:root {
    --primary: #0d6efd;
    --secondary: #6610f2;
    --warning: #f59e0b;
    --success: #16a34a;
    --danger: #dc2626;
    --text: #1f2937;
    --muted: #6b7280;
    --bg: #f4f7fb;
    --card: #ffffff;
    --border: rgba(15, 23, 42, 0.08);
    --shadow: 0 12px 30px rgba(2, 6, 23, 0.08);
    --radius: 18px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text);
}

a {
    text-decoration: none;
}

/* ================= NAVBAR ================= */
.navbar {
    background: rgba(17, 24, 39, 0.92) !important;
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

    .navbar .nav-link,
    .navbar .dropdown-item {
        font-weight: 500;
    }

        .navbar .nav-link:hover,
        .navbar .dropdown-item:hover {
            color: #fff !important;
        }

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    height: 50px;
    width: auto;
    object-fit: contain;
}

.brand-text {
    font-size: 24px;
    font-weight: 800;
    letter-spacing: 0.5px;
    display: flex;
    gap: 6px;
    align-items: center;
}

.brand-main {
    color: #ffffff;
}

.brand-highlight {
    background: linear-gradient(45deg, #fde68a, #f59e0b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* ================= DROPDOWNS ================= */
.dropdown-submenu {
    position: relative;
}

    .dropdown-submenu > .dropdown-menu {
        top: 0;
        left: 100%;
        margin-top: -1px;
        border-radius: 14px;
        min-width: 220px;
    }

    .nav-item.dropdown:hover > .dropdown-menu,
    .dropdown-submenu:hover > .dropdown-menu {
        display: block;
    }

.dropdown-menu {
    border-radius: 14px;
    padding: 8px;
    box-shadow: 0 18px 40px rgba(2, 6, 23, 0.14);
}

.dropdown-item {
    border-radius: 10px;
    padding: 10px 14px;
}

    .dropdown-item:hover {
        background: rgba(13, 110, 253, 0.08);
    }

.dropdown-submenu > a::after {
    float: right;
    margin-top: 6px;
    margin-right: -10px;
}

/* ================= HERO ================= */
.hero-section {
    position: relative;
    overflow: hidden;
    background: radial-gradient(circle at top left, rgba(255,255,255,0.16), transparent 30%), radial-gradient(circle at bottom right, rgba(255,255,255,0.10), transparent 25%), linear-gradient(135deg, #0b5ed7 0%, #6610f2 100%);
    padding: 150px 20px 105px;
    margin-top: 56px;
    color: white;
    text-align: center;
}

    .hero-section::before {
        content: "";
        position: absolute;
        inset: 0;
        background-image: linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
        background-size: 28px 28px;
        opacity: 0.25;
        pointer-events: none;
    }

.hero-content {
    position: relative;
    z-index: 2;
}

.hero-badge {
    display: inline-block;
    padding: 10px 18px;
    border-radius: 999px;
    background: rgba(255,255,255,0.14);
    border: 1px solid rgba(255,255,255,0.18);
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 22px;
}

.hero-section h1 {
    font-weight: 800;
    letter-spacing: -0.5px;
}

.hero-section .lead {
    color: rgba(255,255,255,0.9);
    max-width: 760px;
    margin: 0 auto;
}

.hero-actions .btn {
    min-width: 190px;
    border-radius: 12px;
    font-weight: 600;
    padding: 14px 22px;
    box-shadow: 0 10px 24px rgba(0,0,0,0.12);
}

/* ================= SECTIONS ================= */
.section-heading {
    margin-bottom: 38px;
}

    .section-heading h2 {
        font-weight: 800;
        margin-bottom: 10px;
    }

    .section-heading p {
        color: var(--muted);
        margin-bottom: 0;
    }

/* ================= COUNTERS ================= */
.counter-section {
    padding: 85px 0;
    text-align: center;
}

.counter-box {
    background: var(--card);
    border-radius: var(--radius);
    padding: 28px 18px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
    height: 100%;
}

    .counter-box:hover {
        transform: translateY(-6px);
        box-shadow: 0 18px 34px rgba(2, 6, 23, 0.10);
    }

.counter {
    font-size: 42px;
    font-weight: 800;
    color: var(--primary);
    line-height: 1;
    margin-bottom: 10px;
}

