:root {
    --primary: #4a6bff;
    --secondary: #6c757d;
    --success: #28a745;
    --light: #f8f9fa;
    --dark: #343a40;
    --gray: #e9ecef;
    --red:#e74c3c;
    --border-radius: 8px;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f7fb;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background-color: white;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    color: var(--primary);
    font-size: 28px;
}

.logo-text {
    font-size: 24px;
    font-weight: 700;
    color: var(--dark);
}

.logo-text span {
    color: var(--primary);
}

nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
}

nav a {
    text-decoration: none;
    color: var(--dark);
    font-weight: 600;
    font-size: 17px;
    padding: 8px 0;
    transition: color 0.3s;
    position: relative;
}

nav a:hover, nav a.active {
    color: var(--primary);
}

nav a.active:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: var(--primary);
    border-radius: 3px;
}

.btn {
    width: 33%;
    padding: 12px 25px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    align-items: center;
    justify-content: center;
    gap: 8px;
    flex: 1;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: none !important;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.btn-primary {
    background-color: var(--primary);
    color: white;
}

.btn-success {
    background-color: var(--success);
    color: white;
}

.btn-download {
    background-color: #17a2b8;
    color: white;
}

.tabs-container {
    background-color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    margin-bottom: 40px;
}

.tabs-header {
    display: flex;
    background-color: var(--gray);
    border-bottom: 1px solid #dee2e6;
    overflow-x: auto;
}

.tab-btn {
    padding: 20px 30px;
    background: none;
    border: none;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    color: var(--secondary);
    transition: all 0.3s;
    min-width: 140px;
    text-align: center;
    white-space: nowrap;
}

.tab-btn:hover {
    background-color: rgba(255, 255, 255, 0.7);
}

.tab-btn.active {
    background-color: white;
    color: var(--primary);
    border-bottom: 3px solid var(--primary);
}

.tab-content {
    display: none;
    padding: 40px;
}

.tab-content.active {
    display: block;
}

.tab-content h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--dark);
}

.tab-content h3 {
    font-size: 1.5rem;
    margin: 30px 0 15px;
    color: var(--dark);
}

.registration-form {
    max-width: 800px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 25px;
}

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

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

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s;
}

.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s;
}

.checkbox-row {
    display: flex;
    gap: 0.5rem;
    align-items: flex-start;
}

.checkbox-row input {
	width: auto;
	margin-top: 0.4rem;
}

.status {
    margin-top: 5px;
    font-size: 14px;
}

.alert {
    display: flex;
    gap: 15px;
    padding: 20px;
    border-radius: 8px;
    margin-top: 15px;
    margin-bottom: 15px;
    align-items: flex-start;
    animation: fadeIn 0.5s;
}

.alert-success {
    background-color: #d5edda;
    color: #155724;
}

.alert-danger {
    background-color: #f8d7da;
    color: #721c24;
}

.alert-icon {
    font-size: 2rem;
}

.alert-success .alert-icon {
    color: #2ecc71;
}

.alert-danger .alert-icon {
    color: #e74c3c;
}

.register-purchase-container {
    display: flex;
    flex-wrap: wrap;
    gap: 70px;
    margin-top: 10px;
}

.register-section {
	width: 48%;
    min-width: 300px;
}

.purchase-info {
	width: 47%;
	flex: 1;
	min-width: 200px;
	background-color: var(--light);
	border-radius: var(--border-radius);
	padding: 10px;
}

.small-note {
	font-size:0.85rem;
	color:#555;
}

.modal {
    display:none;
    position:fixed;
    inset:0;
    background:rgba(0,0,0,0.6);
    align-items:center;
    justify-content:center;
    padding:20px;
}

.modal-content {
    background:#fff;
    color:#222;
    max-width:800px;
    max-height:80vh;
    overflow:auto;
    padding:30px;
    border-radius:16px;
}

.modal-close {
    float:right;
    cursor:pointer;
    font-size:24px;
}

a {
    color:#0066ff;
}

.price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--red);
    margin: 10px 0;
}

.required {
	color: #f5222d;
}

.download-options {
	max-width: 100%;
	gap: 30px;
	margin-top: 20px;
}

.download-card {
    border: 1px solid var(--gray);
    border-radius: var(--border-radius);
    padding: 30px;
    text-align: center;
    transition: all 0.3s;
}

.download-card:hover {
    box-shadow: var(--shadow);
    transform: translateY(-5px);
}

.download-card h4 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--dark);
}

.download-card .version {
    display: inline-block;
    background-color: var(--primary);
    color: white;
    padding: 5px 15px;
    border-radius: 50px;
    font-size: 0.9rem;
    margin-bottom: 20px;
}

.download-card .file-size {
    color: var(--secondary);
    margin-bottom: 10px;
    font-size: 0.95rem;
}

.download-card .md5-code {
    color: var(--secondary);
    margin-bottom: 30px;
    font-size: 0.8rem;
}

.version-history {
    margin-top: 50px;
}

.version-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    background-color: var(--light);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.version-table th, .version-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #dee2e6;
}

.version-table th {
    background-color: var(--primary);
    color: white;
    font-weight: 600;
}

.version-table tr:last-child td {
    border-bottom: none;
}

.version-table tr:hover {
    background-color: rgba(0, 0, 0, 0.02);
}

.install-steps {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.install-step {
    text-align: center;
    padding: 25px;
    background-color: var(--light);
    border-radius: var(--border-radius);
}

.install-step .step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    background-color: var(--primary);
    color: white;
    border-radius: 50%;
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 20px;
}

.install-step h4 {
    margin-bottom: 10px;
    color: var(--dark);
}

footer {
    background-color: var(--dark);
    color: white;
}

.copyright {
    text-align: center;
    padding-top: 20px;
    padding-bottom: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
}

@keyframes fadeIn {
    from { opacity:0; }
    to { opacity:1; }
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 20px;
    }

    nav ul {
        gap: 20px;
    }

    .tabs-header {
        flex-direction: row;
        overflow-x: auto;
    }

    .tab-btn {
        min-width: 120px;
        padding: 15px 20px;
        font-size: 16px;
    }

    .tab-content {
        padding: 30px 20px;
    }

    .install-steps {
        grid-template-columns: 1fr;
    }

    .version-table {
        display: block;
        overflow-x: auto;
    }

    .register-purchase-container {
        flex-direction: column;
    }
}

/* ===== 新增：PayPal 按钮容器样式 ===== */
#paypal-button-wrapper {
    margin-top: 20px;
    justify-content: center;
}

#paypal-container-T4SD9JBNKDRW8 {
    width: 100%;
    max-width: 400px;
}

/* 邮箱输入框容器：用来把按钮内嵌在输入框里面 */
        .input-email-wrap {
            position: relative;
            width:100%;
        }

        .input-email-wrap input {
            width:100%;
            padding:14px 120px 14px 16px; /* 右侧预留按钮空间 */
            border: 2px solid #e0e0e0;
            border-radius: 8px;
            font-size: 1rem;
    	    transition: all 0.3s;
        }
	
	.send-code-btn {
            position: absolute;
            right:12px;
            top:50%;
            transform: translateY(-50%);
            background:transparent;
            border:none;
            color:#0056ff;
            font-size:17px;
            cursor:pointer;
            white-space:nowrap;
        }

	.purchase-guide {
		margin-top: 10px;
		padding: 25px;
		background-color: var(--light);
		border-radius: var(--border-radius);
	}