/* General Body & Typography */
body {
    font-family: 'Inter', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f9fafb;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Plus Jakarta Sans', 'Segoe UI', sans-serif;
    color: #1a202c;
    margin-top: 0;
    margin-bottom: 0.5em;
}

a {
    color: #4a90e2;
    text-decoration: none;
    transition: color 0.3s ease;
}
a:hover {
    color: #357bd8;
    text-decoration: underline;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
    text-decoration: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: #4a90e2;
    color: #fff;
    border: 1px solid #4a90e2;
}
.btn-primary:hover {
    background-color: #357bd8;
    border-color: #357bd8;
}

.btn-secondary {
    background-color: #e2e8f0;
    color: #2d3748;
    border: 1px solid #e2e8f0;
}
.btn-secondary:hover {
    background-color: #cbd5e0;
    border-color: #cbd5e0;
}

.btn-outline {
    background-color: transparent;
    color: #4a90e2;
    border: 1px solid #4a90e2;
}
.btn-outline:hover {
    background-color: #e0f2fe;
    color: #357bd8;
}

.btn-lg {
    padding: 12px 24px;
    font-size: 1.1rem;
}

/* Header Styles */
.site-header {
    background-color: #fff;
    border-bottom: 1px solid #e2e8f0;
    padding: 15px 0;
    position: relative;
    z-index: 1000;
}

.main-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.main-nav .logo img {
    height: 40px;
    width: auto;
}

.main-nav .nav-links {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 25px;
}

.main-nav .nav-links li a {
    font-weight: 500;
    color: #4a5568;
    padding: 5px 0;
    position: relative;
}
.main-nav .nav-links li a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0;
    height: 2px;
    background-color: #4a90e2;
    transition: width 0.3s ease;
}
.main-nav .nav-links li a:hover::after {
    width: 100%;
}

.nav-item-dropdown {
    position: relative;
}

.nav-item-dropdown .dropdown-menu {
    display: none;
    position: absolute;
    background-color: #fff;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    list-style: none;
    padding: 10px 0;
    margin: 0;
    min-width: 160px;
    z-index: 100;
    border-radius: 8px;
    top: 100%;
    left: 0;
}

.nav-item-dropdown:hover .dropdown-menu {
    display: block;
}

.nav-item-dropdown .dropdown-menu li a {
    padding: 10px 20px;
    display: block;
    color: #4a5568;
    white-space: nowrap;
    text-decoration: none;
    font-weight: 400;
}

.nav-item-dropdown .dropdown-menu li a:hover {
    background-color: #f0f8ff;
    color: #357bd8;
    text-decoration: none;
}

.main-nav .auth-buttons {
    display: flex;
    gap: 10px;
}

.hamburger-menu {
    display: none; /* Hidden on desktop */
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    z-index: 1001;
}
.hamburger-menu .bar {
    display: block;
    width: 25px;
    height: 3px;
    background-color: #333;
    margin: 5px 0;
    transition: all 0.3s ease;
}

/* Hero Section */
.hero-section {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 80px 0;
    gap: 40px;
    flex-wrap: wrap;
}

.hero-content {
    flex: 1;
    min-width: 300px;
}

.hero-content h1 {
    font-size: 3.5rem;
    line-height: 1.1;
    margin-bottom: 20px;
    font-weight: 800;
}

.hero-content .lead-text {
    font-size: 1.25rem;
    color: #4a5568;
    margin-bottom: 30px;
}

.hero-actions {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
}

.trust-badges img {
    height: 30px;
    margin-right: 15px;
}

.hero-image {
    flex: 1;
    min-width: 300px;
    text-align: center;
}
.hero-image img {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.announcement-bar {
    background-color: #f0f8ff;
    color: #2c5282;
    padding: 10px 0;
    text-align: center;
    font-size: 0.9rem;
    border-bottom: 1px solid #bee3f8;
}
.announcement-bar a {
    color: #2c5282;
    font-weight: 600;
    text-decoration: underline;
}

/* Footer Styles */
.site-footer {
    background-color: #1a202c;
    color: #cbd5e0;
    padding: 60px 0 30px;
    font-size: 0.95rem;
}

.site-footer a {
    color: #a0aec0;
}
.site-footer a:hover {
    color: #e2e8f0;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo img {
    height: 32px;
    margin-bottom: 15px;
}

.col-about p {
    margin-bottom: 20px;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background-color: #2d3748;
    color: #a0aec0;
    margin-right: 10px;
    transition: background-color 0.3s ease, color 0.3s ease;
}
.social-links a:hover {
    background-color: #4a5568;
    color: #fff;
}

.col-links h3, .col-newsletter h3 {
    color: #fff;
    font-size: 1.1rem;
    margin-bottom: 20px;
}

