/* ========================================
   三角洲游戏支持服务 - 数据理性风格
   灰色/蓝色为主，信息密集
   ======================================== */

/* CSS 变量定义 */
:root {
    /* 灰色背景系 */
    --color-bg: #0f1114;
    --color-bg-alt: #141619;
    --color-bg-card: #1a1d21;
    --color-bg-elevated: #1e2227;
    
    /* 蓝色强调 */
    --color-primary: #3b82f6;
    --color-primary-light: #60a5fa;
    --color-primary-dark: #2563eb;
    --color-primary-bg: rgba(59, 130, 246, 0.1);
    
    /* 状态色 */
    --color-success: #22c55e;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    
    /* 文字颜色 */
    --color-text: #e5e7eb;
    --color-text-secondary: #9ca3af;
    --color-text-muted: #6b7280;
    
    /* 边框 */
    --color-border: #2d3139;
    --color-border-light: #3d4149;
    
    /* 字体 */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Microsoft YaHei", sans-serif;
    --font-mono: "SF Mono", "Consolas", "Monaco", monospace;
    --font-size: 15px;
    --line-height: 1.7;
    
    /* 间距 */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4.5rem;
    
    /* 容器 */
    --container: 1200px;
}

/* ========================================
   基础重置
   ======================================== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: var(--font-size);
}

body {
    font-family: var(--font-sans);
    line-height: var(--line-height);
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
}

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

::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 4px;
}

/* ========================================
   通用样式
   ======================================== */
.container {
    width: 100%;
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

a {
    color: var(--color-primary-light);
    text-decoration: none;
    transition: color 0.2s;
}

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

ul {
    list-style: none;
}

/* ========================================
   导航
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(15, 17, 20, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--color-text);
}

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

.logo-icon {
    color: var(--color-primary);
    font-size: 1rem;
}

.logo-text {
    font-size: 0.9rem;
    font-weight: 600;
}

.nav-menu {
    display: flex;
    gap: 0.125rem;
}

.nav-menu a {
    display: block;
    padding: 0.4rem 0.65rem;
    font-size: 0.8rem;
    color: var(--color-text-secondary);
}

.nav-menu a:hover {
    color: var(--color-text);
}

/* ========================================
   Hero
   ======================================== */
.hero {
    padding: calc(56px + var(--space-2xl)) 0 var(--space-2xl);
    border-bottom: 1px solid var(--color-border);
}

.hero-content {
    max-width: 700px;
}

.hero-tag {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--color-primary);
    letter-spacing: 2px;
    margin-bottom: var(--space-sm);
}

.hero-title {
    font-size: 2.25rem;
    font-weight: 700;
    line-height: 1.25;
    margin-bottom: var(--space-md);
}

.hero-desc {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-xl);
}

.hero-metrics {
    display: flex;
    gap: var(--space-xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
}

.metric {
    text-align: left;
}

.metric-value {
    display: block;
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary-light);
    line-height: 1;
    margin-bottom: 0.25rem;
}

.metric-label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* ========================================
   通用区块
   ======================================== */
.section {
    padding: var(--space-2xl) 0;
}

.section-alt {
    background: var(--color-bg-alt);
}

.section-header {
    margin-bottom: var(--space-xl);
}

.section-tag {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.65rem;
    color: var(--color-primary);
    letter-spacing: 2px;
    margin-bottom: var(--space-xs);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
}

.section-desc {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

/* ========================================
   服务概览
   ======================================== */
.overview-intro {
    max-width: 800px;
    margin-bottom: var(--space-xl);
}

.overview-intro p {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    line-height: 1.9;
}

.overview-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-md);
}

.overview-item {
    padding: var(--space-md);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
}

.overview-item h3 {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.overview-item p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
}

/* ========================================
   表格样式
   ======================================== */
.modes-table,
.comparison-table {
    overflow-x: auto;
    margin-bottom: var(--space-lg);
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
}

th, td {
    padding: 0.875rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}

th {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    background: var(--color-bg-card);
}

tr:hover td {
    background: var(--color-bg-card);
}

tr.highlight td {
    background: var(--color-primary-bg);
}

.rating {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--color-primary);
    letter-spacing: 1px;
}

