/* 基础变量 */
:root {
    --primary: #2563EB;
    --primary-hover: #1D4ED8;
    --bg-main: #FFFFFF;
    --bg-light: #F9FAFB;
    --bg-dark: #1F2937;
    --text-main: #111827;
    --text-muted: #4B5563;
    --border: #E5E7EB;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* 全局重置 */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-family); color: var(--text-main); line-height: 1.6; background-color: var(--bg-main); -webkit-font-smoothing: antialiased; }
a { text-decoration: none; color: inherit; }
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.text-center { text-align: center; }
.bg-light { background-color: var(--bg-light); }
.bg-dark { background-color: var(--bg-dark); color: #FFF; }
.section { padding: 100px 0; }
.section-title { font-size: 32px; font-weight: 700; text-align: center; margin-bottom: 60px; color: var(--text-main); }

/* 按钮通用 */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 12px 24px; border-radius: 8px; font-size: 15px; font-weight: 600; cursor: pointer; transition: all 0.2s ease; border: 1.5px solid transparent; }
.btn-primary { background-color: var(--primary); color: #FFF; }
.btn-primary:hover { background-color: var(--primary-hover); transform: translateY(-1px); }
.btn-outline { background-color: transparent; border-color: var(--border); color: var(--text-main); }
.btn-outline:hover { border-color: var(--text-muted); }
.btn-lg { padding: 14px 32px; font-size: 16px; }

/* 导航栏 */
.navbar { position: fixed; top: 0; width: 100%; background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); z-index: 1000; transition: box-shadow 0.3s ease; }
.nav-container { display: flex; justify-content: space-between; align-items: center; height: 72px; }
.nav-logo { font-size: 20px; font-weight: 800; color: var(--primary); letter-spacing: 0.5px; }
.nav-links { display: flex; gap: 32px; }
.nav-links a { font-size: 15px; font-weight: 500; color: var(--text-muted); transition: color 0.2s; }
.nav-links a:hover { color: var(--primary); }

/* 第一屏 Hero */
.hero { padding: 120px 0 60px; min-height: 100vh; display: flex; align-items: center; position: relative; }
.hero-container { display: flex; align-items: center; justify-content: space-between; gap: 40px; }
.hero-content { flex: 1; max-width: 540px; }
.hero-title { font-size: 48px; font-weight: 800; line-height: 1.25; margin-bottom: 24px; }
.hero-title span { color: var(--primary); }
.hero-desc { font-size: 18px; color: var(--text-muted); margin-bottom: 40px; line-height: 1.7; }
.hero-buttons { display: flex; gap: 16px; }
.hero-visual { flex: 1; display: flex; justify-content: flex-end; position: relative; }

/* CSS 模拟手机界面 */
.phone-mockup { width: 320px; height: 640px; background: #FFF; border: 12px solid #111827; border-radius: 40px; position: relative; box-shadow: 0 24px 60px rgba(0, 0, 0, 0.1); overflow: hidden; display: flex; flex-direction: column; }
.phone-notch { position: absolute; top: 0; left: 50%; transform: translateX(-50%); width: 120px; height: 24px; background: #111827; border-radius: 0 0 16px 16px; z-index: 10; }
.phone-screen { flex: 1; background: #F5F7FA; display: flex; flex-direction: column; }
.mock-chat { flex: 1; padding: 40px 16px 16px; display: flex; flex-direction: column; gap: 16px; font-size: 13px; overflow-y: hidden; }
.chat-bubble { padding: 12px 16px; border-radius: 16px; max-width: 90%; line-height: 1.5; }
.chat-bubble.ai { background: #FFFFFF; color: #1F2937; align-self: flex-start; border-radius: 4px 16px 16px 16px; border: 1px solid #E5E7EB; box-shadow: 0 2px 8px rgba(0,0,0,0.02); }
.chat-bubble.user { background: var(--primary); color: #FFF; align-self: flex-end; border-radius: 16px 16px 4px 16px; }
.chat-file { align-self: flex-end; background: #FFFFFF; border: 1px solid #E5E7EB; border-radius: 12px; padding: 10px 14px; display: flex; align-items: center; gap: 10px; max-width: 85%; color: #1F2937; }
.chat-file svg { color: var(--primary); }
.file-name { font-weight: 600; font-size: 12px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 140px; }
.file-size { font-size: 11px; color: #6B7280; }
.mock-input-bar { background: #FFFFFF; border-top: 1px solid #E5E7EB; padding: 12px 16px; display: flex; align-items: center; gap: 12px; }
.mock-input { flex: 1; background: #F3F4F6; border-radius: 20px; height: 36px; display: flex; align-items: center; padding: 0 16px; color: #9CA3AF; font-size: 13px; }
.mock-send { width: 32px; height: 32px; background: var(--primary); border-radius: 50%; opacity: 0.5; }

