/* CSS Color Challenges — app theme (all chrome colors via variables) */

:root {
    --bg: #0f1117;
    --bg-elevated: #171a23;
    --bg-panel: #1c2030;
    --bg-input: #12151e;
    --border: #2a3044;
    --border-strong: #3d4663;
    --text: #e8ebf4;
    --text-muted: #9aa3bc;
    --text-faint: #6b7490;
    --accent: #7aa2ff;
    --accent-strong: #3a86ff;
    --accent-soft: rgba(122, 162, 255, 0.14);
    --success: #06d6a0;
    --success-soft: rgba(6, 214, 160, 0.14);
    --danger: #ff5d8f;
    --danger-soft: rgba(255, 93, 143, 0.14);
    --warning: #ffb703;
    --warning-soft: rgba(255, 183, 3, 0.14);
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
    --font: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    --mono: ui-monospace, "Cascadia Code", "SF Mono", Menlo, Consolas, monospace;
}

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

html,
body {
    margin: 0;
    padding: 0;
    min-height: 100%;
}

body {
    font-family: var(--font);
    background:
        radial-gradient(1200px 500px at 10% -10%, rgba(58, 134, 255, 0.18), transparent 60%),
        radial-gradient(900px 400px at 100% 0%, rgba(255, 0, 110, 0.12), transparent 55%),
        var(--bg);
    color: var(--text);
    line-height: 1.5;
}

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

/* ---------- noscript / fatal error ---------- */

.noscript-banner,
.fatal-error {
    max-width: 1280px;
    margin: 16px auto 0;
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--warning);
    background: var(--warning-soft);
    color: var(--text);
    font-size: 0.95rem;
    line-height: 1.45;
}

.noscript-banner a {
    color: var(--accent);
}

.fatal-error {
    border-color: var(--danger);
    background: var(--danger-soft);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
}

.fatal-error[hidden] {
    display: none !important;
}

.fatal-error-msg {
    color: var(--text-muted);
    font-family: var(--mono);
    font-size: 0.85rem;
}

.fatal-error-reload {
    margin-left: auto;
}

/* ---------- skeleton placeholders ---------- */

.challenge-card[data-skeleton],
.level-tab[data-skeleton] {
    opacity: 0.85;
}

.challenge-card[disabled] {
    cursor: default;
    opacity: 0.85;
}

.challenge-card[disabled]:hover {
    border-color: transparent;
}

/* ---------- header ---------- */

.site-header {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 20px 24px 8px;
    max-width: 1280px;
    margin: 0 auto;
}

.brand {
    display: flex;
    align-items: center;
    gap: 14px;
}

.brand-mark {
    font-size: 2rem;
    filter: drop-shadow(0 4px 10px rgba(58, 134, 255, 0.45));
}

.brand-text h1 {
    margin: 0;
    font-size: 1.45rem;
    letter-spacing: -0.02em;
}

.brand-sub {
    margin: 2px 0 0;
    color: var(--text-muted);
    font-size: 0.92rem;
}

.progress-block {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 6px;
    min-width: 200px;
}

.progress-track {
    width: 220px;
    height: 10px;
    border-radius: 999px;
    background: var(--bg-panel);
    border: 1px solid var(--border);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    width: 0;
    border-radius: inherit;
    background: linear-gradient(90deg, var(--accent-strong), var(--success));
    transition: width 0.35s ease;
}

.progress-label {
    font-size: 0.82rem;
    color: var(--text-muted);
    font-variant-numeric: tabular-nums;
}

/* ---------- level tabs ---------- */

.level-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    padding: 12px 24px;
    max-width: 1280px;
    margin: 0 auto;
}

.level-tab {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--bg-elevated);
    color: var(--text);
    cursor: pointer;
    font: inherit;
    transition: border-color 0.15s ease, background 0.15s ease, transform 0.15s ease;
}

.level-tab:hover {
    border-color: var(--border-strong);
    transform: translateY(-1px);
}

