:root {
    --primary: #667eea;
    --primary-dark: #5568d3;
    --secondary: #764ba2;
    --success: #52c41a;
    --warning: #faad14;
    --danger: #ff4d4f;
    --text-primary: #333;
    --text-secondary: #666;
    --text-light: #999;
    --bg-primary: #fff;
    --bg-secondary: #f5f5f5;
    --border-color: #e8e8e8;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s ease;
}

[data-theme="dark"] {
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --text-light: #707070;
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --border-color: #2d2d44;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.4);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 16px;
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loading-overlay.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader {
    width: 48px;
    height: 48px;
    border: 3px solid var(--border-color);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.loading-overlay p {
    margin-top: 16px;
    color: var(--text-secondary);
    font-size: 14px;
}

.app {
    opacity: 0;
    transition: opacity 0.3s ease;
}

.app.loaded {
    opacity: 1;
}

.header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 12px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo-icon {
    font-size: 24px;
}

.logo-text {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.theme-toggle {
    width: 36px;
    height: 36px;
    border: none;
    background: var(--bg-secondary);
    border-radius: 50%;
    cursor: pointer;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.theme-toggle:hover {
    background: var(--border-color);
}

.main-content {
    padding: 16px 0;
}

.hero-section {
    margin-bottom: 20px;
}

.hero-notice {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: var(--radius-md);
    padding: 20px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
    color: white;
}

.notice-icon {
    font-size: 28px;
    flex-shrink: 0;
}

.notice-text {
    flex: 1;
}

.notice-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
}

.notice-desc {
    font-size: 14px;
    opacity: 0.9;
    line-height: 1.5;
}

.quick-links {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    margin-bottom: 24px;
}

.quick-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 16px 8px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.quick-link:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.quick-link-icon {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
}

.quick-link span {
    font-size: 13px;
    color: var(--text-primary);
    font-weight: 500;
}

.section-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
    background: var(--bg-primary);
    padding: 4px;
    border-radius: var(--radius-md);
}

.tab-btn {
    flex: 1;
    padding: 10px 16px;
    border: none;
    background: transparent;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
}

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

.tab-content {
    display: none;
}

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

.activity-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.activity-card {
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    padding: 16px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.activity-card:hover {
    box-shadow: var(--shadow-md);
}

.activity-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 8px;
}

.activity-tag {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 12px;
    color: white;
}

.activity-time {
    font-size: 12px;
    color: var(--text-light);
}

.activity-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
    line-height: 1.4;
}

.activity-desc {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.activity-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.activity-platform {
    font-size: 12px;
    color: var(--primary);
    font-weight: 500;
}

.activity-arrow {
    font-size: 18px;
    color: var(--text-light);
}

.strategy-grid {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.strategy-card {
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    padding: 16px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.strategy-card:hover {
    box-shadow: var(--shadow-md);
}

.strategy-header {
    display: flex;
    gap: 8px;
    margin-bottom: 8px;
}

.strategy-platform,
.strategy-type {
    font-size: 11px;
    padding: 2px 6px;
    border-radius: 4px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
}

.strategy-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
    line-height: 1.4;
}

.strategy-summary {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.strategy-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.strategy-date {
    font-size: 12px;
    color: var(--text-light);
}

.strategy-arrow {
    font-size: 18px;
    color: var(--text-light);
}

.platform-section {
    margin-top: 32px;
    text-align: center;
    padding: 24px 16px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
}

.section-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.section-desc {
    font-size: 13px;
    color: var(--text-secondary);
}

.empty-state {
    text-align: center;
    padding: 40px 16px;
    color: var(--text-light);
}

.footer {
    text-align: center;
    padding: 24px 16px;
    color: var(--text-light);
    font-size: 12px;
}

.back-to-top {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 44px;
    height: 44px;
    border: none;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    font-size: 18px;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

[data-theme="dark"] .hero-notice {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    border: 1px solid var(--border-color);
}

@media (max-width: 480px) {
    .quick-links {
        grid-template-columns: repeat(2, 1fr);
    }

    .quick-link {
        padding: 12px 8px;
    }

    .quick-link-icon {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }

    .hero-notice {
        padding: 16px;
    }

    .notice-title {
        font-size: 15px;
    }

    .notice-desc {
        font-size: 13px;
    }
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --text-primary: #e0e0e0;
        --text-secondary: #a0a0a0;
        --text-light: #707070;
        --bg-primary: #1a1a2e;
        --bg-secondary: #16213e;
        --border-color: #2d2d44;
    }
}