/* ===========================================
   百度SEM 落地页 - 响应式 mobile-first 样式
   深圳市方程精密机械有限公司
   品牌色: 深褐 #5D3A1A + 橙红 #D9531E CTA
   =========================================== */

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

:root {
    --color-primary: #5D3A1A;       /* 深褐 - 方程精密品牌色 */
    --color-primary-dark: #3D2611;
    --color-primary-light: #F5F1E8; /* 米白辅色 */
    --color-accent: #D9531E;        /* 橙红 CTA */
    --color-accent-dark: #B33E15;
    --color-text: #333333;
    --color-text-light: #555;
    --color-text-muted: #888;
    --color-bg: #fff;
    --color-bg-alt: #F5F1E8;
    --color-border: #e1dccd;
    --color-success: #28a745;
    --color-error: #dc3545;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.12);
    --shadow-lg: 0 10px 30px rgba(0,0,0,0.18);
    --radius: 4px;
    --radius-lg: 8px;
    --container-max: 1200px;
    --transition: 0.3s ease;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--color-text);
    line-height: 1.6;
    background: var(--color-bg);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-dark); }

.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 16px;
}

/* ====== Header ====== */
.site-header {
    position: sticky;
    top: 0;
    background: rgba(255,255,255,0.96);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 100;
}
.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}
.site-logo {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: 12px;
}
.site-logo-img {
    width: 40px; height: 40px;
    object-fit: contain;
}
.site-nav { display: flex; align-items: center; gap: 16px; }
.site-nav a {
    color: var(--color-text);
    font-size: 14px;
}
.cta-phone {
    color: var(--color-accent);
    font-weight: 700;
    font-size: 15px;
}

/* ====== Hero ====== */
.hero {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: #fff;
    padding: 50px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 30% 50%, rgba(255,255,255,0.08) 0%, transparent 50%);
}
.hero > .container { position: relative; }
.hero .badge {
    display: inline-block;
    background: rgba(255,255,255,0.15);
    color: #fff;
    padding: 6px 16px;
    border-radius: 999px;
    font-size: 13px;
    margin-bottom: 16px;
    border: 1px solid rgba(255,255,255,0.2);
}
.hero h1 {
    font-size: 26px;
    line-height: 1.3;
    margin-bottom: 16px;
    font-weight: 800;
}
.hero p.lead {
    font-size: 15px;
    opacity: 0.92;
    margin-bottom: 28px;
    max-width: 640px;
    margin-left: auto;
    margin-right: auto;
}
.hero-cta {
    display: inline-block;
    background: var(--color-accent);
    color: #fff;
    padding: 14px 36px;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 16px;
    box-shadow: var(--shadow-md);
    transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}
.hero-cta:hover {
    transform: translate-y(-2px);
    box-shadow: var(--shadow-lg);
    background: var(--color-accent-dark);
    color: #fff;
}
.hero-trust {
    margin-top: 28px;
    font-size: 13px;
    opacity: 0.85;
}

/* ====== Hero with QR code (应用场景向) ====== */
.hero-app {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: #fff;
    padding: 40px 0;
    position: relative;
}
.hero-app .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}
.hero-app-content { flex: 1; }
.hero-app h1 {
    font-size: 24px;
    line-height: 1.3;
    margin-bottom: 12px;
    font-weight: 800;
}
.hero-app p.lead {
    font-size: 14px;
    opacity: 0.92;
    margin-bottom: 20px;
}
.hero-app .cta-primary {
    display: inline-block;
    background: var(--color-accent);
    color: #fff;
    padding: 12px 28px;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 15px;
}
.hero-app-qr {
    flex-shrink: 0;
    width: 110px;
    background: #fff;
    padding: 8px;
    border-radius: var(--radius);
    text-align: center;
}
.hero-app-qr img {
    width: 94px;
    height: 94px;
    background: #ddd;
    border-radius: 2px;
}
.hero-app-qr p {
    color: var(--color-primary);
    font-size: 12px;
    font-weight: 700;
    margin-top: 4px;
}

/* ====== Sections ====== */
section { padding: 50px 0; }
section.alt { background: var(--color-bg-alt); }

.section-title {
    font-size: 24px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 10px;
    color: var(--color-primary);
}
.section-subtitle {
    text-align: center;
    color: var(--color-text-light);
    margin-bottom: 36px;
    font-size: 14px;
}

