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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --success-color: #10b981;
    --error-color: #ef4444;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-primary);
}

.container {
    width: 100%;
    max-width: 600px;
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    padding: 40px;
    margin: 20px 0;
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header {
    text-align: center;
    margin-bottom: 40px;
}

.header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
}

.form-container {
    margin-bottom: 30px;
}

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

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.input-group input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: #fff;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.btn-generate {
    width: 100%;
    padding: 14px 24px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.btn-generate:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(37, 99, 235, 0.3);
}

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

.btn-text {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.info-box {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    border: 2px solid #fbbf24;
    border-radius: 10px;
    padding: 12px 16px;
    margin-bottom: 20px;
    text-align: center;
}

.info-box p {
    margin: 0;
    color: #92400e;
    font-size: 0.9rem;
    font-weight: 600;
}

.info-box strong {
    color: #78350f;
    font-size: 1.1rem;
}

.result-container {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 2px solid var(--border-color);
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.success-message {
    background: linear-gradient(135deg, var(--success-color) 0%, #059669 100%);
    color: white;
    padding: 12px 20px;
    border-radius: 10px;
    text-align: center;
    font-weight: 600;
    margin-bottom: 20px;
}

.qrcode-display {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.qrcode-image-container {
    background: white;
    padding: 20px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    justify-content: center;
}

.qrcode-image-container img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
}

.qrcode-info {
    width: 100%;
    background: #f9fafb;
    border-radius: 10px;
    padding: 20px;
}

.info-item {
    margin-bottom: 12px;
    display: flex;
    justify-content: space-between;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.info-item:last-child {
    margin-bottom: 0;
    border-bottom: none;
    padding-bottom: 0;
}

.info-label {
    font-weight: 600;
    color: var(--text-secondary);
}

.info-value {
    color: var(--text-primary);
    word-break: break-all;
    text-align: right;
    flex: 1;
    margin-left: 10px;
}

.action-buttons {
    display: flex;
    gap: 12px;
    margin-top: 20px;
}

.btn-download, .btn-clear {
    flex: 1;
    padding: 12px 20px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-download {
    background: linear-gradient(135deg, var(--success-color) 0%, #059669 100%);
    color: white;
    box-shadow: var(--shadow);
}

.btn-clear {
    background: linear-gradient(135deg, #6366f1 0%, #4f46e5 100%);
    color: white;
    box-shadow: var(--shadow);
}

.btn-download:hover, .btn-clear:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.error-message {
    background: linear-gradient(135deg, var(--error-color) 0%, #dc2626 100%);
    color: white;
    padding: 16px 20px;
    border-radius: 10px;
    margin-top: 20px;
    text-align: center;
    font-weight: 600;
    animation: shake 0.5s;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

.loading {
    text-align: center;
    padding: 40px 20px;
}

.spinner {
    border: 4px solid rgba(37, 99, 235, 0.1);
    border-top-color: #2563eb;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

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

.loading p {
    color: var(--text-secondary);
    font-weight: 600;
}

footer {
    text-align: center;
    color: rgba(255, 255, 255, 0.8);
    padding: 20px;
    font-size: 0.85rem;
}

/* 響應式設計 */
@media (max-width: 768px) {
    .container {
        padding: 30px 20px;
    }

    .header h1 {
        font-size: 2rem;
    }

    .action-buttons {
        flex-direction: column;
    }

    .btn-download, .btn-clear {
        width: 100%;
    }
}

/* 隱藏的元素 */
[style*="display: none"] {
    display: none !important;
}