/* ========================================
   和川官网 - COS风格设计系统
   HECHUAN Website - COS-inspired Design
   ======================================== */

/* ---------- CSS Variables ---------- */
:root {
    /* Colors - 极简黑白灰 + 石材暖色 */
    --color-black: #000000;
    --color-white: #FFFFFF;
    --color-gray-100: #F7F7F7;
    --color-gray-200: #EBEBEB;
    --color-gray-300: #D4D4D4;
    --color-gray-500: #737373;
    --color-gray-700: #404040;
    --color-stone: #C4B5A6;
    --color-stone-light: #E8E2DB;

    /* Typography */
    --font-sans: 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
    --font-weight-light: 300;
    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;

    /* Spacing */
    --space-xs: 8px;
    --space-sm: 16px;
    --space-md: 24px;
    --space-lg: 48px;
    --space-xl: 80px;
    --space-2xl: 120px;

    /* Layout */
    --max-width: 1400px;
    --header-height: 80px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    font-weight: var(--font-weight-regular);
    line-height: 1.6;
    color: var(--color-black);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a:hover {
    opacity: 0.7;
}

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

button {
    font-family: inherit;
    border: none;
    background: none;
    cursor: pointer;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--space-md);
    }
}

/* ---------- Language Banner ---------- */
.lang-banner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--color-black);
    color: var(--color-white);
    padding: var(--space-xs) var(--space-md);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--space-sm);
    font-size: 12px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    z-index: 1001;
    transform: translateY(-100%);
    transition: transform var(--transition-normal);
}

.lang-banner.visible {
    transform: translateY(0);
}

.lang-switch {
    color: var(--color-white);
    text-decoration: underline;
    font-size: 12px;
    letter-spacing: 0.1em;
}

.close-banner {
    position: absolute;
    right: var(--space-md);
    color: var(--color-white);
    font-size: 18px;
}

/* ---------- Header ---------- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--color-white);
    z-index: 1000;
    transition: box-shadow var(--transition-normal);
}

.header.scrolled {
    box-shadow: 0 1px 0 var(--color-gray-200);
}

.nav {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
}

.logo-cn {
    font-size: 24px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.3em;
}

.logo-en {
    font-size: 10px;
    font-weight: var(--font-weight-regular);
    letter-spacing: 0.4em;
    color: var(--color-gray-500);
}

.nav-links {
    display: flex;
    gap: var(--space-lg);
}

.nav-links a {
    font-size: 13px;
    font-weight: var(--font-weight-regular);
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.lang-toggle {
    font-size: 12px;
    letter-spacing: 0.1em;
    padding: var(--space-xs) var(--space-sm);
    border: 1px solid var(--color-black);
    transition: all var(--transition-fast);
}

.lang-toggle:hover {
    background: var(--color-black);
    color: var(--color-white);
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: var(--space-xs);
}

.menu-toggle span {
    width: 24px;
    height: 1px;
    background: var(--color-black);
    transition: all var(--transition-fast);
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .menu-toggle {
        display: flex;
    }
}

/* ---------- Mobile Menu ---------- */
.mobile-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-white);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.mobile-menu.active {
    opacity: 1;
    visibility: visible;
}

.mobile-menu-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-lg);
}

.mobile-menu-content a {
    font-size: 24px;
    font-weight: var(--font-weight-light);
    letter-spacing: 0.2em;
    text-transform: uppercase;
}

/* ---------- Hero Section ---------- */
.hero {
    height: 100vh;
    min-height: 600px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--space-xl);
    background: linear-gradient(to bottom, var(--color-stone-light), var(--color-white));
    position: relative;
}

.hero-content {
    max-width: 800px;
}

.hero-title {
    font-size: clamp(32px, 6vw, 56px);
    font-weight: var(--font-weight-light);
    letter-spacing: 0.15em;
    line-height: 1.3;
    margin-bottom: var(--space-md);
}

.hero-subtitle {
    font-size: clamp(12px, 1.5vw, 14px);
    font-weight: var(--font-weight-regular);
    letter-spacing: 0.2em;
    color: var(--color-gray-500);
    margin-bottom: var(--space-lg);
}

.hero-cta {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    background: var(--color-black);
    color: var(--color-white);
    font-size: 12px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    transition: all var(--transition-fast);
}

