/* YouNews Support Website Styles - Black/White/Gray with Red Accent */

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #1a1a1a;
    background-color: #ffffff;
}

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

/* Header and Navigation */
header {
    background: #ffffff;
    border-bottom: 1px solid #e5e5e5;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1a1a1a;
    letter-spacing: -0.5px;
}

.logo-subtitle {
    font-size: 1rem;
    font-weight: normal;
    color: #666666;
    margin-left: 0.5rem;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #666666;
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 8px 12px;
    border-radius: 0;
    border: none;
}

.nav-links a:hover {
    color: #dc2626;
}

.nav-links a.active {
    color: #dc2626;
    font-weight: 600;
}

/* Buttons */
.btn-primary,
.btn-secondary {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 0;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: #1a1a1a;
    color: #ffffff;
}

.btn-primary:hover {
    background: #dc2626;
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: #1a1a1a;
    border: 2px solid #1a1a1a;
}

.btn-secondary:hover {
    background: #1a1a1a;
    color: #ffffff;
}

/* Hero Section */
.hero {
    padding: 1rem 0 4rem 0;
    background: #ffffff;
    background-image: 
        radial-gradient(circle at 20% 20%, rgba(220, 38, 38, 0.03) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(220, 38, 38, 0.02) 0%, transparent 50%),
        linear-gradient(135deg, #fafafa 0%, #ffffff 100%);
    color: #1a1a1a;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
    color: #1a1a1a;
    text-align: center;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: #666666;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-images {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
}

.hero-images .app-screenshot {
    height: 500px;
    width: auto;
    border-radius: 20px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.15);
    border: 1px solid #e5e5e5;
    transition: transform 0.3s ease;
}

.hero-images .app-screenshot:hover {
    transform: translateY(-4px);
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 1rem;
}

.btn-large {
    padding: 18px 48px;
    font-size: 1.25rem;
    font-weight: 700;
}

.card h3 {
    font-size: 0.9rem;
    font-weight: 600;
    color: #1a1a1a;
    margin-bottom: 8px;
}

.card p {
    font-size: 0.8rem;
    color: #666666;
    margin-bottom: 4px;
}

.card .source {
    font-size: 0.7rem;
    color: #999999;
}

/* Features Section */
.value-prop {
    padding: 4rem 0;
    background: #f5f5f5;
}

.value-prop h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1a1a1a;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: #ffffff;
    padding: 2rem;
    border-radius: 0;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
    border-top: 4px solid #dc2626;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px rgba(0,0,0,0.15);
}

.feature-card.coming-soon {
    background: #f5f5f5;
    border-top: 4px solid #999999;
    opacity: 0.7;
}

.feature-card.coming-soon .icon,
.feature-card.coming-soon h3,
.feature-card.coming-soon p {
    color: #999999;
}

.coming-soon-badge {
    display: inline-block;
    background: #999999;
    color: #ffffff;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-top: 1rem;
}

.feature-card .icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: #dc2626;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: #1a1a1a;
}

.feature-card p {
    color: #666666;
    line-height: 1.6;
}

/* Download Section */
.download {
    padding: 4rem 0;
    text-align: center;
    background: #ffffff;
}

.download-note {
    color: #666666;
    margin-top: 1rem;
    font-size: 1rem;
}

/* Principles Page */
.principles-hero {
    padding: 4rem 0 5rem 0;
    background: #ff3b30;
    color: #ffffff;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.principles-hero::after {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 22% 28%, rgba(255, 255, 255, 0.16) 0%, transparent 45%),
                radial-gradient(circle at 78% 72%, rgba(204, 37, 48, 0.22) 0%, transparent 55%);
    pointer-events: none;
}

.principles-hero .container {
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-block;
    padding: 0.4rem 1rem;
    background: rgba(220, 38, 38, 0.15);
    color: #fca5a5;
    letter-spacing: 2px;
    font-size: 0.75rem;
    text-transform: uppercase;
    border: 1px solid rgba(252, 165, 165, 0.3);
    border-radius: 999px;
    margin-bottom: 1.5rem;
}

