding: 14px;
    border-radius: 18px;
}

.must-know-search {
    display: grid;
    grid-template-columns: minmax(170px, 0.55fr) minmax(220px, 1fr) auto;
    gap: 10px;
    align-items: end;
}

.must-know-search label {
    display: grid;
    gap: 5px;
    margin: 0;
}

.must-know-search label span {
    color: #475569;
    font-size: 0.78rem;
    font-weight: 800;
}

.must-know-search select,
.must-know-search input {
    width: 100%;
    min-height: 44px;
    border: 1px solid rgba(15, 23, 42, 0.14);
    border-radius: 14px;
    background: #f8fafc;
    color: #111827;
    padding: 0 14px;
    font-weight: 700;
    outline: none;
}

.must-know-search select:focus,
.must-know-search input:focus {
    border-color: rgba(13, 148, 136, 0.8);
    box-shadow: 0 0 0 4px rgba(20, 184, 166, 0.16);
}

.must-know-category-strip {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding: 12px 0 2px;
    scrollbar-width: thin;
}

.must-know-category-chip {
    border: 1px solid rgba(15, 23, 42, 0.12);
    background: #f8fafc;
    color: #334155;
    padding: 0 14px;
    font-size: 0.9rem;
}

.must-know-category-chip.is-active {
    border-color: rgba(13, 148, 136, 0.45);
    background: #ccfbf1;
    color: #0f766e;
}

.must-know-language-summary {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 14px;
    padding: 12px 14px;
    border-radius: 18px;
}

.must-know-language-summary img {
    width: 46px;
    height: 34px;
    object-fit: cover;
    border-radius: 8px;
    box-shadow: 0 8px 20px rgba(15, 23, 42, 0.18);
}

.must-know-language-summary div {
    display: grid;
    line-height: 1.15;
}

.must-know-language-summary strong {
    color: #0f172a;
    font-size: 1rem;
}

.must-know-language-summary span,
.must-know-language-summary small {
    color: #64748b;
    font-weight: 700;
}

.must-know-language-summary small {
    margin-left: auto;
}

.must-know-status {
    min-height: 24px;
    margin: 10px 4px 0;
    color: #0f766e;
    font-weight: 800;
}

.must-know-status.is-error {
    color: #be123c;
}

.must-know-sections {
    display: grid;
    gap: 14px;
    margin-top: 4px;
}

.must-know-section {
    padding: 14px;
    border-radius: 18px;
}

.must-know-section > header {
    display: flex;
    align-items: start;
    justify-content: space-between;
    gap: 12px;
    padding: 2px 2px 12px;
}

.must-know-section h2 {
    margin: 0;
    color: #0f172a;
    font-size: 1.04rem;
    line-height: 1.2;
    letter-spacing: 0;
}

.must-know-section p {
    margin: 3px 0 0;
    color: #64748b;
    font-size: 0.9rem;
    font-weight: 650;
}

.must-know-section > header > span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    height: 30px;
    border-radius: 999px;
    background: #f1f5f9;
    color: #475569;
    font-weight: 900;
}

.must-know-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
}

.must-know-card {
    display: grid;
    grid-template-columns: 34px minmax(0, 1fr) auto;
    gap: 10px;
    align-items: start;
    min-height: 122px;
    padding: 12px;
    border: 1px solid rgba(15, 23, 42, 0.12);
    border-radius: 14px;
    background: #ffffff;
}

.must-know-card.is-in-bucket {
    border-color: rgba(13, 148, 136, 0.35);
    background: #f0fdfa;
}

.must-know-card.is-preparing {
    opacity: 0.72;
}

.must-know-check {
    display: block;
    width: 28px;
    height: 28px;
    margin: 0;
    cursor: pointer;
}

.must-know-check input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.must-know-check span {
    display: block;
    width: 28px;
    height: 28px;
    border-radius: 9px;
    border: 2px solid rgba(15, 23, 42, 0.2);
    background: #ffffff;
    transition: background 0.16s ease, border-color 0.16s ease, box-shadow 0.16s ease;
}

