:root {
    --primary-color: #2196F3;
    --text-color: #333;
    --bg-color: #f5f7fa;
    --card-bg: #fff;
    --spacing-lg: 24px;
    --spacing-md: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Microsoft JhengHei";
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

/* Header */
.guide-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 60px;
    background: #fff;
    border-bottom: 1px solid #eee;
    display: flex;
    align-items: center;
    padding: 0 var(--spacing-md);
    z-index: 1000;
}

.back-link {
    text-decoration: none;
    color: var(--primary-color);
    font-size: 20px;
    font-weight: bold;
    display: flex;
    align-items: center;
}

.back-link::before {
    content: '←';
    margin-right: 8px;
    font-size: 24px;
}

.lang-toggle {
    margin-left: auto;
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 6px 15px;
    border-radius: 20px;
    font-weight: bold;
    cursor: pointer;
}

/* Content Area */
.guide-container {
    max-width: 800px;
    margin: 80px auto 40px;
    padding: 0 var(--spacing-md);
}

.intro-section {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
}

.intro-section h1 {
    font-size: 32px;
    color: var(--primary-color);
    margin-bottom: 10px;
}

/* Cards */
.guide-card {
    background: var(--card-bg);
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    padding: var(--spacing-lg);
    margin-bottom: 24px;
    border-left: 6px solid var(--primary-color);
}

.guide-card h2 {
    font-size: 24px;
    margin-top: 0;
    color: var(--primary-color);
}

.content-block {
    margin-top: 20px;
}

.content-block p {
    font-size: 19px;
}

.tab-buttons {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.tab-btn {
    flex: 1;
    padding: 12px;
    border: 2px solid #ddd;
    background: #f9f9f9;
    border-radius: 10px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s;
}

.tab-btn.active {
    border-color: var(--primary-color);
    background: #e3f2fd;
    color: var(--primary-color);
}

.tab-content {
    display: none;
}

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

.tut-image {
    width: 66%;
    max-width: 66%;
    border-radius: 12px;
    margin: 0 auto 20px;
    border: 1px solid #eee;
    display: block;
}

.tip-box {
    background: #e3f2fd;
    padding: 15px;
    border-radius: 10px;
    margin-top: 15px;
    font-size: 18px;
    color: #1565c0;
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.tip-box::before {
    content: '💡';
}

/* Footer */
.guide-footer {
    text-align: center;
    padding: 40px 20px;
    color: #888;
    font-size: 18px;
    border-top: 1px solid #eee;
    margin-top: 40px;
}

[lang="en"] {
    display: none;
}

body.lang-en [lang="zh"] {
    display: none;
}

body.lang-en [lang="en"] {
    display: block;
}

@media (max-width: 600px) {
    .intro-section h1 {
        font-size: 28px;
    }
}

/* Dark Mode */
body.dark-theme {
    --bg-color: #121212;
    --card-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --primary-color: #3d5afe;
}

body.dark-theme .guide-header {
    background: #1e1e1e;
    border-bottom-color: #333;
}

body.dark-theme .intro-section h1 {
    color: #fff;
}

body.dark-theme .guide-card {
    background: #1e1e1e;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    border-left-color: #3d5afe;
}

body.dark-theme .guide-card h2 {
    color: #3d5afe;
}

body.dark-theme .tab-btn {
    background: #252525;
    border-color: #333;
    color: #aaa;
}

body.dark-theme .tab-btn.active {
    background: #1a237e;
    border-color: #3d5afe;
    color: #fff;
}

body.dark-theme .tip-box {
    background: #1a1a00;
    color: #cca300;
}

body.dark-theme .guide-footer {
    border-top-color: #333;
}

body.dark-theme .tut-image {
    border-color: #333;
    filter: brightness(0.8);
}

.share-card {
    background: #fafafa;
}

.share-box {
    background: #f1f3f5;
    padding: 20px;
    border-radius: 12px;
    margin: 20px 0;
}