.principles-hero h1 {
    font-size: 2.4rem;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    color: #ffffff;
}

.principles-hero .hero-subtitle {
    color: #d1d1d1;
    max-width: 720px;
}

.principles-manifesto {
    background: #ffffff;
    padding: 4rem 0;
}

.manifesto-card {
    background: linear-gradient(135deg, #ffffff 0%, #f7f7f7 100%);
    border: 1px solid #e5e5e5;
    padding: 3rem;
    box-shadow: 0 18px 48px rgba(0,0,0,0.1);
    border-radius: 0;
    position: relative;
    overflow: hidden;
}

.manifesto-card::before {
    content: "";
    position: absolute;
    top: -120px;
    right: -120px;
    width: 240px;
    height: 240px;
    background: rgba(220, 38, 38, 0.08);
    border-radius: 50%;
}

.manifesto-card h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: #1a1a1a;
}

.manifesto-card p {
    font-size: 1.1rem;
    color: #333333;
    line-height: 1.8;
}

.manifesto-quote {
    margin-top: 2rem;
    font-size: 1.2rem;
    font-weight: 600;
    color: #dc2626;
}

.principles-list {
    background: #0f0f0f;
    color: #ffffff;
    padding: 4rem 0;
}

.principles-list .container {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

.principle-item {
    display: block;
    padding: 2rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    position: relative;
}

.principle-item::before {
    content: "";
    position: absolute;
    inset: 0;
    border-left: 4px solid #dc2626;
    pointer-events: none;
}

.principle-content h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: #ffffff;
}

.principle-content p {
    color: #d4d4d4;
    margin-bottom: 0.8rem;
    line-height: 1.8;
}

.principle-highlight {
    color: #f87171;
    font-weight: 600;
}

.principles-cta {
    padding: 4rem 0 5rem 0;
    background: #ffffff;
    text-align: center;
}

.principles-cta h2 {
    font-size: 2.2rem;
    margin-bottom: 1.5rem;
    color: #1a1a1a;
}

.principles-cta p {
    font-size: 1.1rem;
    color: #333333;
    max-width: 680px;
    margin: 0 auto 1rem auto;
}

.cta-note {
    color: #dc2626;
    font-weight: 600;
}

@media (max-width: 768px) {
    .principles-hero {
        padding: 3.5rem 0 3.5rem 0;
    }

    .principles-hero h1 {
        font-size: 2rem;
    }

    .manifesto-card {
        padding: 2rem;
    }

    .principles-list .container {
        gap: 2rem;
    }

    .principle-item {
        padding: 1.5rem;
    }
}

/* Page Hero */
.page-hero {
    padding: 3rem 0;
    background: #f5f5f5;
    text-align: center;
}

.page-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #1a1a1a;
}

.page-hero p {
    font-size: 1.2rem;
    color: #666666;
}

.last-updated {
    color: #999999;
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* Legal Pages */
.legal-content {
    padding: 3rem 0;
}

.legal-toc {
    background: #f5f5f5;
    padding: 2rem;
    border-radius: 0;
    margin-bottom: 2rem;
    border-left: 4px solid #dc2626;
}

.legal-toc h3 {
    margin-bottom: 1rem;
    color: #1a1a1a;
}

.legal-toc ul {
    list-style: none;
}

.legal-toc li {
    margin-bottom: 0.5rem;
}

.legal-toc a {
    color: #dc2626;
    text-decoration: none;
}

.legal-toc a:hover {
    text-decoration: underline;
    color: #991b1b;
}

.legal-text h2 {
    margin: 2rem 0 1rem 0;
    color: #1a1a1a;
    font-size: 1.5rem;
    border-bottom: 2px solid #dc2626;
    padding-bottom: 0.5rem;
}

.legal-text h3 {
    margin: 1.5rem 0 1rem 0;
    color: #1a1a1a;
    font-size: 1.25rem;
}

.legal-text h4 {
    margin: 1rem 0 0.5rem 0;
    color: #1a1a1a;
    font-size: 1.1rem;
}

.legal-text ul {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

.legal-text li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

.legal-text p {
    margin-bottom: 1rem;
    line-height: 1.6;
    color: #333333;
}

