/* ================= 核心 CSS 变量 (双主题系统) ================= */
:root {
    /* 默认暗夜主题 (玄夜紫 + 古铜金) */
    --bg-main: #0a0510;
    --bg-gradient: linear-gradient(135deg, #180a2b 0%, #05020a 100%);
    --nav-bg: rgba(10, 5, 16, 0.7);
    --glass-bg: rgba(255, 255, 255, 0.04);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    
    --text-primary: #fcfaf5;
    --text-secondary: #a89bbd;
    --text-inverse: #0a0510;
    
    --accent-gold: #d4af37;
    --accent-gold-hover: #f3d782;
    --btn-gradient: linear-gradient(135deg, #e4c571 0%, #c29b28 100%);
    --moon-glow: rgba(212, 175, 55, 0.15);
    --mountain-silhouette: #08030d;
    
    --font-heading: "Noto Serif SC", "Songti SC", "STSong", serif;
    --font-body: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", sans-serif;
}
    --transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
}

:root[data-theme="light"] {
    /* 明亮主题 (素雅白 + 明月金) */
    --bg-main: #f8f6f2;
    --bg-gradient: linear-gradient(135deg, #fdfbf7 0%, #ebe5df 100%);
    --nav-bg: rgba(253, 251, 247, 0.8);
    --glass-bg: rgba(255, 255, 255, 0.6);
    --glass-border: rgba(0, 0, 0, 0.05);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.05);
    
    --text-primary: #2c1a3b;
    --text-secondary: #685a7a;
    --text-inverse: #ffffff;
    
    --accent-gold: #b58d1e;
    --accent-gold-hover: #d4af37;
    --btn-gradient: linear-gradient(135deg, #d4af37 0%, #a67b14 100%);
    --moon-glow: rgba(212, 175, 55, 0.08);
    --mountain-silhouette: #dfd8d1;
}

/* ================= 基础重置 ================= */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: var(--font-body);
    background-color: var(--bg-main);
    
    /* 🌟 新增：调用星空背景图 🌟 */
    background-image: url('background.png'); 
    background-size: cover; /* 自动缩放铺满屏幕 */
    background-position: center center; /* 居中显示 */
    background-repeat: no-repeat; /* 不重复平铺 */
    background-attachment: fixed; /* 页面滚动时背景固定（高级视差感） */
    
    color: var(--text-primary);
    overflow-x: hidden;
    transition: var(--transition);
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* ================= 顶栏导航 (Sticky Header) ================= */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--nav-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--glass-border);
    transition: var(--transition);
}
.nav-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-gold);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.nav-links {
    display: flex;
    gap: 2.5rem;
    font-weight: 500;
}
.nav-links a:hover { color: var(--accent-gold); transition: color 0.3s; }
.nav-actions { display: flex; align-items: center; gap: 1.5rem; }

/* 太极主题切换按钮 */
.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.6s ease-in-out;
    color: var(--text-primary);
}
.theme-toggle:hover { transform: rotate(180deg); }
.theme-toggle svg { width: 100%; height: 100%; fill: currentColor; }

.login-btn {
    border: 1px solid var(--accent-gold);
    color: var(--accent-gold);
    padding: 0.4rem 1.2rem;
    border-radius: 20px;
    font-size: 0.9rem;
    transition: var(--transition);
}
.login-btn:hover { background: var(--accent-gold); color: var(--text-inverse); }

/* ================= 主屏背景 (环境氛围) ================= */
.hero-section {
    position: relative;
    min-height: calc(100vh - 70px);
    
    /* 🌟 修改：移除原有的纯色渐变，改为透明，让 body 的星空图透出来 🌟 */
    background: transparent; 
    
    display: flex;
    align-items: center;
    overflow: hidden;
    padding: 4rem 2rem;
}

/* 大圆月亮 */
.moon-bg {
    position: absolute;
    top: 10%;
    left: 50%;
    transform: translateX(-50%);
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: radial-gradient(circle, var(--moon-glow) 0%, transparent 60%);
    z-index: 0;
    pointer-events: none;
}
/* 远山剪影 */
.mountain-bg {
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 25vh;
    background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%2308030d" fill-opacity="1" d="M0,256L48,229.3C96,203,192,149,288,144C384,139,480,181,576,197.3C672,213,768,203,864,181.3C960,160,1056,128,1152,138.7C1248,149,1344,203,1392,229.3L1440,256L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path><path fill="%231a0b2b" opacity="0.5" d="M0,128L60,149.3C120,171,240,213,360,208C480,203,600,149,720,138.7C840,128,960,160,1080,170.7C1200,181,1320,171,1380,165.3L1440,160L1440,320L1380,320C1320,320,1200,320,1080,320C960,320,840,320,720,320C600,320,480,320,360,320C240,320,120,320,60,320L0,320Z"></path></svg>');
    background-size: cover;
    background-position: bottom center;
    z-index: 0;
    transition: var(--transition);
}
[data-theme="light"] .mountain-bg {
    background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23dfd8d1" fill-opacity="1" d="M0,256L48,229.3C96,203,192,149,288,144C384,139,480,181,576,197.3C672,213,768,203,864,181.3C960,160,1056,128,1152,138.7C1248,149,1344,203,1392,229.3L1440,256L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
}

