@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700;900&display=swap');

/* 全局样式 */
:root {
    --primary-color: #4A90E2;
    --secondary-color: #6c757d;
    --accent-color: #78C0FF;
    --text-color: #f4e7db;
    --light-text: #f4e7db;
    --dark-bg: #181a20;
    --light-bg: #23272f;
    --card-bg: #23272f;
    --header-bg: #181a20;
    --footer-bg: #181a20;
    --input-bg: #23272f;
    --border-color: #333a45;
    --box-shadow: 0 6px 20px rgba(0,0,0,0.3);
    --border-radius: 6px;
    --primary-color-rgb: 74, 144, 226;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.5;
    color: var(--text-color);
    background-color: var(--dark-bg);
} 

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    background: transparent;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

.section-header {
    text-align: center;
    margin-bottom: 35px;
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    color: var(--accent-color);
}

.section-header p {
    font-size: 1.1rem;
    color: #b0b0b0;
    max-width: 700px;
    margin: 0 auto;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
}

.btn.primary {
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: var(--light-text);
    border: none;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}
.btn.primary:hover {
    background: linear-gradient(90deg, var(--accent-color) 0%, var(--primary-color) 100%);
    box-shadow: 0 6px 15px rgba(0,0,0,0.3);
    filter: brightness(1.1);
}

.btn.primary:hover {
    background-color: var(--accent-color);
    transform: translateY(-3px);
    box-shadow: var(--box-shadow);
}

.btn.secondary {
    background-color: transparent;
    color: var(--accent-color);
    border: 2px solid var(--accent-color);
    transition: background 0.3s, color 0.3s;
}
.btn.secondary:hover {
    background: var(--accent-color);
    color: #fff;
    border-color: var(--accent-color);
} 

.btn.secondary:hover {
    background-color: var(--primary-color);
    color: var(--light-text);
    transform: translateY(-3px);
    box-shadow: var(--box-shadow);
}

/* 导航栏 */
header {
    background: rgba(24,26,32,0.85);
    backdrop-filter: blur(8px);
    box-shadow: 0 2px 20px rgba(0,0,0,0.7);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid #23272f;
}


header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo {
    display: flex;
    align-items: center;
}

.logo img {
    height: 40px;
    margin-right: 10px;
}

.logo h1 {
    font-size: 1.8rem;
    color: var(--accent-color);
    font-weight: 900;
    letter-spacing: 1px;
    text-shadow: 0 2px 10px #222a;
} 

nav ul {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
}

nav ul li {
    margin-left: 20px;
}

nav ul li a {
    color: var(--light-text);
    font-weight: 500;
    transition: color 0.3s, border-bottom 0.3s;
    white-space: nowrap;
    padding: 6px 0;
    border-bottom: 2px solid transparent;
}
nav ul li a:hover, nav ul li a:focus {
    color: var(--accent-color);
    border-bottom: 2px solid var(--accent-color);
    text-shadow: 0 0 8px var(--accent-color);
}


nav ul li a:hover {
    color: var(--secondary-color);
}

.language-selector select {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--primary-color);
    padding: 5px 25px 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
} 

.language-selector select:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.language-selector select:focus {
    outline: none;
    box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.3);
}

.mobile-menu-btn {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* 主页横幅 */
.hero {
    min-height: 88vh;
    padding: 0;
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #20222a 0%, #23272f 100%);
}
.hero::before {
    content: '';
    position: absolute;
    left: 0; top: 0; right: 0; bottom: 0;
    z-index: 0;
    background: linear-gradient(120deg, rgba(24,26,32,0.6) 60%, rgba(44,49,65,0.2) 100%), url('../images/hero-bg.jpg') center center/cover no-repeat;
    opacity: 1;
    transform: scaleX(-1);
}
.hero .container {
    position: relative;
    z-index: 2;
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 500px;
    background: none;
    box-shadow: none;
    padding: 0;
}
.hero-main {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 600px;
    gap: 28px;
}
.hero-brand {
    display: flex;
    align-items: center;
    gap: 18px;
    margin-bottom: 6px;
}
.hero-logo {
    width: 60px;
    height: 60px;
    border-radius: 18px;
    background: rgba(44,49,65,0.8);
    box-shadow: 0 4px 24px #000a;
    padding: 6px;
}
.hero-brand-title {
    font-size: 2.2rem;
    color: var(--accent-color);
    font-weight: 900;
    letter-spacing: 2px;
    text-shadow: 0 2px 16px #222a;
}
.hero-content {
    text-align: center;
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
}
.hero-title {
    font-size: 2.8rem;
    color: var(--accent-color);
    font-weight: 900;
    margin-bottom: 18px;
    text-shadow: 0 4px 32px #000a;
}
.hero-desc {
    font-size: 1.18rem;
    color: #b0b0b0;
    margin-bottom: 36px;
    opacity: 0.96;
    line-height: 1.8;
}
.cta-buttons {
    display: flex;
    justify-content: center;
    gap: 22px;
}


