/* CSS Reset and Base Styles */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    /* Color Palette - Light teal/cyan theme */
    --color-background: #F7FBFF;
    --color-surface: #FFFFFF;
    --color-surface-alt: #EEF2F6;
    --color-text-primary: #0F172A;
    --color-text-secondary: #475569;
    --color-muted: #64748B;
    --color-primary: #0EA5A5;
    --color-primary-weak: #CCFBF1;
    --color-primary-strong: #0D9488;
    --color-success: #16A34A;
    --color-warning: #F59E0B;
    --color-danger: #DC2626;
    --color-divider: #E2E8F0;

    /* Typography */
    --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", "Roboto", Arial, sans-serif;
    --font-mono: "Roboto Mono", ui-monospace, "SFMono-Regular", "Menlo", "Consolas", monospace;

    /* Typography Scale */
    --font-size-h1: 28px;
    --font-size-h2: 22px;
    --font-size-h3: 18px;
    --font-size-body: 16px;
    --font-size-label: 13px;
    --font-size-caption: 12px;

    /* Line Heights */
    --line-height-tight: 1.2;
    --line-height-base: 1.6;

    /* Letter Spacing */
    --letter-spacing-heading: 0.2px;
    --letter-spacing-body: 0px;

    /* Layout */
    --container-max-width: 1200px;
    --sidebar-width: 280px;
    --grid-gutter: 16px;
    --card-min-width: 260px;

    /* Elevation Shadows */
    --elevation-level1: 0 1px 2px rgba(2, 6, 23, 0.07), 0 1px 1px rgba(2, 6, 23, 0.05);
    --elevation-level2: 0 8px 24px rgba(2, 6, 23, 0.08), 0 2px 8px rgba(2, 6, 23, 0.06);

    /* Border Radius */
    --radius-sm: 10px;
    --radius-md: 12px;
    --radius-lg: 14px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Focus Ring */
    --focus-ring-width: 2px;
    --focus-ring-color: #22D3EE;
    --focus-ring-offset: 2px;

    /* Motion */
    --duration-fast: 120ms;
    --duration-base: 180ms;
    --duration-slow: 240ms;
    --easing-in-out: cubic-bezier(0.4, 0, 0.2, 1);
    --easing-out: cubic-bezier(0, 0, 0.2, 1);
}

/* Base Styles */
html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: var(--font-size-body);
    line-height: var(--line-height-base);
    letter-spacing: var(--letter-spacing-body);
    color: var(--color-text-primary);
    background-color: var(--color-background);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Focus Management */
*:focus {
    outline: none;
}

*:focus-visible {
    outline: var(--focus-ring-width) solid var(--focus-ring-color);
    outline-offset: var(--focus-ring-offset);
    border-radius: var(--radius-md);
}

/* Utility Classes */
.visually-hidden {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

.hidden {
    display: none !important;
}

.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Skip Link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--color-primary);
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: var(--radius-sm);
    z-index: 1000;
    transition: top var(--duration-base) var(--easing-out);
}

.skip-link:focus {
    top: 6px;
}

/* Header */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(6px);
    border-bottom: 1px solid var(--color-divider);
    box-shadow: var(--elevation-level2);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 0;
}

.header-brand {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.brand-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: var(--font-size-h1);
    font-weight: 700;
    letter-spacing: var(--letter-spacing-heading);
    color: var(--color-text-primary);
}

.brand-icon {
    font-size: 24px;
}

.brand-subtitle {
    font-size: var(--font-size-label);
    color: var(--color-text-secondary);
    font-weight: 500;
}

.header-nav {
    display: flex;
    gap: 8px;
}

/* Navigation Buttons */
.nav-button {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 14px;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: var(--font-size-body);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--duration-base) var(--easing-in-out);
    text-decoration: none;
}

.nav-button:hover {
    background: var(--color-surface-alt);
    transform: translateY(-1px);
}

.nav-button[aria-pressed="true"] {
    background: var(--color-primary-weak);
    color: #065F5B;
    border-color: var(--color-primary);
}

.nav-icon {
    font-size: 16px;
}

/* Main Layout */
.main {
    padding: 32px 0;
}

.section {
    margin-bottom: 48px;
}

.section-layout {
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr;
    gap: var(--grid-gutter);
    align-items: start;
}

