/**
 * Practice Problems for Elementor - Frontend Scoped Stylesheet
 * All selectors are scoped under .pp-widget-container to eliminate CSS leakage.
 */

/* 1. CONTAINER & BASE RESET */
.pp-widget-container {
    box-sizing: border-box;
    width: 100%;
    margin: 0 auto;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: #1e293b;
    line-height: 1.5;
}

.pp-widget-container *,
.pp-widget-container *::before,
.pp-widget-container *::after {
    box-sizing: border-box;
}

/* 2. HERO / HEADER */
.pp-hero-card {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: #ffffff;
    border-radius: 16px;
    padding: 36px 32px;
    margin-bottom: 28px;
    box-shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.1), 0 8px 10px -6px rgba(15, 23, 42, 0.1);
    position: relative;
    overflow: hidden;
}

.pp-hero-eyebrow {
    display: inline-block;
    font-size: 0.8125rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: #38bdf8;
    background: rgba(56, 189, 248, 0.12);
    padding: 4px 12px;
    border-radius: 9999px;
    margin-bottom: 12px;
}

.pp-hero-title {
    font-size: 2.25rem;
    font-weight: 800;
    letter-spacing: -0.025em;
    line-height: 1.2;
    margin: 0 0 12px 0;
    color: #f8fafc;
}

.pp-hero-desc {
    font-size: 1.0625rem;
    line-height: 1.6;
    color: #94a3b8;
    margin: 0;
    max-width: 680px;
}

.pp-hero-cta-wrapper {
    margin-top: 20px;
}

.pp-hero-cta-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 22px;
    font-size: 0.9375rem;
    font-weight: 600;
    background-color: #38bdf8;
    color: #0f172a;
    border-radius: 8px;
    text-decoration: none;
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.pp-hero-cta-btn:hover {
    background-color: #7dd3fc;
    transform: translateY(-1px);
    color: #0f172a;
}

/* 3. FILTER TOOLBAR */
.pp-filters-bar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 16px;
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    padding: 16px 20px;
    margin-bottom: 24px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.03);
}

.pp-filters-bar.layout-column {
    flex-direction: column;
    align-items: stretch;
}

.pp-filters-bar.layout-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.pp-filter-group {
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.pp-filter-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: #64748b;
    white-space: nowrap;
}

/* Select Control */
.pp-select-control {
    padding: 8px 32px 8px 14px;
    font-size: 0.875rem;
    font-weight: 500;
    color: #1e293b;
    background-color: #f8fafc;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    outline: none;
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.pp-select-control:focus {
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

/* Pills Group */
.pp-pills-group {
    display: inline-flex;
    flex-wrap: wrap;
    gap: 6px;
}

.pp-pill-btn {
    border: 1px solid #e2e8f0;
    background: #f8fafc;
    color: #475569;
    padding: 6px 14px;
    border-radius: 9999px;
    font-size: 0.8125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
    line-height: 1.3;
}

.pp-pill-btn:hover {
    border-color: #cbd5e1;
    background: #f1f5f9;
    color: #1e293b;
}

.pp-pill-btn.active {
    background: #0f172a;
    border-color: #0f172a;
    color: #ffffff;
    box-shadow: 0 2px 4px rgba(15, 23, 42, 0.15);
}

/* Search Input */
.pp-filter-search {
    flex-grow: 1;
    min-width: 180px;
}

.pp-search-input {
    width: 100%;
    padding: 8px 14px;
    font-size: 0.875rem;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    background: #ffffff;
    color: #1e293b;
    outline: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.pp-search-input:focus {
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

/* Filter Actions (Reset & Expand) */
.pp-filter-actions {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-left: auto;
}

.pp-action-btn {
    border: 1px solid #e2e8f0;
    background: #ffffff;
    color: #475569;
    padding: 7px 14px;
    border-radius: 8px;
    font-size: 0.8125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.pp-action-btn:hover {
    background: #f1f5f9;
    border-color: #cbd5e1;
    color: #0f172a;
}