.level-tab.active {
    border-color: var(--accent);
    background: var(--accent-soft);
    box-shadow: 0 0 0 1px var(--accent) inset;
}

.level-tab-name {
    font-weight: 700;
    font-size: 0.92rem;
}

.level-tab-days {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.level-tab-count {
    font-size: 0.75rem;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
}

/* ---------- layout ---------- */

.layout {
    display: grid;
    grid-template-columns: minmax(220px, 280px) 1fr;
    gap: 20px;
    padding: 8px 24px 32px;
    max-width: 1280px;
    margin: 0 auto;
    align-items: start;
}

.sidebar {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px;
    position: sticky;
    top: 16px;
}

.sidebar-title {
    margin: 0 0 10px;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-faint);
}

.challenge-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.challenge-card {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
    text-align: left;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    background: var(--bg-panel);
    color: var(--text);
    cursor: pointer;
    font: inherit;
    transition: border-color 0.15s ease, background 0.15s ease;
}

.challenge-card:hover {
    border-color: var(--border-strong);
}

.challenge-card.active {
    border-color: var(--accent);
    background: var(--accent-soft);
}

.challenge-card.done {
    border-color: rgba(6, 214, 160, 0.35);
}

.challenge-card.done.active {
    border-color: var(--accent);
}

.badge {
    flex: 0 0 auto;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.82rem;
    font-weight: 700;
    background: var(--bg-input);
    border: 1px solid var(--border);
}

.badge-done {
    background: var(--success-soft);
    border-color: var(--success);
    color: var(--success);
}

.badge-peek {
    background: var(--warning-soft);
    border-color: var(--warning);
}

.badge-num {
    color: var(--text-muted);
}

.challenge-card-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 0;
}

.challenge-card-title {
    font-weight: 650;
    font-size: 0.92rem;
}

.challenge-card-tag {
    font-size: 0.78rem;
    color: var(--text-muted);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ---------- workspace ---------- */

.workspace {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 18px;
    min-width: 0;
}

.challenge-header {
    margin-bottom: 14px;
}

.challenge-meta {
    margin: 0;
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--accent);
    font-weight: 700;
}

.challenge-title {
    margin: 4px 0 2px;
    font-size: 1.35rem;
    letter-spacing: -0.01em;
}

.challenge-tagline {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.95rem;
}

.challenge-description {
    margin: 10px 0 0;
    color: var(--text);
    font-size: 0.95rem;
    max-width: 70ch;
}

.chips {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 10px;
}

.chip {
    font-size: 0.75rem;
    padding: 3px 9px;
    border-radius: 999px;
    background: var(--bg-panel);
    border: 1px solid var(--border);
    color: var(--text-muted);
}

/* ---------- panes ---------- */

.panes {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 12px;
}

.pane {
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.pane-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-faint);
    padding: 8px 10px;
    border-bottom: 1px solid var(--border);
    background: rgba(0, 0, 0, 0.18);
}

.pane-label-preview {
    color: var(--accent);
}

.pane iframe {
    width: 100%;
    height: 240px;
    border: 0;
    background: #fff;
    display: block;
}

/* ---------- editor ---------- */

.editor-block {
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.editor-tabs {
    display: flex;
    gap: 4px;
    padding: 6px 8px 0;
    border-bottom: 1px solid var(--border);
    background: rgba(0, 0, 0, 0.18);
}

.editor-tab {
    font: inherit;
    font-size: 0.8rem;
    font-weight: 700;
    padding: 6px 12px;
    border: 0;
    border-radius: 8px 8px 0 0;
    color: var(--text-faint);
    background: transparent;
    cursor: pointer;
}

.editor-tab[hidden] {
    display: none !important;
}

.editor-tab.active {
    color: var(--text);
    background: var(--bg-panel);
    box-shadow: inset 0 -2px 0 var(--accent);
}