/* Sidebar */
.sidebar {
    position: sticky;
    top: 120px;
}

.sidebar-content {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Search Section */
.search-section {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.search-input {
    width: 100%;
    padding: 10px 12px;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-body);
    color: var(--color-text-primary);
    transition: all var(--duration-base) var(--easing-in-out);
}

.search-input::placeholder {
    color: #94A3B8;
}

.search-input:focus {
    border-color: var(--color-primary-strong);
}

.search-hint {
    font-size: var(--font-size-caption);
    color: var(--color-muted);
    text-align: center;
}

.search-hint kbd {
    padding: 2px 4px;
    background: var(--color-surface-alt);
    border: 1px solid var(--color-divider);
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 10px;
}

/* Filter Sections */
.filter-section {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.filter-title {
    font-size: var(--font-size-h3);
    font-weight: 600;
    color: var(--color-text-primary);
}

.filter-group {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag-filters {
    max-height: 200px;
    overflow-y: auto;
}

/* Chips */
.chip {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 6px 10px;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-full);
    font-size: var(--font-size-label);
    font-weight: 500;
    color: var(--color-text-primary);
    cursor: pointer;
    transition: all var(--duration-base) var(--easing-in-out);
    text-decoration: none;
}

.chip:hover {
    background: var(--color-surface-alt);
}

.chip.active,
.chip[aria-pressed="true"] {
    background: var(--color-primary-weak);
    color: #065F5B;
    border-color: var(--color-primary);
}

.chip-count {
    padding: 1px 4px;
    background: var(--color-surface-alt);
    border-radius: var(--radius-full);
    font-size: 10px;
    font-weight: 600;
}

.chip.active .chip-count {
    background: rgba(255, 255, 255, 0.7);
}

/* Stats Section */
.stats-section {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.stats-title {
    font-size: var(--font-size-h3);
    font-weight: 600;
    color: var(--color-text-primary);
}

.progress-bar {
    height: 6px;
    background: var(--color-divider);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--color-primary);
    border-radius: var(--radius-full);
    transition: width var(--duration-slow) var(--easing-out);
}

.stats-text {
    font-size: var(--font-size-label);
    color: var(--color-text-secondary);
    text-align: center;
}

/* Content Area */
.content {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.content-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
}

.section-title {
    font-size: var(--font-size-h2);
    font-weight: 700;
    letter-spacing: var(--letter-spacing-heading);
    color: var(--color-text-primary);
}

.content-actions {
    display: flex;
    gap: 8px;
}

/* Buttons */
.button {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 14px;
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-body);
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all var(--duration-base) var(--easing-in-out);
    box-shadow: var(--elevation-level1);
}

.button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.button.primary {
    background: var(--color-primary);
    color: white;
}

.button.primary:hover {
    filter: brightness(1.03);
    transform: translateY(-1px);
    box-shadow: var(--elevation-level2);
}

.button.ghost {
    background: var(--color-surface);
    color: var(--color-text-primary);
    border: 1px solid var(--color-divider);
}

.button.ghost:hover {
    background: var(--color-surface-alt);
}

/* Challenge Grid */
.challenge-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(var(--card-min-width), 1fr));
    gap: var(--grid-gutter);
}

/* Challenge Cards */
.challenge {
    display: flex;
    flex-direction: column;
    padding: 14px;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-lg);
    box-shadow: var(--elevation-level1);
    cursor: pointer;
    transition: all var(--duration-base) var(--easing-in-out);
    text-decoration: none;
    color: inherit;
}

.challenge:hover {
    transform: translateY(-1px);
    box-shadow: var(--elevation-level2);
}

.challenge.completed {
    border-color: var(--color-success);
    background: linear-gradient(135deg, var(--color-surface) 0%, #F0FDF4 100%);
}

.challenge-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 8px;
}

.challenge-title {
    font-size: var(--font-size-h3);
    font-weight: 600;
    color: var(--color-text-primary);
    line-height: var(--line-height-tight);
}

.challenge-difficulty {
    padding: 3px 8px;
    background: var(--color-surface-alt);
    color: var(--color-text-secondary);
    font-size: var(--font-size-caption);
    font-weight: 600;
    border-radius: var(--radius-full);
    white-space: nowrap;
}

.challenge-difficulty.Beginner {
    background: #F0FDF4;
    color: var(--color-success);
}

