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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    font-weight: 700;
}

.subtitle {
    font-size: 1.1em;
    opacity: 0.9;
}

main {
    padding: 40px 30px;
}

.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}

.form-section {
    /* Form takes left side */
}

.result-section {
    position: sticky;
    top: 20px;
    text-align: center;
    background: #f9f9f9;
    padding: 30px;
    border-radius: 12px;
    min-height: 400px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.qr-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-height: 300px;
}

.qr-placeholder svg {
    border-radius: 8px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

.form-group textarea,
.form-group input[type="number"],
.form-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    font-family: inherit;
    transition: border-color 0.3s;
}

.form-group textarea:focus,
.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: #667eea;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.btn-primary,
.btn-secondary {
    padding: 14px 28px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    width: 100%;
    margin-top: 10px;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
}

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

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    background: #f5f5f5;
    color: #333;
    margin: 0 5px;
}

.btn-secondary:hover {
    background: #e0e0e0;
}

.qr-display {
    width: 100%;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.qr-display img {
    max-width: 100%;
    max-height: 400px;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    background: white;
    padding: 10px;
}

.qr-actions {
    margin-top: 20px;
    display: flex;
    gap: 10px;
    width: 100%;
    justify-content: center;
}

.error-message {
    background: #fee;
    color: #c33;
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    border-left: 4px solid #c33;
}

@media (max-width: 900px) {
    .main-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .result-section {
        position: static;
        min-height: auto;
    }
}

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

    header h1 {
        font-size: 2em;
    }

    main {
        padding: 30px 20px;
    }

    .main-content {
        gap: 20px;
    }

    .result-section {
        padding: 20px;
    }
}