:root {
    --accent-yellow: #ffe934;
    --accent-orange: #ff9f1c;
    --accent-pink: #d23d97;
    --accent-indigo: #4f42c9;
    --primary-blue: #1f6fd1;
    --primary-blue-dark: #1746a2;
    --primary-blue-soft: #eaf4ff;
    --ink: #111827;
    --muted: #667085;
    --line: #e7edf5;
    --paper: #ffffff;
    --soft: #f8fbff;
}

body {
    background: #ffffff !important;
}

.lesson-page {
    display: grid;
    gap: 1.5rem;
}

.lesson-hero {
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(31, 111, 209, 0.12);
    border-radius: 20px;
    background:
        linear-gradient(125deg, rgba(232, 244, 255, 0.98), rgba(245, 250, 255, 0.96), rgba(226, 239, 255, 0.94)),
        linear-gradient(90deg, rgba(255, 233, 52, 0.16), rgba(210, 61, 151, 0.08), rgba(31, 111, 209, 0.18));
    box-shadow: 0 16px 48px rgba(31, 111, 209, 0.06);
    padding: clamp(1rem, 2.5vw, 1.35rem);
}

.lesson-hero::before {
    content: "";
    position: absolute;
    inset: 0 0 auto;
    height: 5px;
    background: linear-gradient(90deg, var(--accent-yellow), var(--accent-orange), var(--accent-pink), var(--accent-indigo), var(--primary-blue));
}

.lesson-back-link,
.lesson-badges span,
.lesson-primary-link,
.lesson-nav-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.lesson-back-link {
    position: relative;
    z-index: 1;
    color: var(--primary-blue);
    font-size: 0.86rem;
    font-weight: 800;
}

.lesson-badges {
    position: relative;
    z-index: 1;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 0.65rem;
}

.lesson-badges span {
    border: 1px solid rgba(31, 111, 209, 0.14);
    border-radius: 999px;
    background: #ffffff;
    color: var(--primary-blue);
    font-size: 0.72rem;
    font-weight: 850;
    padding: 0.28rem 0.6rem;
}

.lesson-badges .lesson-completed-badge {
    background: rgba(22, 163, 74, 0.12);
    color: #15803d;
}

.lesson-hero h1 {
    position: relative;
    z-index: 1;
    color: var(--primary-blue-dark);
    font-size: clamp(1.4rem, 2.5vw, 1.85rem);
    font-weight: 900;
    line-height: 1.15;
    margin: 0.45rem 0 0;
}

.lesson-hero p {
    position: relative;
    z-index: 1;
    color: var(--muted);
    margin-top: 0.35rem;
    font-size: 0.92rem;
}

.lesson-card,
.lesson-navigation {
    border: 1px solid var(--line);
    border-radius: 22px;
    background: var(--paper);
    box-shadow: 0 14px 36px rgba(31, 111, 209, 0.055);
}

.lesson-card {
    overflow: hidden;
}

.lesson-card__header,
.lesson-quiz-header {
    border-bottom: 1px solid var(--line);
    padding: 1.25rem 1.5rem;
}

.lesson-card__header h2,
.lesson-quiz-header h2 {
    color: var(--ink);
    font-size: 1.35rem;
    font-weight: 950;
}

.lesson-card__body {
    padding: 1.5rem;
}

.lesson-text {
    color: #334155;
    line-height: 1.9;
}

.lesson-text ol {
    list-style-type: decimal !important;
    padding-left: 2rem !important;
    margin-top: 0.5rem !important;
    margin-bottom: 0.75rem !important;
}

.lesson-text ul {
    list-style-type: disc !important;
    padding-left: 2rem !important;
    margin-top: 0.5rem !important;
    margin-bottom: 0.75rem !important;
}

.lesson-text a {
    color: var(--primary-blue);
    font-weight: 800;
    text-decoration: underline;
    transition: color 180ms ease;
}

.lesson-text a:hover {
    color: var(--primary-blue-dark);
}

.lesson-pdf {
    width: 100%;
    height: 620px;
    border: 1px solid var(--line);
    border-radius: 16px;
}

.lesson-video {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: 16px;
}

.lesson-alert {
    border-radius: 16px;
    background: #fef2f2;
    color: #b91c1c;
    font-size: 0.9rem;
    font-weight: 800;
    padding: 1rem;
}