.challenge-difficulty.Intermediate {
    background: #FFFBEB;
    color: var(--color-warning);
}

.challenge-difficulty.Advanced {
    background: #FEF2F2;
    color: var(--color-danger);
}

.challenge-difficulty.Expert {
    background: #1E1B4B;
    color: #C7D2FE;
}

.challenge-description {
    font-size: var(--font-size-body);
    color: var(--color-text-secondary);
    line-height: var(--line-height-base);
    margin-bottom: 12px;
    flex: 1;
}

.challenge-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 12px;
    border-top: 1px solid var(--color-divider);
}

.challenge-time {
    font-size: var(--font-size-label);
    color: var(--color-muted);
    font-weight: 500;
}

.challenge-tags {
    display: flex;
    gap: 4px;
    flex-wrap: wrap;
}

.challenge-tag {
    padding: 2px 6px;
    background: var(--color-surface-alt);
    color: var(--color-text-secondary);
    font-size: 10px;
    font-weight: 500;
    border-radius: var(--radius-full);
}

.challenge-status {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: var(--font-size-label);
    font-weight: 600;
}

.challenge-status.completed {
    color: var(--color-success);
}

.challenge-status-icon {
    font-size: 12px;
}

/* Grid Footer */
.grid-footer {
    display: flex;
    justify-content: center;
    padding: 24px 0;
}

.results-count {
    font-size: var(--font-size-label);
    color: var(--color-muted);
    font-weight: 500;
}

/* Flashcards Section */
.flashcard-container {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.flashcard-header {
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.flashcard-progress .progress-text {
    margin-top: 8px;
}

.flashcard-main {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.flashcard {
    min-height: 300px;
    padding: 32px;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-lg);
    box-shadow: var(--elevation-level2);
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: center;
}

.flashcard-question {
    font-size: 24px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 24px;
    line-height: var(--line-height-tight);
}

.flashcard-choices {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 12px;
    margin-bottom: 24px;
}

.choice-button {
    padding: 12px 16px;
    background: var(--color-surface);
    border: 2px solid var(--color-divider);
    border-radius: var(--radius-md);
    font-size: var(--font-size-body);
    font-weight: 500;
    color: var(--color-text-primary);
    cursor: pointer;
    transition: all var(--duration-base) var(--easing-in-out);
}

.choice-button:hover {
    border-color: var(--color-primary);
    background: var(--color-primary-weak);
}

.choice-button.selected {
    border-color: var(--color-primary);
    background: var(--color-primary);
    color: white;
}

.choice-button.correct {
    border-color: var(--color-success);
    background: var(--color-success);
    color: white;
}

.choice-button.incorrect {
    border-color: var(--color-danger);
    background: var(--color-danger);
    color: white;
}

.flashcard-answer {
    font-size: var(--font-size-h3);
    font-weight: 600;
    color: var(--color-success);
    padding: 16px;
    background: #F0FDF4;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-success);
}

.flashcard-hint {
    font-size: var(--font-size-body);
    color: var(--color-warning);
    font-style: italic;
    padding: 12px;
    background: #FFFBEB;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-warning);
}

.flashcard-controls {
    display: flex;
    flex-direction: column;
    gap: 16px;
    align-items: center;
}

.flashcard-navigation {
    display: flex;
    gap: 12px;
}

.flashcard-stats {
    display: flex;
    justify-content: center;
    gap: 32px;
    padding: 24px;
    background: var(--color-surface-alt);
    border-radius: var(--radius-lg);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.stat-label {
    font-size: var(--font-size-label);
    color: var(--color-text-secondary);
    font-weight: 500;
}

.stat-value {
    font-size: var(--font-size-h2);
    font-weight: 700;
    color: var(--color-text-primary);
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
    backdrop-filter: blur(4px);
}

.modal {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--elevation-level2);
    max-width: 800px;
    width: 95%;
    max-height: 90vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    position: relative;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 24px;
    border-bottom: 1px solid var(--color-divider);
}

.modal-title {
    font-size: var(--font-size-h2);
    font-weight: 600;
    color: var(--color-text-primary);
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    color: var(--color-muted);
    cursor: pointer;
    padding: 4px;
    border-radius: var(--radius-sm);
    transition: all var(--duration-base) var(--easing-in-out);
}