.hero .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.hero-content {
    flex: 1;
}

.hero-content h2 {
    font-size: 3.2rem;
    margin-bottom: 20px;
    color: var(--accent-color);
    font-weight: 900;
    text-shadow: 0 2px 24px #000a;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    color: #fff6ed;
}

.cta-buttons {
    display: flex;
    gap: 15px;
}

.hero-image {
    flex: 1;
}

.hero-image img {
    border-radius: 10px;
    box-shadow: var(--box-shadow);
}

/* 核心功能 */
.features {
    padding: 60px 0 0 0;
    background-color: var(--dark-bg);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.feature-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    padding: 24px 20px 20px 20px;
    margin-bottom: 20px;
    transition: box-shadow 0.3s, border 0.3s;
    color: var(--text-color);
    border: 1.5px solid transparent;
}
.feature-card:hover {
    box-shadow: 0 8px 25px rgba(var(--primary-color-rgb), 0.4);
    border: 1.5px solid var(--accent-color);
}

.feature-icon {
    width: 70px;
    height: 70px;
    margin-bottom: 20px;
}

.feature-icon img {
    height: 48px;
    margin-bottom: 18px;
    background: #23272f;
    border-radius: 50%;
    padding: 10px;
    box-shadow: 0 2px 8px #000a;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--accent-color);
}

.feature-card ul li {
    color: var(--text-color);
    margin-bottom: 8px;
    position: relative;
    padding-left: 20px;
}

.feature-card ul li:before {
    content: "•";
    color: var(--primary-color);
    font-weight: bold;
    position: absolute;
    left: 0;
}

/* 增强功能 */
.advanced-features {
    background: var(--dark-bg);
    padding: 60px 0;
}

.advanced-tabs {
    max-width: 900px;
    margin: 0 auto;
}

.tabs-nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.tab-btn {
    padding: 12px 20px;
    margin: 0 5px 10px;
    background-color: transparent;
    border: 1.5px solid var(--secondary-color);
    color: var(--secondary-color);
    border-radius: var(--border-radius);
    font-weight: 500;
    cursor: pointer;
    transition: background 0.3s, color 0.3s, border 0.3s, box-shadow 0.3s;
}
.tab-btn.active, .tab-btn:hover {
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: #fff;
    border: 1.5px solid var(--accent-color);
    box-shadow: 0 2px 8px rgba(var(--primary-color-rgb), 0.3);
}

.tab-btn.active {
    background-color: var(--primary-color);
    color: #fff;
}

.tab-pane {
    display: none;
    background: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    color: var(--text-color);
    padding: 32px 24px;
    margin-top: 16px;
    border: 1.5px solid #23272f;
}

.tab-pane.active {
    display: block;
}

.tab-content-inner {
    display: flex;
    align-items: center;
    gap: 30px;
}

.tab-image {
    flex: 1;
}

.tab-image img {
    border-radius: var(--border-radius);
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
}

.tab-text {
    flex: 1;
}

.tab-text h3 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.tab-text ul li {
    margin-bottom: 10px;
    position: relative;
    padding-left: 25px;
}

.tab-text ul li:before {
    content: "✓";
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* 技术架构 */
.architecture {
    background: var(--dark-bg);
    padding: 60px 0;
}

.architecture-diagram {
    text-align: center;
    margin-bottom: 35px;
}

.architecture-diagram img {
    max-width: 800px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.architecture-details {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

