:root {
    --black: #1a1a1a;
    --white: #ffffff;
    --gray-100: #f5f5f5;
    --gray-200: #e5e5e5;
    --gray-300: #d4d4d4;
    --gray-400: #a3a3a3;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --accent: #c8a46d;
    --accent-light: #dfc294;
    --font-zh: 'Noto Sans SC', -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --font-en: 'Inter', -apple-system, sans-serif;
    --max-w: 1200px;
    --header-h: 72px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-zh);
    color: var(--gray-800);
    background: var(--white);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 24px;
}

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    height: var(--header-h);
    background: transparent;
    transition: background 0.35s ease, box-shadow 0.35s ease;
}

.site-header.scrolled {
    background: rgba(255,255,255,0.95);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    box-shadow: 0 1px 0 var(--gray-200);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-h);
}

.logo a {
    display: flex;
    flex-direction: column;
    text-decoration: none;
    line-height: 1.2;
}

.logo-zh {
    font-size: 20px;
    font-weight: 700;
    color: var(--white);
    transition: color 0.3s;
}

.scrolled .logo-zh {
    color: var(--black);
}

.logo-en {
    font-family: var(--font-en);
    font-size: 11px;
    font-weight: 400;
    letter-spacing: 0.08em;
    color: rgba(255,255,255,0.6);
    text-transform: uppercase;
    transition: color 0.3s;
}

.scrolled .logo-en {
    color: var(--gray-400);
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: 36px;
}

.main-nav a {
    font-size: 14px;
    font-weight: 500;
    color: rgba(255,255,255,0.85);
    text-decoration: none;
    letter-spacing: 0.02em;
    padding: 4px 0;
    position: relative;
    transition: color 0.3s;
}

.scrolled .main-nav a {
    color: var(--gray-600);
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width 0.3s;
}

.main-nav a:hover::after,
.main-nav a.active::after {
    width: 100%;
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--white);
}

.scrolled .main-nav a:hover,
.scrolled .main-nav a.active {
    color: var(--black);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    flex-direction: column;
    gap: 5px;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 1.5px;
    background: var(--white);
    transition: all 0.3s;
    border-radius: 1px;
}

.scrolled .menu-toggle span {
    background: var(--black);
}

.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero-image {
    position: absolute;
    inset: 0;
    background: var(--gray-800);
}

.hero-image::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        linear-gradient(135deg, #2c2c2c 0%, #1a1a1a 30%, #333 50%, #1a1a1a 70%, #2c2c2c 100%);
    opacity: 0.6;
}

.hero-image::after {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 70% 40%, rgba(200,164,109,0.08) 0%, transparent 60%),
        linear-gradient(180deg, transparent 40%, rgba(0,0,0,0.4) 100%);
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: repeating-linear-gradient(
        90deg,
        transparent 0px,
        transparent 120px,
        rgba(255,255,255,0.02) 120px,
        rgba(255,255,255,0.02) 121px
    );
}

.hero-content {
    position: relative;
    z-index: 2;
}

.hero-title {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.hero-line {
    font-size: clamp(40px, 7vw, 80px);
    font-weight: 300;
    letter-spacing: 0.04em;
    color: var(--white);
    line-height: 1.1;
}

.hero-line.accent {
    font-weight: 700;
    color: var(--accent);
    font-size: clamp(48px, 8vw, 96px);
}

.hero-subtitle {
    margin-top: 24px;
    font-family: var(--font-en);
    font-size: 14px;
    letter-spacing: 0.15em;
    color: rgba(255,255,255,0.5);
    text-transform: uppercase;
}

.section {
    padding: 100px 0;
}

.section-header {
    margin-bottom: 60px;
    max-width: 480px;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--black);
    margin-bottom: 12px;
    letter-spacing: 0.01em;
}

.section-desc {
    font-size: 15px;
    color: var(--gray-400);
    font-weight: 400;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2px;
    background: var(--gray-200);
}

.project-card {
    position: relative;
    background: var(--white);
    padding: 60px 40px;
    cursor: pointer;
    transition: background 0.3s;
    overflow: hidden;
}

.project-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gray-100);
    opacity: 0;
    transition: opacity 0.4s;
}

.project-card:hover::before {
    opacity: 1;
}

.project-card > * {
    position: relative;
    z-index: 1;
}

.project-number {
    font-family: var(--font-en);
    font-size: 12px;
    color: var(--gray-400);
    letter-spacing: 0.1em;
    margin-bottom: 16px;
    display: block;
}

.project-card h3 {
    font-size: 22px;
    font-weight: 500;
    color: var(--black);
    margin-bottom: 8px;
}

.project-type {
    font-size: 13px;
    color: var(--gray-400);
    margin-bottom: 20px;
}

.project-desc {
    font-size: 14px;
    color: var(--gray-500);
    line-height: 1.8;
    max-width: 340px;
}

