@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap');

:root {
    --sidebar-width: 16rem;
    --color-primary: rgb(21, 29, 81);
    --color-accent: rgb(147, 117, 199);
    --color-text-main: rgb(21, 29, 81);
    --color-text-muted: rgb(62, 70, 116);
    --color-surface: #ffffff;
    --color-border: #e2e8f0;
    --color-hover: rgba(21, 29, 81, 0.06);
    --color-muted-bg: #f8fafc;
    --font-main: 'Plus Jakarta Sans', sans-serif;
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --text-xs: 0.6875rem;
    --text-sm: 0.8125rem;
    --text-base: 0.9375rem;
    --text-md: 1rem;
}

html {
    font-size: 93.75%;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    font-family: var(--font-main);
    font-size: var(--text-base);
    color: var(--color-text-muted);
    margin: 0;
    background-color: var(--color-surface);
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

.icon {
    width: 1rem;
    height: 1rem;
    flex-shrink: 0;
}

.page-content {
    padding: clamp(0.75rem, 3vw, 1.5rem);
    width: 100%;
    max-width: 100%;
}

.subject-page {
    max-width: 64rem;
    margin: 0 auto;
    padding: clamp(0.75rem, 3vw, 3rem) clamp(0.75rem, 3vw, 1.5rem);
    width: 100%;
}

@media (min-width: 1024px) {
    .page-content {
        padding: 3rem;
    }

    .subject-page {
        padding: 3rem 1.5rem;
    }
}

@media (min-width: 1600px) {
    .page-content,
    .subject-page {
        max-width: 90rem;
        margin-left: auto;
        margin-right: auto;
    }
}

.breadcrumb,
.breadcrumbs {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.625rem;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    font-size: clamp(0.6875rem, 1.5vw, 0.75rem);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    color: var(--color-text-muted);
    margin-bottom: clamp(1rem, 2.5vw, 1.5rem);
}

.breadcrumb-home {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.25rem;
    background-color: var(--color-bg-soft, #f5f4fa);
    border: 1px solid transparent;
    color: var(--color-text-muted);
    transition: color var(--transition-fast), border-color var(--transition-fast);
}

.breadcrumb-home:hover {
    color: var(--color-primary);
    border-color: var(--color-border);
}

.breadcrumb-home svg {
    width: 0.875rem;
    height: 0.875rem;
}

.breadcrumb-separator {
    color: var(--color-border, #e5e7eb);
}

.breadcrumb a,
.breadcrumb-link {
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
    text-decoration: none;
}

.breadcrumb a:hover,
.breadcrumb-link:hover {
    color: var(--color-primary);
}

.breadcrumb-segment {
    color: var(--color-text-muted);
}

.breadcrumb-current {
    color: #5b4b9a;
    font-weight: 700;
}

.page-title {
    font-size: clamp(1.75rem, 4vw, 2.25rem);
    font-weight: 700;
    color: var(--color-text-main);
    margin: 0 0 0.5rem;
    letter-spacing: -0.02em;
}

.page-subtitle {
    margin: 0 0 clamp(1.25rem, 4vw, 2.5rem);
    color: var(--color-text-muted);
    font-size: clamp(var(--text-sm), 2.8vw, var(--text-base));
    line-height: 1.5;
}

.subjects-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

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

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

.subject-card {
    display: block;
    border: 1px solid var(--color-border);
    border-radius: 0.5rem;
    padding: 1.5rem;
    background-color: var(--color-surface);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.subject-card:hover {
    background-color: var(--hover-surface, #182059);
    border-color: var(--hover-surface, #182059);
    box-shadow: none;
}

.subject-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.subject-card-icon {
    width: 1.25rem;
    height: 1.25rem;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

.subject-card:hover .subject-card-icon {
    color: #ffffff;
}

.subject-card-number {
    font-size: 0.75rem;
    font-variant-numeric: tabular-nums;
    color: var(--color-text-muted);
}