.counter-label {
    color: var(--muted);
    font-weight: 600;
    margin-bottom: 0;
}

/* ================= MCQ ================= */
.mcq-section {
    padding: 90px 0;
}

.mcq-card {
    background: var(--card);
    padding: 26px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    margin-bottom: 24px;
    transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.3s ease, color 0.3s ease;
}

    .mcq-card:hover {
        transform: translateY(-4px);
        box-shadow: 0 18px 34px rgba(2, 6, 23, 0.10);
    }

.mcq-question-number {
    display: inline-block;
    margin-bottom: 10px;
    color: var(--primary);
    font-weight: 700;
}

.mcq-card p {
    margin-bottom: 0;
    font-size: 16px;
    line-height: 1.65;
}

.option {
    padding: 13px 14px;
    border: 1px solid #dbe2ea;
    border-radius: 12px;
    margin-bottom: 10px;
    cursor: pointer;
    transition: all 0.2s ease;
    background: #fff;
    font-weight: 500;
}

    .option:hover {
        background: #f8fafc;
        border-color: #cbd5e1;
    }

.disabled-option {
    pointer-events: none;
    opacity: 0.95;
}

.option-correct {
    background: #dcfce7 !important;
    border-color: #22c55e !important;
    color: #166534 !important;
}

.option-wrong {
    background: #fee2e2 !important;
    border-color: #ef4444 !important;
    color: #991b1b !important;
}

.answer-box {
    padding: 14px 16px;
    border-radius: 12px;
    border: 1px solid #dbe2ea;
    margin-top: 12px;
    background: #f8fafc;
    color: var(--text);
    line-height: 1.6;
}

.btn-explanation {
    border-radius: 10px;
    font-weight: 600;
}

/* ================= NEWS ================= */
.sidebar-sticky {
    position: sticky;
    top: 92px;
}

.news-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 20px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

    .news-card .card-header {
        padding: 18px 20px;
        font-weight: 700;
        letter-spacing: 0.2px;
    }

.news-item {
    transition: background-color 0.25s ease;
}

    .news-item:hover {
        background-color: #f8fafc;
    }

.news-link {
    color: var(--text);
    transition: color 0.2s ease;
    line-height: 1.5;
}

    .news-link:hover {
        color: var(--primary);
    }

/* ================= FEATURES ================= */
.why-section {
    padding: 90px 0;
}

.feature-card {
    background: var(--card);
    padding: 34px 28px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.3s ease, color 0.3s ease;
    height: 100%;
}

    .feature-card:hover {
        transform: translateY(-8px);
        box-shadow: 0 18px 34px rgba(2, 6, 23, 0.10);
    }

    .feature-card h5 {
        font-weight: 700;
        margin-bottom: 10px;
    }

    .feature-card p {
        color: var(--muted);
        margin-bottom: 0;
    }

/* ================= TESTIMONIAL ================= */
.testimonial-card {
    background: var(--card);
    padding: 25px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: background 0.3s ease, color 0.3s ease;
}

/* ================= FINAL CTA ================= */
.final-cta {
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, #6610f2, #0d6efd);
    padding: 95px 20px;
    text-align: center;
    color: white;
}

    .final-cta::before {
        content: "";
        position: absolute;
        inset: 0;
        background: radial-gradient(circle at top right, rgba(255,255,255,0.15), transparent 22%);
        pointer-events: none;
    }

    .final-cta .container {
        position: relative;
        z-index: 2;
    }

    .final-cta h2 {
        font-weight: 800;
        margin-bottom: 14px;
    }

    .final-cta p {
        color: rgba(255,255,255,0.9);
        margin-bottom: 0;
    }

/* ================= DARK MODE ================= */
.dark-mode {
    background: #0f172a !important;
    color: #f8fafc !important;
}

    .dark-mode .counter-box,
    .dark-mode .mcq-card,
    .dark-mode .feature-card,
    .dark-mode .testimonial-card,
    .dark-mode .news-card {
        background: #111827;
        color: #f8fafc;
        border-color: rgba(255,255,255,0.08);
        box-shadow: 0 16px 36px rgba(0,0,0,0.28);
    }

        .dark-mode .section-heading p,
        .dark-mode .counter-label,
        .dark-mode .feature-card p,
        .dark-mode .news-link {
            color: rgba(248,250,252,0.8);
        }

