/* Explain: Styling for various UI components like chips, cards, and forms. */
.chip {
    display: inline-flex;
    align-items: center;
    padding: 0.2rem 0.6rem;
    border-radius: 999px;
    font-size: 0.72rem;
    font-weight: 700;
    background: var(--surface-alt);
    color: var(--text-muted);
}

.chip--easy {
    background: #dcfce7;
    color: #166534;
}

.chip--medium {
    background: #fef3c7;
    color: #92400e;
}

.chip--hard {
    background: #fee2e2;
    color: #991b1b;
}

.badge-soft {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.3rem 0.75rem;
    border-radius: 999px;
    background: var(--primary-soft);
    color: var(--primary-color);
    font-size: 0.78rem;
    font-weight: 700;
}

/* Hero problem card */
.hero-card {
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
}

.hero-card__top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.hero-card__tag {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 0.95rem;
}

.hero-card__question {
    margin-top: 1.25rem;
    font-size: 1.12rem;
    font-weight: 600;
}

.hero-card__solution {
    margin-top: 0.9rem;
    display: grid;
    gap: 0.35rem;
    padding: 0.9rem 1rem;
    border-radius: 12px;
    background: var(--surface-alt);
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: 0.98rem;
    color: var(--text-muted);
}

.hero-card__result {
    color: var(--primary-color);
    font-weight: 700;
}

.hero-card__footer {
    margin-top: 1.25rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.hero-card__chapter {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.hero-card__chapter i {
    margin-inline-end: 0.35rem;
    color: var(--accent-color);
}

.play-btn {
    display: grid;
    place-items: center;
    width: 46px;
    height: 46px;
    flex: 0 0 auto;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #fff;
    box-shadow: 0 10px 22px rgba(79, 70, 229, 0.35);
}

/* Presentation */
.prezentare {
    display: grid;
    gap: 2.25rem;
}

@media (min-width: 1024px) {
    .prezentare {
        grid-template-columns: 1fr 1fr;
        align-items: start;
        gap: 3rem;
    }
}

.prezentare__cards {
    display: grid;
    gap: 1rem;
}

.check-list {
    margin: 1.25rem 0 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 0.6rem;
}

.check-list li {
    display: flex;
    align-items: flex-start;
    gap: 0.6rem;
    font-size: 0.95rem;
    color: var(--text-muted);
}

.check-list i {
    margin-top: 0.3rem;
    color: var(--success-color);
}

.struct-card {
    display: flex;
    gap: 1rem;
    padding: 1.1rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
}

.struct-card__icon {
    display: grid;
    place-items: center;
    width: 44px;
    height: 44px;
    flex: 0 0 auto;
    border-radius: 12px;
    background: var(--accent-soft);
    color: var(--accent-color);
    font-size: 1.05rem;
}

.struct-card__title {
    font-size: 1rem;
    font-weight: 700;
}

.struct-card__meta {
    margin-top: 0.15rem;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--primary-color);
}

.struct-card__desc {
    margin-top: 0.35rem;
    font-size: 0.88rem;
    color: var(--text-muted);
}

/* Feature cards */
.feature-grid {
    display: grid;
    gap: 1.25rem;
}

@media (min-width: 640px) {
    .feature-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 1024px) {
    .feature-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
}

.feature-card {
    display: flex;
    flex-direction: column;
    height: 100%;
    padding: 1.55rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: #c7d2fe;
    box-shadow: var(--shadow-md);
}

.feature-card__icon {
    display: grid;
    place-items: center;
    width: 46px;
    height: 46px;
    margin-bottom: 1rem;
    border-radius: 14px;
    background: var(--primary-soft);
    color: var(--primary-color);
    font-size: 1.15rem;
}

.feature-card__title {
    font-size: 1.02rem;
    font-weight: 700;
}

.feature-card__text {
    margin-top: 0.5rem;
    font-size: 0.92rem;
    color: var(--text-muted);
}

/* Chapter preview + list */
.chapter-preview {
    display: grid;
    gap: 0.85rem;
}