.subject-card-title {
    font-size: var(--text-base);
    font-weight: 500;
    color: var(--color-text-main);
    margin: 0;
    transition: color var(--transition-fast);
}

.subject-card:hover .subject-card-title,
.subject-card:hover .subject-card-meta,
.subject-card:hover .subject-card-number {
    color: #ffffff;
}

.subject-card-meta {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin: 0.5rem 0 0;
}

.animate-on-scroll,
.animate-on-scroll.is-visible {
    opacity: 1;
    transform: none;
}

/* Subject page */
.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin-bottom: 2rem;
}

.back-link:hover {
    color: var(--color-text-main);
}

.pillar-list {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.pillar-card {
    border: 1px solid var(--color-border);
    border-radius: 0.5rem;
    padding: 1.5rem;
}

@media (min-width: 1024px) {
    .pillar-card {
        padding: 2rem;
    }
}

.pillar-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.pillar-icon-wrap {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 0.375rem;
    background-color: rgba(21, 29, 81, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.pillar-icon-wrap svg {
    width: 1.25rem;
    height: 1.25rem;
    color: var(--color-primary);
}

.pillar-title {
    font-size: var(--text-md);
    font-weight: 700;
    color: var(--color-text-main);
    margin: 0;
}

.pillar-subtitle {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin: 0.25rem 0 0;
}

.pillar-description {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin: 0 0 1.5rem;
}

.pillar-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.pillar-link {
    display: inline-block;
    padding: 0.5rem 1rem;
    font-size: var(--text-sm);
    border: 1px solid var(--color-border);
    border-radius: 0.375rem;
    transition: border-color var(--transition-fast), color var(--transition-fast);
}

.pillar-link:hover {
    background-color: var(--hover-surface, #182059);
    border-color: var(--hover-surface, #182059);
    color: #ffffff;
}

.pillar-link-pill {
    padding: 0.625rem 1.25rem;
    border-radius: 9999px;
    background-color: rgba(21, 29, 81, 0.1);
    color: var(--color-primary);
    border: none;
    font-weight: 500;
}

.pillar-link-pill:hover {
    background-color: var(--hover-surface, #182059);
    color: #ffffff;
}

.exam-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
}

@media (min-width: 640px) {
    .exam-grid {
        grid-template-columns: repeat(5, 1fr);
    }
}

.exam-tile {
    text-align: center;
    padding: 1rem;
    border: 1px solid var(--color-border);
    border-radius: 0.5rem;
    transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.exam-tile:hover {
    border-color: var(--hover-surface, #182059);
    background-color: var(--hover-surface, #182059);
}

.exam-tile-label {
    font-size: 0.75rem;
    font-variant-numeric: tabular-nums;
    color: var(--color-text-muted);
    margin: 0 0 0.25rem;
}

.exam-tile-name {
    font-size: var(--text-sm);
    font-weight: 500;
    margin: 0;
    transition: color var(--transition-fast);
}

.exam-tile:hover .exam-tile-name,
.exam-tile:hover .exam-tile-label {
    color: #ffffff;
}

/* Quiz page */
.quiz-layout {
    display: flex;
    align-items: stretch;
    background-color: var(--color-surface);
}

.quiz-sidebar {
    width: 4rem;
    flex-shrink: 0;
    border-right: 1px solid var(--color-border);
    background-color: var(--color-surface);
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1.5rem 0;
    gap: 0.5rem;
    overflow-y: auto;
    overflow-x: hidden;
    -webkit-overflow-scrolling: touch;
    overscroll-behavior: contain;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.quiz-sidebar::-webkit-scrollbar {
    display: none;
}

.quiz-question-num {
    width: 2.25rem;
    height: 2.25rem;
    border-radius: 0.375rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-variant-numeric: tabular-nums;
    color: var(--color-text-muted);
    cursor: pointer;
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.quiz-question-num:hover {
    background-color: var(--color-muted-bg);
}

