/* GTACA 赛博日落 (Cyber Sunset) 终极主题样式 */

:root {
    /* 核心色板 */
    --bg-deep: #050505;
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-card: rgba(25, 25, 35, 0.6);
    --bg-glass: rgba(10, 10, 15, 0.7);
    
    /* 文本颜色 */
    --text-primary: #ffffff;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    /* 强调色 - 日落渐变 */
    --accent-orange: #ff6b6b;
    --accent-purple: #845ec2;
    --accent-blue: #2c73d2;
    
    --gradient-sunset: linear-gradient(135deg, #ff6b6b 0%, #d65db1 50%, #845ec2 100%);
    --gradient-ocean: linear-gradient(135deg, #2c73d2 0%, #0081cf 100%);
    --gradient-dark: linear-gradient(180deg, rgba(10,10,15,0) 0%, #0a0a0f 100%);
    
    /* 状态色 */
    --success: #00d2d3;
    --warning: #ff9f43;
    --danger: #ff5252;
    
    /* 边框与阴影 */
    --border-light: rgba(255, 255, 255, 0.08);
    --border-glow: rgba(255, 107, 107, 0.3);
    --shadow-card: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 20px rgba(132, 94, 194, 0.2);
    
    /* 动画 */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 基础重置与排版 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-deep);
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(132, 94, 194, 0.08) 0%, transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(255, 107, 107, 0.05) 0%, transparent 25%);
    color: var(--text-primary);
    line-height: 1.7;
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-fast);
}

ul {
    list-style: none;
}

/* 容器系统 */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
}

/* 导航栏 - 玻璃拟态 */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-light);
    height: 72px;
    display: flex;
    align-items: center;
}

nav .container {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 24px;
    font-weight: 800;
    background: var(--gradient-sunset);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
    position: relative;
}

.nav-brand::after {
    content: 'RP';
    position: absolute;
    right: -24px;
    top: 0;
    font-size: 10px;
    background: var(--accent-blue);
    -webkit-text-fill-color: white;
    padding: 2px 4px;
    border-radius: 4px;
    font-weight: 700;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    position: relative;
    padding: 8px 0;
}

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

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-sunset);
    transition: width 0.3s ease;
    border-radius: 2px;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

/* Hero 区域 - 沉浸式视觉 */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
    margin-top: -72px; /* 抵消导航栏高度 */
    background: url('https://images.unsplash.com/photo-1561578913-68d3023028c2?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=80') center/cover no-repeat;
}

.hero::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, 
        rgba(5, 5, 5, 0.3) 0%,
        rgba(5, 5, 5, 0.8) 60%,
        var(--bg-deep) 100%
    );
}

.hero-content {
    position: relative;
    z-index: 10;
    max-width: 800px;
    padding: 0 20px;
    animation: fadeInUp 1s ease-out;
}

.hero h1 {
    font-size: clamp(40px, 5vw, 72px);
    line-height: 1.1;
    font-weight: 900;
    margin-bottom: 24px;
    letter-spacing: -2px;
    text-shadow: 0 0 40px rgba(0,0,0,0.5);
}

.hero h1 span {
    background: var(--gradient-sunset);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.hero p {
    font-size: clamp(16px, 2vw, 20px);
    color: var(--text-secondary);
    margin-bottom: 48px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* 按钮组件 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 32px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 15px;
    cursor: pointer;
    transition: var(--transition-fast);
    border: none;
    outline: none;
}

.btn-primary {
    background: var(--gradient-sunset);
    color: white;
    box-shadow: 0 4px 20px rgba(255, 107, 107, 0.3);
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: 0.5s;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(255, 107, 107, 0.5);
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-block {
    width: 100%;
}

/* 特性部分 */
.features {
    padding: 120px 0;
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: 80px;
}

.section-title {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 16px;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    padding: 40px;
    border-radius: 24px;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: rgba(132, 94, 194, 0.5);
    box-shadow: var(--shadow-glow);
    background: rgba(30, 30, 45, 0.8);
}

.feature-icon {
    font-size: 40px;
    margin-bottom: 24px;
    display: inline-block;
    padding: 16px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 16px;
    border: 1px solid var(--border-light);
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.6;
}

/* 表单组件 */
.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 14px 16px;
    background: rgba(10, 10, 15, 0.6);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    color: white;
    font-family: inherit;
    font-size: 15px;
    transition: var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent-purple);
    box-shadow: 0 0 0 4px rgba(132, 94, 194, 0.1);
    background: rgba(10, 10, 15, 0.9);
}

/* 认证页面 - 居中布局 */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    position: relative;
}

.auth-page::before {
    content: '';
    position: absolute;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(132,94,194,0.15) 0%, transparent 70%);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: -1;
}

.auth-card {
    background: rgba(20, 20, 30, 0.7);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid var(--border-light);
    border-radius: 32px;
    padding: 48px;
    width: 100%;
    max-width: 440px;
    box-shadow: var(--shadow-card);
}

.auth-card h1 {
    font-size: 28px;
    text-align: center;
    margin-bottom: 8px;
}

.auth-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 32px;
    font-size: 15px;
}

.auth-footer {
    text-align: center;
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid var(--border-light);
    font-size: 14px;
    color: var(--text-muted);
}

.auth-footer a {
    color: var(--accent-orange);
    font-weight: 600;
}

/* 讨论区列表 */
.discussion-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.discussion-item {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    padding: 24px;
    border-radius: 16px;
    transition: var(--transition-fast);
    cursor: pointer;
    display: flex;
    flex-direction: column;
}

.discussion-item:hover {
    border-color: var(--accent-purple);
    background: rgba(30, 30, 45, 0.9);
    transform: translateX(4px);
}

.discussion-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.discussion-meta {
    display: flex;
    gap: 16px;
    font-size: 13px;
    color: var(--text-muted);
}

/* 通知系统 */
.notification {
    position: fixed;
    top: 90px;
    right: 24px;
    padding: 16px 24px;
    border-radius: 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    box-shadow: 0 10px 40px rgba(0,0,0,0.4);
    display: flex;
    align-items: center;
    gap: 12px;
    transform: translateX(120%);
    transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 2000;
    backdrop-filter: blur(12px);
}

.notification.show {
    transform: translateX(0);
}

.notification.success { border-left: 4px solid var(--success); }
.notification.error { border-left: 4px solid var(--danger); }
.notification.warning { border-left: 4px solid var(--warning); }

/* 页脚 */
footer {
    border-top: 1px solid var(--border-light);
    padding: 60px 0;
    text-align: center;
    color: var(--text-muted);
    font-size: 14px;
    margin-top: auto;
    background: var(--bg-primary);
}

/* 动画关键帧 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 移动端适配 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero h1 {
        font-size: 40px;
    }
    
    .auth-card {
        padding: 32px 24px;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
}