/* =========================================
   基础设置
========================================= */

:root {

    --background: #f7f7f5;
    --surface: #ffffff;
    --surface-soft: #f1f1ef;

    --text-primary: #242424;
    --text-secondary: #606060;
    --text-tertiary: #8a8a8a;

    --border: #dededb;
    --border-light: #e8e8e5;

    --accent: #0067c0;

    --max-width: 1200px;

    --radius-small: 8px;
    --radius-medium: 14px;
    --radius-large: 22px;

    --transition-fast: 180ms ease;
    --transition-normal: 320ms ease;
}


/* =========================================
   Reset
========================================= */

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


html {
    scroll-behavior: smooth;
}


body {

    background: var(--background);

    color: var(--text-primary);

    font-family:
        "Segoe UI",
        "Microsoft YaHei",
        "PingFang SC",
        Arial,
        sans-serif;

    line-height: 1.7;

    -webkit-font-smoothing: antialiased;
}


button,
a {
    font-family: inherit;
}


button {
    border: 0;
}


a {
    color: inherit;
    text-decoration: none;
}


/* =========================================
   Header
========================================= */

.site-header {

    position: fixed;

    top: 0;
    left: 0;

    width: 100%;

    z-index: 1000;

    background: rgba(247, 247, 245, 0.88);

    border-bottom: 1px solid var(--border-light);

    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
}


.navbar {

    width: min(
        calc(100% - 48px),
        var(--max-width)
    );

    height: 64px;

    margin: auto;

    display: flex;

    align-items: center;

    justify-content: space-between;
}


/* =========================================
   Brand
========================================= */

.brand {

    display: flex;

    align-items: center;

    gap: 10px;

    font-weight: 600;

    letter-spacing: -0.02em;
}


.brand-mark {

    width: 32px;
    height: 32px;

    display: flex;

    align-items: center;
    justify-content: center;

    border-radius: 9px;

    background: var(--text-primary);

    color: white;

    font-size: 15px;

    font-weight: 600;
}


.brand-name {
    font-size: 15px;
}


/* =========================================
   Navigation
========================================= */

.nav-links {

    display: flex;

    align-items: center;

    gap: 4px;
}


.nav-link {

    position: relative;

    padding: 7px 15px;

    border-radius: 8px;

    color: var(--text-secondary);

    font-size: 14px;

    transition:
        background var(--transition-fast),
        color var(--transition-fast);
}


.nav-link:hover {

    background: var(--surface-soft);

    color: var(--text-primary);
}


.nav-link.active {

    background: var(--surface);

    color: var(--text-primary);
}


/* =========================================
   Mobile Menu
========================================= */

.mobile-menu-button {

    display: none;

    width: 40px;
    height: 40px;

    background: transparent;

    cursor: pointer;
}


.mobile-menu-button span {

    display: block;

    width: 20px;
    height: 1.5px;

    margin: 5px auto;

    background: var(--text-primary);

    transition: transform var(--transition-normal);
}


.mobile-nav {

    display: none;

    border-top: 1px solid var(--border-light);

    background: var(--background);

    padding: 8px 24px 16px;
}


.mobile-nav a {

    display: block;

    padding: 12px 0;

    border-bottom: 1px solid var(--border-light);

    color: var(--text-secondary);
}


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


/* =========================================
   Main
========================================= */

.page-container {

    padding-top: 64px;

    min-height: calc(100vh - 64px);
}


.page-section {

    display: none;

    min-height: calc(100vh - 64px);

    animation: pageEnter 420ms ease both;
}


.page-section.active {
    display: block;
}


@keyframes pageEnter {

    from {

        opacity: 0;

        transform: translateY(18px);

    }

    to {

        opacity: 1;

        transform: translateY(0);

    }

}


/* =========================================
   Hero
========================================= */

.hero {

    width: min(
        calc(100% - 48px),
        var(--max-width)
    );

    min-height: calc(100vh - 64px);

    margin: auto;

    display: grid;

    grid-template-columns:
        minmax(0, 1.4fr)
        minmax(280px, 0.6fr);

    align-items: center;

    gap: 80px;
}


.eyebrow {

    margin-bottom: 12px;

    color: var(--text-tertiary);

    font-size: 12px;

    font-weight: 600;

    letter-spacing: 0.12em;
}


.hero-title {

    max-width: 850px;

    font-size: clamp(
        48px,
        7vw,
        88px
    );

    line-height: 1.05;

    letter-spacing: -0.055em;

    font-weight: 650;
}


.hero-title span {
    display: block;
}


.hero-description {

    max-width: 620px;

    margin-top: 28px;

    color: var(--text-secondary);

    font-size: 20px;

    line-height: 1.7;
}


.hero-actions {

    display: flex;

    align-items: center;

    gap: 12px;

    margin-top: 36px;
}


/* =========================================
   Buttons
========================================= */

