/*
 * Enhanced Xiaomi Style Theme - Beijing Hongsheng
 * Clean, Professional, High-contrast, Rich Layouts
 */

:root {
    --primary-color: #ff6700;
    --primary-hover: #f56600;
    --text-main: #333333;
    --text-secondary: #757575;
    --text-muted: #b0b0b0;
    --bg-light: #f5f5f5;
    --bg-dark: #1c1c1c;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow-sm: 0 2px 10px rgba(0,0,0,0.05);
    --shadow-md: 0 8px 20px rgba(0,0,0,0.08);
    --shadow-lg: 0 15px 30px rgba(0,0,0,0.12);
    --transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Inter", "Helvetica Neue", Helvetica, Arial, "Microsoft Yahei", sans-serif;
    line-height: 1.6;
    color: var(--text-main);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

.container {
    max-width: 1226px;
    margin: 0 auto;
    padding: 0 20px;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    display: block;
}

/* --- Typography --- */
h1, h2, h3, h4 {
    font-weight: 600;
    line-height: 1.2;
}

.section-title {
    text-align: center;
    font-size: 36px;
    margin-bottom: 20px;
    position: relative;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 18px;
    max-width: 700px;
    margin: 0 auto 60px;
}

/* --- Header & Nav --- */
header {
    height: 80px;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    transition: var(--transition);
}

header.scrolled {
    height: 70px;
    box-shadow: var(--shadow-sm);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo img {
    height: 36px;
}

nav.desktop-nav ul {
    display: flex;
    gap: 40px;
}

nav.desktop-nav a {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-main);
}

nav.desktop-nav a:hover, nav.desktop-nav a.active {
    color: var(--primary-color);
}

/* --- Hero Section --- */
.hero {
    padding: 120px 0;
    background: linear-gradient(135deg, #f9f9f9 0%, #eeeeee 100%);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -50px;
    left: 50%;
    transform: translateX(-50%);
    width: 120%;
    height: 100px;
    background: var(--white);
    border-radius: 50%;
}

.hero h1 {
    font-size: 56px;
    margin-bottom: 24px;
    letter-spacing: -1px;
}

.hero p {
    font-size: 22px;
    color: var(--text-secondary);
    margin-bottom: 48px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

/* --- Buttons --- */
.btn {
    display: inline-block;
    padding: 16px 48px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    text-align: center;
    border-radius: 2px;
    transition: var(--transition);
}

.btn.primary {
    background-color: var(--primary-color);
    color: var(--white);
    border: 1px solid var(--primary-color);
}

.btn.primary:hover {
    background-color: var(--primary-hover);
    box-shadow: 0 4px 15px rgba(255, 103, 0, 0.3);
}

.btn.secondary {
    background-color: transparent;
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.btn.secondary:hover {
    background-color: var(--bg-light);
    border-color: var(--text-secondary);
}

/* --- Content Sections --- */
section {
    padding: 100px 0;
}

.bg-light { background-color: var(--bg-light); }
.bg-dark {
    background-color: var(--bg-dark);
    color: var(--white);
}
.bg-dark .section-subtitle { color: var(--text-muted); }

/* --- Service Grid --- */
.service-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.service-card {
    background: var(--white);
    padding: 60px 40px;
    text-align: center;
    border-radius: 0;
    border: 1px solid transparent;
    transition: var(--transition);
}

.service-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-10px);
}

.service-icon img {
    height: 80px;
    margin: 0 auto 40px;
}

.service-card h3 {
    font-size: 24px;
    margin-bottom: 20px;
}

.service-card p {
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.8;
}

/* --- Features Grid --- */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.feature-item {
    text-align: center;
    padding: 40px 20px;
    transition: var(--transition);
}

.feature-item:hover {
    transform: scale(1.05);
}

.feature-icon img {
    height: 60px;
    margin: 0 auto 24px;
}

.feature-item h3 {
    font-size: 18px;
    margin-bottom: 12px;
}

.feature-item p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* --- Stats Section --- */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
    display: block;
}