.quiz-question-num.is-active {
    background-color: var(--color-primary);
    color: #ffffff;
    font-weight: 700;
}

.quiz-question-num.is-answered:not(.is-active) {
    background-color: var(--color-muted-bg);
    color: var(--color-text-main);
}

.quiz-question-num-check {
    display: none;
    width: 0.875rem;
    height: 0.875rem;
}

.quiz-question-num.is-answered:not(.is-active) .quiz-question-num-label {
    display: none;
}

.quiz-question-num.is-answered:not(.is-active) .quiz-question-num-check {
    display: block;
}

.quiz-main {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
}

.quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--color-border);
}

@media (min-width: 1024px) {
    .quiz-header {
        padding: 1rem 2.5rem;
    }
}

.quiz-progress-wrap {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.quiz-progress-ring {
    position: relative;
    width: 3rem;
    height: 3rem;
}

.quiz-progress-ring svg {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.progress-ring-bg {
    stroke: var(--color-border);
}

.progress-ring-fill {
    stroke: var(--color-primary);
    transition: stroke-dashoffset 0.3s;
}

.quiz-progress-text {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

.quiz-meta {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

.quiz-meta strong {
    color: var(--color-text-main);
    font-weight: 500;
}

.quiz-header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.quiz-context {
    font-size: 0.75rem;
    font-variant-numeric: tabular-nums;
    color: var(--color-text-muted);
}

@media (max-width: 640px) {
    .quiz-layout {
        --quiz-mobile-nav-height: 3.25rem;
        height: 100vh;
        height: 100dvh;
        overflow: hidden;
        display: grid;
        grid-template-areas:
            "header"
            "body";
        grid-template-rows: auto minmax(0, 1fr);
        position: relative;
    }

    .quiz-main {
        display: contents;
    }

    .quiz-header {
        grid-area: header;
        flex-wrap: nowrap;
        align-items: center;
        padding: 0.625rem 0.75rem;
        gap: 0.5rem;
    }

    .quiz-progress-wrap {
        flex: 1;
        min-width: 0;
        gap: 0.625rem;
    }

    .quiz-progress-ring {
        width: 2.5rem;
        height: 2.5rem;
        flex-shrink: 0;
    }

    .quiz-progress-text {
        font-size: 0.625rem;
    }

    .quiz-meta {
        font-size: 0.75rem;
        line-height: 1.3;
        min-width: 0;
    }

    .quiz-meta p {
        margin: 0;
    }

    .quiz-timer {
        margin-top: 0.125rem;
        font-size: 0.6875rem;
    }

    .quiz-header-right {
        flex-shrink: 0;
        gap: 0.375rem;
    }

    .quiz-context {
        display: none;
    }

    .quiz-sidebar {
        position: fixed;
        left: 0;
        right: 0;
        bottom: 0;
        z-index: 30;
        width: 100%;
        flex-direction: row;
        align-items: center;
        justify-content: flex-start;
        padding: 0.5rem 0.75rem;
        padding-bottom: max(0.5rem, env(safe-area-inset-bottom, 0px));
        gap: 0.375rem;
        border-right: none;
        border-top: 1px solid var(--color-border);
        border-bottom: none;
        box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.08);
        background-color: var(--color-surface);
        overflow-x: auto;
        overflow-y: hidden;
        scroll-snap-type: x proximity;
        scrollbar-width: none;
        -ms-overflow-style: none;
    }

    .quiz-question-num {
        flex-shrink: 0;
        width: 2rem;
        height: 2rem;
        font-size: 0.6875rem;
        scroll-snap-align: center;
    }

    .quiz-body {
        grid-area: body;
        min-height: 0;
    }

    .quiz-question {
        margin-bottom: 1.25rem;
    }

    .quiz-option {
        padding: 0.75rem 0.875rem;
    }

    .quiz-actions {
        flex-direction: column;
        align-items: stretch;
        gap: 0.5rem;
    }