.hero-cta:hover {
    opacity: 1;
    background: var(--color-gray-700);
}

.hero-scroll {
    position: absolute;
    bottom: var(--space-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
}

.hero-scroll span {
    font-size: 10px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-gray-500);
}

.scroll-line {
    width: 1px;
    height: 40px;
    background: var(--color-gray-300);
    animation: scrollPulse 2s infinite;
}

@keyframes scrollPulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.3;
    }
}

/* ---------- Section Common Styles ---------- */
section {
    padding: var(--space-2xl) 0;
}

.section-header {
    margin-bottom: var(--space-xl);
}

.section-label {
    display: block;
    font-size: 11px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-gray-500);
    margin-bottom: var(--space-sm);
}

.section-title {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: var(--font-weight-light);
    letter-spacing: 0.1em;
}

/* ---------- Services Section ---------- */
.services {
    background: var(--color-white);
}

.services-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
}

.service-card {
    position: relative;
    overflow: hidden;
}

.service-featured {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 0;
    background: var(--color-gray-100);
}

.service-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 4/3;
}

.service-featured .service-image {
    aspect-ratio: auto;
    min-height: 400px;
}

.service-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-normal);
}

.service-card:hover .service-image img {
    transform: scale(1.02);
}

.service-content {
    padding: var(--space-lg);
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.service-number {
    font-size: 11px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.2em;
    color: var(--color-gray-500);
    margin-bottom: var(--space-sm);
}

.service-content h3 {
    font-size: 24px;
    font-weight: var(--font-weight-light);
    letter-spacing: 0.1em;
    margin-bottom: var(--space-sm);
}

.service-content p {
    font-size: 14px;
    line-height: 1.8;
    color: var(--color-gray-700);
}

.service-list {
    list-style: none;
    margin-top: var(--space-md);
}

.service-list li {
    font-size: 13px;
    color: var(--color-gray-700);
    padding: var(--space-xs) 0;
    border-bottom: 1px solid var(--color-gray-200);
}

.service-list li:last-child {
    border-bottom: none;
}

.service-badge {
    display: inline-block;
    margin-top: var(--space-sm);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-black);
    color: var(--color-white);
    font-size: 10px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.1em;
}

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

    .service-featured {
        grid-template-columns: 1fr;
    }

    .service-featured .service-image {
        min-height: 300px;
    }
}

/* ---------- Projects Section ---------- */
.projects {
    background: var(--color-gray-100);
}

.projects-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: var(--space-md);
}

.project-card {
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.project-large {
    grid-row: span 2;
}

.project-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 3/4;
}

.project-large .project-image {
    aspect-ratio: auto;
    height: 100%;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-normal);
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-info {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: var(--space-lg);
    background: linear-gradient(to top, rgba(0, 0, 0, 0.8), transparent);
    color: var(--color-white);
}

.project-category {
    font-size: 10px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    opacity: 0.8;
}

.project-info h3 {
    font-size: 20px;
    font-weight: var(--font-weight-light);
    letter-spacing: 0.05em;
    margin: var(--space-xs) 0;
}

.project-info p {
    font-size: 12px;
    opacity: 0.8;
}

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

    .project-large {
        grid-row: span 1;
    }

    .project-image {
        aspect-ratio: 16/9;
    }
}

/* ---------- About Section ---------- */
.about {
    background: var(--color-white);
}

.about-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--space-xl);
    align-items: center;
}

.about-text h2 {
    font-size: clamp(24px, 3vw, 32px);
    font-weight: var(--font-weight-light);
    letter-spacing: 0.1em;
    margin: var(--space-md) 0;
}

.about-text p {
    font-size: 14px;
    line-height: 2;
    color: var(--color-gray-700);
    margin-bottom: var(--space-sm);
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 48px;
    font-weight: var(--font-weight-light);
    line-height: 1;
    margin-bottom: var(--space-xs);
}

.stat-label {
    font-size: 12px;
    letter-spacing: 0.1em;
    color: var(--color-gray-500);
}

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

    .about-stats {
        margin-top: var(--space-lg);
    }
}

/* ---------- Contact Section ---------- */
.contact {
    background: var(--color-black);
    color: var(--color-white);
}

.contact-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: var(--space-xl);
    align-items: center;
}

.contact .section-label {
    color: var(--color-gray-500);
}

.contact h2 {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: var(--font-weight-light);
    letter-spacing: 0.1em;
    margin: var(--space-md) 0;
}

