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

:root {
    --cream: #F5F0E8;
    --linen: #E8E0D5;
    --thread-red: #B85450;
    --thread-blue: #4A6B8A;
    --thread-gold: #C4A35A;
    --thread-green: #5A7A5A;
    --charcoal: #2D2A26;
    --warm-gray: #8A8580;
}

body {
    font-family: 'Cormorant Garamond', Georgia, serif;
    background: var(--cream);
    min-height: 100vh;
    color: var(--charcoal);
    -webkit-text-size-adjust: 100%;
    background-image:
        repeating-linear-gradient(
            0deg,
            transparent,
            transparent 20px,
            rgba(0,0,0,0.02) 20px,
            rgba(0,0,0,0.02) 21px
        ),
        repeating-linear-gradient(
            90deg,
            transparent,
            transparent 20px,
            rgba(0,0,0,0.02) 20px,
            rgba(0,0,0,0.02) 21px
        );
}

.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px 10px;
}

@media (min-width: 768px) {
    .app-container {
        padding: 40px 20px;
    }
}

header {
    text-align: center;
    margin-bottom: 50px;
    position: relative;
}

header::before,
header::after {
    content: '✕ ✕ ✕ ✕ ✕';
    display: block;
    letter-spacing: 12px;
    color: var(--thread-red);
    font-size: 10px;
    opacity: 0.6;
}

h1 {
    font-size: clamp(2rem, 6vw, 4rem);
    font-weight: 400;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    margin: 20px 0;
    background: linear-gradient(135deg, var(--thread-red), var(--thread-gold));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.subtitle {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.85rem;
    color: var(--warm-gray);
    letter-spacing: 0.3em;
    text-transform: uppercase;
}

.upload-zone {
    border: 2px dashed var(--thread-gold);
    border-radius: 4px;
    padding: 60px 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background:
        linear-gradient(135deg, transparent 49.5%, var(--linen) 49.5%, var(--linen) 50.5%, transparent 50.5%),
        linear-gradient(-135deg, transparent 49.5%, var(--linen) 49.5%, var(--linen) 50.5%, transparent 50.5%);
    background-size: 20px 20px;
    position: relative;
    overflow: hidden;
}

.upload-zone:hover {
    border-color: var(--thread-red);
    background-color: rgba(255,255,255,0.5);
}

.upload-zone.dragging {
    border-color: var(--thread-red);
    border-style: solid;
    transform: scale(1.01);
}

.upload-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    opacity: 0.7;
}

.upload-text {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.upload-hint {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.75rem;
    color: var(--warm-gray);
}

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
    margin: 20px 0;
    padding: 20px;
    background: var(--linen);
    border-radius: 4px;
}

@media (min-width: 768px) {
    .controls {
        gap: 30px;
        margin: 40px 0;
        padding: 30px;
    }
}

.control-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.control-group label {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--warm-gray);
}

.control-group input[type="range"] {
    width: 150px;
    height: 8px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--cream);
    border-radius: 3px;
    outline: none;
}

@media (max-width: 767px) {
    .control-group input[type="range"] {
        width: 100%;
        min-width: 200px;
    }
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: var(--thread-red);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

.control-group input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: var(--thread-red);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

.control-value {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.9rem;
    font-weight: 500;
}

.workspace {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    margin-top: 20px;
}

@media (min-width: 900px) {
    .workspace {
        grid-template-columns: minmax(350px, 400px) minmax(550px, 1fr);
        gap: 40px;
        margin-top: 40px;
    }
}

.preview-panel, .pattern-panel {
    background: white;
    border-radius: 4px;
    padding: 20px;
    box-shadow:
        0 1px 3px rgba(0,0,0,0.05),
        0 10px 40px rgba(0,0,0,0.08);
    min-width: 0; /* Prevent overflow */
    overflow: hidden; /* Contain content */
}

.panel-header {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    color: var(--warm-gray);
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--linen);
}

.original-image {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 2px;
}

.pattern-container {
    width: 100%;
    height: 60vh;
    overflow: auto;
    background:
        linear-gradient(90deg, var(--linen) 1px, transparent 1px),
        linear-gradient(var(--linen) 1px, transparent 1px);
    background-size: 10px 10px;
    padding: 20px;
    border-radius: 2px;
    position: relative;
}

.pattern-svg {
    display: block;
    max-width: none;
    height: auto;
    transition: transform 0.2s ease;
}

.zoom-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 15px;
    padding: 10px;
    background: var(--linen);
    border-radius: 4px;
}