.code-pane {
    display: flex;
    flex-direction: column;
}

.code-editor {
    width: 100%;
    border: 0;
    resize: vertical;
    min-height: 180px;
    padding: 12px 14px;
    background: var(--bg-input);
    color: #d7e0ff;
    font-family: var(--mono);
    font-size: 0.86rem;
    line-height: 1.55;
    tab-size: 4;
    outline: none;
}

.code-editor:focus {
    box-shadow: inset 0 0 0 2px var(--accent-soft);
}

.js-pane .code-editor {
    min-height: 140px;
    border-top: 1px solid var(--border);
    color: #c8f5d9;
}

.js-pane[hidden],
.quiz-pane[hidden],
.code-pane[hidden],
#codePane[hidden] {
    display: none !important;
}

/* ---------- quiz ---------- */

.quiz-pane {
    padding: 12px 14px 16px;
}

.quiz-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    border: 0;
    margin: 0;
    padding: 0;
}

.quiz-q {
    margin: 0;
    padding: 12px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-input);
}

.quiz-q legend {
    font-weight: 650;
    padding: 0 6px;
    font-size: 0.95rem;
}

.quiz-opt {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 8px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.92rem;
}

.quiz-opt:hover {
    background: var(--accent-soft);
}

.quiz-opt input {
    accent-color: var(--accent-strong);
}

.quiz-explain {
    margin: 8px 0 0;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.quiz-q.quiz-correct {
    border-color: var(--success);
    background: var(--success-soft);
}

.quiz-q.quiz-wrong {
    border-color: var(--danger);
    background: var(--danger-soft);
}

/* ---------- actions & toast ---------- */

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 14px;
}

.btn {
    font: inherit;
    font-weight: 700;
    padding: 10px 16px;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    cursor: pointer;
    transition: transform 0.12s ease, filter 0.12s ease, background 0.12s ease;
}

.btn:hover {
    transform: translateY(-1px);
    filter: brightness(1.06);
}

.btn:active {
    transform: translateY(0);
}

.btn:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    transform: none;
    filter: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-strong), #6c5ce7);
    color: #fff;
    box-shadow: 0 6px 18px rgba(58, 134, 255, 0.35);
}

.btn-secondary {
    background: var(--bg-panel);
    border-color: var(--border-strong);
    color: var(--text);
}

.btn-ghost {
    background: transparent;
    border-color: var(--border);
    color: var(--text-muted);
}

.toast {
    margin-top: 12px;
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    border: 1px solid var(--border);
    background: var(--bg-panel);
}

.toast-pass {
    border-color: var(--success);
    background: var(--success-soft);
    color: #b8ffe9;
}

.toast-fail {
    border-color: var(--danger);
    background: var(--danger-soft);
    color: #ffd6e3;
}

.toast-info {
    border-color: var(--accent);
    background: var(--accent-soft);
    color: #d6e4ff;
}

/* ---------- celebration ---------- */

.celebration {
    pointer-events: none;
    position: fixed;
    inset: 0;
    overflow: hidden;
    z-index: 50;
}

.confetti {
    position: absolute;
    top: -12px;
    width: 10px;
    height: 14px;
    border-radius: 2px;
    opacity: 0.95;
    animation: confetti-fall linear forwards;
}

@keyframes confetti-fall {
    0% {
        transform: translateY(0) rotate(0deg);
        opacity: 1;
    }
    100% {
        transform: translateY(105vh) rotate(720deg);
        opacity: 0;
    }
}

/* ---------- footer ---------- */

.site-footer {
    max-width: 1280px;
    margin: 0 auto;
    padding: 8px 24px 28px;
    color: var(--text-faint);
    font-size: 0.85rem;
}

.site-footer p {
    margin: 0;
}

/* ---------- responsive ---------- */

@media (max-width: 900px) {
    .layout {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
    }

    .challenge-list {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }

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

    .progress-block {
        align-items: flex-start;
    }
}

@media (max-width: 560px) {
    .site-header,
    .level-tabs,
    .layout,
    .site-footer {
        padding-left: 14px;
        padding-right: 14px;
    }