.stat-label {
    font-size: 16px;
    color: var(--text-muted);
}

/* --- Process Section --- */
.process-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    position: relative;
}

.process-grid::before {
    content: '';
    position: absolute;
    top: 50px;
    left: 10%;
    right: 10%;
    height: 2px;
    background: var(--border-color);
    z-index: 0;
}

.process-item {
    text-align: center;
    position: relative;
    z-index: 1;
}

.process-step {
    width: 60px;
    height: 60px;
    background: var(--white);
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 700;
    margin: 0 auto 24px;
}

.process-item h3 {
    font-size: 20px;
    margin-bottom: 12px;
}

/* --- Leadership Grid --- */
.leadership-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.team-member {
    background: var(--white);
    padding: 30px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.team-member:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
    transform: translateY(-5px);
}

.member-photo img {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    margin: 0 auto 20px;
    border: 3px solid var(--bg-light);
}

.member-info h3 {
    font-size: 18px;
    margin-bottom: 8px;
}

.member-title {
    display: block;
    font-size: 13px;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 12px;
    text-transform: uppercase;
}

.member-info p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* --- Footer --- */
footer {
    background: #fcfcfc;
    padding: 80px 0 40px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    margin-bottom: 60px;
}

.footer-info {
    max-width: 400px;
}

.footer-info p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 10px;
}

.footer-links {
    display: flex;
    gap: 100px;
}

.footer-column h4 {
    font-size: 14px;
    margin-bottom: 30px;
    color: var(--text-main);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-column ul li {
    margin-bottom: 15px;
}

.footer-column a {
    font-size: 14px;
    color: var(--text-secondary);
}

.footer-column a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 40px;
    text-align: center;
    color: var(--text-muted);
    font-size: 13px;
}

.footer-bottom p {
    margin-bottom: 10px;
}

/* --- Mobile Nav --- */
.mobile-menu-button {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
}

.mobile-menu-button span {
    width: 100%;
    height: 2px;
    background-color: var(--text-main);
    transition: var(--transition);
}

.mobile-nav {
    display: none;
    position: fixed;
    top: 80px;
    left: 0;
    width: 100%;
    height: calc(100vh - 80px);
    background: var(--white);
    z-index: 999;
    padding: 40px 20px;
    overflow-y: auto;
}

.mobile-nav.active {
    display: block;
}

.mobile-nav ul li {
    margin-bottom: 30px;
    text-align: center;
}

.mobile-nav a {
    font-size: 24px;
    font-weight: 500;
}

/* --- Responsive --- */
@media (max-width: 1100px) {
    .hero h1 { font-size: 42px; }
    .service-grid { grid-template-columns: repeat(2, 1fr); }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .leadership-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-links { gap: 50px; }
    .contact-grid { grid-template-columns: 1fr; }
    .contact-form-card { padding: 32px; }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    header { height: 60px; }
    .mobile-menu-button { display: flex; }
    .desktop-nav { display: none; }
    .hero { padding: 80px 0; }
    .hero h1 { font-size: 32px; }
    .hero p { font-size: 16px; }
    .hero-buttons { flex-direction: column; }
    .service-grid, .feature-grid, .stats-grid, .process-grid, .leadership-grid { grid-template-columns: 1fr; }
    .process-grid::before { display: none; }
    .footer-content { flex-direction: column; gap: 40px; }
    .contact-title { font-size: 28px; }
    .contact-card { flex-direction: column; text-align: center; }
    .contact-icon { margin: 0 auto 16px; }
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
    .terms-item h2 { font-size: 24px; }
}

/* --- Additional Sections (Rich Content) --- */
.tag-container {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 20px;
}

.tag {
    padding: 6px 16px;
    background: var(--bg-light);
    color: var(--text-secondary);
    font-size: 13px;
    border-radius: 20px;
    transition: var(--transition);
}

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

.card-rich {
    background: var(--white);
    padding: 50px;
    border: 1px solid var(--border-color);
    margin-bottom: 40px;
}

.card-rich h3 {
    font-size: 28px;
    margin-bottom: 24px;
    color: var(--primary-color);
}