.lesson-file-action {
    margin-top: 1rem;
    text-align: center;
}

.lesson-primary-link,
.lesson-nav-button,
.lesson-submit-button,
.lesson-score-pill {
    justify-content: center;
    border-radius: 14px;
    font-size: 0.92rem;
    font-weight: 900;
    min-height: 46px;
    padding: 0.75rem 1rem;
}

.lesson-primary-link,
.lesson-nav-button--primary,
.lesson-submit-button {
    background: var(--primary-blue);
    color: #ffffff;
}

.lesson-primary-link:hover,
.lesson-nav-button--primary:hover,
.lesson-submit-button:hover {
    background: var(--primary-blue-dark);
}

.lesson-primary-link--youtube {
    background: #dc2626;
    color: #ffffff;
}

.lesson-primary-link--youtube:hover {
    background: #b91c1c;
}

.lesson-score-pill {
    background: rgba(22, 163, 74, 0.12);
    color: #15803d;
}

.lesson-score-pill--score {
    background: rgba(255, 233, 52, 0.28);
    color: #9a6a00;
}

.lesson-result-summary {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 0.55rem;
}

.lesson-score-pill--correct {
    background: rgba(22, 163, 74, 0.12);
    color: #15803d;
}

.lesson-score-pill--wrong {
    background: #fef2f2;
    color: #b91c1c;
}

.lesson-score-pill--pending {
    background: rgba(255, 159, 28, 0.13);
    color: #c96200;
}

.lesson-navigation {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem;
}

.lesson-nav-button--secondary {
    border: 1px solid rgba(31, 111, 209, 0.18);
    background: #ffffff;
    color: var(--primary-blue);
}

.lesson-nav-button--secondary:hover {
    background: var(--primary-blue-soft);
}

.lesson-nav-button--finish {
    background: #16a34a;
    color: #ffffff;
}

.lesson-nav-button--finish:hover {
    background: #15803d;
}

.lesson-quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.lesson-quiz-header p {
    color: #c96200;
    font-size: 0.78rem;
    font-weight: 950;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.lesson-quiz-list {
    display: grid;
    gap: 1rem;
    padding: 1.5rem;
}

.lesson-quiz-item {
    border: 1px solid var(--line);
    border-radius: 16px;
    background: #ffffff;
    padding: 1.5rem;
    box-shadow: 0 4px 12px rgba(31, 111, 209, 0.015);
    transition: border-color 220ms ease, box-shadow 220ms ease, transform 220ms ease;
}

.lesson-quiz-item:hover {
    border-color: rgba(31, 111, 209, 0.2);
    box-shadow: 0 12px 28px rgba(31, 111, 209, 0.05);
    transform: translateY(-2px);
}

.lesson-quiz-item p {
    color: var(--ink);
    font-size: 1.05rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.6;
}

.lesson-options {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.8rem;
}

.lesson-option,
.lesson-option-result {
    min-width: 0;
}

.lesson-option span,
.lesson-option-result {
    display: grid;
    grid-template-columns: 2.35rem minmax(0, 1fr);
    align-items: center;
    gap: 0.75rem;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    background: #f8fafc;
    color: #475569;
    padding: 0.75rem 1rem;
    min-height: 54px;
    transition: all 220ms cubic-bezier(0.16, 1, 0.3, 1);
}

.lesson-option:hover span {
    border-color: rgba(31, 111, 209, 0.35);
    background: var(--primary-blue-soft);
    color: var(--primary-blue);
    box-shadow: 0 6px 16px rgba(31, 111, 209, 0.06);
    transform: translateY(-1px);
}

.lesson-option:hover span strong {
    background: var(--primary-blue);
    color: #ffffff;
    border-color: var(--primary-blue);
}

.lesson-option strong,
.lesson-option-result strong {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.1rem;
    height: 2.1rem;
    border-radius: 50%;
    background: #ffffff;
    color: var(--primary-blue);
    font-size: 0.85rem;
    font-weight: 800;
    border: 1px solid rgba(31, 111, 209, 0.18);
    transition: all 220ms cubic-bezier(0.16, 1, 0.3, 1);
}

.lesson-option em,
.lesson-option-result em {
    min-width: 0;
    color: #334155;
    font-style: normal;
    font-weight: 600;
    line-height: 1.45;
    overflow-wrap: anywhere;
}