/* ====== Pain Points (应用场景向) ====== */
.pain-list {
    max-width: 700px;
    margin: 0 auto;
}
.pain-item {
    background: #fff;
    border-left: 4px solid var(--color-accent);
    padding: 14px 18px;
    margin-bottom: 12px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    font-size: 15px;
}
.pain-item::before {
    content: '☹ ';
    color: var(--color-accent);
    margin-right: 6px;
}

/* ====== Feature Grid ====== */
.feature-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}
.feature-card {
    background: #fff;
    padding: 24px 20px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
    transition: transform var(--transition), box-shadow var(--transition);
}
.feature-card .feature-img {
    width: 100%;
    height: 160px;
    object-fit: cover;
    border-radius: var(--radius);
    margin-bottom: 14px;
    background: var(--color-bg-alt);
}
.feature-card.feature-noicon .feature-icon { display: none; }
.feature-card:hover {
    transform: translate-y(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary);
}
.feature-icon {
    width: 44px; height: 44px;
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-radius: var(--radius);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    margin-bottom: 14px;
}
.feature-card h3 {
    font-size: 16px;
    margin-bottom: 6px;
    color: var(--color-text);
}
.feature-card p {
    font-size: 14px;
    color: var(--color-text-light);
    line-height: 1.5;
}

/* ====== Overview Image (参数全景) ====== */
.overview-wrap {
    margin-top: 28px;
    text-align: center;
}
.overview-img {
    max-width: 720px;
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

/* ====== PLC Persuasion (产品向专用) ====== */
.why-plc {
    background: var(--color-bg-alt);
    border-radius: var(--radius-lg);
    padding: 28px 22px;
    margin: 0 auto;
    max-width: 800px;
}
.why-plc h3 {
    text-align: center;
    color: var(--color-primary);
    font-size: 18px;
    margin-bottom: 18px;
}
.why-plc ul {
    list-style: none;
}
.why-plc li {
    padding: 8px 0;
    font-size: 14px;
    color: var(--color-text);
    border-bottom: 1px dashed var(--color-border);
}
.why-plc li:last-child { border-bottom: none; }

/* ====== Spec Table ====== */
.spec-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.spec-table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    box-shadow: var(--shadow-sm);
    border-radius: var(--radius-lg);
    overflow: hidden;
    font-size: 14px;
}
.spec-table th, .spec-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}
.spec-table th {
    background: var(--color-primary);
    color: #fff;
    font-weight: 600;
    white-space: nowrap;
}
.spec-table tr:last-child td { border-bottom: none; }
.spec-table tr:nth-child(even) td { background: var(--color-bg-alt); }

/* ====== Application Chips ====== */
.app-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
}
.chip {
    background: #fff;
    padding: 8px 18px;
    border-radius: 999px;
    font-size: 13px;
    border: 1px solid var(--color-border);
    color: var(--color-text);
    transition: all var(--transition);
}
.chip:hover {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}

/* ====== Trust Bar ====== */
.trust-bar {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    text-align: center;
}
.trust-item {
    background: #fff;
    padding: 20px 12px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
}
.trust-num {
    font-size: 28px;
    font-weight: 800;
    color: var(--color-primary);
    display: block;
    line-height: 1.1;
}
.trust-label {
    font-size: 13px;
    color: var(--color-text-light);
    margin-top: 4px;
}

/* ====== Process Steps (应用场景向) ====== */
.process-list {
    max-width: 720px;
    margin: 0 auto;
}
.process-step {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 16px 0;
    border-bottom: 1px dashed var(--color-border);
}
.process-step:last-child { border-bottom: none; }
.process-num {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    background: var(--color-primary);
    color: #fff;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 16px;
}
.process-text {
    flex: 1;
    font-size: 15px;
    padding-top: 4px;
}

/* ====== Coverage List (应用场景向) ====== */
.coverage-list {
    list-style: none;
    max-width: 720px;
    margin: 0 auto;
}
.coverage-list li {
    padding: 10px 0 10px 28px;
    font-size: 15px;
    border-bottom: 1px solid var(--color-border);
    position: relative;
}
.coverage-list li::before {
    content: '•';
    color: var(--color-accent);
    font-weight: 800;
    position: absolute;
    left: 8px;
    font-size: 18px;
}

/* ====== Qualifications Block (应用场景向) ====== */
.qual-list {
    max-width: 720px;
    margin: 0 auto;
    background: #fff;
    padding: 20px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
}
.qual-list li {
    padding: 6px 0;
    font-size: 14px;
    list-style: none;
}