/* Counter Bar */
.pp-counter-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 4px 14px 4px;
    font-size: 0.875rem;
    font-weight: 600;
    color: #64748b;
}

/* 4. PROBLEM CARDS & LIST */
.pp-problems-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.pp-problem-card {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    padding: 24px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.pp-problem-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px -3px rgba(0, 0, 0, 0.07), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
    border-color: #cbd5e1;
}

/* Card Header & Badges */
.pp-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.pp-card-meta-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.pp-badge-id {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    height: 32px;
    padding: 0 8px;
    border-radius: 8px;
    background: #f1f5f9;
    color: #334155;
    font-size: 0.875rem;
    font-weight: 700;
    border: 1px solid #e2e8f0;
}

.pp-badge-topic {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 6px;
    background: #f8fafc;
    color: #475569;
    font-size: 0.8125rem;
    font-weight: 600;
    border: 1px solid #e2e8f0;
}

/* Difficulty Badges */
.pp-badge-difficulty {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border: 1px solid transparent;
}

.pp-badge-difficulty.easy {
    background: #ecfdf5;
    color: #059669;
    border-color: #a7f3d0;
}

.pp-badge-difficulty.medium {
    background: #fffbeb;
    color: #d97706;
    border-color: #fde68a;
}

.pp-badge-difficulty.hard {
    background: #fef2f2;
    color: #dc2626;
    border-color: #fecaca;
}

/* Problem Statement */
.pp-statement-content {
    font-size: 1.0625rem;
    line-height: 1.65;
    color: #1e293b;
    margin-bottom: 18px;
    background: #f8fafc;
    padding: 16px 18px;
    border-radius: 10px;
    border: 1px solid #f1f5f9;
    word-break: break-word;
}

.pp-problem-title {
    font-size: 1.1875rem;
    font-weight: 700;
    color: #0f172a;
    margin: 0;
    line-height: 1.45;
    font-family: inherit;
}

.pp-statement-content p:last-child {
    margin-bottom: 0;
}

/* 5. SOLUTION ACCORDION */
.pp-solution-wrapper {
    margin-top: 14px;
}

.pp-solution-toggle-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 9px 18px;
    border-radius: 8px;
    border: 1px solid #cbd5e1;
    background: #ffffff;
    color: #1e293b;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.pp-solution-toggle-btn:hover {
    background: #f8fafc;
    border-color: #94a3b8;
}

.pp-toggle-icon {
    transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.pp-solution-toggle-btn.expanded .pp-toggle-icon {
    transform: rotate(180deg);
}

.pp-solution-content {
    margin-top: 16px;
    padding: 20px 22px;
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-left: 4px solid #3b82f6;
    border-radius: 10px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

.pp-solution-title {
    font-size: 0.9375rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #334155;
    margin: 0 0 14px 0;
}

.pp-steps-list {
    list-style: none;
    padding: 0;
    margin: 0 0 16px 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.pp-step-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    font-size: 0.9375rem;
    line-height: 1.55;
    color: #334155;
}

.pp-step-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 24px;
    height: 24px;
    border-radius: 9999px;
    background: #e2e8f0;
    color: #1e293b;
    font-size: 0.75rem;
    font-weight: 700;
    margin-top: 1px;
    flex-shrink: 0;
}

.pp-step-body {
    flex-grow: 1;
}

.pp-solution-html-body {
    font-size: 0.9375rem;
    line-height: 1.65;
    color: #334155;
    margin-bottom: 12px;
}

.pp-solution-html-body ol,
.pp-solution-html-body ul {
    padding-left: 24px;
    margin: 12px 0;
}

.pp-solution-html-body li {
    margin-bottom: 8px;
}

.pp-solution-html-body h3,
.pp-solution-html-body h4 {
    font-size: 1rem;
    font-weight: 700;
    margin: 10px 0 8px 0;
    color: #1e293b;
}