.must-know-check input:checked + span {
    border-color: #0f766e;
    background: #0f766e;
    box-shadow: inset 0 0 0 6px #ffffff;
}

.must-know-check input:focus-visible + span {
    box-shadow: 0 0 0 4px rgba(20, 184, 166, 0.25);
}

.must-know-check input:disabled + span {
    cursor: default;
    opacity: 0.72;
}

.must-know-card-main {
    min-width: 0;
}

.must-know-card-topline {
    display: flex;
    align-items: center;
    gap: 8px;
    min-width: 0;
}

.must-know-card-main strong {
    display: block;
    min-width: 0;
    color: #111827;
    font-size: 1.08rem;
    line-height: 1.25;
    overflow-wrap: anywhere;
}

.must-know-speaker-badge {
    flex: 0 0 auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 999px;
    color: #ffffff;
    font-size: 1rem;
    font-weight: 900;
    box-shadow: 0 8px 18px rgba(15, 23, 42, 0.14);
}

.must-know-speaker-badge.is-female {
    background: #ec4899;
}

.must-know-speaker-badge.is-male {
    background: #0ea5e9;
}

.must-know-english,
.must-know-pronunciation {
    display: block;
    margin-top: 3px;
    overflow-wrap: anywhere;
}

.must-know-english {
    color: #1f2937;
    font-size: 0.96rem;
    font-weight: 850;
}

.must-know-pronunciation {
    color: #64748b;
    font-size: 0.86rem;
    font-weight: 800;
}

.must-know-card-main p {
    margin: 8px 0 0;
    color: #64748b;
    font-size: 0.86rem;
    line-height: 1.32;
}

.must-know-card-actions {
    display: grid;
    gap: 6px;
    justify-items: end;
}

.must-know-card-actions a {
    min-height: 32px;
    border: 1px solid rgba(13, 148, 136, 0.25);
    background: #ecfeff;
    color: #0f766e;
    padding: 0 12px;
    font-size: 0.82rem;
}

.must-know-card-actions span,
.must-know-card-actions small {
    color: #64748b;
    font-size: 0.78rem;
    font-weight: 850;
}

.must-know-empty {
    margin-top: 16px;
    padding: 32px;
    border-radius: 18px;
    border: 1px dashed rgba(15, 23, 42, 0.2);
    text-align: center;
}

@media (prefers-color-scheme: dark) {
    .must-know-page {
        color: #e5e7eb;
    }

    .must-know-hero,
    .must-know-toolbar,
    .must-know-language-summary,
    .must-know-section,
    .must-know-card {
        border-color: rgba(148, 163, 184, 0.25);
        background: #0b111a;
        box-shadow: none;
    }

    .must-know-hero h1,
    .must-know-language-summary strong,
    .must-know-section h2,
    .must-know-card-main strong,
    .must-know-english {
        color: #f8fafc;
    }

    .must-know-player-link,
    .must-know-search button {
        background: #2dd4bf;
        color: #031316;
    }

    .must-know-search select,
    .must-know-search input,
    .must-know-category-chip,
    .must-know-section > header > span {
        border-color: rgba(148, 163, 184, 0.26);
        background: #111827;
        color: #e5e7eb;
    }

    .must-know-card.is-in-bucket {
        border-color: rgba(45, 212, 191, 0.45);
        background: #0f2f2b;
    }

    .must-know-check span {
        border-color: rgba(226, 232, 240, 0.35);
        background: #111827;
    }
}

@media (max-width: 760px) {
    .must-know-page {
        padding: 8px 0 36px;
    }

    .must-know-hero,
    .must-know-toolbar,
    .must-know-language-summary,
    .must-know-section {
        border-radius: 14px;
    }

    .must-know-search {
        grid-template-columns: 1fr;
    }

    .must-know-search button {
        width: 100%;
    }

    .must-know-grid {
        grid-template-columns: 1fr;
    }

    .must-know-card {
        grid-template-columns: 32px minmax(0, 1fr);
    }

    .must-know-card-actions {
        grid-column: 2;
        grid-template-columns: auto auto;
        justify-content: start;
        justify-items: start;
    }
}