.col-links ul {
    list-style: none;
    padding: 0;
    margin: 0;
}
.col-links ul li {
    margin-bottom: 10px;
}

.newsletter-form {
    display: flex;
    margin-top: 15px;
}
.newsletter-form input[type="email"] {
    flex-grow: 1;
    padding: 10px 15px;
    border: 1px solid #4a5568;
    border-radius: 8px 0 0 8px;
    background-color: #2d3748;
    color: #fff;
    outline: none;
}
.newsletter-form input[type="email"]::placeholder {
    color: #a0aec0;
}
.newsletter-form button {
    padding: 10px 20px;
    border-radius: 0 8px 8px 0;
    border: 1px solid #4a90e2;
    background-color: #4a90e2;
    color: #fff;
    cursor: pointer;
    transition: background-color 0.3s ease;
}
.newsletter-form button:hover {
    background-color: #357bd8;
    border-color: #357bd8;
}

.privacy-note {
    font-size: 0.85rem;
    margin-top: 10px;
}

.footer-bottom {
    border-top: 1px solid #2d3748;
    padding-top: 30px;
    margin-top: 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.legal-links {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    gap: 20px;
}

.language-selector select {
    background-color: #2d3748;
    color: #fff;
    border: 1px solid #4a5568;
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    outline: none;
}

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: #4a90e2;
    color: #fff;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    transition: background-color 0.3s ease, transform 0.3s ease;
    z-index: 999;
    opacity: 0; /* Hidden by default */
    visibility: hidden;
}
.back-to-top:hover {
    background-color: #357bd8;
    transform: translateY(-3px);
}
.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

/* Utility Classes */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    margin: -1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* Responsive Adjustments */
@media (max-width: 992px) {
    .main-nav .nav-links {
        display: none; /* Hide on smaller screens */
        flex-direction: column;
        width: 100%;
        text-align: center;
        background-color: #fff;
        position: absolute;
        top: 70px; /* Adjust based on header height */
        left: 0;
        padding: 20px 0;
        box-shadow: 0 5px 10px rgba(0,0,0,0.1);
    }
    .main-nav .nav-links.active {
        display: flex;
    }
    .nav-item-dropdown:hover .dropdown-menu { /* Ensure dropdowns work on hover for larger screens, but not mobile */
        display: none;
    }
    .nav-item-dropdown.active .dropdown-menu { /* For mobile, activate with JS */
        display: block;
        position: static;
        box-shadow: none;
        min-width: unset;
        background-color: #f0f8ff;
        padding: 0;
        border-radius: 0;
        margin-top: 10px;
    }
    .nav-item-dropdown.active .dropdown-menu li a {
        padding: 8px 20px;
        color: #333;
    }
    .main-nav .nav-links li {
        margin: 10px 0;
    }
    .main-nav .auth-buttons {
        display: none;
    }
    .main-nav .auth-buttons.active {
        display: flex;
        flex-direction: column;
        width: 100%;
        gap: 10px;
        padding: 10px 20px;
        background-color: #fff;
        box-shadow: 0 5px 10px rgba(0,0,0,0.1);
        position: absolute;
        top: calc(70px + var(--nav-links-height, 0px)); /* Dynamic positioning */
        left: 0;
    }
    .hamburger-menu {
        display: block;
    }
    .hero-section {
        flex-direction: column;
        text-align: center;
        padding: 60px 0;
    }
    .hero-actions {
        justify-content: center;
    }
    .hero-content h1 {
        font-size: 2.5rem;
    }
    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .social-links {
        justify-content: center;
        margin-bottom: 20px;
    }
    .newsletter-form {
        justify-content: center;
    }
    .newsletter-form input[type="email"] {
        border-radius: 8px;
        margin-bottom: 10px;
    }
    .newsletter-form button {
        border-radius: 8px;
    }
    .footer-bottom {
        flex-direction: column;
        gap: 20px;
    }
    .legal-links {
        flex-direction: column;
        gap: 10px;
    }
}

@media (max-width: 600px) {
    .hero-content h1 {
        font-size: 2rem;
    }
    .hero-content .lead-text {
        font-size: 1rem;
    }
    .btn-lg {
        padding: 10px 20px;
        font-size: 1rem;
    }
    .hero-actions {
        flex-direction: column;
        gap: 10px;
    }
    .newsletter-form {
        flex-direction: column;
        align-items: center;
    }
    .newsletter-form input[type="email"],
    .newsletter-form button {
        width: 100%;
        max-width: 300px;
        border-radius: 8px;
    }
    .newsletter-form input[type="email"] {
        margin-bottom: 10px;
    }
}
/* 移动端内容区防溢出（系统追加，请勿删除） */
@media (max-width: 768px) {
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}