.modal-close:hover {
    background: var(--color-surface-alt);
    color: var(--color-text-primary);
}

.modal-body {
    padding: 20px;
    overflow-y: auto;
    flex: 1;
    min-height: 0;
}

.modal-section {
    margin-bottom: 16px;
    padding: 16px;
    background: var(--color-surface);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-divider);
    border-left: 4px solid var(--color-primary);
    box-shadow: var(--elevation-level1);
}

.modal-section:last-child {
    margin-bottom: 0;
}

.modal-section-title {
    font-size: var(--font-size-h3);
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.modal-section-title::before {
    content: "•";
    color: var(--color-primary);
    font-weight: bold;
    font-size: 20px;
}

.modal-section-content {
    color: var(--color-text-primary);
    line-height: var(--line-height-base);
    font-size: 15px;
}

.modal-criteria-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.modal-criteria-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: var(--color-surface-alt);
    border-radius: var(--radius-sm);
}

.modal-criteria-icon {
    color: var(--color-success);
    font-weight: bold;
}

.modal-footer {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
    padding: 24px;
    border-top: 1px solid var(--color-divider);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }

    .section-layout {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .sidebar {
        position: static;
        order: 2;
    }

    .content {
        order: 1;
    }

    .content-header {
        flex-direction: column;
        align-items: stretch;
    }

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

    .header-content {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }

    .flashcard {
        min-height: 250px;
        padding: 24px;
    }

    .flashcard-question {
        font-size: 20px;
    }

    .flashcard-choices {
        grid-template-columns: 1fr;
    }

    .flashcard-navigation {
        flex-direction: column;
        width: 100%;
    }

    .flashcard-stats {
        gap: 16px;
    }

    .modal {
        margin: 8px;
        max-width: none;
        width: calc(100% - 16px);
        max-height: 95vh;
    }

    .modal-header {
        padding: 16px;
    }

    .modal-body {
        padding: 16px;
    }

    .modal-footer {
        padding: 16px;
    }

    .modal-section {
        margin-bottom: 12px;
        padding: 12px;
    }

    .modal-section-title {
        font-size: 16px;
    }

    .modal-section-content {
        font-size: 14px;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .challenge:hover {
        transform: none;
    }

    .button:hover {
        transform: none;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --color-divider: #000000;
        --elevation-level1: 0 2px 4px rgba(0, 0, 0, 0.3);
        --elevation-level2: 0 4px 8px rgba(0, 0, 0, 0.3);
    }

    .challenge {
        border-width: 2px;
    }

    .button {
        border-width: 2px;
    }
}

/* Practice Editor Styles */
.practice-layout {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 24px;
    align-items: start;
}

.practice-sidebar {
    position: sticky;
    top: 120px;
}

.practice-controls {
    display: flex;
    flex-direction: column;
    gap: 20px;
    padding: 20px;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-lg);
    box-shadow: var(--elevation-level1);
}

.exercise-selector {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-label {
    font-size: var(--font-size-label);
    font-weight: 600;
    color: var(--color-text-primary);
}

.exercise-select {
    width: 100%;
    padding: 10px 12px;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-body);
    color: var(--color-text-primary);
    cursor: pointer;
}

.exercise-select:focus {
    border-color: var(--color-primary-strong);
    outline: none;
}

.exercise-info {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.exercise-description h4,
.exercise-goals h4 {
    font-size: var(--font-size-h3);
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 8px;
}

.exercise-description p,
.exercise-goals p {
    font-size: var(--font-size-body);
    color: var(--color-text-secondary);
    line-height: var(--line-height-base);
    margin-bottom: 8px;
}

.exercise-goals ul {
    margin: 8px 0;
    padding-left: 20px;
    color: var(--color-text-secondary);
}

.exercise-goals li {
    margin-bottom: 4px;
}

.practice-actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.button.success {
    background: var(--color-success);
    color: white;
}

.button.success:hover {
    filter: brightness(1.05);
    transform: translateY(-1px);
}

.button.secondary {
    background: var(--color-muted);
    color: white;
}

.button.secondary:hover {
    filter: brightness(1.05);
    transform: translateY(-1px);
}

.practice-stats {
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding-top: 16px;
    border-top: 1px solid var(--color-divider);
}

