@font-face {
    font-family: 'Söhne';
    src: local('Inter'), local('Helvetica Neue');
    font-weight: 300 500;
}

:root {
    --primary: #1a1a1a;
    --accent: #1e3a5f;
    --bg: #fcfcfa;
    --bg-warm: #f7f6f3;
    --border: #e8e6e1;
    --text: #1a1a1a;
    --text-secondary: #6b6b6b;
    --text-light: #8a8a8a;
}

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

body {
    font-family: 'Söhne', 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.65;
    font-size: 16px;
    font-weight: 400;
}

.lang-zh {
    display: none;
}

body.chinese .lang-en {
    display: none;
}

body.chinese .lang-zh {
    display: block;
}

body.chinese .lang-zh-inline {
    display: inline;
}

body.chinese .lang-en-inline {
    display: none;
}

.lang-en-inline {
    display: inline;
}

.lang-zh-inline {
    display: none;
}

/* Nav */
nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    padding: 1.25rem 4rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(252, 252, 250, 0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
}

.logo {
    font-weight: 500;
    font-size: 0.9rem;
    letter-spacing: 0.08em;
    color: var(--primary);
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 2.5rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    font-size: 0.9rem;
    font-weight: 400;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--text);
}

.lang-toggle {
    font-size: 0.8rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.4rem 0.9rem;
    border: 1px solid var(--border);
    border-radius: 20px;
    background: transparent;
    transition: all 0.2s;
}

.lang-toggle:hover {
    border-color: var(--text);
    color: var(--text);
}

/* Hero */
.hero {
    padding: 12rem 4rem 6rem;
    max-width: 800px;
    position: relative;
}

.hero::after {
    content: '';
    position: absolute;
    right: -3rem;
    top: 8rem;
    width: 500px;
    height: 400px;
    background-image: url('assets/waves1.png');
    background-size: contain;
    background-repeat: no-repeat;
    opacity: 0.3;
    pointer-events: none;
    z-index: -1;
}

.hero h1 {
    font-family: 'Instrument Serif', Georgia, serif;
    font-size: 3.5rem;
    font-weight: 400;
    margin-bottom: 1.5rem;
    line-height: 1.15;
    letter-spacing: -0.02em;
}

.hero h1 em {
    font-style: italic;
}

.hero-desc {
    font-size: 1.15rem;
    font-weight: 300;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    max-width: 560px;
    line-height: 1.75;
}

.hero-cta {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.9rem 1.6rem;
    background: var(--primary);
    color: white;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 400;
    letter-spacing: 0.02em;
    transition: all 0.3s;
}

.hero-cta:hover {
    background: var(--accent);
}

.hero-cta svg {
    width: 16px;
    height: 16px;
    transition: transform 0.3s;
}

.hero-cta:hover svg {
    transform: translateX(3px);
}

/* Analysis Section */
.analysis {
    padding: 6rem 4rem;
    background: var(--bg-warm);
}

.analysis-header {
    max-width: 600px;
    margin-bottom: 4rem;
}

.section-label {
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.15em;
    color: var(--text-light);
    margin-bottom: 1rem;
    text-transform: uppercase;
}

.analysis-header h2 {
    font-family: 'Instrument Serif', Georgia, serif;
    font-size: 2.25rem;
    font-weight: 400;
    letter-spacing: -0.01em;
    margin-bottom: 1rem;
}

.analysis-header p {
    font-size: 1.05rem;
    font-weight: 300;
    color: var(--text-secondary);
    line-height: 1.7;
}

.analysis-flow {
    display: grid;
    grid-template-columns: 1fr 200px 1fr;
    gap: 0;
    align-items: center;
}

.input-modules {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.module {
    background: white;
    border: 1px solid var(--border);
    padding: 1.75rem;
    transition: all 0.3s;
}

.module:hover {
    border-color: var(--accent);
}

.module-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1rem;
}

.module-icon {
    width: 40px;
    height: 40px;
    background: var(--bg-warm);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.module-icon svg {
    width: 20px;
    height: 20px;
    color: var(--accent);
}

.module h3 {
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.module p {
    font-size: 0.9rem;
    font-weight: 300;
    color: var(--text-secondary);
    line-height: 1.6;
}

.module-image {
    width: 100%;
    height: 120px;
    background: var(--bg-warm);
    border: 1px dashed var(--border);
    margin-top: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 0.8rem;
    overflow: hidden;
}

.module-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.output-module {
    background: var(--primary);
    color: white;
    padding: 2.5rem;
    height: fit-content;
    margin: 0;
    align-self: center;
}

.output-module .module-icon {
    background: rgba(255, 255, 255, 0.1);
}

.output-module .module-icon svg {
    color: white;
}

.output-module h3 {
    color: white;
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.output-module p {
    color: rgba(255, 255, 255, 0.75);
    font-size: 0.95rem;
    line-height: 1.7;
}