    .brand-text h1 {
        font-size: 1.2rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}

.activity-switch {
    display: flex;
    align-items: stretch;
    gap: 10px;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

.activity-switch .level-tabs {
    flex: 1;
    max-width: none;
    margin: 0;
    padding: 12px 0;
}

.shape-mode-tab {
    display: flex;
    flex: 0 0 auto;
    flex-direction: column;
    justify-content: center;
    gap: 2px;
    min-width: 150px;
    margin: 12px 0;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-elevated);
    color: var(--text);
    cursor: pointer;
    font: inherit;
    text-align: left;
    transition: border-color 0.15s ease, background 0.15s ease, transform 0.15s ease;
}

.shape-mode-tab:hover {
    border-color: var(--border-strong);
    transform: translateY(-1px);
}

.shape-mode-tab.active {
    border-color: var(--success);
    background: var(--success-soft);
    box-shadow: 0 0 0 1px var(--success) inset;
}

.shape-mode-name {
    font-size: 0.92rem;
    font-weight: 700;
}

.shape-mode-count {
    color: var(--success);
    font-size: 0.75rem;
    font-variant-numeric: tabular-nums;
}

.learning-tools {
    display: grid;
    grid-template-columns: minmax(190px, 1fr) auto minmax(260px, 1.1fr);
    align-items: center;
    gap: 14px 20px;
    max-width: 1280px;
    margin: 0 auto;
    padding: 14px 24px 10px;
}

.learning-tools-copy,
.profile-form,
.audio-tools {
    min-width: 0;
}

.learning-tools-greeting {
    margin: 0;
    color: var(--text);
    font-weight: 750;
}

.learning-tools-status,
.audio-status {
    margin: 3px 0 0;
    color: var(--text-muted);
    font-size: 0.78rem;
}

.profile-form,
.audio-tools {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
}

.profile-form label,
.audio-tools label {
    color: var(--text-muted);
    font-size: 0.78rem;
    font-weight: 650;
}

.profile-form input[type="text"],
.audio-tools select {
    min-height: 36px;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-sm);
    background: var(--bg-input);
    color: var(--text);
    font: inherit;
}

.profile-form input[type="text"] {
    width: 130px;
    padding: 6px 9px;
}

.audio-tools select {
    max-width: 190px;
    padding: 5px 8px;
}

.audio-tools input[type="range"] {
    width: 90px;
    accent-color: var(--accent-strong);
}

.audio-tools .btn,
.profile-form .btn {
    padding: 7px 10px;
    font-size: 0.8rem;
}

.feedback-card {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-top: 12px;
    padding: 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-panel);
}

.feedback-card[hidden],
.shape-feedback[hidden] {
    display: none;
}

.feedback-icon {
    display: inline-flex;
    flex: 0 0 auto;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--warning-soft);
    color: var(--warning);
    font-size: 1.15rem;
    font-weight: 800;
}

.feedback-card h3,
.shape-feedback h3 {
    margin: 0 0 3px;
    font-size: 1rem;
}

.feedback-card p,
.shape-feedback p {
    margin: 0;
}

.feedback-card .feedback-hint,
.shape-feedback .feedback-hint {
    margin-top: 6px;
    color: var(--text-muted);
    font-size: 0.88rem;
}

.feedback-card details {
    margin-top: 8px;
    color: var(--text-muted);
    font-size: 0.8rem;
}

.feedback-card summary {
    cursor: pointer;
    color: var(--text-muted);
}

.feedback-card details p {
    margin-top: 5px;
    font-family: var(--mono);
    white-space: pre-wrap;
}

.feedback-pass {
    border-color: var(--success);
    background: var(--success-soft);
}

.feedback-pass .feedback-icon {
    background: var(--success-soft);
    color: var(--success);
}

