/* ==========================================
   GLOBAL APPLE / LULULEMON LIGHT MODE UI
   ========================================== */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@500;600;700&family=Inter:wght@300;400;500;600&display=swap');

:root {
    --primary: #FF6B00; 
    --bg-base: #FFFFFF;
    --bg-surface: #F5F5F7; 
    --bg-card: #FFFFFF;
    --border: rgba(0, 0, 0, 0.06);
    --text-main: #1D1D1F; 
    --text-muted: #86868B;
    --text-light: #A1A1A6;
    
    --radius-lg: 24px;
    --shadow-soft: 0 12px 36px rgba(0, 0, 0, 0.04);
    --shadow-hover: 0 24px 48px rgba(0, 0, 0, 0.08);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { 
    background-color: var(--bg-base); color: var(--text-main); 
    font-family: 'Inter', sans-serif; line-height: 1.6; overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { font-family: 'Space Grotesk', sans-serif; letter-spacing: -0.03em; color: var(--text-main); }
.mono-text { font-family: 'Inter', sans-serif; color: var(--text-muted); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.1em; font-weight: 600; display: block; margin-bottom: 12px;}
p { color: var(--text-muted); font-size: 1.1rem; }

/* Layouts */
.container { max-width: 1200px; margin: 0 auto; padding: 0 5%; }
.section-padding { padding: 120px 0; border-bottom: 1px solid var(--border); position: relative;}
.section-header { text-align: center; margin-bottom: 80px; max-width: 800px; margin-left: auto; margin-right: auto; }
.section-header h2 { font-size: clamp(2.5rem, 5vw, 3.5rem); margin-bottom: 16px; color: var(--text-main);}
.split-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 32px; }

/* Cards & Buttons */
.card { background: var(--bg-card); border: 1px solid var(--border); padding: 48px; border-radius: var(--radius-lg); box-shadow: var(--shadow-soft); transition: all 0.4s ease; }
.card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); }

.btn { background: var(--text-main); color: #FFFFFF; border: none; padding: 16px 36px; border-radius: 40px; font-weight: 500; font-size: 0.95rem; cursor: pointer; transition: all 0.3s ease; display: inline-block; text-decoration: none; font-family: 'Inter', sans-serif;}
.btn:hover { background: #000000; transform: scale(1.02); }
.btn.outline { background: transparent; border: 1px solid rgba(0,0,0,0.1); color: var(--text-main); }
.btn.outline:hover { background: rgba(0,0,0,0.05); }

/* Navigation (Global) */
nav { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; display: flex; justify-content: space-between; align-items: center; padding: 16px 5%; background: rgba(255, 255, 255, 0.85); backdrop-filter: saturate(180%) blur(20px); -webkit-backdrop-filter: saturate(180%) blur(20px); border-bottom: 1px solid var(--border); }

/* Logo 布局 */
.logo { display: flex; align-items: center; gap: 10px; cursor: pointer; text-decoration: none;}
.logo-icon { width: 32px; height: 32px; object-fit: contain; filter: brightness(0); /* 强制原本白色的Logo在白底上变黑，如果你的新Logo已经是黑色的，可以删掉这句 */ }
.logo-main { font-size: 1.4rem; font-weight: 700; letter-spacing: -0.04em; color: var(--text-main); font-family: 'Space Grotesk', sans-serif;}

/* 右侧菜单栏布局 */
.nav-right { display: flex; align-items: center; gap: 16px; position: relative; }
.menu-btn { background: none; border: none; color: var(--text-main); font-size: 1.4rem; cursor: pointer; padding: 8px; display: flex; align-items: center; justify-content: center; border-radius: 8px; transition: background 0.2s; }
.menu-btn:hover { background: rgba(0,0,0,0.05); }

/* 下拉菜单统一设计 */
.dropdown-menu { display: none; position: absolute; top: 50px; right: 0; background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px; padding: 12px 0; min-width: 220px; box-shadow: var(--shadow-hover); z-index: 1001; }
.dropdown-menu.active { display: block; }
.dropdown-menu a { display: block; padding: 12px 24px; color: var(--text-main); text-decoration: none; font-size: 0.95rem; font-weight: 500; transition: background 0.2s; font-family: 'Inter', sans-serif;}
.dropdown-menu a:hover { background: var(--bg-surface); color: var(--primary); }

@media (max-width: 768px) {
    #nav-pilot-btn { display: none; /* 手机端隐藏CTA按钮以节省空间，只留语言和汉堡菜单 */ }
}

/* Dropdown Menu */
.dropdown-menu { display: none; position: absolute; top: 50px; right: 0; background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px; padding: 12px 0; min-width: 150px; box-shadow: var(--shadow-hover); z-index: 1001; }
.dropdown-menu.active { display: block; }
.dropdown-menu a { display: block; padding: 10px 24px; color: var(--text-main); text-decoration: none; font-size: 0.9rem; transition: background 0.2s; }
.dropdown-menu a:hover { background: var(--bg-surface); }

/* Form Elements */
.form-group { margin-bottom: 24px; text-align: left; }
.form-group label { display: block; margin-bottom: 8px; font-weight: 500; font-size: 0.9rem; color: var(--text-main); }
.form-group input, .form-group textarea, .form-group select { width: 100%; padding: 16px; background: var(--bg-surface); border: 1px solid transparent; color: var(--text-main); border-radius: 12px; font-family: 'Inter', sans-serif; font-size: 1rem; transition: all 0.3s; outline: none; }
.form-group input:focus, .form-group textarea:focus, .form-group select:focus { background: white; border-color: var(--text-main); box-shadow: 0 0 0 4px rgba(0,0,0,0.05); }

/* Footer (Global Dark to anchor the page) */
footer { padding: 80px 5% 40px; background: #1D1D1F; text-align: center; color: white;}
footer a { color: white; text-decoration: none; }

@media (max-width: 900px) {
    .split-layout { grid-template-columns: 1fr; gap: 40px; }
    .nav-links { display: none; } /* On mobile, hide nav links for simplicity in this demo */
}
/* ==========================================
   NAVIGATION BAR OVERRIDES (桌面暴露，手机折叠)
   ========================================== */
.nav-links-exposed { display: flex; gap: 32px; align-items: center; margin-right: 16px; }
.nav-link { color: var(--text-main); text-decoration: none; font-size: 0.95rem; font-weight: 500; transition: color 0.3s; font-family: 'Inter', sans-serif; letter-spacing: -0.01em;}
.nav-link:hover { color: var(--primary); }
.mobile-only-link { display: none !important; } /* 电脑端隐藏汉堡菜单里的替补项 */

@media (max-width: 900px) {
    .nav-links-exposed { display: none; } /* 手机端隐藏外露菜单 */
    .mobile-only-link { display: block !important; } /* 手机端让汉堡菜单里的替补项显示出来 */
    
    /* 适配极小屏幕：如果手机太窄，隐藏文字按钮，只保留图标 */
    #nav-pilot-btn { display: none; } 
}