/* FAQ Page */
.faq-categories {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.category-btn {
    padding: 8px 16px;
    border: 1px solid #666666;
    background: #ffffff;
    border-radius: 0;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #1a1a1a;
}

.category-btn.active {
    background: #dc2626;
    color: #ffffff;
    border-color: #dc2626;
}

.faq-category {
    display: none;
}

.faq-category.active {
    display: block;
}

.faq-item {
    margin-bottom: 1.5rem;
    border: 1px solid #e5e5e5;
    border-radius: 0;
    overflow: hidden;
}

.faq-question {
    padding: 1.5rem;
    background: #f5f5f5;
    cursor: pointer;
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #1a1a1a;
}

.faq-question::after {
    content: '+';
    font-size: 1.5rem;
    color: #dc2626;
}

.faq-item.open .faq-question::after {
    content: '−';
}

.faq-answer {
    padding: 1.5rem;
    background: #ffffff;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-answer.open {
    max-height: 500px;
}

/* Contact Page */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.contact-methods {
    margin-bottom: 2rem;
}

.contact-method {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: #ffffff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    border: 1px solid #e5e5e5;
}

.method-icon {
    font-size: 2rem;
    flex-shrink: 0;
    color: #dc2626;
}

.method-content h3 {
    margin-bottom: 0.5rem;
    color: #1a1a1a;
}

.method-content p {
    color: #666666;
    margin-bottom: 0.25rem;
}

.method-content a {
    color: #dc2626;
    text-decoration: none;
}

.method-content a:hover {
    text-decoration: underline;
    color: #991b1b;
}

.contact-form-section h2 {
    margin-bottom: 2rem;
}

.contact-form {
    background: #ffffff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    border: 1px solid #e5e5e5;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #1a1a1a;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid #666666;
    border-radius: 0;
    font-size: 1rem;
    font-family: inherit;
    background: #ffffff;
    color: #1a1a1a;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #dc2626;
}

.checkbox-group {
    display: flex;
    align-items: center;
}

.checkbox-label {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-weight: normal !important;
    color: #1a1a1a;
}

.checkbox-label input[type="checkbox"] {
    width: auto;
    margin-right: 0.5rem;
    accent-color: #dc2626;
}

.form-status {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 0;
    font-weight: 500;
}

.status-loading {
    background: #f5f5f5;
    color: #1a1a1a;
    border-left: 4px solid #dc2626;
}

.status-success {
    background: #f5f5f5;
    color: #1a1a1a;
    border-left: 4px solid #dc2626;
}

.status-error {
    background: #f5f5f5;
    color: #1a1a1a;
    border-left: 4px solid #dc2626;
}

.support-hours {
    margin: 3rem 0;
    padding: 2rem;
    background: #f5f5f5;
    border-radius: 0;
    border-left: 4px solid #1a1a1a;
}

.hours-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.hours-item h3 {
    margin-bottom: 1rem;
    color: #1a1a1a;
}

.hours-item p {
    color: #666666;
    line-height: 1.6;
}

.quick-links {
    margin: 3rem 0;
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.quick-link {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: #ffffff;
    border-radius: 8px;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
    border: 1px solid #e5e5e5;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.quick-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
    border-color: #dc2626;
}

.link-icon {
    font-size: 2rem;
    flex-shrink: 0;
    color: #dc2626;
}

.link-text h3 {
    margin-bottom: 0.25rem;
    color: #1a1a1a;
    font-size: 1.1rem;
}

.link-text p {
    color: #666666;
    font-size: 0.9rem;
}

/* Features Page */
.feature-detail {
    padding: 3rem 0;
}

.feature-detail.alternate {
    background: #f5f5f5;
}

.feature-content h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #1a1a1a;
}

.lead {
    font-size: 1.2rem;
    color: #666666;
    margin-bottom: 2rem;
}

.feature-showcase {
    display: flex;
    gap: 4rem;
    align-items: center;
    margin: 3rem 0;
}

.feature-text {
    flex: 1;
}

.feature-image {
    flex: 1;
    text-align: center;
}

.feature-image img {
    width: 50%;
    height: 50%;
    object-fit: cover; /* 保持图片比例，裁剪多余部分 */
}

