.back-link {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    margin: 0 0 18px 2px;
    color: var(--muted);
    text-decoration: none;
    font-size: .87rem;
    font-weight: 760;
    transition: color .18s ease, transform .18s ease;
}

.back-link:hover {
    color: var(--primary-strong);
    transform: translateX(-2px);
}

.image-joiner-app {
    padding-bottom: 56px;
}

.compact-hero {
    margin-top: 28px;
    padding: 42px;
}

.workspace-grid {
    display: grid;
    grid-template-columns: minmax(300px, 380px) 1fr;
    gap: 22px;
    margin-top: 22px;
    align-items: start;
}

.control-panel,
.preview-panel {
    display: grid;
    gap: 18px;
}

.panel-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 24px;
    box-shadow: var(--shadow-soft);
    padding: 22px;
}

.panel-card h2 {
    margin: 0 0 16px;
    font-size: 1.08rem;
    color: var(--text);
}

.upload-zone {
    min-height: 160px;
    border: 1.5px dashed color-mix(in srgb, var(--accent, #12a8f5) 55%, var(--border));
    border-radius: 22px;
    display: grid;
    place-items: center;
    text-align: center;
    padding: 26px 20px;
    cursor: pointer;
    color: var(--muted);
    background: color-mix(in srgb, var(--surface-2) 72%, transparent);
    transition: transform .18s ease, border-color .18s ease, background .18s ease;
}

.upload-zone:hover,
.upload-zone.is-dragover {
    transform: translateY(-2px);
    border-color: #12a8f5;
    background: color-mix(in srgb, #12a8f5 10%, var(--surface));
}

.upload-zone i {
    font-size: 2.5rem;
    color: #12a8f5;
    margin-bottom: 10px;
}

.upload-zone strong {
    color: var(--text);
    font-size: 1.02rem;
}

.upload-zone span {
    display: block;
    margin-top: 8px;
    font-size: .92rem;
    line-height: 1.5;
}

.upload-zone input {
    display: none;
}

.file-actions {
    margin-top: 14px;
    display: flex;
    justify-content: flex-end;
}

.primary-button,
.secondary-button,
.download-button {
    border: 0;
    border-radius: 16px;
    min-height: 46px;
    padding: 0 18px;
    font-weight: 750;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 9px;
    cursor: pointer;
    text-decoration: none;
    transition: transform .18s ease, opacity .18s ease, background .18s ease;
}

.primary-button:hover,
.secondary-button:hover,
.download-button:hover {
    transform: translateY(-1px);
}

.primary-button {
    color: white;
    background: linear-gradient(135deg, #12a8f5, #16b984);
    box-shadow: 0 16px 34px rgba(18,168,245,.24);
}

.secondary-button {
    background: var(--surface-2);
    color: var(--text);
    border: 1px solid var(--border);
}

.download-button {
    color: white;
    background: linear-gradient(135deg, #7567ee, #12a8f5);
}

.download-button.is-disabled {
    pointer-events: none;
    opacity: .45;
    filter: grayscale(.35);
}

.layout-options {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}

.layout-option {
    border: 1px solid var(--border);
    background: var(--surface-2);
    color: var(--muted);
    border-radius: 18px;
    min-height: 112px;
    display: grid;
    gap: 10px;
    place-items: center;
    padding: 12px;
    font-weight: 750;
    cursor: pointer;
    transition: transform .18s ease, border-color .18s ease, background .18s ease, color .18s ease;
}

.layout-option:hover,
.layout-option.is-active {
    transform: translateY(-2px);
    border-color: #12a8f5;
    color: var(--text);
    background: color-mix(in srgb, #12a8f5 9%, var(--surface));
}

.layout-icon {
    width: 72px;
    height: 54px;
    display: grid;
    gap: 6px;
    border: 2px solid #12a8f5;
    border-radius: 12px;
    padding: 8px;
    background: color-mix(in srgb, #12a8f5 8%, transparent);
}

.layout-icon b {
    display: block;
    background: #12a8f5;
    border-radius: 4px;
}

.horizontal-icon {
    grid-template-columns: repeat(3, 1fr);
}

.vertical-icon {
    width: 48px;
    height: 72px;
    grid-template-rows: repeat(3, 1fr);
}

.grid-icon {
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, 1fr);
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
}

.form-grid label {
    display: grid;
    gap: 7px;
    color: var(--muted);
    font-size: .88rem;
    font-weight: 700;
}

.form-grid input,
.form-grid select {
    width: 100%;
    height: 44px;
    border-radius: 14px;
    border: 1px solid var(--border);
    background: var(--surface-2);
    color: var(--text);
    padding: 0 12px;
    font: inherit;
    box-sizing: border-box;
}

.form-grid input[type="range"] {
    padding: 0;
}

.form-grid input[type="color"] {
    padding: 4px;
}

.form-grid small {
    color: var(--muted);
}

.action-stack {
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
    margin-top: 18px;
}

.panel-title-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.panel-title-row h2 {
    margin: 0;
}

.panel-title-row span {
    color: var(--muted);
    font-size: .88rem;
    font-weight: 700;
}

.image-list {
    min-height: 148px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(138px, 1fr));
    gap: 12px;
}

.image-list.empty {
    display: grid;
    grid-template-columns: 1fr;
    place-items: center;
}

.empty-state {
    min-height: 128px;
    display: grid;
    place-items: center;
    text-align: center;
    gap: 7px;
    color: var(--muted);
    padding: 24px;
}

.empty-state i {
    font-size: 2rem;
    color: color-mix(in srgb, #12a8f5 75%, var(--text));
}

.empty-state strong {
    color: var(--text);
}

.image-item {
    border: 1px solid var(--border);
    border-radius: 18px;
    overflow: hidden;
    background: var(--surface-2);
    position: relative;
}

.image-item[draggable="true"] {
    cursor: grab;
}

.image-item.is-dragging {
    opacity: .55;
}

.image-thumb {
    aspect-ratio: 1 / 1;
    background: #121926;
    display: grid;
    place-items: center;
}

.image-thumb img {
    max-width: 100%;
    max-height: 100%;
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.image-meta {
    display: grid;
    gap: 3px;
    padding: 10px;
    font-size: .8rem;
}

.image-meta strong {
    color: var(--text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.image-meta span {
    color: var(--muted);
}

.remove-image {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 0;
    background: rgba(7,17,31,.72);
    color: white;
    cursor: pointer;
}

.canvas-wrap {
    min-height: 420px;
    border-radius: 22px;
    background: #151a22;
    border: 1px solid var(--border);
    display: grid;
    place-items: center;
    padding: 20px;
    overflow: auto;
    position: relative;
}

#resultCanvas {
    display: none;
    max-width: 100%;
    height: auto;
    box-shadow: 0 14px 34px rgba(0,0,0,.28);
}

.canvas-wrap.has-result #resultCanvas {
    display: block;
}

.canvas-wrap.has-result .canvas-empty {
    display: none;
}

@media (max-width: 960px) {
    .workspace-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 680px) {
    .compact-hero,
    .panel-card {
        padding: 20px;
        border-radius: 20px;
    }

    .layout-options,
    .form-grid {
        grid-template-columns: 1fr;
    }

    .layout-option {
        min-height: 92px;
    }

    .canvas-wrap {
        min-height: 300px;
        padding: 12px;
    }
}