/* Editor Area */
.editor-area {
    display: flex;
    flex-direction: column;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-lg);
    box-shadow: var(--elevation-level1);
    overflow: hidden;
}

.editor-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--color-surface-alt);
    border-bottom: 1px solid var(--color-divider);
}

.editor-tabs {
    display: flex;
    gap: 8px;
}

.editor-tab {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-label);
    font-weight: 500;
    color: var(--color-text-primary);
}

.editor-tab.active {
    background: var(--color-primary-weak);
    border-color: var(--color-primary);
    color: #065F5B;
}

.tab-icon {
    font-size: 14px;
}

.editor-status {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: var(--font-size-label);
    font-family: var(--font-mono);
}

.vim-mode {
    padding: 4px 8px;
    background: var(--color-primary);
    color: white;
    border-radius: var(--radius-sm);
    font-weight: 600;
    min-width: 60px;
    text-align: center;
}

.vim-mode.mode-insert {
    background: var(--color-warning);
}

.vim-mode.mode-visual {
    background: var(--color-success);
}

.cursor-position {
    color: var(--color-muted);
    font-weight: 500;
}

.editor-container {
    position: relative;
    flex: 1;
    min-height: 400px;
}

.editor-footer {
    padding: 8px 16px;
    background: var(--color-surface-alt);
    border-top: 1px solid var(--color-divider);
    font-family: var(--font-mono);
    font-size: var(--font-size-label);
}

.command-line {
    display: flex;
    align-items: center;
    gap: 4px;
    min-height: 20px;
}

.command-prompt {
    color: var(--color-primary);
    font-weight: 600;
}

.command-text {
    color: var(--color-text-primary);
}

/* CodeMirror Overrides */
.CodeMirror {
    font-family: var(--font-mono) !important;
    font-size: 14px !important;
    line-height: 1.4 !important;
    border: none !important;
    height: auto !important;
}

.CodeMirror-scroll {
    min-height: 400px;
}

.CodeMirror-cursor {
    border-left: 2px solid var(--color-primary) !important;
}

.CodeMirror-selected {
    background: var(--color-primary-weak) !important;
}

.CodeMirror-line {
    padding: 0 4px !important;
}

.CodeMirror-gutters {
    background: var(--color-surface-alt) !important;
    border-right: 1px solid var(--color-divider) !important;
}

.CodeMirror-linenumber {
    color: var(--color-muted) !important;
    font-size: 12px !important;
}

/* Feedback Modal */
.feedback-modal {
    max-width: 500px;
}

.feedback-header {
    text-align: center;
    padding: 24px 24px 16px;
    border-bottom: 1px solid var(--color-divider);
}

.feedback-header.success {
    background: linear-gradient(135deg, #F0FDF4 0%, #DCFCE7 100%);
}

.feedback-header.warning {
    background: linear-gradient(135deg, #FFFBEB 0%, #FEF3C7 100%);
}

.feedback-icon {
    font-size: 48px;
    margin-bottom: 12px;
}

.feedback-title {
    font-size: var(--font-size-h2);
    font-weight: 700;
    color: var(--color-text-primary);
    margin: 0;
}

.feedback-body {
    padding: 24px;
}

.feedback-message {
    font-size: var(--font-size-body);
    color: var(--color-text-primary);
    line-height: var(--line-height-base);
    margin-bottom: 16px;
    text-align: center;
}

.achievement {
    padding: 16px;
    background: #F0FDF4;
    border: 1px solid var(--color-success);
    border-radius: var(--radius-md);
    text-align: center;
}

.achievement p {
    margin: 0 0 8px 0;
    color: var(--color-success);
    font-weight: 600;
}

.achievement p:last-child {
    margin-bottom: 0;
}

.tip {
    padding: 16px;
    background: #FFFBEB;
    border: 1px solid var(--color-warning);
    border-radius: var(--radius-md);
}

.tip p {
    margin: 0;
    color: #92400E;
}

.modal-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

/* Medium Screen Responsive Design */
@media (max-width: 1024px) {
    .modal-overlay.editor-active .modal {
        max-width: 95%;
        width: 95%;
    }

    .practice-layout {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .practice-sidebar {
        position: static;
        order: 2;
    }

    .editor-area {
        order: 1;
    }
}

@media (max-width: 768px) {
    .practice-controls {
        padding: 16px;
    }

