:root {
    --color-primary: #4f8cff;
    --color-primary-dark: #2964c8;
    --color-bg: #fafbfc;
    --color-bg-light: #f7f9fa;
    --color-bg-section: #eaf4ff;
    --color-danger: #d32f2f;
    --color-success: #05c46b;
    --color-text: #222;
    --color-text-light: #6a7685;
    --color-border: #e0e4e8;
    --color-shadow: rgba(79,140,255,0.07);
    --color-shadow-item: rgba(79,140,255,0.06);
    --color-shadow-preview: rgba(79,140,255,0.05);
    --radius: 12px;
    --radius-small: 7px;
    --radius-toast: 6px;
    --font-main: 'Inter', Arial, sans-serif;
    --font-mono: 'Fira Mono', 'Consolas', 'Menlo', monospace;
    --transition: 0.2s;
}

body {
    margin: 0;
    font-family: var(--font-main);
    background: var(--color-bg);
    color: var(--color-text);
}

.container {
    max-width: 900px;
    margin: 2em auto;
    background: #fff;
    border-radius: var(--radius);
    box-shadow: 0 2px 16px var(--color-shadow);
    padding-bottom: 2em;
    overflow: hidden;
}

.header {
    padding: 2em 2em 1em 2em;
    border-bottom: 1px solid #f0f1f2;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.7em;
}

.logo h1 {
    font-size: 2em;
    font-weight: 600;
    margin: 0;
    letter-spacing: -1px;
}

.subtitle {
    color: var(--color-text-light);
    margin: 0.5em 0 0 0;
}

.main {
    padding: 2em;
}

.upload-section {
    margin-bottom: 2em;
}

.upload-area {
    border: 2px dashed var(--color-border);
    border-radius: 8px;
    background: var(--color-bg-light);
    text-align: center;
    padding: 2.5em 1em;
    cursor: pointer;
    transition: border-color var(--transition);
}

.upload-area.drag-over {
    border-color: var(--color-primary);
    background: var(--color-bg-section);
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.7em;
}

.upload-icon {
    color: var(--color-primary);
    opacity: 0.7;
    width: 48px;    
    height: 48px;
 }
.logo-icon {
    width: 48px;      /* or whatever size you prefer */
    height: 48px;
}
.logo-icon,.upload-icon {
    max-width: 100%;
    max-height: 100%;
    display: inline-block;
}
.browse-btn {
    padding: 0.6em 1.2em;
    font-size: 1em;
    background: var(--color-primary);
    color: #fff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: 500;
    box-shadow: 0 1px 6px var(--color-shadow);
    transition: background var(--transition);
}

.browse-btn:hover {
    background: var(--color-primary-dark);
}

.gallery-section {
    margin-bottom: 2em;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1em;
}

.clear-btn {
    background: none;
    border: none;
    color: var(--color-danger);
    font-size: 1em;
    cursor: pointer;
    font-weight: 500;
    padding: 0.2em 0.7em;
}

.image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
    gap: 1em;
}

.image-item {
    background: var(--color-bg-light);
    border-radius: var(--radius-small);
    padding: 1em;
    text-align: center;
    position: relative;
    box-shadow: 0 1px 6px var(--color-shadow-item);
}

.image-preview {
    max-width: 60px;
    max-height: 60px;
    margin-bottom: 0.6em;
}

.image-name {
    font-size: 0.98em;
    color: #444;
    margin-bottom: 0.2em;
    word-break: break-all;
}

.image-dimensions {
    font-size: 0.87em;
    color: #888;
    margin-bottom: 0.2em;
}

.remove-btn {
    position: absolute;
    top: 7px;
    right: 7px;
    background: #fff;
    color: var(--color-danger);
    border: 1px solid var(--color-border);
    border-radius: 50%;
    width: 22px;
    height: 22px;
    font-size: 1em;
    line-height: 19px;
    cursor: pointer;
    font-weight: 600;
    text-align: center;
    transition: background var(--transition);
}

.remove-btn:hover {
    background: #ffeaea;
    border-color: var(--color-danger);
}

.config-section {
    margin-bottom: 2em;
}

.config-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.3em 2em;
}

.config-group {
    display: flex;
    flex-direction: column;
}

.radio-group {
    display: flex;
    gap: 1.5em;
    margin-top: 0.5em;
}

.radio-option {
    display: flex;
    align-items: center;
    gap: 0.5em;
    cursor: pointer;
}

