/* Inner Page Design System */
.section {
    padding: 72px 0;
}

.section.bg-light {
    background: linear-gradient(180deg, #f7faff 0%, #eef4fb 100%);
}

.section-header {
    max-width: 760px;
    margin: 0 auto 34px;
    text-align: center;
}

.section-title {
    margin: 0 0 10px;
    color: #0f223d;
    font-size: clamp(1.75rem, 3vw, 2.4rem);
    line-height: 1.15;
    letter-spacing: -0.03em;
}

.section-title span {
    color: #0f6cbd;
}

.section-subtitle {
    margin: 0;
    color: #5d7289;
    font-size: 1rem;
    line-height: 1.75;
}

.detail-section {
    position: relative;
}

.detail-section .container {
    position: relative;
}

.detail-section-actions {
    display: flex;
    justify-content: center;
    margin-top: 24px;
}

.detail-empty-state {
    grid-column: 1 / -1;
    display: grid;
    justify-items: center;
    gap: 10px;
    padding: 34px 24px;
    border-radius: 26px;
    border: 1px dashed rgba(15, 108, 189, 0.24);
    background: linear-gradient(180deg, rgba(240, 247, 255, 0.92), rgba(255, 255, 255, 0.98));
    text-align: center;
    color: #4f647b;
    box-shadow: 0 18px 36px -30px rgba(11, 31, 58, 0.26);
}

.detail-empty-state i {
    width: 56px;
    height: 56px;
    border-radius: 18px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: rgba(15, 108, 189, 0.1);
    color: #0f6cbd;
    font-size: 1.25rem;
}

.detail-empty-state h3 {
    margin: 0;
    color: #10233f;
    font-size: 1.1rem;
}

.detail-empty-state p {
    margin: 0;
    max-width: 520px;
    line-height: 1.7;
}

.detail-empty-state__actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    margin-top: 8px;
}

.subjects-grid,
.related-subjects,
.related-topics {
    gap: 22px;
}

.subject-card,
.related-topic-card,
.related-subject-card,
.question-preview-card {
    position: relative;
    overflow: hidden;
    min-height: 100%;
    display: flex;
    flex-direction: column;
    gap: 14px;
    padding: 24px;
    border-radius: 24px;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(243, 247, 253, 0.96));
    border: 1px solid rgba(214, 224, 237, 0.92);
    box-shadow: 0 16px 34px -28px rgba(11, 31, 58, 0.35);
    transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.subject-card::before,
.related-topic-card::before,
.related-subject-card::before,
.question-preview-card::before {
    content: "";
    position: absolute;
    inset: 0 0 auto;
    height: 4px;
    background: linear-gradient(90deg, #0f6cbd, #f26522);
    opacity: 0.92;
}

.subject-card:hover,
.related-topic-card:hover,
.related-subject-card:hover,
.question-preview-card:hover,
.topic-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 24px 44px -30px rgba(11, 31, 58, 0.42);
    border-color: rgba(15, 108, 189, 0.24);
}

.subject-card h3,
.related-topic-card h3,
.related-subject-card h3,
.question-preview-card h3,
.topic-item h3 {
    margin: 0;
    color: #10233f;
    font-size: 1.1rem;
    line-height: 1.35;
}

.subject-card p,
.related-topic-card p,
.related-subject-card p,
.question-preview-card p {
    margin: 0;
    color: #62758a;
    line-height: 1.7;
}

.subject-icon,
.quick-card-icon,
.exam-icon {
    width: 60px;
    height: 60px;
    border-radius: 18px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(180deg, #133b6f, #0f6cbd);
    color: #ffffff;
    font-size: 1.45rem;
    box-shadow: 0 12px 26px -18px rgba(15, 108, 189, 0.52);
}

.subject-footer {
    margin-top: auto;
    padding-top: 4px;
}

.btn-text {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: #0f6cbd;
    font-weight: 800;
    letter-spacing: -0.01em;
}

.topic-item {
    position: relative;
    gap: 20px;
    padding: 22px 24px;
    border-radius: 24px;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(244, 248, 253, 0.96));
    border: 1px solid rgba(214, 224, 237, 0.92);
    box-shadow: 0 18px 36px -30px rgba(11, 31, 58, 0.34);
}

.topic-item::before {
    content: "";
    position: absolute;
    left: 0;
    top: 20px;
    bottom: 20px;
    width: 4px;
    border-radius: 999px;
    background: linear-gradient(180deg, #0f6cbd, #f26522);
}

.topic-info {
    gap: 16px;
}

.topic-number {
    width: 48px;
    height: 48px;
    border-radius: 16px;
    background: rgba(15, 108, 189, 0.1);
    box-shadow: inset 0 0 0 1px rgba(15, 108, 189, 0.08);
}