/* 滚动提示 */
.scroll-indicator { position: absolute; bottom: 40px; left: 50%; transform: translateX(-50%); color: var(--text-muted); animation: bounce 2s infinite; }
@keyframes bounce { 0%, 20%, 50%, 80%, 100% { transform: translateY(0) translateX(-50%); } 40% { transform: translateY(-10px) translateX(-50%); } 60% { transform: translateY(-5px) translateX(-50%); } }

/* 网格系统 */
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

/* 痛点模块 */
.feature-item { background: #FFF; padding: 32px 24px; border-radius: 16px; box-shadow: 0 4px 20px rgba(0,0,0,0.03); border: 1px solid var(--border); transition: transform 0.2s; }
.feature-item:hover { transform: translateY(-4px); }
.icon-box { width: 48px; height: 48px; border-radius: 12px; background: #EFF6FF; color: var(--primary); display: flex; align-items: center; justify-content: center; margin-bottom: 20px; }
.feature-item h3 { font-size: 18px; font-weight: 700; margin-bottom: 12px; }
.feature-item p { font-size: 14px; color: var(--text-muted); line-height: 1.6; }

/* 核心功能图文排版 */
.feature-row { display: flex; align-items: center; justify-content: space-between; gap: 60px; margin-bottom: 100px; }
.feature-row:last-child { margin-bottom: 0; }
.feature-row.reverse { flex-direction: row-reverse; }
.feature-text { flex: 1; max-width: 480px; }
.feature-text h3 { font-size: 28px; font-weight: 700; margin-bottom: 16px; color: var(--text-main); }
.feature-text p { font-size: 16px; color: var(--text-muted); line-height: 1.7; }
.feature-visual { flex: 1; min-height: 380px; background: var(--bg-light); border-radius: 24px; border: 1px solid var(--border); display: flex; align-items: center; justify-content: center; overflow: hidden; }
.product-visual { padding: 28px; background: linear-gradient(145deg, #F9FAFB, #EFF6FF); }
.panel-chat, .profile-panel, .analysis-panel, .job-panel {
    width: min(100%, 420px);
    background: rgba(255,255,255,0.92);
    border: 1px solid rgba(229,231,235,0.92);
    box-shadow: 0 18px 50px rgba(15,23,42,0.08);
}
.panel-chat { border-radius: 22px; padding: 18px; display: flex; flex-direction: column; gap: 12px; }
.panel-topbar { height: 28px; display: flex; align-items: center; gap: 6px; color: #6B7280; font-size: 12px; border-bottom: 1px solid #EEF2F7; padding-bottom: 12px; margin-bottom: 4px; }
.panel-topbar span { width: 8px; height: 8px; border-radius: 50%; background: #CBD5E1; }
.panel-topbar strong { margin-left: 8px; font-weight: 600; color: #334155; }
.panel-message { max-width: 84%; padding: 11px 13px; border-radius: 15px; font-size: 13px; line-height: 1.55; }
.panel-message.ai { background: #F8FAFC; border: 1px solid #E5E7EB; color: #1F2937; border-top-left-radius: 4px; }
.panel-message.user { align-self: flex-end; background: var(--primary); color: #fff; border-bottom-right-radius: 4px; }
.panel-message.wide { max-width: 96%; }
.panel-thinking { display: flex; align-items: center; gap: 10px; color: #64748B; font-size: 12px; padding-left: 4px; }
.thin-line { width: 28px; height: 2px; background: #93C5FD; border-radius: 999px; }

.profile-panel { border-radius: 20px; padding: 22px; }
.profile-head { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 18px; }
.profile-kicker { display: block; color: var(--primary); font-size: 12px; font-weight: 700; margin-bottom: 4px; }
.profile-head h4 { font-size: 20px; line-height: 1.3; }
.profile-score { width: 48px; height: 48px; border-radius: 50%; background: #EFF6FF; color: var(--primary); display: flex; align-items: center; justify-content: center; font-weight: 800; }
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.tag-row span { background: #EEF2FF; color: #1D4ED8; border: 1px solid #DBEAFE; border-radius: 999px; padding: 5px 10px; font-size: 12px; font-weight: 600; }
.profile-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.profile-grid div { background: #F8FAFC; border: 1px solid #E5E7EB; border-radius: 12px; padding: 12px; }
.profile-grid label { display: block; color: #64748B; font-size: 12px; margin-bottom: 4px; }
.profile-grid strong { font-size: 13px; color: #111827; }

