:root {
    --edu-solver-green: #15803d;
    --edu-solver-green-dark: #166534;
    --edu-solver-border: #dbe3ee;
    --edu-solver-text: #172033;
    --edu-solver-muted: #64748b;
    --edu-solver-surface: #ffffff;
}

html:has(body.edu-online-solver-page) {
    overflow: hidden;
}

body.edu-online-solver-page {
    min-width: 320px;
    margin: 0;
    overflow: hidden;
    background: #dfe6ef;
    color: var(--edu-solver-text);
}

.edu-online-solver-page *,
.edu-online-solver-page *::before,
.edu-online-solver-page *::after {
    box-sizing: border-box;
}

.edu-solver-skip:focus {
    z-index: 1000000;
}

.edu-solver-app {
    display: flex;
    width: 100%;
    height: 100vh;
    height: 100dvh;
    min-height: 0;
    flex-direction: column;
    overflow: hidden;
    background: #e9eef5;
}

.admin-bar .edu-solver-app {
    height: calc(100vh - 32px);
    height: calc(100dvh - 32px);
}

.edu-solver-appbar {
    position: relative;
    z-index: 5;
    display: flex;
    min-height: 70px;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding: 10px 20px;
    border-bottom: 1px solid var(--edu-solver-border);
    background: var(--edu-solver-surface);
    box-shadow: 0 2px 10px rgba(15, 23, 42, 0.06);
}

.edu-solver-title-area,
.edu-solver-export-actions,
.edu-solver-toolbar,
.edu-solver-tool-group,
.edu-solver-tool,
.edu-solver-color,
.edu-solver-width,
.edu-solver-action {
    display: flex;
    align-items: center;
}

.edu-solver-title-area {
    min-width: 0;
    gap: 12px;
}

.edu-solver-back {
    display: inline-grid;
    width: 42px;
    height: 42px;
    flex: 0 0 42px;
    place-items: center;
    border: 1px solid var(--edu-solver-border);
    border-radius: 11px;
    background: #f8fafc;
    color: #334155;
    text-decoration: none;
    transition: 160ms ease;
}

.edu-solver-back:hover {
    border-color: #86efac;
    background: #f0fdf4;
    color: var(--edu-solver-green);
}

.edu-solver-title-copy {
    min-width: 0;
}

.edu-solver-title-copy > span {
    display: block;
    margin-bottom: 2px;
    color: var(--edu-solver-green);
    font-size: 11px;
    font-weight: 800;
    letter-spacing: .08em;
    line-height: 1.2;
    text-transform: none;
}

.edu-solver-title-copy h1 {
    overflow: hidden;
    margin: 0;
    color: var(--edu-solver-text);
    font-size: clamp(15px, 2vw, 18px);
    font-weight: 700;
    line-height: 1.3;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.edu-solver-export-actions {
    flex: 0 0 auto;
    gap: 8px;
}

.edu-solver-action {
    min-height: 42px;
    gap: 8px;
    padding: 8px 14px;
    cursor: pointer;
    border: 1px solid #bbf7d0;
    border-radius: 10px;
    background: #f0fdf4;
    color: var(--edu-solver-green-dark);
    font: inherit;
    font-size: 13px;
    font-weight: 700;
    transition: 160ms ease;
}

.edu-solver-action:hover:not(:disabled) {
    border-color: var(--edu-solver-green);
    background: var(--edu-solver-green);
    color: #fff;
}

.edu-solver-action:disabled {
    cursor: wait;
    opacity: .55;
}

.edu-solver-toolbar {
    position: relative;
    z-index: 4;
    min-height: 66px;
    flex: 0 0 auto;
    gap: 10px;
    padding: 10px 16px;
    overflow-x: auto;
    border-bottom: 1px solid var(--edu-solver-border);
    background: #f8fafc;
    scrollbar-color: #cbd5e1 transparent;
    scrollbar-width: thin;
}

.edu-solver-tool-group {
    min-height: 44px;
    flex: 0 0 auto;
    gap: 6px;
    padding: 4px;
    border: 1px solid var(--edu-solver-border);
    border-radius: 11px;
    background: #fff;
}

.edu-solver-tool,
.edu-solver-icon-button,
.edu-solver-zoom-value {
    min-height: 36px;
    cursor: pointer;
    border: 0;
    border-radius: 8px;
    background: transparent;
    color: #475569;
    font: inherit;
    transition: 140ms ease;
}