@media (min-width: 640px) {
    .chapter-preview {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 1024px) {
    .chapter-preview {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.chapter-preview__item {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    padding: 1rem 1.1rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    font-size: 0.95rem;
    font-weight: 600;
    transition: transform 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.chapter-preview__item:hover {
    transform: translateY(-3px);
    border-color: #c7d2fe;
    color: var(--primary-color);
}

.chapter-preview__item i {
    width: 20px;
    text-align: center;
    color: var(--secondary-color);
}

.chapter-list {
    display: grid;
    gap: 0.9rem;
}

.chapter {
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: box-shadow 0.25s ease, border-color 0.25s ease;
}

.chapter.is-open {
    border-color: #c7d2fe;
    box-shadow: var(--shadow-md);
}

.chapter__head {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.9rem;
    padding: 1rem 1.1rem;
    background: none;
    border: 0;
    text-align: start;
}

.chapter__num {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    flex: 0 0 auto;
    border-radius: 12px;
    background: var(--primary-soft);
    color: var(--primary-color);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 0.95rem;
}

.chapter__icon {
    display: none;
}

@media (min-width: 640px) {
    .chapter__icon {
        display: grid;
        place-items: center;
        width: 42px;
        height: 42px;
        flex: 0 0 auto;
        border-radius: 12px;
        background: var(--surface-alt);
        color: var(--secondary-color);
    }
}

.chapter__meta {
    flex: 1 1 auto;
    min-width: 0;
}

.chapter__title {
    display: block;
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1rem;
}

.chapter__desc {
    display: block;
    margin-top: 0.2rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.chapter__count {
    display: none;
    font-size: 0.75rem;
    color: var(--text-muted);
    white-space: nowrap;
}

@media (min-width: 640px) {
    .chapter__count {
        display: inline;
    }
}

.chapter__chevron {
    flex: 0 0 auto;
    color: var(--text-muted);
    transition: transform 0.25s ease;
}

.chapter.is-open .chapter__chevron {
    transform: rotate(180deg);
}

.chapter__body {
    padding: 0 1.1rem 1.2rem;
    border-top: 1px solid var(--border-color);
}

.chapter__exercises {
    display: grid;
    gap: 0.9rem;
    padding-top: 1.1rem;
}

/* Exercise card */
.exercise-list {
    display: grid;
    gap: 1rem;
    margin-top: 1.6rem;
}

@media (min-width: 1024px) {
    .exercise-list {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

.exercise-card {
    display: flex;
    flex-direction: column;
    padding: 1.1rem;
    border-radius: var(--radius-sm);
    background: var(--surface-alt);
    border: 1px solid var(--border-color);
}

.exercise-card__head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.exercise-card__chapter {
    font-size: 0.74rem;
    font-weight: 700;
    letter-spacing: 0.07em;
    text-transform: uppercase;
    color: var(--secondary-color);
}

.exercise-card__title {
    margin-top: 0.5rem;
    font-size: 1rem;
    font-weight: 700;
}

.exercise-card__question,
.exercise-card__answer {
    margin-top: 0.85rem;
}

.exercise-card__label {
    display: block;
    margin-bottom: 0.25rem;
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-muted);
}

.exercise-card__text {
    font-size: 0.94rem;
}

.exercise-card__answer .exercise-card__text {
    padding: 0.6rem 0.75rem;
    border: 1px dashed var(--border-color);
    border-radius: 10px;
    background: var(--surface-color);
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: 0.9rem;
}

.exercise-card__video {
    margin-top: 1rem;
    align-self: flex-start;
}

.empty-note {
    font-size: 0.92rem;
    color: var(--text-muted);
}

/* Papers */
.year-group {
    margin-top: 2.75rem;
}

.year-group--first {
    margin-top: 0;
}

.year-group__title {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    margin: 0 0 1.35rem;
    font-size: 1.35rem;
    font-weight: 800;
    color: var(--primary-color);
}

.year-group__title::after {
    content: "";
    flex: 1 1 auto;
    height: 1px;
    background: var(--border-color);
}

.year-group__title i {
    color: var(--secondary-color);
    font-size: 1.05rem;
}

