/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Typography */
h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 20px;
}

h2 {
    font-size: 2.2rem;
    font-weight: 600;
    margin-bottom: 15px;
}

h3 {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: 10px;
}

p {
    font-size: 1.1rem;
    margin-bottom: 15px;
}

/* Brand typography (Oswald) – 仅用于导航与页尾 Banner */
.nav-links li a,
.footer-banner h2,
.footer-banner h3 {
    font-family: 'Oswald', sans-serif;
    font-weight: 700;
}

/* Section 与卡片标题、Hero 标题使用 Montserrat，正常字宽 */
.hero-content h1,
.hero-content h2,
.section-title,
.ad-card h3,
.app-card h3,
.success-case-name {
    font-family: 'Montserrat', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    font-weight: 700;
}

/* Header & Navigation */
header {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px 5%;
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

header.scrolled {
    padding: 10px 5%;
}

.logo-container {
    position: absolute;
    left: 5%;
    display: flex;
    align-items: center;
}

.logo {
    height: 200px; /* Enlarged logo */
    width: auto;
    object-fit: contain;
    transition: height 0.3s ease;
}

header.scrolled .logo {
    height: 100px; /* Shrink logo slightly on scroll for better UX */
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-links li a {
    font-size: 1rem;
    text-transform: uppercase;
    position: relative;
    padding-bottom: 5px;
    transition: color 0.3s ease;
}

.nav-links li a:hover,
.nav-links li a.active {
    color: #000;
}

.nav-links li a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: #000;
    transition: width 0.3s ease;
}

.nav-links li a:hover::after,
.nav-links li a.active::after {
    width: 100%;
}

/* Hero Section */
.hero {
    height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background-image: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url('https://images.unsplash.com/photo-1552820728-8b83bb6b773f?q=80&w=2070&auto=format&fit=crop');
    background-size: cover;
    background-position: center;
    color: #fff;
    padding: 0 20px;
}

.hero-content {
    max-width: 800px;
    animation: fadeIn 1.5s ease;
}

.hero-content h1 {
    font-size: 4.5rem;
    text-transform: uppercase;
    letter-spacing: 4px;
    margin-bottom: 30px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-content h2 {
    font-size: 2.5rem;
    font-weight: 400;
    margin-bottom: 10px;
}

/* Buttons */
.hero-ctas {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 40px;
}

.btn-primary,
.btn-secondary {
    display: inline-block;
    padding: 15px 40px;
    font-size: 1.1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn-primary {
    background-color: #fff;
    color: #000;
    border: 2px solid #fff;
}

.btn-primary:hover {
    background-color: transparent;
    color: #fff;
}

.btn-secondary {
    background-color: transparent;
    color: #fff;
    border: 2px solid #fff;
}

.btn-secondary:hover {
    background-color: #fff;
    color: #000;
}

/* Section shared */
.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 15px;
}

.section-subtitle {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 50px;
    font-size: 1.15rem;
    color: #555;
}

/* Advertising Section */
.advertising-section {
    padding: 100px 5%;
    background-color: #1a252e;
    background-image: url('https://upload.wikimedia.org/wikipedia/commons/8/80/World_map_-_low_resolution.svg');
    background-repeat: no-repeat;
    background-position: center;
    background-size: cover;
    background-blend-mode: soft-light;
    color: #fff;
}

.advertising-inner {
    max-width: 1100px;
    margin: 0 auto;
}

.advertising-section .section-title,
.advertising-section .section-subtitle {
    color: #fff;
}

.advertising-section .section-subtitle {
    color: rgba(255, 255, 255, 0.85);
}

.advertising-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.ad-card {
    display: flex;
    flex-direction: column;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 16px;
    padding: 40px 35px;
    border: 1px solid rgba(255, 255, 255, 0.15);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.ad-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.ad-card h3 {
    font-size: 1.6rem;
    margin-bottom: 20px;
    color: #fff;
}

.ad-card p {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 20px;
    line-height: 1.6;
    font-size: 1rem;
}

.ad-card ul {
    list-style: none;
    margin-bottom: 28px;
}

.ad-card li {
    padding: 8px 0;
    padding-left: 24px;
    position: relative;
    color: rgba(255, 255, 255, 0.9);
}

.ad-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #7dd3fc;
}

.ad-card-cta {
    display: inline-block;
    margin-top: auto;
    padding: 12px 28px;
    background: #fff;
    color: #1a252e;
    font-weight: 600;
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-radius: 8px;
    transition: background 0.3s ease, color 0.3s ease;
}

.ad-card-cta:hover {
    background: transparent;
    color: #fff;
    border: 2px solid #fff;
}

/* Our App Section */
.our-app-section {
    padding: 100px 5%;
    background-color: #f8f9fa;
}