.lesson-quiz-form label {
    cursor: pointer;
}

.lesson-quiz-form input[type="radio"] {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.lesson-quiz-form input[type="radio"]:checked + span {
    border-color: var(--primary-blue);
    background: var(--primary-blue-soft);
    color: var(--primary-blue);
    box-shadow: 0 4px 12px rgba(31, 111, 209, 0.08);
}

.lesson-quiz-form input[type="radio"]:checked + span strong {
    background: var(--primary-blue);
    color: #ffffff;
    border-color: var(--primary-blue);
}

.lesson-option-result.is-correct {
    border-color: rgba(22, 163, 74, 0.35);
    background: rgba(22, 163, 74, 0.06);
    color: #16a34a;
}

.lesson-option-result.is-correct strong {
    background: #16a34a;
    color: #ffffff;
    border-color: #16a34a;
}

.lesson-option-result.is-wrong {
    border-color: rgba(220, 38, 38, 0.35);
    background: rgba(220, 38, 38, 0.04);
    color: #dc2626;
}

.lesson-option-result.is-wrong strong {
    background: #dc2626;
    color: #ffffff;
    border-color: #dc2626;
}

.lesson-option-result small {
    grid-column: 2;
    color: inherit;
    font-size: 0.76rem;
    font-weight: 900;
    margin-top: 0.25rem;
}

.lesson-submit-button {
    width: fit-content;
    justify-self: end;
}

.lesson-result-note {
    border-radius: 16px;
    background: var(--primary-blue-soft);
    color: var(--primary-blue);
    font-weight: 850;
    padding: 1rem;
}

.lesson-essay-panel,
.lesson-essay-result,
.lesson-reference-box {
    display: grid !important;
    grid-template-columns: 1fr !important;
    gap: 0.8rem !important;
}

.lesson-essay-panel label {
    display: grid;
    gap: 0.4rem;
}

.lesson-essay-panel label span,
.lesson-reference-box strong,
.lesson-essay-result strong {
    color: var(--ink);
    font-size: 0.88rem;
    font-weight: 900;
}

.lesson-essay-panel textarea,
.lesson-essay-panel input {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: #ffffff;
    min-height: 46px;
    padding: 0.75rem 0.9rem;
    transition: border-color 180ms ease, box-shadow 180ms ease;
}

.lesson-essay-panel textarea:focus,
.lesson-essay-panel input:focus {
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 4px var(--primary-blue-soft);
    outline: none;
}

.lesson-essay-panel textarea {
    resize: vertical;
}

.lesson-reference-box,
.lesson-essay-result,
.lesson-grade-box {
    border: 1px solid var(--line);
    border-radius: 16px;
    background: var(--soft);
    padding: 1rem;
}

.lesson-reference-box p,
.lesson-essay-result p,
.lesson-grade-box p {
    color: var(--muted);
    font-weight: 650;
    line-height: 1.7;
}

.lesson-reference-box a,
.lesson-essay-result a {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    color: var(--primary-blue);
    font-weight: 850;
}

.lesson-grade-box.is-graded {
    background: rgba(22, 163, 74, 0.12);
}

.lesson-grade-box.is-pending {
    background: rgba(255, 159, 28, 0.13);
}

@media (max-width: 640px) {
    .lesson-hero {
        border-radius: 16px;
        padding: 1rem;
    }

    .lesson-navigation,
    .lesson-quiz-header {
        align-items: stretch;
        flex-direction: column;
    }

    .lesson-result-summary {
        justify-content: stretch;
    }

    .lesson-navigation > div,
    .lesson-nav-button,
    .lesson-primary-link,
    .lesson-submit-button,
    .lesson-score-pill {
        width: 100%;
    }

    .lesson-options {
        grid-template-columns: 1fr;
    }
}

.lesson-essay {
    margin-top: 12px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.lesson-essay-field {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.lesson-essay-field label {
    font-size: 13px;
    font-weight: 600;
    color: #555;
}

.lesson-essay-field textarea {
    width: 100%;
    min-height: 110px;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 10px;
    font-size: 14px;
}

.lesson-essay-field input[type="file"] {
    font-size: 13px;
}

.lesson-essay-field textarea:focus {
    border-color: #4f46e5;
    outline: none;
}

