/* ==========================================
   1. CSS Variables & Reset (全局变量与重置)
=========================================== */
:root {
    --primary-color: #0a1118;
    --accent-color: #ffffff;
    --text-dark: #1a1a1a;
    --text-gray: #666666;
    --transition-speed: 1.2s;
}

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

body {
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    background-color: var(--accent-color);
    color: var(--text-dark);
    overflow-x: hidden;
    line-height: 1.4;
}

/* ==========================================
   2. Custom Cursor (艺术感自定义鼠标)
=========================================== */
@media (pointer: fine) { * { cursor: none !important; } }
.cursor-dot, .cursor-outline { 
    position: fixed; top: 0; left: 0; 
    transform: translate(-50%, -50%); 
    border-radius: 50%; z-index: 9999; 
    pointer-events: none; mix-blend-mode: difference; 
}
.cursor-dot { width: 8px; height: 8px; background-color: #fff; }
.cursor-outline { 
    width: 40px; height: 40px; border: 1px solid rgba(255, 255, 255, 0.8); 
    transition: width 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), 
                height 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), 
                background-color 0.3s ease, border-color 0.3s ease; 
}
.cursor-outline.hovering { width: 80px; height: 80px; background-color: rgba(255, 255, 255, 1); border-color: transparent; }
@media (max-width: 768px) { .cursor-dot, .cursor-outline { display: none !important; } }

/* ==========================================
   3. Navigation (导航栏)
=========================================== */
nav { 
    position: fixed; top: 0; width: 100%; padding: 25px 60px; display: flex; 
    justify-content: space-between; align-items: center; z-index: 100; 
    background-color: transparent; transition: transform 0.4s cubic-bezier(0.2, 1, 0.3, 1), background-color 0.3s, box-shadow 0.3s; 
}
nav.nav-white-bg { background-color: #ffffff; box-shadow: 0 4px 30px rgba(0, 0, 0, 0.05); }
.nav-hidden { transform: translateY(-100%); }
.nav-links { display: flex; gap: 40px; list-style: none; }
.nav-links a { color: var(--accent-color); text-decoration: none; font-size: 13px; font-weight: 600; letter-spacing: 1px; transition: color 0.3s; position: relative; }
nav.nav-white-bg .nav-links a { color: var(--text-dark); }
.nav-logo-img { height: 50px; object-fit: contain; position: relative; z-index: 1002; filter: brightness(0) invert(1); transition: height 0.3s ease, filter 0.3s ease; }
nav.nav-white-bg .nav-logo-img { height: 35px; filter: brightness(0); }

.mobile-menu-btn { display: none; flex-direction: column; gap: 6px; z-index: 1002; cursor: pointer; }
.mobile-menu-btn span { width: 28px; height: 2px; background-color: var(--accent-color); transition: all 0.3s ease; }
nav.nav-white-bg .mobile-menu-btn span { background-color: var(--text-dark); }
.mobile-menu-btn.active span:nth-child(1) { transform: translateY(8px) rotate(45deg); background-color: var(--text-dark); }
.mobile-menu-btn.active span:nth-child(2) { opacity: 0; }
.mobile-menu-btn.active span:nth-child(3) { transform: translateY(-8px) rotate(-45deg); background-color: var(--text-dark); }

/* ==========================================
   4. Text Animation Engine (GPU加速逐字动效)
=========================================== */
.word { display: inline-block; white-space: nowrap; }
.char { 
    opacity: 0; display: inline-block; 
    transform: translate3d(0, 15px, 0) scale(0.95); 
    transition: opacity 0.5s cubic-bezier(0.2, 1, 0.3, 1), transform 0.5s cubic-bezier(0.2, 1, 0.3, 1), color 0.6s; 
    will-change: transform, opacity; 
}
.is-visible .char { opacity: 1; transform: translate3d(0, 0, 0) scale(1); }

/* 文本颜色自适应容器 */
.bg-light .char, .bg-gray .char { color: var(--text-dark); }
.bg-light p .char, .bg-gray p .char { color: var(--text-gray); }
.bg-dark .char { color: #ffffff; }
.bg-dark p .char, .bg-dark .section-subtitle .char { color: #aaaaaa; }
.light-text .char { color: #ffffff !important; }
.dark-text .char { color: var(--text-dark) !important; }
.hero-content .char { color: #ffffff; } 

/* ==========================================
   5. Common Layout & Typography (通用排版)
=========================================== */
.section-title { font-size: clamp(2.5rem, 5vw, 4rem); font-weight: 800; text-align: center; margin-bottom: 30px; letter-spacing: -1px; line-height: 1.1; }
.section-subtitle { font-size: 1.1rem; text-align: center; text-transform: uppercase; letter-spacing: 4px; margin-bottom: 15px; font-weight: 600; color: var(--text-gray); }
.content-section { padding: 120px 5vw; }
.bg-light { background-color: #ffffff; }
.bg-gray { background-color: #f7f8fa; }
.bg-dark { background-color: var(--primary-color); color: #fff; }