    .quiz-actions .btn-secondary,
    .quiz-actions .btn-primary {
        width: 100%;
        text-align: center;
        margin-right: 0;
    }
}

@media (min-width: 641px) {
    .quiz-layout {
        position: relative;
        display: block;
        height: auto;
        overflow: visible;
    }

    .quiz-sidebar {
        position: absolute;
        top: 0;
        left: 0;
        bottom: 0;
        z-index: 1;
        width: 4rem;
        flex: none;
        flex-direction: column;
        align-items: center;
        padding: 1.5rem 0;
        border-right: 1px solid var(--color-border);
        border-top: none;
        box-shadow: none;
        overflow-x: hidden;
        overflow-y: auto;
        scroll-snap-type: none;
        touch-action: pan-y;
    }

    .quiz-main {
        margin-left: 4rem;
        display: flex;
        flex-direction: column;
        overflow: visible;
    }

    .quiz-body {
        flex: 0 0 auto;
        overflow: visible;
    }

    .quiz-question-num {
        flex-shrink: 0;
        width: 2.25rem;
        height: 2.25rem;
        font-size: 0.75rem;
        scroll-snap-align: unset;
    }
}

@media (min-width: 1024px) {
    .quiz-sidebar {
        width: 5rem;
    }

    .quiz-main {
        margin-left: 5rem;
    }
}

@media (max-width: 639px) {
    .quiz-context {
        display: none;
    }
}

.quiz-close-btn {
    width: 2rem;
    height: 2rem;
    border-radius: 0.375rem;
    border: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--transition-fast);
}

.quiz-close-btn:hover {
    background-color: var(--color-muted-bg);
}

.quiz-body {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: 2rem 1.5rem;
}

@media (min-width: 1024px) {
    .quiz-body {
        padding: 3rem 4rem;
    }
}

@media (min-width: 1280px) {
    .quiz-body {
        padding: 3rem 6rem;
    }
}

@media (min-width: 641px) {
    .quiz-body {
        flex: 0 0 auto;
        min-height: 0;
        overflow: visible;
        overscroll-behavior: auto;
    }
}

@media (max-width: 640px) {
    .quiz-body {
        padding: 1rem 0.75rem;
        padding-bottom: calc(var(--quiz-mobile-nav-height) + env(safe-area-inset-bottom, 0px) + 1.5rem);
    }

    .quiz-actions {
        padding-bottom: 0.25rem;
    }
}

.quiz-content {
    max-width: 42rem;
    margin: 0 auto;
}

.quiz-question {
    font-size: var(--text-base);
    line-height: 1.7;
    color: var(--color-text-main);
    margin: 0 0 2rem;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.quiz-option {
    width: 100%;
    text-align: left;
    padding: 1rem 1.25rem;
    border-radius: 0.5rem;
    border: 2px solid var(--color-border);
    transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.quiz-option:hover {
    border-color: rgba(21, 29, 81, 0.4);
    background-color: var(--color-muted-bg);
}

.quiz-option-inner {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.quiz-option-letter {
    width: 2rem;
    height: 2rem;
    border-radius: 50%;
    border: 2px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-sm);
    font-variant-numeric: tabular-nums;
    flex-shrink: 0;
}

.quiz-option-text {
    font-size: var(--text-base);
    line-height: 1.6;
    padding-top: 0.125rem;
}

.quiz-actions {
    margin-top: 2rem;
    display: flex;
    justify-content: flex-end;
}

.btn-primary {
    padding: 0.75rem 1.5rem;
    font-size: var(--text-sm);
    font-weight: 500;
    background-color: var(--color-primary);
    color: #ffffff;
    border-radius: 0.375rem;
    transition: opacity var(--transition-fast);
}

.btn-primary:hover {
    background-color: var(--hover-surface, #182059);
    opacity: 1;
}

