:root {
    --primary: #0066ff;
    --primary-dark: #0044b3;
    --accent: #00d2ff;
    --bg-main: #f4f7fb;
    --bg-card: rgba(255, 255, 255, 0.9);
    --text-dark: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --radius-lg: 16px;
    --radius-md: 8px;
    --shadow: 0 10px 30px -10px rgba(0, 102, 255, 0.1);
    --shadow-hover: 0 20px 40px -15px rgba(0, 102, 255, 0.2);

    /* LOGO 字体（Inter，SIL OFL 1.1，可免费商用） */
    --logo-font: 'Inter', sans-serif;
    --logo-size: 1.6rem;
    --logo-weight: 700;
    --logo-spacing: -0.5px;
}

/* 本地自托管字体：不依赖外网，内网也能正常渲染（Inter · SIL OFL 1.1） */
@font-face {
    font-family: 'Inter';
    font-style: normal;
    font-weight: 300;
    font-display: swap;
    src: url('fonts/Inter-300.woff2') format('woff2');
}
@font-face {
    font-family: 'Inter';
    font-style: normal;
    font-weight: 400;
    font-display: swap;
    src: url('fonts/Inter-400.woff2') format('woff2');
}
@font-face {
    font-family: 'Inter';
    font-style: normal;
    font-weight: 500;
    font-display: swap;
    src: url('fonts/Inter-500.woff2') format('woff2');
}
@font-face {
    font-family: 'Inter';
    font-style: normal;
    font-weight: 600;
    font-display: swap;
    src: url('fonts/Inter-600.woff2') format('woff2');
}
@font-face {
    font-family: 'Inter';
    font-style: normal;
    font-weight: 700;
    font-display: swap;
    src: url('fonts/Inter-700.woff2') format('woff2');
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-dark);
    line-height: 1.7;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* Navbar */
.navbar {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    flex-direction: column;
}

.logo-title {
    font-family: var(--logo-font);
    font-size: var(--logo-size);
    font-weight: var(--logo-weight);
    color: var(--primary);
    text-decoration: none;
    letter-spacing: var(--logo-spacing);
}

.logo-sub {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.nav-links {
    display: flex;
    gap: 1.8rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.lang-switch {
    display: flex;
    gap: 0.3rem;
    background: #eef2f6;
    padding: 0.2rem;
    border-radius: var(--radius-md);
}

.lang-switch a {
    text-decoration: none;
    padding: 0.3rem 0.7rem;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    border-radius: 6px;
    transition: all 0.3s ease;
}

.lang-switch a.active, .lang-switch a:hover {
    background: var(--primary);
    color: #ffffff;
}

/* Hero Section */
.hero {
    position: relative;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0044b3 100%);
    color: #ffffff;
    padding: 6rem 1rem;
    text-align: center;
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.badge {
    background: rgba(0, 210, 255, 0.15);
    color: var(--accent);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    display: inline-block;
    margin-bottom: 1rem;
    border: 1px solid rgba(0, 210, 255, 0.3);
}

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.4rem;
    color: var(--accent);
    margin-bottom: 1rem;
    font-weight: 400;
}

.hero-description {
    font-size: 1.05rem;
    color: #cbd5e1;
    margin-bottom: 2rem;
}

.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all 0.3s ease;
}

.btn-primary {
    background: var(--primary);
    color: #ffffff;
    box-shadow: 0 4px 15px rgba(0, 102, 255, 0.4);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

/* Layout and Cards */
.main-layout {
    padding: 4rem 0;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    box-shadow: var(--shadow);
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
    border-color: rgba(0, 102, 255, 0.3);
}

.card-icon {
    font-size: 2.5rem;
    background: #e0f2fe;
    padding: 0.8rem;
    border-radius: 12px;
}

.card-body h2 {
    font-size: 1.5rem;
    color: var(--text-dark);
    margin-bottom: 0.8rem;
}

