static/style.css

:root {
    --bg-dark: #0f172a;
    --card-bg: #1e293b;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border: #334155;
    --success: #10b981;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 2rem;
}

.container {
    max-width: 1200px;
    width: 100%;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeIn 0.8s ease-out;
}

header h1 {
    font-size: 3rem;
    letter-spacing: -1px;
}

header h1 span {
    color: var(--accent);
}

header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

main {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: 2rem;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 1.5rem;
    padding: 2rem;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
}

h2 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.control-group {
    margin-bottom: 2rem;
}

.control-group label {
    display: block;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
    font-weight: 500;
}

.upload-box {
    border: 2px dashed var(--border);
    border-radius: 1rem;
    padding: 1.5rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.02);
}

.upload-box:hover {
    border-color: var(--accent);
    background: rgba(99, 102, 241, 0.05);
}

.upload-box svg {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.upload-box p {
    font-size: 0.85rem;
}

.upload-box span {
    color: var(--accent);
    font-weight: 600;
}

.slider-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

input[type="range"] {
    width: 100%;
    accent-color: var(--accent);
}

.btn-primary {
    width: 100%;
    background: var(--accent);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.preview-area {
    display: flex;
    flex-direction: column;
}

.preview-card {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    min-height: 500px;
}

#preview-wrapper {
    position: relative;
    display: inline-block;
    line-height: 0;
}

.preview-img {
    max-width: 100%;
    max-height: 80vh;
    border-radius: 0.5rem;
    display: block;
}

.draggable-logo {
    position: absolute;
    cursor: grab;
    z-index: 20;
    transition: transform 0.1s ease;
    user-select: none;
    -webkit-user-drag: none;
    pointer-events: auto;
}

.draggable-logo:hover {
    filter: drop-shadow(0 0 12px rgba(99, 102, 241, 0.9));
    outline: 2px dashed rgba(255, 255, 255, 0.8);
    outline-offset: 4px;
}

.draggable-logo:active {
    cursor: grabbing;
    transform: scale(0.98);
}

.placeholder-msg {
    color: var(--text-secondary);
    text-align: center;
    max-width: 300px;
}

.loading-overlay {
    position: absolute;
    inset: 0;
    background: rgba(15, 23, 42, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 1rem;
    z-index: 10;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(99, 102, 241, 0.1);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

#debug-mask-area {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

#debug-mask-area h3 {
    font-size: 0.9rem;
    color: var(--text-dim);
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

#mask-container img {
    max-width: 100%;
    border-radius: 8px;
    opacity: 0.7;
    filter: grayscale(1) invert(1) brightness(1.5);
    border: 1px dashed var(--accent);
}

/* Input with Unit */
.dimension-row {
    display: flex;
    gap: 12px;
}

.input-with-unit {
    flex: 1;
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 4px 12px;
    transition: all 0.3s ease;
}

.input-with-unit:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 2px rgba(0, 242, 254, 0.2);
}

.input-with-unit input {
    background: transparent;
    border: none;
    color: white;
    font-size: 1.1rem;
    font-weight: 500;
    width: 100%;
    outline: none;
    padding: 8px 0;
}

.unit-label {
    color: var(--text-dim);
    font-size: 0.9rem;
    font-weight: 600;
    margin-left: 8px;
}

/* Preset Group */
.preset-group {
    display: flex;
    gap: 8px;
}

.preset-btn {
    flex: 1;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-dim);
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.preset-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

.preset-btn.active {
    background: var(--primary-grad);
    border-color: transparent;
    color: var(--bg-dark);
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(0, 242, 254, 0.3);
}

.hidden {
    display: none !important;
}

/* Responsive */
@media (max-width: 900px) {
    main {
        grid-template-columns: 1fr;
    }
}