.paper-grid {
    display: grid;
    gap: 1.5rem;
}

@media (min-width: 640px) {
    .paper-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 1024px) {
    .paper-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.paper-card {
    display: flex;
    flex-direction: column;
    height: 100%;
    overflow: hidden;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.paper-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.paper-card__media {
    position: relative;
    display: block;
    aspect-ratio: 16 / 9;
    overflow: hidden;
    background: var(--surface-alt);
}

.paper-card__media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}

.paper-card:hover .paper-card__media img {
    transform: scale(1.05);
}

.paper-card__year {
    position: absolute;
    inset-block-start: 0.75rem;
    inset-inline-start: 0.75rem;
    padding: 0.25rem 0.7rem;
    border-radius: 999px;
    background: rgba(15, 23, 42, 0.82);
    color: #fff;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 0.85rem;
}

.paper-card__body {
    display: flex;
    flex-direction: column;
    flex: 1 1 auto;
    gap: 0.6rem;
    padding: 1.25rem;
}

.paper-card__title {
    font-size: 1.03rem;
    font-weight: 700;
}

.paper-card__title a:hover {
    color: var(--primary-color);
}

.paper-card__text {
    flex: 1 1 auto;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.paper-card__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 0.35rem;
}

.year-strip {
    display: grid;
    gap: 0.85rem;
}

@media (min-width: 640px) {
    .year-strip {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 1024px) {
    .year-strip {
        grid-template-columns: repeat(5, minmax(0, 1fr));
    }
}

.year-chip {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
    padding: 1.1rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.year-chip:hover {
    transform: translateY(-3px);
    border-color: #c7d2fe;
}

.year-chip__year {
    font-family: var(--font-heading);
    font-size: 1.45rem;
    font-weight: 800;
    color: var(--primary-color);
}

.year-chip__label {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.year-chip i {
    margin-top: 0.5rem;
    color: var(--secondary-color);
}

/* CTA band */
.cta-band {
    padding: 2.5rem 1.75rem;
    border-radius: var(--radius-lg);
    text-align: center;
    color: #fff;
    background: linear-gradient(135deg, #312e81, #4f46e5 55%, #0ea5e9);
}

.cta-band h2 {
    color: #fff;
}

.cta-band p {
    margin-top: 0.75rem;
    color: rgba(255, 255, 255, 0.88);
}

.cta-band__actions {
    margin-top: 1.75rem;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
}

.btn-ghost-light {
    background: rgba(255, 255, 255, 0.14);
    border: 1px solid rgba(255, 255, 255, 0.38);
    color: #fff;
}

.btn-ghost-light:hover {
    background: rgba(255, 255, 255, 0.26);
}

/* Paper detail */
.paper-detail {
    padding-block: 1.75rem 3.5rem;
}

.breadcrumbs {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.breadcrumbs a:hover {
    color: var(--primary-color);
}

.breadcrumbs i {
    font-size: 0.62rem;
}

.paper-detail__grid {
    display: grid;
    gap: 2rem;
}

@media (min-width: 1024px) {
    .paper-detail__grid {
        grid-template-columns: 1.6fr 1fr;
        align-items: start;
        gap: 2.5rem;
    }
}

.paper-detail__title {
    margin-top: 0.85rem;
    font-size: clamp(1.65rem, 4vw, 2.4rem);
    font-weight: 800;
}

.paper-detail__desc {
    margin-top: 0.9rem;
    font-size: 1.02rem;
    color: var(--text-muted);
}

.paper-detail__actions {
    margin-top: 1.6rem;
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.paper-detail__side {
    padding: 1.5rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.meta-list {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 0.9rem;
}

.meta-list li {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    padding-bottom: 0.75rem;
    font-size: 0.92rem;
    border-bottom: 1px dashed var(--border-color);
}

.meta-list li:last-child {
    padding-bottom: 0;
    border-bottom: 0;
}

.meta-list__label {
    color: var(--text-muted);
}

.exercises-block {
    margin-top: 3.25rem;
}

/* Contact */
.contact-grid {
    display: grid;
    gap: 2rem;
}

@media (min-width: 1024px) {
    .contact-grid {
        grid-template-columns: 1.1fr 0.9fr;
        align-items: start;
    }
}