.grid-two-columns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

@media (max-width: 768px) {
    .grid-two-columns {
        grid-template-columns: 1fr;
    }
    .hero h1 {
        font-size: 2.2rem;
    }
    .nav-links {
        display: none;
    }
}

/* Contact Section & Form */
.contact-wrapper {
    background: #ffffff;
    border-radius: var(--radius-lg);
    padding: 3rem;
    box-shadow: var(--shadow);
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 3rem;
    margin-top: 2rem;
}

@media (max-width: 900px) {
    .contact-wrapper {
        grid-template-columns: 1fr;
    }
}

.contact-info h2 {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.direct-email {
    margin-top: 2rem;
    padding: 1rem;
    background: #f1f5f9;
    border-radius: var(--radius-md);
}

.direct-email a {
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

/* 蜜罐字段：真人看不见，填了就是机器人 */
.hp-field {
    position: absolute !important;
    left: -9999px !important;
    top: -9999px !important;
    width: 1px;
    height: 1px;
    opacity: 0;
    pointer-events: none;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.form-group label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-dark);
}

.form-group input, .form-group textarea {
    padding: 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 0.95rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus, .form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

/* Smart Interactive reCAPTCHA Styling */
.smart-captcha-box {
    background: #f9fafb;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    padding: 0.8rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 320px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.captcha-checkbox-wrapper {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    cursor: pointer;
    user-select: none;
}

.captcha-checkbox {
    width: 26px;
    height: 26px;
    border: 2px solid #c1c1c1;
    border-radius: 4px;
    background: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.captcha-checkbox.checked {
    border-color: #22c55e;
}

.captcha-label {
    font-size: 0.9rem;
    color: #374151;
    font-weight: 500;
}

.captcha-brand {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.1rem;
    font-size: 0.65rem;
    color: #9ca3af;
}

.captcha-logo {
    width: 18px;
    height: 18px;
}

.spinner {
    display: none;
    width: 14px;
    height: 14px;
    border: 2px solid #e5e7eb;
    border-top: 2px solid #0066ff;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.checkmark {
    display: none;
    width: 18px;
    height: 18px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.checkbox-group {
    flex-direction: row;
    align-items: center;
    gap: 0.6rem;
}

.checkbox-group input {
    width: auto;
    cursor: pointer;
}

.checkbox-group label {
    font-weight: 400;
    font-size: 0.85rem;
}

.btn-submit {
    background: var(--primary);
    color: #ffffff;
    font-size: 1rem;
    padding: 0.9rem;
    margin-top: 0.5rem;
}

.btn-submit:hover {
    background: var(--primary-dark);
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.alert-success { background: #dcfce7; color: #15803d; }
.alert-danger { background: #fee2e2; color: #b91c1c; }
.alert-info { background: #e0f2fe; color: #0369a1; }

/* Privacy Page Specific Styles */
.privacy-page {
    padding: 3rem 0;
}

.privacy-card {
    background: #ffffff;
    border-radius: var(--radius-lg);
    padding: 3rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.privacy-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1.5rem;
}

.privacy-updated {
    color: var(--text-muted);
}

.privacy-card h1 {
    color: var(--primary);
    font-size: 2.2rem;
}

.privacy-card h2 {
    color: var(--text-dark);
    font-size: 1.3rem;
    margin-top: 1.8rem;
    margin-bottom: 0.6rem;
}

.privacy-card p, .privacy-card ul {
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.privacy-card ul {
    padding-left: 1.5rem;
}

.privacy-email-link {
    color: var(--primary);
    text-decoration: none;
}

.privacy-email-link:hover {
    text-decoration: underline;
}

.back-link {
    display: inline-block;
    margin-bottom: 1.5rem;
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
}

.back-link:hover {
    text-decoration: underline;
}

/* Footer */
footer {
    background: #0f172a;
    color: #94a3b8;
    padding: 2.5rem 0;
    text-align: center;
    font-size: 0.9rem;
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.footer-links a {
    color: #cbd5e1;
    text-decoration: none;
}

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