.modes-notes {
    background: var(--color-bg-card);
    padding: var(--space-md);
    border: 1px solid var(--color-border);
}

.modes-notes h4 {
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.modes-notes li {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    padding: 0.35rem 0;
}

.modes-notes strong {
    color: var(--color-text);
}

/* ========================================
   成本分析
   ======================================== */
.analysis-scenario {
    margin-bottom: var(--space-xl);
}

.analysis-scenario h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.scenario-table {
    overflow-x: auto;
    margin-bottom: var(--space-sm);
}

.scenario-table table {
    min-width: 600px;
}

.scenario-table tr.total td {
    font-weight: 600;
    background: var(--color-bg-card);
    border-top: 2px solid var(--color-border-light);
}

.scenario-note {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    font-style: italic;
}

.analysis-factors h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.factors-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-md);
}

.factor {
    padding: var(--space-md);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
}

.factor-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-primary-light);
    margin-bottom: var(--space-xs);
}

.factor p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* ========================================
   执行路径
   ======================================== */
.process-flow {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--space-md);
}

.flow-step {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
}

.step-header {
    padding: var(--space-md);
    border-bottom: 1px solid var(--color-border);
}

.step-num {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--color-primary);
    margin-bottom: 0.25rem;
}

.step-header h3 {
    font-size: 0.95rem;
    font-weight: 600;
}

.step-body {
    padding: var(--space-md);
}

.step-body p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: var(--space-sm);
}

.step-checklist {
    list-style: none;
}

.step-checklist li {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    padding: 0.25rem 0;
    padding-left: 1rem;
    position: relative;
}

.step-checklist li::before {
    content: '·';
    position: absolute;
    left: 0;
    color: var(--color-primary);
}

/* ========================================
   能力对比
   ======================================== */
.comparison-table table {
    min-width: 800px;
}

.compare-value {
    display: inline-block;
    padding: 0.2rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 2px;
    margin-bottom: 0.25rem;
}

.compare-value.high {
    background: rgba(34, 197, 94, 0.15);
    color: var(--color-success);
}

.compare-value.medium {
    background: rgba(245, 158, 11, 0.15);
    color: var(--color-warning);
}

.compare-value.low {
    background: rgba(239, 68, 68, 0.15);
    color: var(--color-danger);
}

.compare-detail {
    display: block;
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.comparison-summary {
    margin-top: var(--space-lg);
}

.comparison-summary h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.summary-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
}

.summary-item {
    padding: var(--space-md);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
}

.summary-item h5 {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.summary-item li {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    padding: 0.3rem 0;
    padding-left: 1rem;
    position: relative;
}

.summary-item li::before {
    content: '·';
    position: absolute;
    left: 0;
    color: var(--color-primary);
}

/* ========================================
   技巧资料
   ======================================== */
.resources-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
}

.resource-card {
    padding: var(--space-md);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    transition: border-color 0.2s;
}

.resource-card:hover {
    border-color: var(--color-border-light);
}

.resource-category {
    display: inline-block;
    font-size: 0.7rem;
    color: var(--color-primary);
    letter-spacing: 0.5px;
    margin-bottom: var(--space-sm);
}

.resource-card h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.resource-card p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: var(--space-sm);
}

.resource-meta {
    display: flex;
    gap: var(--space-md);
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* ========================================
   FAQ
   ======================================== */
.faq-content {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
}

.faq-column {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.faq-item {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
}

.faq-item summary {
    display: block;
    padding: var(--space-md);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    list-style: none;
    position: relative;
    padding-right: 2.5rem;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    position: absolute;
    right: var(--space-md);
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.25rem;
    font-weight: 300;
    color: var(--color-text-muted);
}

.faq-item[open] summary::after {
    content: '−';
}

.faq-answer {
    padding: 0 var(--space-md) var(--space-md);
}

.faq-answer p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-sm);
}

.faq-answer ul {
    list-style: none;
}

.faq-answer li {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    padding: 0.3rem 0;
    padding-left: 1rem;
    position: relative;
}

.faq-answer li::before {
    content: '·';
    position: absolute;
    left: 0;
    color: var(--color-primary);
}

