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

:root {
    --primary-color: #8B7355;
    --secondary-color: #6B5744;
    --accent-color: #FF8C42;
    --text-color: #2c2c2c;
    --text-light: #666666;
    --bg-color: #ffffff;
    --bg-alt: #F8F5F1;
    --border-color: #e5e5e5;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--bg-color);
}

html {
    scroll-behavior: smooth;
}

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

/* Language Tabs */
.language-tabs {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    padding: 0.75rem 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1001;
}

.language-tabs .container {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
}

.lang-tab {
    background-color: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.lang-tab:hover {
    background-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.lang-tab.active {
    background-color: white;
    color: var(--primary-color);
    border-color: white;
}

/* Navigation Bar */
.navbar {
    background-color: var(--bg-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 52px;
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-img {
    width: 50px;
    height: 50px;
    object-fit: contain;
    border-radius: 8px;
}

.nav-brand h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 700;
    margin: 0;
}

.nav-subtitle {
    font-size: 0.875rem;
    color: var(--text-light);
    margin: 0;
}

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

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
    padding: 0.5rem 0.25rem;
    font-size: 0.95rem;
}

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

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    margin: 3px 0;
    transition: 0.3s;
}

/* Cover Section */
.cover-section {
    position: relative;
    width: 100%;
    height: 300px;
    overflow: hidden;
}

.cover-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.cover-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, transparent 0%, rgba(255,255,255,0.3) 100%);
}

/* Hero Section */
.hero {
    padding: 3rem 0;
    background-color: var(--bg-color);
}

.hero-columns {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 3rem;
    align-items: start;
}

.hero-image {
    position: relative;
}

.hero-image img {
    width: 100%;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
}

.badge-container {
    margin-top: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.badge {
    background: linear-gradient(135deg, #ff6b6b 0%, #ff8787 100%);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    text-align: center;
    box-shadow: var(--shadow);
}

.badge-alt {
    background: linear-gradient(135deg, var(--accent-color) 0%, #ffb366 100%);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    text-align: center;
    box-shadow: var(--shadow);
}

.hero-content h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    line-height: 1.3;
}

.hero-content p {
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

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

.btn-app {
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    color: white;
    border: 2px solid #4CAF50;
    position: relative;
    overflow: hidden;
}

.btn-app:hover {
    background: linear-gradient(135deg, #45a049 0%, #3d8b40 100%);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-app::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn-app:hover::before {
    left: 100%;
}

/* Sections */
.section {
    padding: 5rem 0;
}

.section-alt {
    background-color: var(--bg-alt);
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--primary-color);
    font-weight: 700;
}

/* About Section */
.about-content {
    max-width: 900px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.9;
    color: var(--text-light);
}

.about-content p {
    margin-bottom: 1.5rem;
}

/* Services Section */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 3rem;
    margin-top: 3rem;
}

.service-card {
    background-color: white;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: all 0.3s ease;
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.service-icon {
    font-size: 3.5rem;
    margin-bottom: 1rem;
}

.service-card h3 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.service-card h4 {
    font-size: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--text-light);
    font-weight: 500;
}

.service-image {
    margin: 2rem 0;
    border-radius: 12px;
    overflow: hidden;
}

.service-image img {
    width: 100%;
    height: auto;
    display: block;
}

.service-card p {
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: 1rem;
    text-align: left;
}

/* SSYDW App Section */
.app-subtitle {
    text-align: center;
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 3rem;
    font-weight: 500;
}

.app-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    max-width: 1000px;
    margin: 0 auto;
}

.app-screenshot {
    text-align: center;
}

.app-image {
    max-width: 300px;
    width: 100%;
    height: auto;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    transition: transform 0.3s ease;
}

.app-image:hover {
    transform: scale(1.05);
}

.feature-list {
    margin-bottom: 2.5rem;
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background-color: white;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.feature-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 2rem;
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-alt);
    border-radius: 12px;
}

.feature-text h4 {
    font-size: 1.25rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.feature-text p {
    color: var(--text-light);
    line-height: 1.6;
    margin: 0;
}