.edu-solver-tool {
    gap: 7px;
    padding: 7px 10px;
    font-size: 12px;
    font-weight: 700;
}

.edu-solver-tool:hover,
.edu-solver-icon-button:hover:not(:disabled),
.edu-solver-zoom-value:hover {
    background: #eef2f7;
    color: #0f172a;
}

.edu-solver-tool.is-active {
    background: var(--edu-solver-green);
    color: #fff;
    box-shadow: 0 4px 10px rgba(21, 128, 61, .22);
}

.edu-solver-icon-button {
    display: inline-grid;
    width: 36px;
    flex: 0 0 36px;
    padding: 0;
    place-items: center;
    font-size: 14px;
}

.edu-solver-icon-button:disabled {
    cursor: not-allowed;
    opacity: .32;
}

.edu-solver-clear {
    color: #b91c1c;
}

.edu-solver-clear:hover:not(:disabled) {
    background: #fef2f2;
    color: #991b1b;
}

.edu-solver-color,
.edu-solver-width {
    height: 36px;
    gap: 8px;
    padding: 5px 8px;
    color: #475569;
    font-size: 11px;
    font-weight: 700;
}

.edu-solver-color input {
    width: 27px;
    height: 27px;
    padding: 2px;
    cursor: pointer;
    border: 1px solid #cbd5e1;
    border-radius: 50%;
    background: #fff;
}

.edu-solver-color input::-webkit-color-swatch-wrapper {
    padding: 0;
}

.edu-solver-color input::-webkit-color-swatch {
    border: 0;
    border-radius: 50%;
}

.edu-solver-width input {
    width: 92px;
    accent-color: var(--edu-solver-green);
}

.edu-solver-width output {
    display: inline-grid;
    min-width: 24px;
    height: 24px;
    place-items: center;
    border-radius: 6px;
    background: #f1f5f9;
    color: #334155;
    font-size: 11px;
}

.edu-solver-page-count {
    min-width: 68px;
    color: var(--edu-solver-muted);
    font-size: 12px;
    text-align: center;
}

.edu-solver-page-count strong {
    color: var(--edu-solver-text);
}

.edu-solver-zoom-value {
    min-width: 62px;
    padding: 0 8px;
    color: #334155;
    font-size: 12px;
    font-weight: 700;
}

.edu-solver-action:focus-visible,
.edu-solver-back:focus-visible,
.edu-solver-tool:focus-visible,
.edu-solver-icon-button:focus-visible,
.edu-solver-zoom-value:focus-visible,
.edu-solver-color input:focus-visible,
.edu-solver-width input:focus-visible {
    outline: 3px solid rgba(34, 197, 94, .28);
    outline-offset: 2px;
}

.edu-solver-workspace {
    position: relative;
    min-width: 0;
    min-height: 0;
    flex: 1;
    overflow: auto;
    overscroll-behavior: contain;
    padding: 24px;
    background-color: #dfe6ef;
    background-image: radial-gradient(rgba(100, 116, 139, .2) 1px, transparent 1px);
    background-size: 18px 18px;
    scrollbar-color: #94a3b8 #dfe6ef;
}

.edu-solver-paper {
    position: relative;
    margin: 0 auto;
    overflow: hidden;
    background: #fff;
    box-shadow: 0 16px 46px rgba(15, 23, 42, .22), 0 2px 8px rgba(15, 23, 42, .12);
}

.edu-solver-paper canvas {
    position: absolute;
    inset: 0;
    display: block;
    width: 100%;
    height: 100%;
}

.edu-solver-drawing-canvas {
    z-index: 2;
    cursor: crosshair;
    touch-action: none;
    -webkit-user-select: none;
    user-select: none;
}

.edu-solver-app.is-erasing .edu-solver-drawing-canvas {
    cursor: cell;
}

.edu-solver-app.is-panning .edu-solver-workspace,
.edu-solver-app.is-panning .edu-solver-paper {
    cursor: grab;
}

.edu-solver-app.is-panning .edu-solver-workspace {
    touch-action: none;
    -webkit-user-select: none;
    user-select: none;
}