    .editor-header {
        flex-direction: column;
        gap: 12px;
        align-items: stretch;
    }

    .editor-status {
        justify-content: center;
    }

    .CodeMirror-scroll {
        min-height: 300px;
    }

    .modal-actions {
        flex-direction: column;
    }

    .modal-overlay.editor-active .modal {
        max-width: none;
        width: calc(100% - 16px);
        max-height: 95vh;
    }

    .editor-controls {
        flex-direction: column;
        gap: 12px;
        align-items: stretch;
    }

    .editor-select {
        min-width: auto;
        width: 100%;
    }
}

/* Two-Part Practice System Styles */
.practice-phase-indicator {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
    padding: 16px;
    background: var(--color-surface-alt);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-divider);
}

.phase-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    border-radius: var(--radius-md);
    transition: all var(--duration-base) var(--easing-in-out);
    opacity: 0.6;
}

.phase-step.active {
    opacity: 1;
    background: var(--color-primary-weak);
    border: 2px solid var(--color-primary);
}

.step-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--color-muted);
    color: white;
    border-radius: 50%;
    font-weight: 600;
    font-size: 14px;
    transition: all var(--duration-base) var(--easing-in-out);
}

.phase-step.active .step-number {
    background: var(--color-primary);
    transform: scale(1.1);
}

.step-title {
    font-size: 13px;
    font-weight: 600;
    color: var(--color-text-secondary);
    text-align: center;
}

.phase-step.active .step-title {
    color: var(--color-primary-strong);
}

.phase-divider {
    width: 40px;
    height: 2px;
    background: var(--color-divider);
    margin: 0 16px;
}

.challenge-overview {
    border-left-color: var(--color-primary) !important;
    background: linear-gradient(135deg, var(--color-primary-weak) 0%, var(--color-surface) 100%);
}

.practice-details {
    transition: all var(--duration-base) var(--easing-in-out);
}

.difficulty-badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: var(--radius-full);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    margin-right: 12px;
}

.difficulty-badge.beginner {
    background: #DCFCE7;
    color: #166534;
}

.difficulty-badge.intermediate {
    background: #FEF3C7;
    color: #92400E;
}

.difficulty-badge.advanced {
    background: #FEE2E2;
    color: #991B1B;
}

.difficulty-badge.expert {
    background: #EDE9FE;
    color: #6B21A8;
}

.duration-info {
    color: var(--color-text-secondary);
    font-size: 14px;
}

.tags-container {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.skill-tag {
    padding: 6px 12px;
    background: var(--color-primary-weak);
    color: var(--color-primary-strong);
    border-radius: var(--radius-full);
    font-size: 13px;
    font-weight: 500;
    border: 1px solid var(--color-primary);
}

.preparation-tips {
    background: linear-gradient(135deg, #FFFBEB 0%, var(--color-surface) 100%);
    border-left-color: var(--color-warning) !important;
}

.tips-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.tips-list li {
    padding: 8px 12px;
    background: var(--color-surface);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--color-warning);
    font-size: 14px;
}

.button-active {
    background: var(--color-warning) !important;
    color: white !important;
    box-shadow: 0 0 0 2px var(--color-warning) !important;
}

/* Modal Editor Integration Styles */
.modal-editor-section {
    border-top: 2px solid var(--color-divider);
    margin-top: 20px;
    padding-top: 20px;
    background: var(--color-surface-alt);
    margin-left: -24px;
    margin-right: -24px;
    padding-left: 24px;
    padding-right: 24px;
}

.editor-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.editor-title {
    margin: 0;
    font-size: 16px;
    font-weight: 600;
    color: var(--color-text-primary);
}

.editor-controls {
    display: flex;
    gap: 8px;
    align-items: center;
}

.editor-select {
    padding: 6px 12px;
    border: 1px solid var(--color-divider);
    border-radius: 8px;
    background: white;
    font-size: 13px;
    color: var(--color-text-primary);
    min-width: 120px;
}

.button.small {
    padding: 6px 12px;
    font-size: 13px;
}

.editor-container {
    border: 1px solid var(--color-divider);
    border-radius: 12px;
    overflow: hidden;
    height: 300px;
    position: relative;
}

.editor-container .CodeMirror {
    height: 100%;
    font-family: var(--font-mono);
    font-size: 14px;
    line-height: 1.5;
}

