/* ============================================
   Foam Concrete Technology - Main Stylesheet
   Changsha Dwell Technology Co., Ltd.
   ============================================ */

/* CSS Variables */
:root {
    --primary: #0d1b2a;
    --primary-dark: #082434;
    --secondary: #14213d;
    --accent: #fca311;
    --accent-hover: #e85d04;
    --text: #1b1b1b;
    --text-light: #4a5568;
    --muted: #6c757d;
    --light: #f8f9fa;
    --lighter: #f1f3f5;
    --white: #ffffff;
    --border: #e9ecef;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 20px 40px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text);
    background: var(--white);
    overflow-x: hidden;
}

.container {
    width: 90%;
    max-width: 1280px;
    margin: 0 auto;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--primary);
}

h1 { font-size: 3rem; margin-bottom: 1rem; }
h2 { font-size: 2.25rem; margin-bottom: 1rem; }
h3 { font-size: 1.5rem; margin-bottom: 0.75rem; }
h4 { font-size: 1.25rem; margin-bottom: 0.5rem; }

p {
    color: var(--text-light);
    margin-bottom: 1rem;
}

a {
    text-decoration: none;
    color: var(--primary);
    transition: var(--transition);
}

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

/* Header & Navigation */
header {
    background: var(--primary);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.logo a {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--white);
    letter-spacing: -0.5px;
}

.menu {
    display: flex;
    gap: 2rem;
    align-items: center;
    flex-wrap: wrap;
}

.menu a {
    color: var(--white);
    font-size: 0.9rem;
    font-weight: 500;
    opacity: 0.9;
    transition: var(--transition);
}

.menu a:hover {
    opacity: 1;
    color: var(--accent);
}

.menu .contact-btn {
    background: var(--accent);
    color: var(--primary);
    padding: 0.5rem 1.25rem;
    border-radius: 2rem;
    opacity: 1;
}

.menu .contact-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
}

.language-selector {
    display: flex;
    gap: 0.5rem;
    margin: 0 1rem;
}

.lang-btn {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.3);
    padding: 0.25rem 0.75rem;
    border-radius: 2rem;
    color: var(--white);
    font-size: 0.8rem;
    cursor: pointer;
    transition: var(--transition);
}

.lang-btn.active {
    background: var(--accent);
    border-color: var(--accent);
    color: var(--primary);
}

.lang-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.mobile-toggle {
    display: none;
    font-size: 1.5rem;
    color: var(--white);
    cursor: pointer;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: var(--white);
    padding: 5rem 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 200" opacity="0.05"><path d="M60 80 L140 80 L110 140 L50 140 Z" fill="white"/><circle cx="100" cy="60" r="15" fill="white"/></svg>') repeat;
    background-size: 200px;
}

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

.hero h1 {
    color: var(--white);
    font-size: 3.5rem;
    margin-bottom: 1.25rem;
}

.hero p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.125rem;
    max-width: 700px;
    margin-bottom: 2rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 2rem;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 1rem;
}

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

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

.btn-outline {
    background: transparent;
    border: 2px solid var(--accent);
    color: var(--accent);
}

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

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

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

.btn-small {
    padding: 0.5rem 1.25rem;
    font-size: 0.875rem;
}

/* Section Styles */
section {
    padding: 5rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title h2 {
    font-size: 2.5rem;
    margin-bottom: 0.75rem;
}

.section-title p {
    color: var(--muted);
    max-width: 700px;
    margin: 0 auto;
}

/* Grid Systems */
.grid {
    display: grid;
    gap: 2rem;
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* Cards */
.card {
    background: var(--white);
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.card-content {
    padding: 1.5rem;
}

.card h3 {
    margin-bottom: 0.75rem;
}

.card p {
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

/* Breadcrumb */
.breadcrumb {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 2rem;
    font-size: 0.875rem;
}

.breadcrumb a {
    color: var(--muted);
}

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

.breadcrumb span {
    color: var(--text);
}

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--primary);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    font-family: inherit;
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(252, 163, 17, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

/* ============================================
   Footer - 横排版本 (Flex 布局)
   ============================================ */
footer {
    background: var(--primary);
    color: var(--white);
    padding: 3rem 0 2rem;
    margin-top: 4rem;
}

/* 使用 Flex 强制横排 */
.footer-grid {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    justify-content: space-between;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-col {
    flex: 1;
    min-width: 0;
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-col p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.85rem;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.footer-col h4 {
    color: var(--white);
    margin-bottom: 1rem;
    font-size: 1.1rem;
    position: relative;
    display: inline-block;
}

.footer-col h4:after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 32px;
    height: 2px;
    background: var(--accent);
    border-radius: 4px;
}

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

.footer-col ul li {
    margin-bottom: 0.5rem;
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.875rem;
    text-decoration: none;
    transition: var(--transition);
}

.footer-col ul li a:hover {
    color: var(--accent);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: var(--white);
    transition: var(--transition);
    text-decoration: none;
}