/* ==========================================
   6. Contact Us Form (原生联系表单)
=========================================== */
.contact-section { position: relative; background-color: #ffffff; padding: 120px 5vw; display: flex; align-items: stretch; justify-content: space-between; gap: 80px; z-index: 5; border-top: 1px solid #eaeaea; }
.contact-left { flex: 0 0 40%; display: flex; flex-direction: column; justify-content: center; }
.cases-sub-title { font-size: 1.1rem; letter-spacing: 4px; text-transform: uppercase; color: var(--text-gray); margin-bottom: 20px; font-weight: 600; }
.cases-main-title { font-size: 3.5rem; font-weight: 800; line-height: 1.1; margin-bottom: 40px; letter-spacing: -1.5px; color: #000000; }
.contact-detail { display: flex; align-items: center; gap: 20px; font-size: 1.1rem; color: var(--text-gray); margin-bottom: 25px; }
.contact-detail svg { width: 24px; height: 24px; stroke: #1a1a1a; flex-shrink: 0; fill: none; }
.contact-right { flex: 1; display: flex; align-items: center; justify-content: center; background: #f7f8fa; padding: 60px; border-radius: 8px; }

.minimal-form { width: 100%; max-width: 500px; position: relative; transition: opacity 0.4s; }
.input-group { position: relative; margin-bottom: 40px; }
.input-group input, .input-group textarea { width: 100%; padding: 10px 0; font-size: 1.1rem; color: var(--text-dark); border: none; border-bottom: 1px solid #ccc; outline: none; background: transparent; resize: none; font-family: inherit; }
.input-group label { position: absolute; top: 10px; left: 0; color: #999; font-size: 1.1rem; transition: 0.3s ease all; pointer-events: none; }
.input-group::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background-color: var(--text-dark); transition: 0.3s ease all; }
.input-group input:focus ~ label, .input-group input:not(:placeholder-shown) ~ label, .input-group textarea:focus ~ label, .input-group textarea:not(:placeholder-shown) ~ label { top: -20px; font-size: 0.85rem; color: var(--text-dark); font-weight: 600; }
.input-group input:focus ~ ::after, .input-group textarea:focus ~ ::after { width: 100%; }

.submit-btn { background-color: var(--text-dark); color: #fff; border: none; padding: 18px 40px; font-size: 1rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; cursor: pointer; transition: background 0.3s, transform 0.3s; width: 100%; border-radius: 4px; }
.submit-btn:hover { background-color: #333; transform: translateY(-2px); }
.success-msg { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); text-align: center; color: var(--text-dark); opacity: 0; pointer-events: none; transition: opacity 0.4s; width: 100%; }
.success-msg h3 { font-size: 2rem; margin-bottom: 10px; }
.success-msg.active { opacity: 1; pointer-events: auto; }

/* ==========================================
   7. Footer (页脚区)
=========================================== */
.site-footer { background-color: var(--primary-color); color: var(--accent-color); padding: 100px 5vw 40px; z-index: 6; position: relative; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 60px; margin-bottom: 80px; }
.footer-logo-img { height: 40px; margin-bottom: 20px; filter: invert(0); }
.footer-desc { color: #888; font-size: 1.1rem; line-height: 1.6; max-width: 300px; }
.footer-col h4 { font-size: 1.2rem; font-weight: 700; margin-bottom: 30px; letter-spacing: 1px; color: #fff; }
.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 15px; }
.footer-col ul li a { color: #888; text-decoration: none; transition: color 0.3s; font-size: 1rem; }
.footer-col ul li a:hover { color: var(--accent-color); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 30px; display: flex; justify-content: space-between; align-items: center; color: #888; font-size: 0.9rem; }
.social-links { display: flex; gap: 20px; }
.social-links a { color: #888; text-decoration: none; transition: color 0.3s; }
.social-links a:hover { color: var(--accent-color); }

/* ==========================================
   8. Global Responsive Adjustments (移动端适配)
=========================================== */
@media (max-width: 1024px) { 
    .contact-section { flex-direction: column; padding: 80px 5vw; gap: 50px; }
    .contact-left, .contact-right { flex: 0 0 100%; width: 100%; }
    .contact-right { padding: 40px 20px; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) { 
    nav { padding: 20px; } 
    .mobile-menu-btn { display: flex; }
    .nav-links { 
        position: fixed; top: 0; left: 0; width: 100%; height: 100vh; background-color: #ffffff; 
        flex-direction: column; justify-content: center; align-items: center; gap: 40px; 
        transform: translateY(-100%); transition: transform 0.5s cubic-bezier(0.77, 0, 0.175, 1); z-index: 1001; 
    }
    .nav-links.active { transform: translateY(0); }
    .nav-links a { color: var(--text-dark); font-size: 1.8rem; font-weight: 800; }
    #navLinks.active + .logo-right .nav-logo-img { filter: brightness(0); height: 35px; } 
    
    .footer-grid { grid-template-columns: 1fr; } 
    .footer-bottom { flex-direction: column; gap: 20px; text-align: center; }
}