.output-module .module-image {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.15);
    color: rgba(255, 255, 255, 0.4);
    overflow: hidden;
}

.output-module .module-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* Value Prop */
.value {
    padding: 6rem 4rem;
    text-align: center;
}

.value-content {
    max-width: 700px;
    margin: 0 auto;
}

.value h2 {
    font-family: 'Instrument Serif', Georgia, serif;
    font-size: 2rem;
    font-weight: 400;
    margin-bottom: 1.25rem;
}

.value p {
    font-size: 1.1rem;
    font-weight: 300;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* About */
.about {
    padding: 6rem 4rem;
    background: var(--bg-warm);
    border-top: 1px solid var(--border);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    max-width: 1000px;
}

.about-text h2 {
    font-family: 'Instrument Serif', Georgia, serif;
    font-size: 2rem;
    font-weight: 400;
    margin-bottom: 1rem;
}

.about-text p {
    font-size: 1rem;
    font-weight: 300;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.about-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.85rem;
    font-weight: 400;
    padding: 0.6rem 1rem;
    background: white;
    border: 1px solid var(--border);
}

.about-badge svg {
    width: 18px;
    height: 18px;
    color: var(--accent);
}

.about-image {
    height: 250px;
    background: var(--bg-warm);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 0.85rem;
    overflow: hidden;
}

.about-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* Logos Banner */
.logos-banner {
    padding: 4rem 4rem;
    background: var(--bg);
    text-align: center;
}

.logos-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 4rem;
    margin-top: 0rem;
}

.logo-item {
    opacity: 0.6;
    transition: opacity 0.3s;
}

.logo-item:hover {
    opacity: 1;
}

.logo-item img {
    height: 40px;
    width: auto;
    max-width: 200px;
    object-fit: contain;
    filter: grayscale(100%);
    transition: filter 0.3s;
}

.logo-item:hover img {
    filter: grayscale(0%);
}

/* Contact */
.contact {
    padding: 8rem 4rem;
    background: var(--primary);
    color: white;
}

.contact-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6rem;
    max-width: 1000px;
}

.contact-text h2 {
    font-family: 'Instrument Serif', Georgia, serif;
    font-size: 2rem;
    font-weight: 400;
    margin-bottom: 1rem;
}

.contact-text p {
    font-size: 1rem;
    font-weight: 300;
    opacity: 0.7;
    line-height: 1.7;
}

.contact-details {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.contact-item {
    margin-bottom: 2rem;
}

.contact-item h4 {
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    opacity: 0.5;
    margin-bottom: 0.75rem;
}

.contact-item p {
    font-size: 0.95rem;
    font-weight: 300;
    opacity: 0.85;
    line-height: 1.8;
}

.contact-item a {
    color: white;
    text-decoration: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    transition: all 0.2s;
}

.contact-item a:hover {
    opacity: 1;
    border-bottom-color: white;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

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

.form-group label {
    display: block;
    font-size: 0.75rem;
    letter-spacing: 0.08em;
    margin-bottom: 0.5rem;
    opacity: 0.5;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.85rem 1rem;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: white;
    font-family: inherit;
    font-size: 0.95rem;
    font-weight: 300;
    transition: all 0.2s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.4);
    background: rgba(255, 255, 255, 0.1);
}

.form-group select option {
    background: var(--primary);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.submit-btn {
    padding: 0.9rem 2rem;
    background: white;
    color: var(--primary);
    border: none;
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    cursor: pointer;
    transition: all 0.3s;
    align-self: flex-start;
}

.submit-btn:hover {
    background: var(--bg-warm);
}

/* Footer */
footer {
    padding: 1.5rem 4rem;
    background: var(--primary);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-logo {
    font-size: 0.8rem;
    font-weight: 500;
    letter-spacing: 0.08em;
    color: white;
    opacity: 0.5;
}

.footer-text {
    font-size: 0.8rem;
    color: white;
    opacity: 0.35;
}

/* Responsive */
@media (max-width: 968px) {
    nav {
        padding: 1rem 2rem;
    }

    .hero::after {
        display: none;
    }

    .hero {
        padding: 9rem 2rem 5rem;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .analysis,
    .value,
    .about,
    .contact {
        padding: 4rem 2rem;
    }

    .analysis-flow {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .flow-connector {
        display: none;
    }

    .output-module {
        margin-top: 0;
    }

    .module-image {
        display: none;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .about-image {
        display: none;
    }

    .contact-layout {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }

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

    .nav-links {
        display: none;
    }

    .logos-banner {
        padding: 3rem 2rem;
    }

    .logos-container {
        gap: 2rem;
    }

    .logo-item img {
        height: 30px;
        max-width: 150px;
    }

    footer {
        padding: 1.5rem 2rem;
        flex-direction: column;
        gap: 0.5rem;
    }
}