.app-download {
    text-align: center;
    padding: 2rem;
    background-color: white;
    border-radius: 16px;
    box-shadow: var(--shadow);
}

.btn-app-large {
    background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
    color: white;
    border: 2px solid #4CAF50;
    padding: 1rem 2.5rem;
    font-size: 1.125rem;
    font-weight: 600;
    border-radius: 12px;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn-app-large:hover {
    background: linear-gradient(135deg, #45a049 0%, #3d8b40 100%);
    transform: translateY(-3px);
    box-shadow: 0 15px 30px rgba(76, 175, 80, 0.3);
}

.btn-app-large::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn-app-large:hover::before {
    left: 100%;
}

.download-note {
    margin-top: 1rem;
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 0;
}

/* Team Section */
.team-content {
    max-width: 900px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.9;
    color: var(--text-light);
    text-align: center;
}

.team-content p {
    margin-bottom: 1.5rem;
}

/* Collaborators Section */
.collaborators-intro {
    text-align: center;
    max-width: 900px;
    margin: 0 auto 3rem;
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-light);
}

.collaborators-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2.5rem;
    margin-top: 3rem;
}

.collaborator-card {
    background-color: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: all 0.3s ease;
}

.collaborator-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.collaborator-logo {
    margin-bottom: 1.5rem;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.collaborator-logo img {
    max-width: 100%;
    max-height: 80px;
    object-fit: contain;
}

.collaborator-card p {
    color: var(--text-light);
    line-height: 1.7;
    font-size: 0.95rem;
    text-align: left;
}

/* Contact Section */
.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info-box,
.video-box {
    background-color: white;
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.contact-info-box h3,
.video-box h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
}

.contact-items {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: start;
    gap: 1rem;
    padding: 1rem;
    background-color: var(--bg-alt);
    border-radius: 8px;
}

.contact-icon {
    font-size: 2rem;
}

.contact-item strong {
    display: block;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.contact-item p {
    color: var(--text-light);
    margin: 0;
}

.video-placeholder {
    background-color: var(--bg-alt);
    padding: 4rem 2rem;
    border-radius: 8px;
    text-align: center;
    color: var(--text-light);
}

.video-placeholder p {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

/* Footer */
.footer {
    background-color: var(--primary-color);
    color: white;
    padding: 3rem 0 1.5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    flex-direction: column;
    align-items: start;
}

.footer-logo img {
    width: 60px;
    height: 60px;
    object-fit: contain;
    border-radius: 8px;
    margin-bottom: 1rem;
    background-color: white;
    padding: 5px;
}

.footer-logo h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.footer-logo p {
    color: rgba(255, 255, 255, 0.8);
}

.footer-links h4,
.footer-contact h4 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
}

.footer-links ul {
    list-style: none;
    padding: 0;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: white;
}

.footer-contact p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 0.5rem;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 0.5rem;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive Design */
@media (max-width: 968px) {
    .hero-columns {
        grid-template-columns: 1fr;
    }

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

    .app-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .app-image {
        max-width: 250px;
    }

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

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

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-logo {
        align-items: center;
    }
}

@media (max-width: 768px) {
    .language-tabs .container {
        gap: 0.3rem;
    }

    .lang-tab {
        padding: 0.4rem 1rem;
        font-size: 0.85rem;
    }

    .navbar {
        top: 50px;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--bg-color);
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow);
        gap: 0;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-menu li {
        width: 100%;
        text-align: center;
        padding: 0.75rem 0;
        border-bottom: 1px solid var(--border-color);
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .cover-section {
        height: 200px;
    }

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

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

    .hero-buttons {
        flex-direction: column;
        gap: 1rem;
    }

    .section {
        padding: 3rem 0;
    }
}

@media (max-width: 480px) {
    .lang-tab {
        padding: 0.35rem 0.75rem;
        font-size: 0.75rem;
    }

    .navbar {
        top: 48px;
    }

    .nav-brand h1 {
        font-size: 1.25rem;
    }

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

    .cover-section {
        height: 150px;
    }

    .section-title {
        font-size: 1.75rem;
    }

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