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

:root {
    --primary-color: #FF6619;
    --bg-color: #141416;
    --text-primary: #ffffff;
    --text-secondary: #999999;
    --border-color: #333333;
    --success-color: #4CAF50;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Language Toggle */
.lang-en { display: none; }
html.show-en .lang-en { display: revert; }
html.show-en .lang-zh { display: none; }

.lang-toggle {
    display: inline-block;
    padding: 6px 14px;
    background: transparent;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.85em;
    font-family: inherit;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.lang-toggle:hover {
    background: var(--primary-color);
    color: #fff;
}

nav .lang-switch {
    display: flex;
    align-items: center;
    padding: 8px 0;
}

/* Header */
header {
    background: linear-gradient(135deg, #1a1a1c 0%, #2a1a0a 100%);
    padding: 40px 0;
    border-bottom: 2px solid var(--primary-color);
    text-align: center;
}

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

header .subtitle {
    font-size: 1.2em;
    color: var(--text-secondary);
}

/* Navigation */
nav {
    background-color: #1a1a1c;
    padding: 0;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    padding: 0 10px;
}

nav a {
    display: block;
    padding: 15px 20px;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.3s ease;
    border-bottom: 2px solid transparent;
}

nav a:hover {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Main Content */
main {
    padding: 40px 0;
    min-height: 60vh;
}

main h2 {
    font-size: 2em;
    margin-bottom: 30px;
    color: var(--primary-color);
    border-bottom: 2px solid var(--primary-color);
    padding-bottom: 15px;
}

main h3 {
    font-size: 1.5em;
    margin: 30px 0 20px 0;
    color: var(--primary-color);
}

main h4 {
    font-size: 1.1em;
    margin: 20px 0 10px 0;
    color: var(--text-primary);
}

main p {
    margin-bottom: 15px;
    color: var(--text-secondary);
    line-height: 1.8;
}

main ul, main ol {
    margin-left: 30px;
    margin-bottom: 15px;
}

main li {
    margin-bottom: 10px;
    color: var(--text-secondary);
}

main a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s ease;
}

main a:hover {
    text-decoration: underline;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #1a1a1c 0%, #2a1a0a 100%);
    padding: 40px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
    margin-bottom: 40px;
}

.hero h2 {
    border: none;
    margin-bottom: 15px;
    padding-bottom: 0;
}

.hero p {
    color: var(--text-primary);
    font-size: 1.1em;
}

/* Features Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 20px 0;
}

.feature-card {
    background-color: #1a1a1c;
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(255, 102, 25, 0.2);
}

.feature-card h3 {
    margin-top: 0;
    margin-bottom: 15px;
}

.feature-card p {
    margin: 0;
}

/* Info Section */
.info {
    background-color: #1a1a1c;
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
    margin-top: 40px;
}

.info ul {
    list-style: none;
    margin-left: 0;
}

.info li {
    margin-bottom: 15px;
}

.info strong {
    color: var(--primary-color);
}

/* Support Section */
.support-section {
    background-color: #1a1a1c;
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
    margin-bottom: 30px;
}

.support-section ul {
    list-style: none;
    margin-left: 0;
}

.support-section li {
    margin-bottom: 12px;
    margin-left: 0;
    padding-left: 25px;
    position: relative;
}

.support-section li:before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

.faq-item {
    background-color: #0a0a0c;
    padding: 20px;
    border-radius: 6px;
    margin-bottom: 20px;
    border-left: 3px solid var(--primary-color);
}

.faq-item h4 {
    color: var(--primary-color);
    margin-top: 0;
    margin-bottom: 15px;
}

.faq-item p {
    margin-bottom: 10px;
}

.faq-item ol, .faq-item ul {
    margin-left: 20px;
}

/* Privacy Section */
.privacy-section {
    background-color: #1a1a1c;
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
    margin-bottom: 30px;
}

.privacy-section h3 {
    margin-top: 0;
}

.privacy-section h4 {
    color: var(--primary-color);
    margin-top: 20px;
}

.privacy-section ul {
    list-style: none;
    margin-left: 0;
}

.privacy-section li {
    margin-bottom: 12px;
    margin-left: 0;
    padding-left: 25px;
    position: relative;
}

.privacy-section li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* Footer */
footer {
    background-color: #0a0a0c;
    padding: 30px 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
    margin-top: 60px;
    color: var(--text-secondary);
}

footer p {
    margin-bottom: 10px;
    font-size: 0.95em;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    margin: 0 10px;
}

footer a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.8em;
    }

    nav ul {
        flex-wrap: wrap;
        gap: 0;
        justify-content: flex-start;
        padding: 0 5px;
    }

    nav a {
        padding: 10px 12px;
        font-size: 0.9em;
    }

    nav .lang-switch {
        padding: 8px 12px;
    }

    main h2 {
        font-size: 1.6em;
    }

    main h3 {
        font-size: 1.2em;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .container {
        padding: 0 15px;
    }

    main {
        padding: 20px 0;
    }
}

@media (max-width: 480px) {
    header {
        padding: 25px 0;
    }

    header h1 {
        font-size: 1.5em;
    }

    header .subtitle {
        font-size: 1em;
    }

    nav a {
        padding: 8px 10px;
        font-size: 0.88em;
    }

    main h2 {
        font-size: 1.3em;
    }

    main h3 {
        font-size: 1.1em;
    }
}

/* Print Styles */
@media print {
    nav { display: none; }
    footer { display: none; }
}