.zoom-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    padding: 0;
    background: var(--charcoal);
    color: var(--cream);
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
    touch-action: manipulation;
}

.zoom-btn:hover {
    background: var(--thread-red);
    transform: translateY(-1px);
}

.zoom-btn:active {
    transform: translateY(0);
}

.zoom-value {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.85rem;
    min-width: 50px;
    text-align: center;
    color: var(--charcoal);
    font-weight: 500;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--linen);
    border-radius: 4px;
    overflow: hidden;
    margin: 20px 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--thread-red), var(--thread-gold));
    transition: width 0.1s ease;
    position: relative;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        90deg,
        transparent 0%,
        rgba(255,255,255,0.3) 50%,
        transparent 100%
    );
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.stats {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--linen);
}

.stat {
    text-align: center;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--thread-blue);
}

.stat-label {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--warm-gray);
}

.color-palette {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--linen);
}

.color-swatch {
    width: 30px;
    height: 30px;
    border-radius: 2px;
    box-shadow: inset 0 0 0 1px rgba(0,0,0,0.1);
    position: relative;
    cursor: pointer;
    transition: transform 0.2s ease;
}

.color-swatch:hover {
    transform: scale(1.2);
    z-index: 1;
}

.color-swatch::after {
    content: attr(data-count);
    position: absolute;
    bottom: -18px;
    left: 50%;
    transform: translateX(-50%);
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.6rem;
    color: var(--warm-gray);
    white-space: nowrap;
}

.download-buttons {
    display: flex;
    gap: 10px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 15px 30px;
    background: var(--charcoal);
    color: var(--cream);
    border: none;
    border-radius: 4px;
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    cursor: pointer;
    transition: all 0.3s ease;
    flex: 1;
    min-width: 200px;
    touch-action: manipulation;
}

@media (min-width: 768px) {
    .download-btn {
        flex: 0 1 auto;
        min-width: auto;
    }
}

.download-btn:hover {
    background: var(--thread-red);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(184, 84, 80, 0.3);
}

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

.download-btn-secondary {
    background: var(--thread-blue);
}

.download-btn-secondary:hover {
    background: var(--thread-gold);
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--warm-gray);
}

.thread-decoration {
    position: fixed;
    pointer-events: none;
    opacity: 0.1;
}

.thread-decoration.top-left {
    top: 20px;
    left: 20px;
    width: 150px;
    height: 150px;
    border-left: 2px solid var(--thread-red);
    border-top: 2px solid var(--thread-red);
}

.thread-decoration.bottom-right {
    bottom: 20px;
    right: 20px;
    width: 150px;
    height: 150px;
    border-right: 2px solid var(--thread-blue);
    border-bottom: 2px solid var(--thread-blue);
}

.converting-text {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 0.75rem;
    color: var(--warm-gray);
    text-align: center;
    margin-top: 10px;
}

/* Radio button group styles */
.radio-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: flex-start;
}

.radio-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--charcoal);
    transition: color 0.2s ease;
    padding: 8px;
    background: white;
    border-radius: 4px;
    min-width: 200px;
}

.radio-group label:hover {
    background: rgba(184, 84, 80, 0.1);
}

.radio-group input[type="radio"] {
    cursor: pointer;
    width: 18px;
    height: 18px;
    accent-color: var(--thread-red);
}

/* Checkbox styles */
.control-group input[type="checkbox"] {
    cursor: pointer;
    width: 16px;
    height: 16px;
    accent-color: var(--thread-red);
    margin-right: 8px;
}

.control-group label:has(input[type="checkbox"]) {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--charcoal);
}

/* Helper text */
.help-text {
    font-size: 0.7rem;
    color: var(--warm-gray);
    font-style: italic;
    margin-top: 5px;
    line-height: 1.4;
    text-transform: none;
    letter-spacing: normal;
}

/* Background color indicator */
.bg-indicator {
    display: inline-block;
    width: 24px;
    height: 24px;
    border: 2px solid var(--warm-gray);
    border-radius: 3px;
    margin-left: 10px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    vertical-align: middle;
}

/* Method hint */
.method-hint {
    background: rgba(74, 107, 138, 0.1);
    padding: 10px;
    border-radius: 4px;
    margin-top: 10px;
    font-size: 0.75rem;
    line-height: 1.5;
    color: var(--charcoal);
}

/* Responsive: single column on smaller screens */
@media (max-width: 899px) {
    .workspace {
        grid-template-columns: 1fr;
    }
}