.project-card .project-thumb {
    width: 100%;
    height: 200px;
    margin-bottom: 20px;
    background: var(--gray-100);
    border-radius: 4px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-card .project-thumb svg {
    width: 48px;
    height: 48px;
    color: var(--gray-300);
}

.about-section {
    background: var(--gray-100);
}

.about-content {
    max-width: 720px;
}

.about-text p {
    font-size: 15px;
    color: var(--gray-600);
    line-height: 2;
    margin-bottom: 16px;
}

.about-intro {
    font-size: 18px !important;
    color: var(--black) !important;
    font-weight: 500;
    line-height: 1.9 !important;
}

.stats {
    display: flex;
    gap: 60px;
    margin-top: 48px;
    padding-top: 40px;
    border-top: 1px solid var(--gray-200);
}

.stat-number {
    font-family: var(--font-en);
    font-size: 40px;
    font-weight: 300;
    color: var(--accent);
    display: block;
    line-height: 1;
    margin-bottom: 6px;
}

.stat-label {
    font-size: 13px;
    color: var(--gray-400);
}

.philosophy-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.philosophy-card {
    padding: 40px;
    background: var(--gray-100);
    border-radius: 4px;
    transition: background 0.3s, transform 0.3s;
}

.philosophy-card:hover {
    background: var(--black);
    transform: translateY(-4px);
}

.philosophy-card:hover h3,
.philosophy-card:hover p {
    color: var(--white);
}

.philosophy-card:hover .ph-icon {
    color: var(--accent);
}

.ph-icon {
    width: 48px;
    height: 48px;
    color: var(--gray-300);
    margin-bottom: 24px;
    transition: color 0.3s;
}

.ph-icon svg {
    width: 100%;
    height: 100%;
}

.philosophy-card h3 {
    font-size: 18px;
    font-weight: 500;
    color: var(--black);
    margin-bottom: 12px;
    transition: color 0.3s;
}

.philosophy-card p {
    font-size: 14px;
    color: var(--gray-500);
    line-height: 1.8;
    transition: color 0.3s;
}

.contact-section {
    background: var(--white);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
}

.contact-item {
    margin-bottom: 28px;
}

.contact-label {
    font-size: 12px;
    font-weight: 500;
    color: var(--gray-400);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    display: block;
    margin-bottom: 4px;
}

.contact-item p,
.contact-item a {
    font-size: 15px;
    color: var(--gray-700);
    text-decoration: none;
}

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

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--gray-200);
    border-radius: 4px;
    font-family: var(--font-zh);
    font-size: 14px;
    background: var(--white);
    color: var(--gray-800);
    transition: border-color 0.3s;
    outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--gray-400);
}

.btn {
    padding: 14px 40px;
    font-family: var(--font-zh);
    font-size: 14px;
    font-weight: 500;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s;
}

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

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

.site-footer {
    padding: 48px 0;
    background: var(--black);
}

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

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

.footer-brand .logo-zh {
    font-size: 16px;
    color: var(--white);
}

.footer-brand .logo-en {
    font-size: 10px;
    color: var(--gray-500);
}

.footer-copy {
    font-size: 13px;
    color: var(--gray-500);
}

@media (max-width: 768px) {
    .main-nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--white);
        padding: 80px 40px 40px;
        transition: right 0.35s ease;
        box-shadow: -4px 0 20px rgba(0,0,0,0.08);
    }

    .main-nav.open {
        right: 0;
    }

    .main-nav ul {
        flex-direction: column;
        gap: 24px;
    }

    .main-nav a {
        font-size: 18px;
        color: var(--black) !important;
    }

    .menu-toggle {
        display: flex;
    }

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

    .philosophy-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .stats {
        gap: 32px;
    }

    .section {
        padding: 60px 0;
    }

    .project-card {
        padding: 36px 24px;
    }

    .hero-line.accent {
        font-size: clamp(36px, 10vw, 56px);
    }

    .hero-line {
        font-size: clamp(28px, 7vw, 40px);
    }
}

.project-card,
.philosophy-card {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 0.6s ease forwards;
}

.project-card:nth-child(1) { animation-delay: 0.05s; }
.project-card:nth-child(2) { animation-delay: 0.1s; }
.project-card:nth-child(3) { animation-delay: 0.15s; }
.project-card:nth-child(4) { animation-delay: 0.2s; }

.philosophy-card:nth-child(1) { animation-delay: 0.1s; }
.philosophy-card:nth-child(2) { animation-delay: 0.2s; }
.philosophy-card:nth-child(3) { animation-delay: 0.3s; }

@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.animate-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.form-success {
    padding: 16px;
    background: rgba(200,164,109,0.1);
    color: var(--accent);
    border-radius: 4px;
    font-size: 14px;
    text-align: center;
    display: none;
}
.form-success.show {
    display: block;
}