.feedback-fail,
.shape-feedback-fail {
    border-color: var(--warning);
    background: linear-gradient(135deg, var(--warning-soft), var(--danger-soft));
}

.feedback-fail .feedback-icon,
.shape-feedback-fail .feedback-icon {
    background: var(--warning-soft);
    color: var(--warning);
}

.shape-match-panel {
    max-width: 1232px;
    margin: 0 auto;
    padding: 8px 24px 32px;
}

.shape-match-header {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-end;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 14px;
    padding: 18px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-elevated);
}

.shape-match-header h2 {
    margin: 4px 0 2px;
    font-size: 1.45rem;
}

.shape-match-header p:not(.challenge-meta) {
    margin: 0;
    color: var(--text-muted);
}

.shape-header-actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: flex-end;
    gap: 8px;
}

.shape-header-actions .btn {
    padding: 8px 11px;
    font-size: 0.82rem;
}

.shape-progress {
    color: var(--success);
    font-size: 0.82rem;
    font-variant-numeric: tabular-nums;
    font-weight: 700;
}

.shape-match-body {
    display: grid;
    grid-template-columns: minmax(250px, 0.8fr) minmax(0, 1.2fr);
    gap: 16px;
}

.shape-target-card,
.shape-question-card {
    min-width: 0;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-elevated);
}

.shape-target-card {
    overflow: hidden;
}

.shape-target-card .pane-label {
    margin: 0;
}

.shape-target-canvas {
    min-height: 300px;
    background: #f4f4f8;
}

.shape-target-canvas .shape {
    flex: 0 0 auto;
}

.shape-position {
    margin: 0;
    padding: 10px 14px;
    color: var(--text-muted);
    font-size: 0.82rem;
    font-weight: 650;
}

.shape-question-card {
    padding: 18px;
}

.shape-question-card > .shape-position {
    margin: -18px -18px 12px;
    padding-bottom: 0;
}

.shape-question-card h3 {
    margin: 0 0 8px;
    font-size: 1.5rem;
}

.shape-status {
    margin: 12px 0;
    color: var(--text-muted);
}

.shape-choices {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
}

.shape-next {
    margin-top: 12px;
}

.chip-revealed {
    border-color: var(--success);
    color: var(--success);
}

.shape-choice {
    min-height: 96px;
    padding: 12px;
    border: 1px solid var(--border-strong);
    border-radius: var(--radius-sm);
    background: var(--bg-input);
    color: var(--text);
    cursor: pointer;
    text-align: left;
    transition: border-color 0.15s ease, background 0.15s ease, transform 0.15s ease;
}

.shape-choice:hover:not(:disabled) {
    border-color: var(--accent);
    transform: translateY(-1px);
}

.shape-choice code {
    display: block;
    color: #d7e0ff;
    font-family: var(--mono);
    font-size: 0.78rem;
    line-height: 1.45;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
}

.shape-choice-correct {
    border-color: var(--success);
    background: var(--success-soft);
}

.shape-choice-wrong {
    border-color: var(--danger);
    background: var(--danger-soft);
}

.shape-feedback {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-top: 14px;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg-panel);
}

.shape-feedback-pass {
    border-color: var(--success);
    background: var(--success-soft);
}

@media (max-width: 900px) {
    .learning-tools {
        grid-template-columns: 1fr;
    }

    .activity-switch {
        flex-direction: column;
        gap: 0;
        padding-right: 14px;
        padding-left: 14px;
    }

    .activity-switch .level-tabs {
        padding-right: 0;
        padding-left: 0;
    }

    .shape-mode-tab {
        align-self: flex-start;
        margin-top: 0;
        margin-bottom: 12px;
    }

    .shape-match-body {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 560px) {
    .learning-tools,
    .shape-match-panel {
        padding-right: 14px;
        padding-left: 14px;
    }

    .shape-match-header {
        align-items: flex-start;
    }

    .shape-header-actions {
        justify-content: flex-start;
    }

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