* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Roboto, system-ui, sans-serif;
}

body {
    background: linear-gradient(145deg, #0f172a 0%, #1e293b 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
}

.tool-container {
    max-width: 900px;
    width: 100%;
    background: rgba(30, 41, 59, 0.8);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.05);
    border-radius: 40px;
    padding: 2.5rem;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.8);
    color: #f1f5f9;
}

.tool-header {
    margin-bottom: 2rem;
    text-align: center;
}

.tool-header .back-link {
    display: inline-block;
    color: #94a3b8;
    text-decoration: none;
    font-size: 1rem;
    margin-bottom: 1rem;
    transition: color 0.2s;
}

.tool-header .back-link:hover {
    color: #60a5fa;
}

.tool-header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    background: linear-gradient(135deg, #60a5fa, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tool-header h1 i {
    margin-right: 0.5rem;
    background: none;
    -webkit-text-fill-color: #60a5fa;
}

.tool-header p {
    color: #cbd5e1;
    font-size: 1.1rem;
}

.tool-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.input-group label {
    font-weight: 600;
    color: #e2e8f0;
    font-size: 1rem;
}

.input-group small {
    color: #94a3b8;
    font-size: 0.85rem;
}

.input-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

input, select {
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 16px;
    padding: 0.8rem 1rem;
    color: white;
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s;
}

input:focus, select:focus {
    border-color: #60a5fa;
}

input[type="color"] {
    padding: 0.3rem;
    height: 45px;
}

select option {
    background: #1e293b;
    color: white;
}

.options {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin: 0.5rem 0;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    color: #cbd5e1;
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: #60a5fa;
    cursor: pointer;
}

.btn-generate {
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    border: none;
    color: white;
    font-weight: 700;
    font-size: 1.2rem;
    padding: 1rem;
    border-radius: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.8rem;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 10px 20px -8px rgba(0,0,0,0.5);
}

.btn-generate:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 25px -8px #3b82f6aa;
}

.result-area {
    margin-top: 1.5rem;
    padding: 1.5rem;
    background: rgba(0,0,0,0.2);
    border-radius: 24px;
    border: 1px solid rgba(255,255,255,0.05);
}

.result-area label {
    font-weight: 600;
    margin-bottom: 1rem;
    display: block;
}

.barcode-preview {
    background: white;
    padding: 2rem;
    border-radius: 20px;
    display: flex;
    justify-content: center;
    margin-bottom: 1.5rem;
    min-height: 150px;
    align-items: center;
}

#barcodeSvg {
    max-width: 100%;
    height: auto;
}

.action-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.btn-download, .btn-copy {
    background: #334155;
    border: none;
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: 30px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    transition: background 0.2s;
}

.btn-download:hover, .btn-copy:hover {
    background: #475569;
}

.btn-download {
    background: #2563eb;
}

.btn-download:hover {
    background: #3b82f6;
}

.info {
    text-align: center;
    color: #94a3b8;
    font-size: 0.9rem;
    margin-top: 1rem;
}

.info-box {
    margin-top: 2rem;
    padding: 1.5rem;
    background: rgba(255,255,255,0.02);
    border-radius: 24px;
    border-left: 4px solid #60a5fa;
}

.info-box h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #e2e8f0;
    margin-bottom: 1rem;
}

.info-box ul {
    padding-left: 1.5rem;
    color: #cbd5e1;
    line-height: 1.8;
}
#barcodeSvg.invalid {
    opacity: 0.3;
    border: 2px solid #ef4444;
    border-radius: 8px;
}
.char-limit-msg {
    color: #ef4444;
    font-size: 0.85rem;
    margin-top: 0.25rem;
}

input.error {
    border-color: #ef4444;
    background-color: rgba(239, 68, 68, 0.1);
}