.our-app-inner {
    max-width: 1100px;
    margin: 0 auto;
}

.app-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 30px;
}

.app-card {
    background: #fff;
    border-radius: 16px;
    padding: 40px 30px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.app-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
}

.app-card-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.app-card-logo {
    width: 64px;
    height: 64px;
    object-fit: contain;
    margin: 0 auto 20px;
    display: block;
    border-radius: 14px;
}

.app-card h3 {
    font-size: 1.4rem;
    margin-bottom: 10px;
    color: #222;
}

.app-card-tagline {
    font-weight: 500;
    color: #666;
}

.app-card p {
    font-size: 0.95rem;
    color: #666;
    margin: 0;
}

/* Success Case Section */
.success-case-section {
    padding: 80px 5%;
    background-color: #fff;
}

.success-case-inner {
    max-width: 900px;
    margin: 0 auto;
}

.success-case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.success-case-card {
    background: #fff;
    border-radius: 16px;
    padding: 40px 30px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.success-case-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
}

.success-case-logo {
    width: 80px;
    height: 80px;
    object-fit: contain;
    margin: 0 auto 20px;
    display: block;
}

.success-case-logo--cropped {
    object-fit: cover;
    border-radius: 12px;
}

.success-case-name {
    font-size: 1.4rem;
    font-weight: 700;
    color: #222;
    margin-bottom: 12px;
}

.success-case-tagline {
    font-weight: 500;
    color: #666;
}

.success-case-desc {
    font-size: 0.95rem;
    color: #555;
    line-height: 1.6;
    margin-bottom: 16px;
}

.success-case-results {
    font-size: 1rem;
    font-weight: 600;
    color: #1a252e;
    margin: 0;
}

/* Contact Section */
.contact-section {
    padding: 100px 5%;
    background-color: #f0f2f5;
}

.contact-inner {
    max-width: 560px;
    margin: 0 auto;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-bottom: 24px;
}

.contact-form label {
    font-size: 0.9rem;
    font-weight: 600;
    color: #333;
    margin-top: 16px;
}

.contact-form label:first-of-type {
    margin-top: 0;
}

.contact-form select,
.contact-form input,
.contact-form textarea {
    padding: 12px 16px;
    font-size: 1rem;
    font-family: inherit;
    border: 1px solid #ccc;
    border-radius: 8px;
    background: #fff;
    transition: border-color 0.2s ease;
}

.contact-form select:focus,
.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: #1a252e;
}

.contact-form textarea {
    resize: vertical;
    min-height: 120px;
}

.contact-submit {
    margin-top: 24px;
    padding: 14px 32px;
    font-size: 1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    background: #1a252e;
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.2s ease;
}

.contact-submit:hover {
    background: #2d3a47;
    transform: translateY(-1px);
}

.contact-email-note {
    text-align: center;
    font-size: 0.95rem;
    color: #555;
}

.contact-email-note a {
    color: #1a252e;
    font-weight: 600;
}

.contact-email-note a:hover {
    text-decoration: underline;
}

/* Footer Banner Section */
.footer-banner {
    background-color: #000;
    color: #fff;
    text-align: center;
    padding: 80px 20px;
}

.footer-banner h2 {
    font-size: 3rem;
    letter-spacing: 5px;
    margin-bottom: 20px;
}

.footer-banner h3 {
    font-weight: 300;
    margin-bottom: 40px;
}

.footer-banner p {
    font-size: 1.2rem;
}

/* Main Footer */
footer {
    background-color: #f5f5f5;
    padding: 60px 5% 20px;
    text-align: center;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto 40px;
    display: flex;
    justify-content: center;
}

.quick-links h4 {
    font-size: 1.2rem;
    margin-bottom: 20px;
    text-transform: uppercase;
}

.quick-links ul {
    list-style: none;
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.quick-links a {
    color: #555;
    transition: color 0.3s ease;
}

.quick-links a:hover {
    color: #000;
}

.footer-bottom {
    border-top: 1px solid #ddd;
    padding-top: 20px;
    color: #777;
    font-size: 0.9rem;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive Design */
@media (max-width: 768px) {
    header {
        flex-direction: column;
        padding: 15px;
    }

    .nav-links {
        margin-top: 20px;
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-content h2 {
        font-size: 1.5rem;
    }

    .hero-ctas {
        flex-direction: column;
        align-items: center;
    }

    .advertising-cards {
        grid-template-columns: 1fr;
    }

    .advertising-section,
    .our-app-section,
    .contact-section {
        padding: 60px 20px;
    }

    .app-grid {
        grid-template-columns: 1fr;
    }

    .section-title {
        font-size: 2rem;
    }
}