.arch-column {
    background: #20222a;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 16px #000c;
    padding: 32px 24px;
    margin-bottom: 28px;
    color: var(--text-color);
    border: 1.5px solid #23272f;
    width: 48%;
}

.arch-column h3 {
    color: var(--accent-color);
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.arch-column ul li {
    margin-bottom: 8px;
    position: relative;
    padding-left: 20px;
}

.arch-column ul li:before {
    content: "•";
    color: var(--primary-color);
    font-weight: bold;
    position: absolute;
    left: 0;
}

/* 联系我们 */
.contact {
    background: var(--dark-bg);
    padding: 60px 0;
}

.contact-container {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
}

.contact-form {
    flex: 1;
    min-width: 300px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 12px;
    border-radius: 6px;
    border: 1.5px solid #23272f;
    background: #23272f;
    color: #e0e0e0;
    margin-bottom: 20px;
    font-size: 1rem;
    transition: border 0.3s, box-shadow 0.3s;
}
.contact-form input:focus,
.contact-form textarea:focus {
    border: 1.5px solid var(--accent-color);
    box-shadow: 0 0 8px var(--accent-color);
    outline: none;
    background: #23272f;
    color: #fff;
}

.contact-info {
    flex: 1;
    min-width: 300px;
    background-color: var(--primary-color);
    color: var(--light-text);
    padding: 30px;
    border-radius: var(--border-radius);
}

.info-item {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
}

.info-item i {
    font-size: 1.5rem;
    margin-right: 15px;
}

.social-links {
    margin-top: 30px;
}

.social-links a {
    display: inline-block;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    text-align: center;
    line-height: 40px;
    margin-right: 10px;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background-color: #fff;
    color: var(--primary-color);
    transform: translateY(-3px);
}

/* 页脚 */
footer {
    background-color: var(--dark-bg);
    color: #fff;
    padding: 50px 0 20px;
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin-bottom: 35px;
}

.footer-logo {
    flex: 1;
    min-width: 200px;
    margin-right: 40px;
    margin-bottom: 30px;
}

.footer-logo img {
    height: 40px;
    margin-bottom: 15px;
}

.footer-logo h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--accent-color);
}

.footer-logo p {
    color: #aaa;
}

.footer-links {
    flex: 2;
    display: flex;
    flex-wrap: wrap;
}

.footer-column {
    flex: 1;
    min-width: 150px;
    margin-bottom: 30px;
}

.footer-column h4 {
    font-size: 1.2rem;
    margin-bottom: 20px;
    color: var(--secondary-color);
}

.footer-column ul li {
    margin-bottom: 10px;
}

.footer-column ul li a {
    color: #aaa;
    transition: color 0.3s;
}

.footer-column ul li a:hover {
    color: #fff;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: #aaa;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .hero .container {
        flex-direction: column;
    }

    .hero-content {
        padding-right: 0;
        margin-bottom: 40px;
        text-align: center;
    }

    .cta-buttons {
        justify-content: center;
    }

    .tab-content-inner {
        flex-direction: column;
    }

    .tab-image {
        margin-bottom: 30px;
    }
}

@media (max-width: 768px) {
    nav {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--header-bg);
        box-shadow: 0 4px 10px rgba(0,0,0,0.3);
        border-bottom: 1px solid var(--border-color);
        padding: 10px 0;
        z-index: 1000;
    }

    nav.active {
        display: block;
    }

    nav ul {
        flex-direction: column;
        align-items: center;
        padding: 0;
    }

    nav ul li {
        margin: 0;
        width: 100%;
        text-align: center;
        padding: 12px 0;
        border-bottom: 1px solid rgba(255,255,255,0.1);
    }

    nav ul li:last-child {
        border-bottom: none;
    }

    nav ul li a {
        display: block;
        padding: 8px 0;
    }

    .language-selector {
        margin-top: 10px;
        padding-top: 10px;
        border-top: 1px solid rgba(255,255,255,0.1);
    }

    .mobile-menu-btn {
        display: block;
        padding: 8px;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .hero-content h2 {
        font-size: 2.5rem;
    }

    .architecture-diagram img {
        width: 100%;
    }
}