*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg: #ffffff;
    --surface: #ffffff;
    --text: #000000;
    --text-secondary: #555555;
    --accent: #000000;
    --accent-hover: #333333;
    --border: #d0d0d0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px 80px;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 48px;
}

header h1 {
    font-size: 1.8rem;
    font-weight: 300;
    letter-spacing: 0.15em;
    text-transform: uppercase;
}

.subtitle {
    color: var(--text-secondary);
    margin-top: 8px;
    font-size: 0.95rem;
    font-weight: 300;
}

/* Steps */
.step {
    margin-bottom: 36px;
}

.step h2 {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Upload area */
.upload-area {
    background: var(--surface);
    border: 1.5px dashed var(--border);
    border-radius: 24px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
    position: relative;
}

.upload-area.dragover {
    border-color: var(--accent);
    background: #f8f8f8;
}

.upload-area.has-image {
    border-style: solid;
    padding: 12px;
    cursor: default;
}

.upload-placeholder {
    color: var(--text-secondary);
}

.upload-placeholder svg {
    margin-bottom: 12px;
    opacity: 0.4;
}

.upload-placeholder p {
    margin-bottom: 6px;
}

.upload-link {
    color: var(--text);
    cursor: pointer;
    text-decoration: underline;
    font-weight: 500;
}

.upload-hint {
    font-size: 0.85rem;
    opacity: 0.5;
}

.preview-image {
    max-width: 100%;
    max-height: 400px;
    border-radius: 16px;
    object-fit: contain;
}

.btn-change {
    margin-top: 12px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 24px;
    padding: 8px 24px;
    font-size: 0.85rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    cursor: pointer;
    transition: background 0.2s;
}

.btn-change:hover {
    background: var(--accent-hover);
}

/* Fabric cards */
.fabrics {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

@media (max-width: 600px) {
    .fabrics {
        grid-template-columns: 1fr;
        max-width: 300px;
    }
}

.fabric-card {
    cursor: pointer;
    overflow: hidden;
    display: grid;
    grid-template-rows: auto auto;
    transition: opacity 0.2s;
}

.fabric-card:hover {
    opacity: 0.85;
}

.fabric-card.selected {
    outline: 3px solid var(--accent);
    outline-offset: -3px;
}

.fabric-bed-preview {
    width: 100%;
    aspect-ratio: 2 / 1.3;
    object-fit: cover;
    display: block;
}

.fabric-patterns {
    display: grid;
    grid-template-columns: 1fr 1fr;
}

.fabric-patterns img {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    display: block;
}


/* Generate button */
.btn-generate {
    width: 100%;
    padding: 14px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 24px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    transition: background 0.2s, opacity 0.2s;
}

.btn-generate:hover:not(:disabled) {
    background: var(--accent-hover);
}

.btn-generate:disabled {
    opacity: 0.25;
    cursor: not-allowed;
}

/* Result */
.result {
    margin-top: 48px;
    padding-top: 32px;
    border-top: 1px solid var(--border);
}

.result h2 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 20px;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

@media (max-width: 520px) {
    .comparison {
        grid-template-columns: 1fr;
    }
}

.comparison-item {
    position: relative;
}

.comparison-label {
    display: inline-block;
    background: rgba(0, 0, 0, 0.7);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 500;
    padding: 3px 8px;
    position: absolute;
    top: 8px;
    left: 8px;
    z-index: 1;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.comparison-item img {
    width: 100%;
    border: 1px solid var(--border);
}

.btn-download {
    display: block;
    text-align: center;
    margin-top: 20px;
    padding: 12px;
    background: transparent;
    border: 1.5px solid var(--accent);
    border-radius: 24px;
    color: var(--accent);
    font-weight: 500;
    font-size: 0.9rem;
    text-decoration: none;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    transition: background 0.2s, color 0.2s;
}

.btn-download:hover {
    background: var(--accent);
    color: #fff;
}

/* Loading */
.loading {
    position: fixed;
    inset: 0;
    background: rgba(255, 255, 255, 0.92);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 100;
    backdrop-filter: blur(4px);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-bottom: 20px;
}

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

.loading p {
    text-align: center;
    font-size: 0.95rem;
    font-weight: 400;
}

.loading-hint {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Error */
.error {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    background: #000;
    color: #fff;
    padding: 12px 20px;
    display: flex;
    align-items: center;
    gap: 12px;
    z-index: 200;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    max-width: 90vw;
}

.error p {
    font-size: 0.85rem;
}

.btn-close-error {
    background: none;
    border: none;
    color: #fff;
    font-size: 1.1rem;
    cursor: pointer;
    opacity: 0.6;
    flex-shrink: 0;
}

.btn-close-error:hover {
    opacity: 1;
}

/* Utility */
.hidden {
    display: none !important;
}