.edu-solver-app.is-pan-dragging .edu-solver-workspace,
.edu-solver-app.is-pan-dragging .edu-solver-paper {
    cursor: grabbing;
}

.edu-solver-app.is-panning .edu-solver-drawing-canvas {
    pointer-events: none;
}

.edu-solver-loading,
.edu-solver-error {
    position: absolute;
    z-index: 3;
    top: 50%;
    left: 50%;
    display: flex;
    width: min(360px, calc(100% - 32px));
    align-items: center;
    flex-direction: column;
    gap: 8px;
    padding: 28px;
    border: 1px solid rgba(255, 255, 255, .72);
    border-radius: 16px;
    background: rgba(255, 255, 255, .94);
    color: var(--edu-solver-muted);
    text-align: center;
    transform: translate(-50%, -50%);
    box-shadow: 0 18px 50px rgba(15, 23, 42, .18);
}

.edu-solver-loading[hidden],
.edu-solver-error[hidden],
.edu-solver-paper[hidden] {
    display: none !important;
}

.edu-solver-loading strong,
.edu-solver-error strong {
    color: var(--edu-solver-text);
    font-size: 16px;
}

.edu-solver-loading > span:last-child,
.edu-solver-error > span:last-child {
    font-size: 13px;
}

.edu-solver-error > i {
    color: #dc2626;
    font-size: 28px;
}

.edu-solver-spinner {
    width: 34px;
    height: 34px;
    margin-bottom: 4px;
    border: 3px solid #dcfce7;
    border-top-color: var(--edu-solver-green);
    border-radius: 50%;
    animation: edu-solver-spin .75s linear infinite;
}

.edu-solver-status {
    min-height: 34px;
    flex: 0 0 auto;
    padding: 8px 16px;
    overflow: hidden;
    border-top: 1px solid var(--edu-solver-border);
    background: #fff;
    color: var(--edu-solver-muted);
    font-size: 11px;
    line-height: 18px;
    text-align: center;
    text-overflow: ellipsis;
    white-space: nowrap;
}

@keyframes edu-solver-spin {
    to { transform: rotate(360deg); }
}

@media (max-width: 782px) {
    .admin-bar .edu-solver-app {
        height: calc(100vh - 46px);
        height: calc(100dvh - 46px);
    }

    .edu-solver-appbar {
        min-height: 62px;
        gap: 10px;
        padding: 8px 10px;
    }

    .edu-solver-back {
        width: 40px;
        height: 40px;
        flex-basis: 40px;
    }

    .edu-solver-title-area {
        gap: 9px;
    }

    .edu-solver-title-copy > span {
        font-size: 9px;
    }

    .edu-solver-title-copy h1 {
        max-width: 42vw;
        font-size: 14px;
    }

    .edu-solver-action {
        width: 40px;
        min-height: 40px;
        justify-content: center;
        padding: 0;
    }

    .edu-solver-action span {
        position: absolute;
        width: 1px;
        height: 1px;
        overflow: hidden;
        clip: rect(0, 0, 0, 0);
        white-space: nowrap;
        clip-path: inset(50%);
    }

    .edu-solver-toolbar {
        min-height: 60px;
        gap: 7px;
        padding: 8px 10px;
    }

    .edu-solver-tool-group {
        min-height: 42px;
    }

    .edu-solver-tool {
        min-height: 34px;
    }

    .edu-solver-tool span,
    .edu-solver-color > span,
    .edu-solver-width > span {
        position: absolute;
        width: 1px;
        height: 1px;
        overflow: hidden;
        clip: rect(0, 0, 0, 0);
        white-space: nowrap;
        clip-path: inset(50%);
    }

    .edu-solver-width input {
        width: 74px;
    }

    .edu-solver-workspace {
        padding: 12px;
    }

    .edu-solver-status {
        min-height: 30px;
        padding: 6px 10px;
        font-size: 10px;
    }
}

@media (max-width: 420px) {
    .edu-solver-title-copy h1 {
        max-width: 34vw;
    }

    .edu-solver-export-actions {
        gap: 5px;
    }

    .edu-solver-workspace {
        padding: 8px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .edu-solver-spinner {
        animation-duration: 1.5s;
    }

    .edu-solver-action,
    .edu-solver-back,
    .edu-solver-tool,
    .edu-solver-icon-button,
    .edu-solver-zoom-value {
        transition: none;
    }
}