.back-to-top {
    position: fixed;
    right: 30px;
    bottom: 30px;
    width: 44px;
    height: 44px;
    background: var(--white);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    display: none;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    z-index: 1000;
    font-size: 20px;
    transition: var(--transition);
}

.back-to-top:hover {
    background: var(--primary-color);
    color: var(--white);
    border-color: var(--primary-color);
    transform: translateY(-5px);
}

/* --- Terms of Service Section --- */
.terms-section {
    padding: 80px 0;
}

.terms-content {
    max-width: 900px;
    margin: 0 auto;
    line-height: 1.8;
}

.terms-item {
    margin-bottom: 60px;
}

.terms-item h2 {
    font-size: 28px;
    margin-bottom: 24px;
    color: var(--text-main);
    position: relative;
    padding-bottom: 12px;
}

.terms-item h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--primary-color);
}

.terms-subsection {
    margin-bottom: 24px;
    padding-left: 20px;
    border-left: 2px solid var(--border-color);
}

.terms-subsection h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--primary-color);
}

.terms-subsection p {
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* Grid Layouts */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-top: 24px;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 24px;
}

.card {
    background: var(--white);
    padding: 24px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--primary-color);
}

.card p {
    color: var(--text-secondary);
    margin-bottom: 0;
    font-size: 14px;
    line-height: 1.6;
}

/* Responsive Design */
@media (max-width: 1100px) {
    .hero h1 { font-size: 42px; }
    .service-grid { grid-template-columns: repeat(2, 1fr); }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .leadership-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-links { gap: 50px; }
    .contact-grid { grid-template-columns: 1fr; }
    .contact-form-card { padding: 32px; }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    header { height: 60px; }
    .mobile-menu-button { display: flex; }
    .desktop-nav { display: none; }
    .hero { padding: 80px 0; }
    .hero h1 { font-size: 32px; }
    .hero p { font-size: 16px; }
    .hero-buttons { flex-direction: column; }
    .service-grid, .feature-grid, .stats-grid, .process-grid, .leadership-grid { grid-template-columns: 1fr; }
    .process-grid::before { display: none; }
    .footer-content { flex-direction: column; gap: 40px; }
    .contact-title { font-size: 28px; }
    .contact-card { flex-direction: column; text-align: center; }
    .contact-icon { margin: 0 auto 16px; }
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
    .terms-item h2 { font-size: 24px; }
}

/* --- Data Dashboard & Charts --- */
.data-dashboard {
    padding: 80px 0;
    background-color: var(--bg-light);
}

.chart-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin-top: 40px;
}

.chart-card {
    background: var(--white);
    padding: 30px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.chart-card:hover {
    box-shadow: var(--shadow-md);
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.chart-header h3 {
    font-size: 18px;
    color: var(--text-main);
}

.chart-badge {
    font-size: 12px;
    background: #f0f0f0;
    padding: 4px 10px;
    border-radius: 12px;
    color: var(--text-secondary);
}

/* Progress Bar Stats */
.progress-stat {
    margin-bottom: 20px;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 14px;
}

.progress-bg {
    height: 8px;
    background: var(--bg-light);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary-color);
    border-radius: 4px;
    transition: width 1.5s cubic-bezier(0.1, 0, 0.2, 1);
}

/* Simple Bar Chart */
.bar-chart {
    display: flex;
    align-items: flex-end;
    justify-content: space-around;
    height: 180px;
    padding-top: 20px;
    border-bottom: 2px solid var(--border-color);
}

.bar-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 40px;
}

.bar-item {
    width: 100%;
    background: var(--primary-color);
    position: relative;
    border-radius: 2px 2px 0 0;
    transition: height 1s ease-out;
}

.bar-item:hover {
    filter: brightness(1.1);
}

.bar-item::before {
    content: attr(data-value);
    position: absolute;
    top: -25px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 600;
}

.bar-label {
    margin-top: 10px;
    font-size: 12px;
    color: var(--text-muted);
}

@media (max-width: 768px) {
    .chart-grid {
        grid-template-columns: 1fr;
    }
}