.content-section {
    margin-bottom: 3rem;
}

.section-heading {
    font-size: var(--text-md);
    font-weight: 700;
    color: var(--color-text-main);
    margin: 0 0 0.5rem;
}

.section-description {
    margin: 0 0 1.5rem;
    color: var(--color-text-muted);
    font-size: var(--text-sm);
    line-height: 1.5;
}

.empty-state {
    color: var(--color-text-muted);
    font-size: var(--text-base);
}

.exam-tile-meta {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin: 0.5rem 0 0;
}

.btn-secondary {
    padding: 0.75rem 1.5rem;
    font-size: var(--text-sm);
    font-weight: 500;
    background-color: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-border);
    border-radius: 0.375rem;
    margin-right: 0.75rem;
}

.btn-secondary:disabled,
.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.quiz-actions {
    gap: 0.75rem;
}

.quiz-option.is-selected {
    border-color: var(--color-primary);
    background-color: rgba(21, 29, 81, 0.05);
}

.quiz-option.is-correct {
    border-color: #16a34a;
    background-color: rgba(22, 163, 74, 0.08);
}

.quiz-option.is-incorrect {
    border-color: #dc2626;
    background-color: rgba(220, 38, 38, 0.08);
}

.quiz-timer {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin: 0.25rem 0 0;
}

.question-extract {
    padding: 1rem;
    margin-bottom: 1.5rem;
    border-left: 3px solid var(--color-accent);
    background-color: var(--color-muted-bg);
    font-size: var(--text-base);
    line-height: 1.6;
}

.question-image-wrap {
    margin-bottom: 1.5rem;
}

.question-image {
    max-width: 100%;
    height: auto;
    border-radius: 0.5rem;
    border: 1px solid var(--color-border);
}

.quiz-rationale {
    margin-top: 1.5rem;
    padding: 1rem;
    border-radius: 0.5rem;
    background-color: rgba(21, 29, 81, 0.05);
}

.quiz-rationale-title {
    font-weight: 600;
    color: var(--color-primary);
    margin: 0 0 0.5rem;
}

.quiz-rationale-text {
    margin: 0;
    font-size: var(--text-base);
    line-height: 1.6;
}

.quiz-question-num {
    border: none;
    background: none;
    font-family: inherit;
}

/* Responsive typography & spacing */
@media (max-width: 1024px) {
    .breadcrumb {
        font-size: clamp(0.6875rem, 2.5vw, 0.8125rem);
        flex-wrap: wrap;
        gap: 0.375rem;
        margin-bottom: 0.375rem;
    }

    .page-title {
        font-size: clamp(1.375rem, 5.5vw, 1.875rem);
    }

    .content-section {
        margin-bottom: clamp(1.5rem, 5vw, 2rem);
    }

    .section-heading {
        font-size: clamp(1rem, 4vw, 1.125rem);
    }

    .section-description {
        margin-bottom: 1rem;
        font-size: clamp(0.8125rem, 2.8vw, 0.9375rem);
    }

    .subject-card {
        padding: clamp(0.875rem, 3vw, 1.25rem);
    }

    .subject-card-header {
        margin-bottom: 0.625rem;
    }

    .exam-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.5rem;
    }

    .exam-tile {
        padding: 0.75rem 0.5rem;
    }

    .exam-tile-name {
        font-size: clamp(0.75rem, 2.8vw, 0.875rem);
    }
}

@media (max-width: 360px) {
    .page-content,
    .subject-page {
        padding-left: 0.625rem;
        padding-right: 0.625rem;
    }

    .subjects-grid {
        gap: 0.625rem;
    }

    .exam-grid {
        grid-template-columns: 1fr;
    }
}

@media (min-width: 1920px) {
    :root {
        --sidebar-width: 18rem;
    }

    .page-title {
        font-size: clamp(2rem, 2vw, 2.75rem);
    }

    .nav-btn {
        font-size: 1rem;
    }
}