.contact-info>p {
    color: var(--color-gray-300);
    font-size: 14px;
}

.contact-details {
    margin-top: var(--space-lg);
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.contact-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.contact-label {
    font-size: 10px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-gray-500);
}

.contact-item a,
.contact-item p {
    font-size: 16px;
    color: var(--color-white);
}

.contact-cta {
    text-align: right;
}

.btn-primary {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    background: var(--color-white);
    color: var(--color-black);
    font-size: 12px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    transition: all var(--transition-fast);
}

.btn-primary:hover {
    opacity: 1;
    background: var(--color-gray-200);
}

@media (max-width: 768px) {
    .contact-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .contact-details {
        align-items: center;
    }

    .contact-item {
        align-items: center;
    }

    .contact-cta {
        text-align: center;
        margin-top: var(--space-lg);
    }
}

/* ---------- Footer ---------- */
.footer {
    background: var(--color-black);
    color: var(--color-white);
    padding: var(--space-lg) 0;
    border-top: 1px solid var(--color-gray-700);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.footer-brand .logo-cn {
    font-size: 18px;
}

.footer-brand .logo-en {
    font-size: 9px;
    color: var(--color-gray-500);
}

.footer-links {
    display: flex;
    gap: var(--space-lg);
}

.footer-links a {
    font-size: 12px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-gray-300);
}

.footer-copyright {
    text-align: right;
}

.footer-copyright p {
    font-size: 11px;
    color: var(--color-gray-500);
    line-height: 1.6;
}

@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }

    .footer-copyright {
        text-align: center;
    }
}

/* ---------- HCMCC Logo Style ---------- */
.logo-main {
    font-size: 28px;
    font-weight: var(--font-weight-semibold);
    letter-spacing: 0.15em;
}

/* ---------- Hero Label ---------- */
.hero-label {
    font-size: 12px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-gray-500);
    margin-bottom: var(--space-md);
}

/* ---------- 6-Grid Services ---------- */
.services .services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
}

.services .service-card {
    background: var(--color-gray-100);
    padding: var(--space-lg);
    transition: all var(--transition-normal);
}

.services .service-card:hover {
    background: var(--color-stone-light);
}

.services .service-card h3 {
    font-size: 20px;
    font-weight: var(--font-weight-medium);
    margin-bottom: 4px;
}

.services .service-en {
    font-size: 10px;
    letter-spacing: 0.15em;
    color: var(--color-gray-500);
    margin-bottom: var(--space-sm);
}

.services .service-list {
    margin-top: var(--space-sm);
}

.services .service-list li {
    font-size: 13px;
    padding: 6px 0;
}

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

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

/* ---------- Methodology PDCA ---------- */
.methodology {
    background: var(--color-gray-100);
    padding: var(--space-xl) 0;
}

.method-content {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
}

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

.method-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    margin: 0 auto var(--space-sm);
    border: 2px solid var(--color-black);
    border-radius: 50%;
    font-size: 24px;
    font-weight: var(--font-weight-semibold);
}

.method-item h4 {
    font-size: 14px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.1em;
    margin-bottom: 4px;
}

.method-item p {
    font-size: 12px;
    color: var(--color-gray-500);
}

@media (max-width: 768px) {
    .method-content {
        gap: var(--space-md);
    }

    .method-icon {
        width: 48px;
        height: 48px;
        font-size: 18px;
    }
}

/* ---------- Clients Bar ---------- */
.clients-bar {
    margin-top: var(--space-xl);
    text-align: center;
}

.clients-label {
    font-size: 11px;
    font-weight: var(--font-weight-medium);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--color-gray-500);
    margin-bottom: var(--space-md);
}

.clients-logos {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--space-lg);
}

.clients-logos span {
    font-size: 14px;
    font-weight: var(--font-weight-medium);
    color: var(--color-gray-700);
    letter-spacing: 0.05em;
}

/* ---------- About Stats Unit ---------- */
.stat-unit {
    font-size: 24px;
}

/* ---------- Footer Brand Update ---------- */
.footer-brand .logo-main {
    font-size: 20px;
}

.footer-brand p {
    font-size: 10px;
    color: var(--color-gray-500);
    letter-spacing: 0.1em;
    margin-top: 4px;
}

/* ---------- Utility Classes ---------- */
.hidden {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
}