.feature-screenshot {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.1);
    border: 1px solid #e5e5e5;
}

.feature-steps {
    margin: 3rem 0;
}

.step {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
    align-items: flex-start;
}

.step-number {
    background: #1a1a1a;
    color: #ffffff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content h3 {
    margin-bottom: 0.5rem;
    color: #1a1a1a;
}

.step-content p {
    color: #666666;
}

.tech-showcase {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

.tech-card {
    background: #ffffff;
    padding: 2rem;
    border-radius: 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    text-align: center;
    border-top: 4px solid #dc2626;
}

.tech-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: #dc2626;
}

.demo-comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin: 3rem 0;
}

.comparison-box {
    background: #ffffff;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    border: 1px solid #e5e5e5;
}

.comparison-highlight {
    border-color: #dc2626;
    box-shadow: 0 4px 16px rgba(220,38,38,0.1);
}

.comparison-box h4 {
    margin-bottom: 1rem;
    color: #1a1a1a;
    font-size: 1.25rem;
    font-weight: 600;
}

.comparison-box ul {
    list-style: none;
    margin-left: 0;
}

.comparison-box li {
    margin-bottom: 0.5rem;
    padding-left: 1.5rem;
    position: relative;
    color: #333333;
}

.comparison-box:nth-child(1) li::before {
    content: '✗';
    color: #666666;
    position: absolute;
    left: 0;
}

.comparison-box:nth-child(2) li::before {
    content: '✓';
    color: #dc2626;
    position: absolute;
    left: 0;
}

/* Footer */
footer {
    background: #1a1a1a;
    color: #ffffff;
    padding: 3rem 0 1rem 0;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
    color: #ffffff;
}

.footer-section h4 {
    margin-bottom: 0.5rem;
    color: #cccccc;
}

.footer-section p,
.footer-section li {
    color: #999999;
    margin-bottom: 0.5rem;
}

.footer-section ul {
    list-style: none;
}

.footer-section a {
    color: #999999;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: #dc2626;
}

.footer-bottom {
    border-top: 1px solid #333333;
    padding-top: 1rem;
    text-align: center;
    color: #666666;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        gap: 1rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-images {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }

    .hero-images .app-screenshot {
        height: 400px;
        max-width: 90%;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

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

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

    .demo-comparison {
        grid-template-columns: 1fr;
    }

    .step {
        flex-direction: column;
        text-align: center;
    }

    .container {
        padding: 0 15px;
    }

    .legal-toc {
        padding: 1rem;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 2rem 0;
    }

    .page-hero h1 {
        font-size: 2rem;
    }

    .download-options {
        flex-direction: column;
        align-items: center;
    }

    .contact-methods {
        text-align: center;
    }

    .contact-method {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    body {
        background-color: #1a1a1a;
        color: #ffffff;
    }

    .value-prop,
    .faq-section .container,
    .legal-toc,
    .contact-form,
    .support-hours,
    .quick-links {
        background: #2a2a2a;
    }

    .feature-card,
    .download-card,
    .tech-card,
    .card {
        background: #2a2a2a;
        color: #ffffff;
    }

    .feature-card h3,
    .tech-card h3,
    .card h3 {
        color: #ffffff;
    }

    .feature-card p,
    .tech-card p,
    .card p {
        color: #cccccc;
    }

    .hero {
        background: linear-gradient(135deg, #2a2a2a 0%, #1a1a1a 100%);
    }

    .nav-links a {
        color: #cccccc;
    }

    .nav-links a:hover {
        color: #dc2626;
    }

    .footer-section a {
        color: #cccccc;
    }

    .footer-section a:hover {
        color: #dc2626;
    }
}

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

/* Loading states */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
        animation: none !important;
    }
}

/* Focus styles */
button:focus,
input:focus,
select:focus,
textarea:focus,
a:focus {
    outline: 2px solid #dc2626;
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .nav-container,
    footer,
    .cta-buttons {
        display: none;
    }
    
    body {
        color: #000000;
        background: #ffffff;
    }
}