    .dark-mode .option {
        border: 1px solid rgba(255,255,255,0.10);
        color: #f8fafc;
        background: #0f172a;
    }

        .dark-mode .option:hover {
            background: #1e293b;
            color: #ffffff;
        }

    .dark-mode .answer-box {
        background: #0f172a;
        border-color: rgba(255,255,255,0.10);
        color: #f8fafc;
    }

    .dark-mode .news-item:hover {
        background-color: #1e293b;
    }

    .dark-mode .btn-explanation {
        background-color: #334155 !important;
        color: #fff !important;
        border: 1px solid rgba(255,255,255,0.08);
    }

    .dark-mode .btn-outline-light {
        border-color: rgba(255,255,255,0.35) !important;
    }

/* ================= RESPONSIVE ================= */
@media (max-width: 991.98px) {
    .sidebar-sticky {
        position: static;
        top: auto;
        margin-top: 24px;
    }

    .hero-section {
        padding: 135px 20px 90px;
    }

        .hero-section h1 {
            font-size: 2.2rem;
        }

    .dropdown-submenu > .dropdown-menu {
        left: 0;
        top: 100%;
    }
}

@media (max-width: 575.98px) {
    .brand-text {
        font-size: 20px;
    }

    .hero-actions .btn {
        width: 100%;
    }

    .counter {
        font-size: 34px;
    }
}

/* ================= SEARCH BOX ================= */
.search-practice-box {
    background: linear-gradient(135deg, #ffffff, #f7fbff);
    border: 1px solid rgba(13, 110, 253, 0.12);
    border-radius: 22px;
    padding: 24px;
    box-shadow: 0 14px 35px rgba(13, 110, 253, 0.08);
}

.search-icon-badge {
    width: 58px;
    height: 58px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    color: #fff;
    background: linear-gradient(135deg, #0d6efd, #6610f2);
    box-shadow: 0 10px 22px rgba(13, 110, 253, 0.25);
}

.search-title {
    font-weight: 700;
    color: #111827;
    margin: 0;
}

.search-subtitle {
    color: #6b7280;
    font-size: 15px;
}

.question-search-group {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
}

.question-search-input {
    flex: 1;
    min-width: 260px;
    height: 58px;
    border-radius: 16px;
    border: 1px solid #dbe2ea;
    padding: 0 18px;
    font-size: 15px;
    box-shadow: none;
}

    .question-search-input:focus {
        border-color: #86b7fe;
        box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.12);
    }

.btn-search-question {
    height: 58px;
    border: none;
    border-radius: 16px;
    padding: 0 24px;
    color: #fff;
    font-weight: 700;
    background: linear-gradient(135deg, #0d6efd, #6610f2);
    box-shadow: 0 12px 24px rgba(13, 110, 253, 0.20);
}

    .btn-search-question:hover {
        color: #fff;
        transform: translateY(-1px);
    }

.btn-clear-search {
    height: 58px;
    border-radius: 16px;
    padding: 0 20px;
    font-weight: 600;
}

.search-result-card {
    border: 2px solid #dbeafe;
    box-shadow: 0 12px 28px rgba(13, 110, 253, 0.08);
}

.search-result-badge {
    display: inline-block;
    background: linear-gradient(135deg, #0d6efd, #6610f2);
    color: #fff;
    padding: 6px 12px;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.3px;
}

mark {
    background: #fff3bf;
    padding: 0 4px;
    border-radius: 4px;
}

.dark-mode .search-practice-box {
    background: #1e1e1e;
    border-color: #333;
    box-shadow: 0 14px 35px rgba(0, 0, 0, 0.25);
}

.dark-mode .search-title,
.dark-mode .search-subtitle {
    color: #ffffff;
}

.dark-mode .question-search-input {
    background: #121212;
    color: #fff;
    border-color: #333;
}

    .dark-mode .question-search-input::placeholder {
        color: #aaa;
    }

.dark-mode .search-result-card {
    border-color: #374151;
}

@media (max-width: 768px) {
    .question-search-group {
        flex-direction: column;
        align-items: stretch;
    }

    .question-search-input,
    .btn-search-question,
    .btn-clear-search {
        width: 100%;
    }
}