/* Answer Box */
.pp-answer-box {
    margin-top: 14px;
    padding: 12px 16px;
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9375rem;
    color: #0f172a;
}

.pp-answer-label {
    color: #2563eb;
    font-weight: 700;
}

.pp-answer-val {
    font-weight: 600;
}

/* 6. PAGINATION */
.pp-pagination-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    margin-top: 32px;
    flex-wrap: wrap;
}

.pp-page-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 40px;
    padding: 0 14px;
    border-radius: 8px;
    border: 1px solid #cbd5e1;
    background: #ffffff;
    color: #334155;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
}

.pp-page-btn:not([disabled]):hover {
    background: #f1f5f9;
    border-color: #94a3b8;
    color: #0f172a;
}

.pp-page-btn.active {
    background: #0f172a;
    border-color: #0f172a;
    color: #ffffff;
    box-shadow: 0 2px 4px rgba(15, 23, 42, 0.15);
}

.pp-page-btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.pp-page-ellipsis {
    padding: 0 4px;
    color: #94a3b8;
    font-weight: 700;
    user-select: none;
}

/* 7. EMPTY STATE */
.pp-empty-state {
    text-align: center;
    padding: 48px 24px;
    background: #ffffff;
    border: 1px dashed #cbd5e1;
    border-radius: 14px;
    margin: 20px 0;
}

.pp-empty-icon {
    color: #94a3b8;
    margin-bottom: 12px;
}

.pp-empty-state h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: #1e293b;
    margin: 0 0 8px 0;
}

.pp-empty-state p {
    font-size: 0.9375rem;
    color: #64748b;
    max-width: 420px;
    margin: 0 auto 18px auto;
}

.pp-empty-reset-btn {
    background: #0f172a;
    color: #ffffff;
    border-color: #0f172a;
    padding: 8px 20px;
}

/* 8. RESPONSIVE BREAKPOINTS */
@media (max-width: 767px) {
    .pp-hero-card {
        padding: 24px 20px;
    }
    .pp-hero-title {
        font-size: 1.625rem;
    }
    .pp-filters-bar {
        flex-direction: column;
        align-items: stretch;
        padding: 16px;
    }
    .pp-filter-group {
        flex-direction: column;
        align-items: stretch;
    }
    .pp-select-control {
        width: 100%;
    }
    .pp-filter-actions {
        margin-left: 0;
        justify-content: space-between;
        width: 100%;
    }
    .pp-card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    .pp-page-btn {
        min-width: 36px;
        height: 36px;
        padding: 0 10px;
        font-size: 0.8125rem;
    }
}

/* 9. MATHEMATICAL NOTATION & MATHJAX SUPPORT */
.pp-math-render {
    max-width: 100%;
}

div.pp-math-render,
section.pp-math-render {
    -webkit-overflow-scrolling: touch;
}

/* INLINE MathJax SVG: no vertical margins, stays naturally centered and aligned with text flow */
.pp-math-render mjx-container[jax="SVG"]:not([display="true"]) {
    margin: 0 !important;
    padding: 0 !important;
    outline: none;
    display: inline-block !important;
    vertical-align: 0 !important;
    line-height: 0 !important;
}

.pp-math-render mjx-container[jax="SVG"]:not([display="true"]) > svg {
    margin: 0 !important;
    display: inline-block !important;
}

/* DISPLAY / BLOCK MathJax SVG */
.pp-math-render mjx-container[jax="SVG"][display="true"] {
    display: block !important;
    text-align: center;
    margin: 12px 0 !important;
    max-width: 100%;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
}

.pp-step-body mjx-container[jax="SVG"][display="true"] {
    margin: 8px 0 !important;
}

.pp-answer-val mjx-container[jax="SVG"]:not([display="true"]) {
    vertical-align: middle !important;
    display: inline-block !important;
    margin: 0 !important;
    padding: 0 !important;
}