/* ============================================
   饭搭子科技 - 官方网站样式
   黑白极简基底 + 深靛蓝强调色 (#4B5CC4)
   专业克制 · 色彩仅用于交互引导
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --black: #1a1a1a;
    --white: #ffffff;
    --gray-100: #f5f5f5;
    --gray-200: #e5e5e5;
    --gray-300: #d4d4d4;
    --gray-400: #a3a3a3;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --gray-900: #171717;
    --accent:       #4B5CC4;
    --accent-light: #EEF0FB;
    --accent-mid:   #A3A8E0;
    --accent-dark:  #3749A8;
    --font-sans: 'Noto Sans SC', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-en: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --max-width: 1100px;
    --nav-height: 64px;
}

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    color: var(--black);
    background: var(--white);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* --- Typography --- */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.3;
    letter-spacing: -0.02em;
}

/* --- Navigation --- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--gray-200);
    z-index: 1000;
    transition: box-shadow 0.3s ease;
}

.nav.scrolled { box-shadow: 0 1px 3px rgba(0,0,0,0.06); }

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    text-decoration: none;
}

.nav-logo-img {
    display: block;
    height: 28px;
    width: auto;
}

.nav-links {
    display: flex;
    gap: 36px;
    list-style: none;
}

.nav-links a {
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-600);
    transition: color 0.2s;
    letter-spacing: -0.01em;
}

.nav-links a:hover { color: var(--accent); }

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--black);
    border-radius: 2px;
    transition: transform 0.3s, opacity 0.3s;
}

.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* --- Hero --- */
.hero {
    padding: calc(var(--nav-height) + 80px) 24px 100px;
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 80px;
    min-height: 100vh;
}

.hero-content { flex: 1; }

.hero-badge {
    display: inline-block;
    font-family: var(--font-en);
    font-size: 12px;
    font-weight: 500;
    color: var(--accent-dark);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    border: 1px solid var(--accent-mid);
    background: var(--accent-light);
    padding: 6px 14px;
    border-radius: 100px;
    margin-bottom: 32px;
}

.hero-title {
    font-size: clamp(36px, 5vw, 56px);
    font-weight: 700;
    line-height: 1.15;
    color: var(--black);
    margin-bottom: 24px;
    letter-spacing: -0.03em;
}

.hero-title-light {
    font-weight: 300;
    color: var(--gray-500);
}

.hero-subtitle {
    font-size: 17px;
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 40px;
    max-width: 540px;
}

.hero-subtitle strong {
    font-weight: 600;
    color: var(--accent-dark);
}

.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-visual {
    flex: 0 0 280px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-svg {
    width: 100%;
    max-width: 280px;
    display: block;
}

/* --- Buttons --- */
.btn {
    display: inline-block;
    padding: 14px 32px;
    font-size: 15px;
    font-weight: 600;
    border-radius: 8px;
    letter-spacing: -0.01em;
    transition: all 0.25s;
    cursor: pointer;
    border: none;
    text-align: center;
}

.btn-primary {
    background: var(--accent);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--accent-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(75, 92, 196, 0.35);
}

.btn-outline {
    background: transparent;
    color: var(--black);
    border: 1.5px solid var(--gray-300);
}

.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent-dark);
    background: var(--accent-light);
}

/* --- Section Shared --- */
section { scroll-margin-top: var(--nav-height); }

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.section-desc {
    font-size: 16px;
    color: var(--gray-500);
    max-width: 480px;
    margin: 0 auto;
}

/* --- About --- */
.about {
    padding: 100px 24px;
    background: var(--accent-light);
    border-top: 1px solid #D5D8F0;
    border-bottom: 1px solid #D5D8F0;
}

.about-grid {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.about-card {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: 12px;
    padding: 36px 32px;
    transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
}

.about-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.06);
    border-color: var(--accent-mid);
}

.about-icon {
    color: var(--accent);
    margin-bottom: 20px;
}

.about-card h3 {
    font-size: 18px;
    margin-bottom: 12px;
}

.about-card p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.8;
}

/* --- Stats --- */
.stats {
    padding: 60px 24px;
    border-bottom: 1px solid var(--gray-200);
}

.stats-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.stat-item {
    text-align: center;
    padding: 24px 16px;
}

.stat-number {
    display: block;
    font-size: 36px;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 6px;
    color: var(--accent);
}

.stat-label {
    font-size: 13px;
    color: var(--gray-500);
    font-weight: 500;
}

/* --- Apps Showcase --- */
.apps {
    padding: 100px 24px;
    max-width: var(--max-width);
    margin: 0 auto;
}

.app-showcase {
    display: flex;
    flex-direction: column;
    gap: 48px;
}

.app-card {
    display: flex;
    gap: 40px;
    align-items: center;
    padding: 48px;
    border: 1px solid var(--gray-200);
    border-radius: 16px;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.app-card:hover {
    border-color: var(--accent-mid);
    box-shadow: 0 4px 20px rgba(75, 92, 196, 0.08);
}

.app-icon {
    flex-shrink: 0;
    width: 120px;
    height: 120px;
    background: var(--accent-light);
    border-radius: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
}