.editor-container .CodeMirror-focused .CodeMirror-cursor {
    border-left: 2px solid var(--color-primary);
}

.editor-status {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 12px;
    background: var(--color-surface-alt);
    border-top: 1px solid var(--color-divider);
    font-family: var(--font-mono);
    font-size: 12px;
}

.status-left {
    display: flex;
    gap: 16px;
    align-items: center;
}

.mode-indicator {
    background: var(--color-primary);
    color: white;
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: 600;
    text-transform: uppercase;
}

.position-indicator {
    color: var(--color-text-secondary);
}

.progress-indicator {
    color: var(--color-text-secondary);
    font-style: italic;
}

.progress-indicator.success {
    color: var(--color-success);
    font-weight: 600;
}

.progress-indicator.warning {
    color: var(--color-warning);
    font-weight: 600;
}

/* Modal size adjustment for editor */
.modal-overlay.editor-active .modal {
    max-width: 1400px;
    width: 95%;
    max-height: 95vh;
}

/* Two-column layout for editor mode */
.modal.editor-mode {
    display: flex;
    flex-direction: column;
}

.modal.editor-mode .modal-body {
    display: flex;
    flex-direction: row;
    gap: 24px;
    padding: 0;
    min-height: 0;
    flex: 1;
}

.modal-content-left {
    flex: 0 0 400px;
    padding: 20px;
    overflow-y: auto;
    border-right: 2px solid var(--color-divider);
    background: var(--color-surface-alt);
    min-height: 0;
}

.modal-content-right {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
    min-width: 0;
}

.modal.editor-mode .modal-editor-section {
    margin: 0;
    padding: 20px;
    border-top: none;
    background: var(--color-surface);
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
}

.modal.editor-mode .modal-editor-section .editor-container {
    flex: 1;
    min-height: 400px;
}

/* Responsive fallback for smaller screens */
@media (max-width: 1200px) {
    .modal.editor-mode .modal-body {
        flex-direction: column;
    }

    .modal-content-left {
        flex: none;
        border-right: none;
        border-bottom: 2px solid var(--color-divider);
        max-height: 300px;
    }

    .modal-content-right {
        flex: 1;
        min-height: 400px;
    }
}

/* Mobile responsive design */
@media (max-width: 768px) {
    .modal.editor-mode {
        max-height: 95vh;
    }

    .modal.editor-mode .modal-body {
        flex-direction: column;
        gap: 16px;
    }

    .modal-content-left {
        flex: none;
        max-height: 250px;
        overflow-y: auto;
        border-bottom: 1px solid var(--color-divider);
        padding: 16px;
    }

    .modal-content-right {
        flex: 1;
        min-height: 350px;
    }

    .modal.editor-mode .modal-editor-section {
        padding: 16px;
    }

    .modal.editor-mode .modal-editor-section .editor-container {
        min-height: 300px;
    }
}

/* Vim mode specific styles */
.CodeMirror.cm-fat-cursor .CodeMirror-cursor {
    width: auto;
    border: 0;
    background: var(--color-primary);
    opacity: 0.8;
}

.CodeMirror.cm-fat-cursor .CodeMirror-cursors .CodeMirror-cursor {
    background: var(--color-primary);
}

/* Search dialog customization */
.CodeMirror-dialog {
    background: var(--color-surface);
    border: 1px solid var(--color-divider);
    border-radius: 8px;
    box-shadow: var(--elevation-level2);
}

.CodeMirror-dialog input {
    font-family: var(--font-mono);
    padding: 8px 12px;
    border: none;
    background: transparent;
    color: var(--color-text-primary);
}

/* Challenge completion animation */
@keyframes completion-flash {
    0% {
        background-color: transparent;
    }

    50% {
        background-color: var(--color-success);
    }

    100% {
        background-color: transparent;
    }
}

.challenge-completed-flash {
    animation: completion-flash 0.6s ease-in-out;
}

/* Dark Mode Support (for future enhancement) */
@media (prefers-color-scheme: dark) {
    :root {
        --color-background: #0F172A;
        --color-surface: #1E293B;
        --color-surface-alt: #334155;
        --color-text-primary: #F8FAFC;
        --color-text-secondary: #CBD5E1;
        --color-muted: #94A3B8;
        --color-divider: #475569;
    }
}