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

.contact-info li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.7);
}

.contact-info li i {
    width: 1.25rem;
    color: var(--accent);
}

.contact-info li a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
}

.contact-info li a:hover {
    color: var(--accent);
}

.contact-info li span {
    color: rgba(255, 255, 255, 0.7);
}

.copyright {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.5);
}

/* 响应式：桌面端横排，平板2列，手机1列 */
@media (max-width: 1024px) {
    .footer-grid {
        flex-wrap: wrap;
    }
    .footer-col {
        flex: 1 1 45%;
    }
}

@media (max-width: 768px) {
    .footer-grid {
        flex-direction: column;
        flex-wrap: wrap;
    }
    .footer-col {
        flex: 1 1 100%;
    }
}

/* Responsive */
@media (max-width: 1024px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    section { padding: 3rem 0; }
    
    .mobile-toggle { display: block; }
    .menu {
        display: none;
        flex-direction: column;
        width: 100%;
        background: var(--primary);
        padding: 1rem;
        margin-top: 1rem;
        gap: 1rem;
    }
    .menu.active { display: flex; }
    
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .form-row { grid-template-columns: 1fr; }
    
    .hero h1 { font-size: 2rem; }
    .hero p { font-size: 1rem; }
}

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

.fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-accent { color: var(--accent); }
.bg-light { background: var(--light); }
.bg-primary { background: var(--primary); color: var(--white); }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.p-3 { padding: 1.5rem; }
.rounded { border-radius: 0.5rem; }
.shadow { box-shadow: var(--shadow); }

/* ============================================
   页面通用样式
   ============================================ */

/* Page Hero - 页面顶部区域 */
.page-hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: var(--white);
    padding: 60px 0;
    text-align: center;
}

.page-hero h1 {
    color: var(--white);
    font-size: 42px;
    margin-bottom: 15px;
}

.page-hero p {
    color: rgba(255,255,255,0.9);
    font-size: 18px;
    max-width: 700px;
    margin: 0 auto;
}

/* 响应式 */
@media (max-width: 768px) {
    .page-hero {
        padding: 40px 0;
    }
    .page-hero h1 {
        font-size: 28px;
    }
    .page-hero p {
        font-size: 16px;
    }
}

/* ============================================
   联系页面样式
   ============================================ */

.contact-section {
    padding: 60px 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 40px;
}

.contact-info {
    background: var(--light);
    padding: 30px;
    border-radius: 12px;
}

.contact-info h3 {
    margin-bottom: 20px;
    color: var(--primary);
}

.contact-info p {
    margin: 15px 0;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-light);
}

.contact-info i {
    width: 25px;
    color: var(--accent);
    font-size: 18px;
}

.contact-form input,
.contact-form textarea,
.contact-form select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    margin-bottom: 15px;
    font-family: inherit;
    font-size: 14px;
    transition: all 0.3s ease;
}

.contact-form input:focus,
.contact-form textarea:focus,
.contact-form select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(252, 163, 17, 0.1);
}

.contact-form button {
    width: 100%;
    padding: 12px;
    font-size: 16px;
}

/* 响应式 */
@media (max-width: 768px) {
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
}

/* ============================================
   卡片网格样式
   ============================================ */

.solutions-grid,
.applications-grid,
.projects-grid,
.equipment-grid,
.tech-grid {
    display: grid;
    gap: 30px;
}

.solutions-grid {
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
}

.applications-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

.projects-grid {
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
}

.equipment-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

.tech-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}

/* 卡片样式 */
.card {
    background: var(--white);
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    cursor: pointer;
    text-align: center;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.12);
}

.card-icon {
    font-size: 40px;
    color: var(--accent);
    margin-bottom: 20px;
}

.card h3 {
    font-size: 20px;
    margin-bottom: 15px;
    color: var(--primary);
}

.card p {
    color: var(--muted);
    font-size: 14px;
    line-height: 1.6;
    margin-bottom: 15px;
}

.card a {
    color: var(--accent);
    font-weight: 600;
    font-size: 14px;
    text-decoration: none;
}

.card a:hover {
    text-decoration: underline;
}

/* 应用卡片 */
.app-card {
    background: var(--light);
    padding: 25px 20px;
    border-radius: 12px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.app-card:hover {
    transform: translateY(-3px);
    background: var(--accent);
}

.app-card:hover i,
.app-card:hover h4 {
    color: var(--primary);
}

.app-card i {
    font-size: 32px;
    color: var(--accent);
    margin-bottom: 10px;
    display: block;
}

.app-card h4 {
    font-size: 14px;
    margin: 0;
    color: var(--text);
}

/* 项目卡片 */
.project-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    cursor: pointer;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.12);
}

.project-image {
    height: 180px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-image i {
    font-size: 60px;
    color: var(--accent);
}

.project-content {
    padding: 20px;
}

.project-content h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.project-location {
    color: var(--accent);
    font-size: 13px;
    margin-bottom: 12px;
}

.project-content a {
    color: var(--accent);
    font-weight: 600;
    font-size: 13px;
    text-decoration: none;
}

/* 响应式 */
@media (max-width: 768px) {
    .solutions-grid,
    .projects-grid,
    .equipment-grid,
    .tech-grid {
        grid-template-columns: 1fr;
    }
    .applications-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .applications-grid {
        grid-template-columns: 1fr;
    }
}