.contact-form {
    display: grid;
    gap: 1.1rem;
    padding: 1.75rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.form-label {
    display: block;
    margin-bottom: 0.4rem;
    font-size: 0.85rem;
    font-weight: 600;
}

.form-status {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.form-status--ok {
    color: var(--success-color);
    font-weight: 600;
}

.form-status--error {
    color: #b91c1c;
    font-weight: 600;
}

.info-stack {
    display: grid;
    gap: 1rem;
}

.info-card {
    display: flex;
    gap: 1rem;
    padding: 1.35rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
}

.info-card__icon {
    display: grid;
    place-items: center;
    width: 44px;
    height: 44px;
    flex: 0 0 auto;
    border-radius: 12px;
    background: var(--primary-soft);
    color: var(--primary-color);
}

.info-card__title {
    font-size: 0.98rem;
    font-weight: 700;
}

.info-card__text {
    margin-top: 0.2rem;
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Prose */
.prose-block {
    max-width: 46rem;
}

.prose-block p {
    margin-top: 1rem;
    font-size: 1.02rem;
    color: var(--text-muted);
}

.prose-block h2 {
    margin-top: 2.5rem;
}

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

@media (min-width: 768px) {
    .stat-row {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
}

.stat {
    padding: 1.1rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    text-align: center;
}

.stat__value {
    font-family: var(--font-heading);
    font-size: 1.85rem;
    font-weight: 800;
    color: var(--primary-color);
}

.stat__label {
    margin-top: 0.2rem;
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* Abonament și controlul accesului */
.plan-card {
    display: grid;
    gap: 1.1rem;
    padding: 1.75rem;
    border-radius: var(--radius-lg);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
}

.plan-price {
    font-family: var(--font-heading);
    font-size: clamp(2.1rem, 6vw, 2.9rem);
    font-weight: 800;
    line-height: 1.1;
    color: var(--primary-color);
}

.plan-price small {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-muted);
}

.plan-list {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 0.55rem;
}

.plan-list li {
    display: flex;
    align-items: flex-start;
    gap: 0.6rem;
    font-size: 0.94rem;
    color: var(--text-muted);
}

.plan-list i {
    margin-top: 0.3rem;
    color: var(--success-color);
}

.abonament-band {
    display: grid;
    gap: 2rem;
    padding: 2rem;
    border-radius: var(--radius-lg);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
}

@media (min-width: 1024px) {
    .abonament-band {
        grid-template-columns: 1.5fr 1fr;
        align-items: center;
        padding: 2.75rem;
    }
}

.abonament-band__card {
    display: grid;
    gap: 0.9rem;
    padding: 1.5rem;
    border-radius: var(--radius-md);
    background: var(--primary-soft);
    border: 1px dashed #c7d2fe;
}

.access-grid {
    display: grid;
    gap: 2rem;
}

@media (min-width: 1024px) {
    .access-grid {
        grid-template-columns: 1.1fr 0.9fr;
        align-items: start;
    }
}

.access-panel {
    display: grid;
    gap: 1.1rem;
    padding: 1.75rem;
    border-radius: var(--radius-md);
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.access-form {
    display: grid;
    gap: 0.7rem;
}

.access-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

.access-status {
    font-size: 0.98rem;
    font-weight: 700;
    color: var(--text-muted);
}

.access-status--active {
    color: var(--success-color);
}

.access-account {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.exercise-card--locked {
    border-style: dashed;
    background: var(--surface-color);
}

.exercise-card__locked {
    margin-top: 1rem;
    display: grid;
    gap: 0.6rem;
    justify-items: start;
    padding: 1rem;
    border-radius: 12px;
    background: var(--primary-soft);
    border: 1px dashed #c7d2fe;
}

.exercise-card__locked i {
    color: var(--primary-color);
}

.exercise-card__locked-text {
    font-size: 0.9rem;
    color: var(--text-muted);
}