/* ================= 黄金布局容器 ================= */
.hero-container {
    max-width: 1280px;
    margin: 0 auto;
    width: 100%;
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 10;
}

/* ================= 左侧：品牌与价值 ================= */
.hero-content { padding-right: 2rem; }
.hero-title {
    font-family: var(--font-heading);
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    
    /* 🌟 新增：文字黑色深阴影，防止背景过亮导致看不清 🌟 */
}
.hero-title span {
    background: linear-gradient(to right, var(--accent-gold-hover), var(--accent-gold));
    -webkit-background-clip: text;
    color: transparent;
}
.hero-subtitle {
    font-size: 1.125rem;
    
    /* 🌟 修改：提亮副标题颜色并加阴影 🌟 */
    color: #ffffff;  
    margin-bottom: 3rem;
    line-height: 1.6;
    max-width: 90%;
}
.feature-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}
.feature-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    padding: 1.5rem 1rem;
    border-radius: 16px;
    backdrop-filter: blur(8px);
    text-align: center;
    transition: transform 0.3s ease;
    
    /* 🌟 新增：给卡片加一点阴影，让它在星空中浮起 🌟 */
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
}
.feature-card:hover { transform: translateY(-5px); border-color: var(--accent-gold); }
.feature-icon { font-size: 1.8rem; margin-bottom: 0.8rem; }
.feature-title { 
    font-weight: 600; 
    font-size: 1rem; 
    margin-bottom: 0.3rem; 

}
.feature-desc { 
    font-size: 0.8rem; 
    color: #e0dced; 
}

.time-prompt {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    
    /* 🌟 修改：加深背景色，突出提示框 🌟 */
    background: rgba(0, 0, 0, 0.4);
    
    color: var(--accent-gold);
    padding: 0.6rem 1.2rem;
    border-radius: 30px;
    font-size: 0.9rem;
    border: 1px solid rgba(212, 175, 55, 0.4);
    box-shadow: 0 2px 10px rgba(0,0,0,0.5);
}

/* ================= 右侧：交互表单区 ================= */
.hero-form-wrapper {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 2.5rem;
    box-shadow: var(--glass-shadow);
}
.form-header { text-align: center; margin-bottom: 2rem; }
.form-header h2 { font-family: var(--font-heading); font-size: 1.8rem; margin-bottom: 0.5rem; }
.form-header p { color: var(--text-secondary); font-size: 0.9rem; }

.form-group { margin-bottom: 1.5rem; }
.form-label { display: block; margin-bottom: 0.5rem; font-size: 0.9rem; color: var(--text-secondary); }

/* 拟物化/现代下拉框 */
.date-select-group { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 0.8rem; }
select {
    width: 100%;
    padding: 0.8rem 1rem;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    border-radius: 12px;
    appearance: none;
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}
[data-theme="light"] select { background: rgba(255, 255, 255, 0.5); }
select:focus { border-color: var(--accent-gold); box-shadow: 0 0 0 2px rgba(212, 175, 55, 0.2); }

/* 性别切换按钮 (Radio转Button样式) */
.gender-toggle { display: flex; gap: 1rem; }
.gender-toggle label {
    flex: 1;
    text-align: center;
    padding: 0.8rem;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    cursor: pointer;
    transition: var(--transition);
}
[data-theme="light"] .gender-toggle label { background: rgba(255, 255, 255, 0.5); }
.gender-toggle input[type="radio"] { display: none; }
.gender-toggle input[type="radio"]:checked + label {
    background: rgba(212, 175, 55, 0.15);
    border-color: var(--accent-gold);
    color: var(--accent-gold);
    font-weight: bold;
}

/* 核心 CTA 按钮 */
.cta-btn {
    width: 100%;
    padding: 1.2rem;
    border: none;
    border-radius: 12px;
    background: var(--btn-gradient);
    color: var(--text-inverse);
    font-size: 1.2rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(212, 175, 55, 0.3);
    transition: transform 0.2s, box-shadow 0.2s;
    margin-top: 1rem;
}
.cta-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(212, 175, 55, 0.5);
}

/* 信任背书 */
.trust-badge {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}
.trust-badge svg { width: 14px; height: 14px; fill: currentColor; }

/* ================= 响应式设计 ================= */
@media (max-width: 968px) {
    .hero-container { grid-template-columns: 1fr; gap: 3rem; }
    .hero-content { padding-right: 0; text-align: center; }
    .hero-title { font-size: 2.8rem; }
    .hero-subtitle { margin: 0 auto 2.5rem; }
    .feature-cards { justify-content: center; }
}
@media (max-width: 768px) {
    .nav-links { display: none; } /* 移动端隐藏中间菜单，保留Logo和按钮 */
    .feature-cards { grid-template-columns: 1fr; gap: 1rem; }
    .hero-title { font-size: 2.2rem; }
    .date-select-group { grid-template-columns: 1fr; }
    .hero-form-wrapper { padding: 1.5rem; }
}