.lesson-essay-attachment {
    font-size: 13px;
    background: #f5f7fb;
    padding: 8px;
    border-radius: 6px;
}

.lesson-essay-attachment a {
    color: #4f46e5;
    font-weight: 500;
}

.lesson-quiz-options {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.lesson-quiz-option {
    display: block;
    padding: 10px 12px;
    border-radius: 10px;
    background: #f9fafb;
    border: 1px solid #e5e7eb;
    font-size: 14px;
}

.lesson-quiz-option.essay-box textarea {
    width: 100%;
    min-height: 100px;
    border: none;
    background: transparent;
    resize: vertical;
    font-size: 14px;
}

.lesson-quiz-option.essay-box textarea:focus {
    outline: none;
}

.lesson-quiz-option.essay-box input[type="file"] {
    width: 100%;
    font-size: 13px;
}

.lesson-quiz-option.essay-box a {
    color: #4f46e5;
    font-weight: 500;
}

/* ── Assignment Form Styling ── */
.lesson-assignment-card {
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #ffffff;
    box-shadow: 0 10px 30px rgba(31, 111, 209, 0.05);
    padding: 1.75rem;
    margin-top: 1.5rem;
}

.lesson-assignment-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
    border-bottom: 1px solid var(--line);
    padding-bottom: 1.25rem;
    margin-bottom: 1.5rem;
}

.lesson-assignment-header__info {
    display: flex;
    align-items: center;
    gap: 0.85rem;
}

.lesson-assignment-header__icon {
    display: grid;
    place-items: center;
    width: 48px;
    height: 48px;
    border-radius: 16px;
    background: var(--primary-blue-soft);
    color: var(--primary-blue);
    font-size: 1.2rem;
}

.lesson-assignment-header h3 {
    font-weight: 950;
    font-size: 1.15rem;
    color: var(--ink);
    margin: 0;
}

.lesson-assignment-header p {
    font-size: 0.82rem;
    color: var(--muted);
    margin: 0.15rem 0 0;
}

.lesson-assignment-status {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.85rem;
    border-radius: 999px;
    font-weight: 850;
    font-size: 0.82rem;
}

.lesson-assignment-status--success {
    background: rgba(5, 150, 105, 0.12);
    color: #059669;
    border: 1px solid rgba(5, 150, 105, 0.2);
}

.lesson-assignment-status--pending {
    background: rgba(245, 158, 11, 0.12);
    color: #d97706;
    border: 1px solid rgba(245, 158, 11, 0.2);
}

.lesson-assignment-form {
    display: grid;
    gap: 1.25rem;
}

.lesson-assignment-field {
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
}

.lesson-assignment-field label {
    font-weight: 850;
    font-size: 0.9rem;
    color: var(--ink);
    display: flex;
    align-items: center;
    gap: 0.45rem;
}

.lesson-assignment-input {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: #f8fafc;
    padding: 0.7rem 0.9rem;
    font-size: 0.88rem;
    color: var(--ink);
    transition: border-color 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.lesson-assignment-input:focus {
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 4px var(--primary-blue-soft);
    background: #ffffff;
    outline: none;
}

.lesson-assignment-file-preview {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--soft);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 0.65rem 0.9rem;
    margin-bottom: 0.25rem;
}

.lesson-assignment-file-preview span {
    font-size: 0.83rem;
    font-weight: 750;
    color: var(--ink);
}

.lesson-assignment-file-preview a {
    font-size: 0.8rem;
    font-weight: 850;
    color: var(--primary-blue);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.lesson-assignment-file-preview a:hover {
    color: var(--primary-blue-dark);
}

.lesson-assignment-hint {
    font-size: 0.78rem;
    color: var(--muted);
    font-weight: 650;
}

.lesson-assignment-submit-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background: var(--primary-blue);
    color: #ffffff;
    border: none;
    border-radius: 14px;
    font-size: 0.92rem;
    font-weight: 900;
    padding: 0.75rem 1.75rem;
    min-height: 48px;
    cursor: pointer;
    box-shadow: 0 4px 14px rgba(31, 111, 209, 0.25);
    transition: background 180ms ease, transform 180ms ease;
}

.lesson-assignment-submit-btn:hover {
    background: var(--primary-blue-dark);
    transform: translateY(-1px);
}