.analysis-panel { border-radius: 20px; padding: 20px; display: flex; flex-direction: column; gap: 12px; }
.upload-strip { display: flex; gap: 12px; align-items: center; background: #F8FAFC; border: 1px solid #E5E7EB; border-radius: 14px; padding: 12px; }
.upload-strip strong { font-size: 13px; color: #111827; }
.upload-strip p { font-size: 12px; color: #64748B; margin-top: 2px; }
.file-chip { width: 44px; height: 44px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 11px; font-weight: 800; color: #fff; flex: none; }
.file-chip.pdf { background: #2563EB; }
.file-chip.video { background: #0F172A; }
.analysis-result { border-left: 3px solid var(--primary); padding: 12px 14px; background: #EFF6FF; border-radius: 0 12px 12px 0; }
.analysis-result span { font-size: 12px; font-weight: 800; color: #1D4ED8; }
.analysis-result p { margin-top: 5px; color: #1F2937; font-size: 13px; line-height: 1.55; }

.job-panel { border-radius: 20px; padding: 18px; display: flex; flex-direction: column; gap: 12px; }
.job-card { display: flex; justify-content: space-between; align-items: center; gap: 14px; background: #FFFFFF; border: 1px solid #E5E7EB; border-radius: 14px; padding: 14px; box-shadow: 0 6px 18px rgba(15,23,42,0.04); }
.job-card strong { display: block; font-size: 14px; color: #111827; }
.job-card span { display: block; font-size: 12px; color: #64748B; margin-top: 3px; }
.job-card em { flex: none; font-style: normal; color: var(--primary); font-size: 12px; font-weight: 800; background: #EFF6FF; border-radius: 999px; padding: 5px 9px; }
.job-card.muted { opacity: 0.72; }
.job-note { font-size: 12px; color: #475569; background: #F8FAFC; border-radius: 12px; padding: 12px; line-height: 1.55; }

/* 使用流程 */
.step-container { display: flex; align-items: flex-start; justify-content: space-between; position: relative; }
.step-item { flex: 1; text-align: center; position: relative; z-index: 2; padding: 0 16px; }
.step-number { width: 48px; height: 48px; border-radius: 50%; background: var(--primary); color: #FFF; font-size: 20px; font-weight: 700; display: flex; align-items: center; justify-content: center; margin: 0 auto 20px; box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2); }
.step-item h4 { font-size: 18px; font-weight: 700; margin-bottom: 10px; }
.step-item p { font-size: 14px; color: var(--text-muted); }
.step-line { flex: 1; height: 2px; background: var(--border); margin-top: 24px; position: relative; z-index: 1; }

/* 适用人群 */
.audience-card { border-left: 4px solid var(--primary); padding: 16px 20px; background: var(--bg-light); border-radius: 0 8px 8px 0; }
.audience-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 8px; }
.audience-card p { font-size: 14px; color: var(--text-muted); }

/* 可信说明 */
.trust-list { display: flex; flex-direction: column; gap: 16px; max-width: 680px; margin: 0 auto; text-align: left; }
.trust-item { display: flex; align-items: flex-start; gap: 12px; background: rgba(255,255,255,0.05); padding: 16px 20px; border-radius: 12px; border: 1px solid rgba(255,255,255,0.1); }
.trust-item span { font-size: 15px; color: #D1D5DB; line-height: 1.5; }

/* 底部 CTA */
.cta-section { padding: 100px 0; border-top: 1px solid var(--border); }
.cta-title { font-size: 36px; font-weight: 800; margin-bottom: 16px; }
.cta-actions { display: flex; justify-content: center; gap: 16px; }

/* 页脚 */
.footer { background: #111827; padding: 40px 0; color: #9CA3AF; font-size: 14px; }
.footer-container { display: flex; flex-direction: column; align-items: center; gap: 24px; }
.footer-logo { font-size: 18px; font-weight: 700; color: #FFF; }
.footer-links { display: flex; gap: 24px; }
.footer-links a:hover { color: #FFF; }
.footer-copy a { text-decoration: underline; }

/* 响应式适配 */
@media (max-width: 992px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .hero-container { flex-direction: column; text-align: center; padding-top: 40px; }
    .hero-buttons { justify-content: center; }
    .feature-row, .feature-row.reverse { flex-direction: column; gap: 40px; text-align: center; }
    .feature-text { max-width: 100%; }
    .feature-visual { width: 100%; }
}
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hero-title { font-size: 28px; }
    .hero { min-height: auto; padding-bottom: 60px; }
    .hero-visual {
        width: 100%;
        display: flex;
        justify-content: center;
        margin-top: 30px;
    }
    .step-container { flex-direction: column; gap: 32px; }
    .step-line { display: none; }
    .grid-4 { grid-template-columns: 1fr; }
    .cta-actions { flex-direction: column; padding: 0 20px; }
    .cta-title { font-size: 28px; }
    .phone-mockup {
        width: 280px;
        height: 560px;
        transform: scale(0.9);
        transform-origin: top center;
        margin-bottom: -50px;
    }
}

@media (max-width: 375px) {
    .phone-mockup {
        transform: scale(0.8);
    }
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    .hero-buttons .btn {
        width: 100%;
    }
}