:root {
    /* YiWaiWai Brand Palette */
    --yww-blue: #0052D4;
    --yww-blue-light: #4364F7;
    --yww-orange: #FF512F;
    --yww-orange-light: #F09819;
    --yww-bg: #F8FAFC;
    --yww-dark: #0F172A;
    --yww-text: #334155;
    
    /* Gradients */
    --grad-blue: linear-gradient(135deg, #0052D4 0%, #4364F7 100%);
    --grad-orange: linear-gradient(135deg, #FF512F 0%, #F09819 100%);
    
    /* System */
    --shadow-soft: 0 10px 30px rgba(0, 82, 212, 0.08);
    --shadow-hover: 0 20px 40px rgba(0, 82, 212, 0.15);
    --radius-main: 20px;
    --transition-yww: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    background-color: var(--yww-bg);
    color: var(--yww-text);
    font-family: "Inter", "SF Pro Display", "PingFang SC", sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
}

/* Navbar */
.nav-yww {
    position: fixed; top: 0; width: 100%; height: 90px;
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 6%; z-index: 1000;
    background: rgba(248, 250, 252, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.03);
}

.logo-yww {
    font-size: 26px; font-weight: 900; color: var(--yww-blue);
    display: flex; align-items: center; gap: 10px;
}
.logo-yww span { color: var(--yww-orange); }

.nav-links { display: flex; gap: 40px; }
.nav-link { 
    text-decoration: none; font-size: 15px; font-weight: 600; 
    color: var(--yww-dark); transition: var(--transition-yww);
}
.nav-link:hover { color: var(--yww-blue); }

.btn-yww {
    padding: 12px 30px; border-radius: 100px; font-weight: 700;
    cursor: pointer; transition: var(--transition-yww); text-decoration: none;
    display: inline-block;
}
.btn-blue { background: var(--grad-blue); color: white; border: none; box-shadow: 0 10px 20px rgba(0, 82, 212, 0.2); }
.btn-blue:hover { transform: translateY(-3px); box-shadow: 0 15px 30px rgba(0, 82, 212, 0.3); }

/* Hero */
.hero-yww {
    padding: 200px 6% 120px; text-align: center;
    background: radial-gradient(circle at top right, rgba(0, 82, 212, 0.05), transparent);
    position: relative; z-index: 1;
}

.hero-yww h1 {
    font-size: clamp(40px, 6vw, 72px); font-weight: 900; color: var(--yww-dark);
    line-height: 1.1; margin-bottom: 30px;
}
.hero-yww h1 span { background: var(--grad-blue); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }

.hero-yww p {
    font-size: 20px; color: var(--yww-text); max-width: 700px; margin: 0 auto 50px;
}

/* Feature Grid */
.feature-section { padding: 100px 6%; }
.section-title { text-align: center; margin-bottom: 80px; }
.section-title h2 { font-size: 36px; font-weight: 800; color: var(--yww-dark); }
.section-title .accent { width: 60px; height: 5px; background: var(--yww-orange); margin: 20px auto; border-radius: 10px; }

.yww-grid {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px; max-width: 1400px; margin: 0 auto;
}

.yww-card {
    background: white; padding: 50px 40px; border-radius: var(--radius-main);
    transition: var(--transition-yww); border: 1px solid rgba(0,0,0,0.02);
    display: flex; flex-direction: column; gap: 20px;
}
.yww-card:hover {
    transform: translateY(-15px); box-shadow: var(--shadow-hover);
}

.card-icon {
    width: 70px; height: 70px; border-radius: 20px;
    display: flex; align-items: center; justify-content: center;
    font-size: 30px; color: white;
}

/* Chat Showcase */
.chat-showcase {
    background: var(--yww-dark); color: white; padding: 120px 6%;
    border-radius: 60px; margin: 0 40px;
}

.chat-flex {
    display: flex; align-items: center; gap: 100px; max-width: 1200px; margin: 0 auto;
}

.chat-content { flex: 1; }
.chat-visual { flex: 1; position: relative; }

.mockup-window {
    background: #1e293b; border-radius: 20px; padding: 20px;
    box-shadow: 0 30px 60px rgba(0,0,0,0.3); border: 1px solid rgba(255,255,255,0.1);
}

/* Stats */
.stats-yww {
    display: flex; justify-content: center; gap: 100px; padding: 80px 6%;
}
.stat-item { text-align: center; }
.stat-value { font-size: 48px; font-weight: 900; color: var(--yww-blue); display: block; }
.stat-label { font-size: 14px; font-weight: 600; text-transform: uppercase; letter-spacing: 2px; opacity: 0.6; }

/* Download Page Specific */
.dl-container { padding: 180px 6% 120px; text-align: center; }
.dl-grid {
    display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px;
    margin-top: 80px; max-width: 1200px; margin-left: auto; margin-right: auto;
}
.dl-card {
    background: white; padding: 60px 40px; border-radius: var(--radius-main);
    transition: var(--transition-yww); box-shadow: var(--shadow-soft);
}
.dl-card:hover { transform: translateY(-10px); box-shadow: var(--shadow-hover); }

/* Footer */
footer {
    padding: 100px 6% 40px; text-align: center;
}
.footer-logo { font-size: 32px; font-weight: 900; margin-bottom: 30px; }

/* Extended Features Section */
.extended-features { padding: 100px 6%; background: white; }
.feature-row { 
    display: flex; align-items: center; gap: 80px; max-width: 1200px; 
    margin: 0 auto 100px; 
}
.feature-row:nth-child(even) { flex-direction: row-reverse; }
.feature-text { flex: 1; }
.feature-image { 
    flex: 1; height: 400px; background: var(--yww-bg); 
    border-radius: var(--radius-main); overflow: hidden;
    box-shadow: var(--shadow-soft); border: 1px solid rgba(0,0,0,0.05);
}
.feature-text h3 { font-size: 32px; font-weight: 800; color: var(--yww-dark); margin-bottom: 20px; }
.feature-text p { font-size: 16px; color: var(--yww-text); opacity: 0.8; }

/* Compliance Footer */
.compliance-bar {
    background: #f1f5f9; padding: 40px 6%; text-align: center;
    border-top: 1px solid #e2e8f0; margin-top: 60px;
}
.compliance-text { 
    font-size: 13px; color: #64748b; line-height: 2; max-width: 1000px; margin: 0 auto; 
}
.warning-text { color: #ef4444; font-weight: 700; margin-top: 10px; display: block; }

/* Responsive */
.reveal { opacity: 0; transform: translateY(30px); transition: all 0.8s ease-out; }
.reveal.active { opacity: 1; transform: translateY(0); }

@media (max-width: 1024px) {
    .chat-flex { flex-direction: column; text-align: center; gap: 60px; }
    .dl-grid { grid-template-columns: 1fr; }
    .stats-yww { flex-direction: column; gap: 40px; }
}
@media (max-width: 768px) {
    .nav-links { display: none; }
    .chat-showcase { margin: 0 10px; border-radius: 30px; }
}