/* ====== QR Block (应用场景向末屏) ====== */
.qr-block {
    background: #fff;
    border: 2px solid var(--color-primary);
    border-radius: var(--radius-lg);
    padding: 28px 22px;
    text-align: center;
    max-width: 360px;
    margin: 0 auto;
}
.qr-block .qr-img {
    width: 180px;
    height: 180px;
    margin: 0 auto;
    background: #eee;
    border-radius: var(--radius);
}
.qr-block .qr-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--color-primary);
    margin: 14px 0 6px;
}
.qr-block .qr-sub {
    font-size: 13px;
    color: var(--color-text-light);
}

/* ====== Lead Form Section ====== */
.lead-form-section {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: #fff;
}
.lead-form-section .section-title { color: #fff; }
.lead-form-section .section-subtitle { color: rgba(255,255,255,0.85); }

.lead-form {
    max-width: 560px;
    margin: 0 auto;
    background: #fff;
    color: var(--color-text);
    padding: 28px 22px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}
.form-row { margin-bottom: 14px; }
.form-row label {
    display: block;
    font-size: 13px;
    margin-bottom: 6px;
    font-weight: 500;
}
.form-row label .req { color: var(--color-accent); margin-left: 2px; }
.form-row label .opt { color: var(--color-text-muted); font-weight: 400; margin-left: 4px; }
.form-row input,
.form-row textarea,
.form-row select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: 15px;
    font-family: inherit;
    transition: border-color var(--transition);
    background: #fff;
}
.form-row input:focus,
.form-row textarea:focus,
.form-row select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(93, 61, 26, 0.12);
}
.form-row textarea { resize: vertical; min-height: 70px; }
.form-honeypot {
    position: absolute;
    left: -9999px;
    width: 1px; height: 1px;
    overflow: hidden;
}

.submit-btn {
    width: 100%;
    padding: 14px;
    background: var(--color-accent);
    color: #fff;
    border: none;
    border-radius: var(--radius);
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: background var(--transition), transform var(--transition);
    margin-top: 4px;
}
.submit-btn:hover { background: var(--color-accent-dark); transform: translate-y(-1px); }
.submit-btn:disabled { background: #ccc; cursor: not-allowed; transform: none; }

.form-status {
    margin-top: 12px;
    padding: 10px 12px;
    border-radius: var(--radius);
    font-size: 14px;
    text-align: center;
    display: none;
}
.form-status.success {
    background: #d4edda;
    color: #155724;
    display: block;
}
.form-status.error {
    background: #f8d7da;
    color: #721c24;
    display: block;
}

.form-privacy {
    margin-top: 10px;
    font-size: 12px;
    color: var(--color-text-muted);
    text-align: center;
}

/* ====== Footer ====== */
.site-footer {
    background: #1a1a1a;
    color: #aaa;
    padding: 24px 0;
    text-align: center;
    font-size: 13px;
}
.site-footer a { color: #fff; }
.site-footer .footer-brand {
    color: #fff;
    font-weight: 600;
    margin-bottom: 6px;
    display: block;
}

/* ====== Floating QR (应用场景向) ====== */
.fab-qr {
    display: none;
    position: fixed;
    right: 16px;
    bottom: 20px;
    background: var(--color-accent);
    color: #fff;
    width: 56px; height: 56px;
    border-radius: 50%;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    box-shadow: var(--shadow-lg);
    z-index: 99;
}

/* ====== Responsive ====== */
@media (min-width: 768px) {
    .container { padding: 0 24px; }
    .hero { padding: 90px 0; }
    .hero h1 { font-size: 40px; }
    .hero p.lead { font-size: 18px; }
    section { padding: 80px 0; }
    .section-title { font-size: 32px; }
    .section-subtitle { font-size: 16px; }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .trust-bar { grid-template-columns: repeat(4, 1fr); }
    .lead-form { padding: 36px 32px; }
    .hero-app { padding: 60px 0; }
    .hero-app h1 { font-size: 32px; }
    .hero-app p.lead { font-size: 16px; }
    .hero-app-qr { width: 140px; }
    .hero-app-qr img { width: 124px; height: 124px; }
}

@media (min-width: 1024px) {
    .hero { padding: 110px 0; }
    .hero h1 { font-size: 48px; }
    .feature-grid { grid-template-columns: repeat(5, 1fr); }
}

@media (max-width: 767px) {
    .site-nav .nav-text { display: none; }
}