.radio-custom {
    width: 16px;
    height: 16px;
    border: 2px solid var(--color-primary);
    border-radius: 50%;
    display: inline-block;
    box-sizing: border-box;
    background: #fff;
    margin-right: 0.2em;
    position: relative;
}

.radio-option input[type="radio"]:checked + .radio-custom {
    background: var(--color-primary);
}

.radio-text {
    font-size: 1em;
    font-weight: 500;
}

#customSizeGroup {
    display: flex;
    align-items: center;
    gap: 1em;
}

#customSizeGroup label {
    margin: 0 0.5em 0 0;
    font-weight: 500;
}

#customSizeGroup input[type="number"] {
    width: 5em;
    min-width: 0;
    padding: 4px 8px;
    border-radius: 4px;
    border: 1px solid #ddd;
    font-size: 1em;
    margin-right: 1em;
}

input[type="number"][disabled] {
    background: var(--color-bg);
    color: var(--color-bg);
    cursor: not-allowed;
    opacity: 0.7;
}

input[type="range"] {
    margin-top: 0.9em;
    width: 100%;
}

.range-value {
    margin-top: 0.3em;
    font-size: 0.97em;
    color: var(--color-primary);
}

.preview-section {
    margin-bottom: 2em;
}

.preview-actions {
    display: flex;
    gap: 1em;
}

.btn {
    padding: 0.6em 1.2em;
    border-radius: 4px;
    font-weight: 500;
    font-size: 1em;
    cursor: pointer;
    border: none;
    box-shadow: 0 1px 6px var(--color-shadow);
}

.btn-primary {
    background: var(--color-primary);
    color: #fff;
}

.btn-secondary {
    background: var(--color-bg-section);
    color: var(--color-primary);
}

.btn:hover {
    filter: brightness(0.98);
}

.preview-container {
    background: var(--color-bg-light);
    border-radius: var(--radius-small);
    padding: 1.1em;
    margin-top: 1em;
    box-shadow: 0 1px 6px var(--color-shadow-preview);
}

.preview-canvas svg {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
}

.css-preview,.html-preview {
    margin-top: 2em;
    background: var(--color-bg-light);
    border-radius: var(--radius-small);
    padding: 1.1em;
    box-shadow: 0 1px 6px var(--color-shadow-preview);
    font-size: 0.98em;
    color: #333;
}

.css-preview h3,.html-preview h3 {
    margin-top: 0;
    margin-bottom: 0.7em;
    font-size: 1.1em;
    color: var(--color-primary);
}

.css-preview pre,.html-preview pre {
    margin: 0;
    background: none;
    font-family: var(--font-mono);
    font-size: 0.98em;
    color: #444;
    overflow-x: auto;
}

/* --- Sprite CSS for fragment identifier usage --- */
.sprite {
    display: inline-block;
    vertical-align: middle;
}

/* All icons: use background-image, size, and no background-position */
[class^="sprite-"], [class*=" sprite-"] {
    display: inline-block;
    background-repeat: no-repeat;
    background-size: contain;
    /* width/height set by per-icon class */
}

/* Example:
.sprite-iconname {
    background-image: url('sprite.svg#sprite-iconname-view');
    width: 24px;
    height: 24px;
}
*/

/* --- Toast notification --- */
.toast {
    position: fixed;
    bottom: 28px;
    left: 50%;
    transform: translateX(-50%);
    min-width: 200px;
    max-width: 350px;
    padding: 0.7em 1.2em;
    background: var(--color-primary);
    color: #fff;
    border-radius: var(--radius-toast);
    font-weight: 500;
    font-size: 1em;
    text-align: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition);
    z-index: 1000;
}

.toast.show {
    opacity: 1;
    pointer-events: auto;
}

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

.toast.error {
    background: var(--color-danger);
}

.toast.info {
    background: var(--color-primary);
}

/* --- Responsive --- */
@media (max-width: 700px) {
    .container {
        margin: 0;
        border-radius: 0;
        box-shadow: none;
    }
    .main {
        padding: 1em;
    }
    .header {
        padding: 1.5em 1em 0.7em 1em;
    }
    .image-grid {
        grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
        gap: 0.7em;
    }
}

@media (max-width: 500px) {
    .config-grid {
        grid-template-columns: 1fr;
        gap: 1em;
    }
    .preview-actions {
        flex-direction: column;
        gap: 0.7em;
    }
    #customSizeGroup {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5em;
    }
}