.topic-meta {
    color: #617589;
    font-weight: 600;
}

.topic-meta span,
.question-meta span {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.progress-bar {
    height: 10px;
    border-radius: 999px;
    background: #e5edf6;
}

.progress-fill {
    border-radius: inherit;
}

.quick-practice-card,
.detail-cta-card {
    align-items: center;
    gap: 32px;
    padding: 34px;
    border-radius: 30px;
    background: linear-gradient(135deg, #0f2240 0%, #133b6f 52%, #1f6bc1 100%);
    border: 1px solid rgba(18, 60, 114, 0.4);
    box-shadow: 0 30px 54px -34px rgba(11, 31, 58, 0.56);
}

.quick-practice-card h2,
.detail-cta-card h2,
.quick-practice-card p,
.detail-cta-card p {
    color: #ffffff;
}

.quick-practice-image img {
    max-width: 220px;
}

.detail-hero-stack {
    position: relative;
    z-index: 1;
    display: grid;
    justify-items: center;
    gap: 14px;
    text-align: center;
}

.subject-hero-kicker,
.topic-hero-kicker {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 14px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.18);
    color: rgba(255, 255, 255, 0.92);
    font-size: 0.82rem;
    font-weight: 800;
    letter-spacing: 0.01em;
}

.detail-hero-copy {
    max-width: 700px;
    margin: 0;
    font-size: 1.02rem;
    line-height: 1.75;
    color: rgba(255, 255, 255, 0.9);
}

.detail-toolbar {
    margin-bottom: 20px;
}

.question-topbar {
    box-shadow: 0 14px 28px -26px rgba(11, 31, 58, 0.36);
}

.desktop-question-page .question-container {
    background: linear-gradient(180deg, #f7faff 0%, #eef4fb 100%);
}

.desktop-question-page .question-main,
.desktop-question-page .palette-card,
.desktop-question-page .premium-sidebar-card {
    border-radius: 26px;
    border: 1px solid rgba(214, 224, 237, 0.92);
    box-shadow: 0 20px 40px -30px rgba(11, 31, 58, 0.34);
}

.desktop-question-page .question-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    margin-bottom: 18px;
}

.desktop-question-page .question-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 14px;
    border-radius: 999px;
    background: rgba(15, 108, 189, 0.1);
    color: #0f6cbd;
    font-size: 0.85rem;
    font-weight: 800;
}

.desktop-question-page .marks,
.desktop-question-page .question-source-badge,
.desktop-question-page .premium-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 6px 12px;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 800;
}

.desktop-question-page .marks {
    background: rgba(242, 101, 34, 0.12);
    color: #c95b1d;
}

.desktop-question-page .question-source-badge {
    background: #fff7ed;
    color: #9a3412;
    border: 1px solid #fed7aa;
}

.desktop-question-page .question-text {
    border-left-width: 0;
    border-radius: 22px;
    background: linear-gradient(180deg, #f7fbff, #edf4fb);
    box-shadow: inset 0 0 0 1px rgba(15, 108, 189, 0.08);
    font-size: 1.06rem;
    line-height: 1.85;
}

.desktop-question-page .option-item {
    border-radius: 18px;
    background: #ffffff;
    box-shadow: 0 10px 24px -26px rgba(11, 31, 58, 0.24);
}

.desktop-question-page .palette-card h4,
.desktop-question-page .premium-sidebar-card h4 {
    margin-top: 0;
    margin-bottom: 14px;
    font-size: 1.02rem;
    color: #10233f;
}

.desktop-question-page .sidebar-link-item {
    border-radius: 16px;
    background: linear-gradient(180deg, #f7fbff, #eef4fb);
    border: 1px solid rgba(214, 224, 237, 0.72);
}

.desktop-question-page .sidebar-link-item:hover {
    background: #eaf3ff;
    border-color: rgba(15, 108, 189, 0.2);
}

.desktop-question-page .question-actions {
    padding-top: 10px;
    border-top: 1px solid rgba(214, 224, 237, 0.86);
}

@media (max-width: 980px) {
    .section {
        padding: 60px 0;
    }

    .detail-section-actions {
        justify-content: stretch;
    }

    .detail-section-actions .btn {
        width: 100%;
        justify-content: center;
    }

    .quick-practice-card,
    .detail-cta-card {
        padding: 28px;
        text-align: center;
    }
}

@media (max-width: 640px) {
    .section {
        padding: 48px 0;
    }

    .section-header {
        margin-bottom: 24px;
    }

    .subject-card,
    .related-topic-card,
    .related-subject-card,
    .question-preview-card,
    .topic-item,
    .quick-practice-card,
    .detail-cta-card {
        padding: 20px;
        border-radius: 22px;
    }

    .subject-icon,
    .quick-card-icon,
    .exam-icon {
        width: 54px;
        height: 54px;
        border-radius: 16px;
        font-size: 1.25rem;
    }

    .detail-empty-state {
        padding: 28px 20px;
    }
}