.faq-answer strong {
    color: var(--color-text);
}

/* ========================================
   更新日志
   ======================================== */
.changelog-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.changelog-item {
    display: flex;
    gap: var(--space-lg);
    padding: var(--space-md);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
}

.changelog-date {
    flex-shrink: 0;
    width: 80px;
    text-align: center;
}

.date-day {
    display: block;
    font-family: var(--font-mono);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-text);
    line-height: 1;
}

.date-month {
    font-size: 0.7rem;
    color: var(--color-text-muted);
}

.changelog-content {
    flex: 1;
}

.changelog-tag {
    display: inline-block;
    padding: 0.15rem 0.5rem;
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    border-radius: 2px;
    margin-bottom: var(--space-xs);
}

.changelog-tag.new {
    background: rgba(59, 130, 246, 0.15);
    color: var(--color-primary-light);
}

.changelog-tag.update {
    background: rgba(34, 197, 94, 0.15);
    color: var(--color-success);
}

.changelog-tag.resource {
    background: rgba(245, 158, 11, 0.15);
    color: var(--color-warning);
}

.changelog-tag.optimize {
    background: rgba(156, 163, 175, 0.15);
    color: var(--color-text-secondary);
}

.changelog-content h3 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.changelog-content p {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
}

/* ========================================
   联系
   ======================================== */
.contact-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: var(--space-xl);
    align-items: start;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-sm);
}

.info-item {
    padding: var(--space-md);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
}

.info-label {
    display: block;
    font-size: 0.7rem;
    color: var(--color-text-muted);
    margin-bottom: 0.25rem;
}

.info-value {
    font-size: 0.9rem;
    font-weight: 500;
}

.contact-form {
    background: var(--color-bg-card);
    padding: var(--space-lg);
    border: 1px solid var(--color-border);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
}

.form-group {
    margin-bottom: var(--space-md);
}

.form-group label {
    display: block;
    font-size: 0.8rem;
    color: var(--color-text-muted);
    margin-bottom: 0.4rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.65rem 0.875rem;
    font-family: var(--font-sans);
    font-size: 0.875rem;
    color: var(--color-text);
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-primary);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--color-text-muted);
}

.form-group select {
    cursor: pointer;
    appearance: none;
    background-image: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="%236b7280" stroke-width="2"><polyline points="6,9 12,15 18,9"/></svg>');
    background-repeat: no-repeat;
    background-position: right 0.875rem center;
    background-size: 1rem;
}

.form-group textarea {
    resize: vertical;
    min-height: 80px;
}

.btn-submit {
    width: 100%;
    padding: 0.75rem;
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 600;
    color: white;
    background: var(--color-primary);
    border: none;
    cursor: pointer;
    transition: background 0.2s;
}

.btn-submit:hover {
    background: var(--color-primary-dark);
}

/* ========================================
   页脚
   ======================================== */
.footer {
    padding: var(--space-xl) 0 var(--space-lg);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--space-xl);
}

.footer-brand .logo {
    margin-bottom: var(--space-xs);
}

.footer-brand > p {
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

.footer-links {
    display: flex;
    gap: var(--space-md);
}

.footer-links a {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
}

.footer-bottom {
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
}

.footer-bottom p {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* ========================================
   响应式
   ======================================== */
@media (max-width: 1024px) {
    .nav-menu {
        display: none;
    }
    
    .overview-grid,
    .factors-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .process-flow {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .resources-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .contact-info {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 768px) {
    .hero-metrics {
        flex-wrap: wrap;
        gap: var(--space-md);
    }
    
    .metric {
        flex: 1 1 40%;
    }
    
    .overview-grid,
    .factors-grid,
    .summary-grid,
    .faq-content,
    .resources-grid {
        grid-template-columns: 1fr;
    }
    
    .process-flow {
        grid-template-columns: 1fr;
    }
    
    .contact-info {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .changelog-item {
        flex-direction: column;
        gap: var(--space-sm);
    }
    
    .changelog-date {
        width: auto;
        text-align: left;
        display: flex;
        align-items: baseline;
        gap: var(--space-xs);
    }
    
    .date-day {
        font-size: 1.25rem;
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--space-lg);
    }
    
    .footer-links {
        flex-wrap: wrap;
    }
}