.app-icon-placeholder {
    border: 2px dashed var(--accent-mid);
    background: transparent;
}

.app-info { flex: 1; }

.app-name {
    font-size: 24px;
    margin-bottom: 12px;
}

.app-name-en {
    font-family: var(--font-en);
    font-weight: 400;
    color: var(--gray-400);
    font-size: 16px;
    margin-left: 8px;
}

.app-desc {
    font-size: 15px;
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 16px;
    max-width: 560px;
}

.app-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.app-tags span {
    font-size: 12px;
    padding: 4px 12px;
    border: 1px solid var(--gray-200);
    border-radius: 100px;
    color: var(--gray-600);
    font-weight: 500;
    background: var(--white);
    transition: border-color 0.2s, color 0.2s;
}

.app-tags span:hover {
    border-color: var(--accent-mid);
    color: var(--accent-dark);
}

.app-link {
    font-size: 14px;
    font-weight: 600;
    color: var(--accent-dark);
    border-bottom: 1.5px solid var(--accent);
    padding-bottom: 2px;
    transition: opacity 0.2s;
}

.app-link:hover { opacity: 0.6; }

.app-link-disabled {
    color: var(--gray-400);
    border-bottom: 1.5px solid var(--gray-300);
    cursor: default;
}

/* --- Services --- */
.services {
    padding: 100px 24px;
    background: linear-gradient(180deg, var(--white) 0%, var(--accent-light) 100%);
    border-top: 1px solid #D5D8F0;
    border-bottom: 1px solid #D5D8F0;
}

.services-grid {
    max-width: var(--max-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.service-item {
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: 10px;
    padding: 32px 28px;
    transition: border-color 0.25s, box-shadow 0.25s;
}

.service-item:hover {
    border-color: var(--accent-mid);
    box-shadow: 0 4px 16px rgba(75, 92, 196, 0.06);
}

.service-item h4 {
    font-size: 16px;
    margin-bottom: 10px;
    color: var(--accent-dark);
}

.service-item p {
    font-size: 13px;
    color: var(--gray-600);
    line-height: 1.8;
}

/* --- Contact --- */
.contact {
    padding: 100px 24px;
    max-width: var(--max-width);
    margin: 0 auto;
}

.contact-content {
    display: flex;
    gap: 80px;
    align-items: center;
}

.contact-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.contact-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--gray-400);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.contact-value {
    font-size: 16px;
    font-weight: 500;
    color: var(--black);
}

.contact-value a {
    color: var(--accent-dark);
    border-bottom: 1.5px solid var(--accent);
    transition: opacity 0.2s;
}

.contact-value a:hover { opacity: 0.6; }

.contact-visual {
    flex: 0 0 280px;
}

.contact-svg {
    width: 100%;
    color: var(--accent);
    opacity: 0.25;
}

/* --- Footer --- */
.footer {
    border-top: 1px solid #D5D8F0;
    padding: 40px 24px;
    background: var(--accent-light);
}

.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.footer-logo {
    font-size: 16px;
    font-weight: 700;
}

.footer-tagline {
    font-size: 13px;
    color: var(--gray-500);
}

.footer-copy {
    text-align: right;
}

.footer-copy p {
    font-size: 12px;
    color: var(--gray-400);
    line-height: 1.8;
}

/* --- Responsive --- */
@media (max-width: 900px) {
    .hero {
        flex-direction: column-reverse;
        gap: 48px;
        padding: calc(var(--nav-height) + 48px) 20px 72px;
        min-height: auto;
        text-align: center;
    }

    .hero-subtitle { margin: 0 auto 40px; }
    .hero-actions { justify-content: center; }
    .hero-visual { flex: 0 0 180px; }
    .hero-svg { max-width: 180px; }

    .about-grid { grid-template-columns: 1fr; max-width: 480px; }
    .stats-inner { grid-template-columns: repeat(2, 1fr); }

    .app-card {
        flex-direction: column;
        text-align: center;
        padding: 32px 24px;
    }
    .app-desc { margin: 0 auto 16px; }
    .app-tags { justify-content: center; }

    .services-grid { grid-template-columns: repeat(2, 1fr); }

    .contact-content {
        flex-direction: column;
        gap: 48px;
    }
    .contact-visual { flex: 0 0 160px; }

    .footer-inner { flex-direction: column; text-align: center; }
    .footer-copy { text-align: center; }

    .nav-toggle { display: flex; }
    .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--white);
        border-bottom: 1px solid var(--gray-200);
        flex-direction: column;
        gap: 0;
        padding: 8px 0;
        box-shadow: 0 4px 12px rgba(0,0,0,0.06);
    }
    .nav-links.active { display: flex; }
    .nav-links a {
        padding: 14px 24px;
        font-size: 15px;
        border-bottom: 1px solid var(--gray-100);
    }
}

@media (max-width: 600px) {
    .services-grid { grid-template-columns: 1fr; }
    .stats-inner { grid-template-columns: 1fr 1fr; gap: 8px; }
    .stat-number { font-size: 28px; }
    .section-title { font-size: 26px; }
}