.primary-button,
.secondary-button {

    min-height: 44px;

    padding: 0 20px;

    border-radius: 9px;

    cursor: pointer;

    font-size: 14px;

    transition:
        background var(--transition-fast),
        border-color var(--transition-fast),
        color var(--transition-fast),
        transform var(--transition-fast);
}


.primary-button {

    background: var(--text-primary);

    color: white;
}


.primary-button:hover {

    background: #3a3a3a;

    transform: translateY(-1px);
}


.secondary-button {

    background: transparent;

    color: var(--text-primary);

    border: 1px solid var(--border);
}


.secondary-button:hover {

    background: var(--surface);

    border-color: #c8c8c4;
}


/* =========================================
   Avatar
========================================= */

.hero-avatar-wrapper {

    display: flex;

    justify-content: center;
}


.avatar-ring {

    width: min(
        360px,
        75vw
    );

    aspect-ratio: 1;

    padding: 12px;

    border: 1px solid var(--border);

    border-radius: 50%;

    background: var(--surface);
}


.avatar {

    width: 100%;
    height: 100%;

    display: block;

    object-fit: cover;

    border-radius: 50%;
}


/* =========================================
   Sections
========================================= */

.section-block {

    width: min(
        calc(100% - 48px),
        var(--max-width)
    );

    margin: 0 auto;

    padding: 120px 0;
}


.section-heading {

    max-width: 620px;

    margin-bottom: 60px;
}


.section-heading h2 {

    font-size: clamp(
        36px,
        5vw,
        58px
    );

    line-height: 1.15;

    letter-spacing: -0.045em;
}


.introduction-content {

    max-width: 760px;

    margin-left: auto;
}


.introduction-content p {

    margin-bottom: 24px;

    color: var(--text-secondary);

    font-size: 18px;
}


/* =========================================
   Feature Cards
========================================= */

.feature-grid {

    display: grid;

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

    gap: 1px;

    padding-top: 0;
}


.feature-card {

    min-height: 260px;

    padding: 32px;

    background: var(--surface);

    border: 1px solid var(--border-light);
}


.feature-number {

    display: block;

    margin-bottom: 60px;

    color: var(--text-tertiary);

    font-size: 13px;
}


.feature-card h3 {

    margin-bottom: 12px;

    font-size: 22px;

    font-weight: 600;
}


.feature-card p {

    color: var(--text-secondary);

    font-size: 15px;
}


/* =========================================
   Inner Pages
========================================= */

.inner-page,
.contact-page {

    width: min(
        calc(100% - 48px),
        var(--max-width)
    );

    margin: auto;

    padding: 100px 0;
}


.page-title {

    max-width: 800px;

    padding: 80px 0;
}


.page-title h1 {

    font-size: clamp(
        52px,
        8vw,
        88px
    );

    line-height: 1;

    letter-spacing: -0.06em;

    margin-bottom: 28px;
}


.page-title > p:last-child {

    color: var(--text-secondary);

    font-size: 19px;
}


/* =========================================
   About
========================================= */

.about-layout {

    display: grid;

    grid-template-columns:
        0.7fr
        1.3fr;

    gap: 100px;

    padding: 60px 0 120px;
}


.about-profile {

    text-align: left;
}


.about-avatar {

    width: 220px;
    height: 220px;

    margin-bottom: 24px;

    border-radius: 50%;

    overflow: hidden;

    border: 1px solid var(--border);
}


.about-avatar img {

    width: 100%;
    height: 100%;

    object-fit: cover;
}


.about-profile h2 {

    font-size: 26px;

    margin-bottom: 5px;
}


.about-profile p {

    color: var(--text-secondary);

    font-size: 14px;
}


.about-content h2 {

    margin-bottom: 30px;

    font-size: 32px;

    letter-spacing: -0.03em;
}


.about-content > p {

    max-width: 700px;

    margin-bottom: 22px;

    color: var(--text-secondary);

    font-size: 17px;
}


/* =========================================
   Info
========================================= */

.info-list {

    margin-top: 48px;

    border-top: 1px solid var(--border);
}


.info-item {

    display: flex;

    align-items: center;

    justify-content: space-between;

    gap: 20px;

    padding: 18px 0;

    border-bottom: 1px solid var(--border);
}


.info-item span {

    color: var(--text-tertiary);

    font-size: 14px;
}


.info-item strong {

    font-size: 14px;

    font-weight: 500;
}


/* =========================================
   Timeline
========================================= */

.timeline {

    padding-top: 0;
}


.timeline-list {

    border-top: 1px solid var(--border);
}


.timeline-item {

    display: grid;

    grid-template-columns: 160px 1fr;

    gap: 40px;

    padding: 34px 0;

    border-bottom: 1px solid var(--border);
}


.timeline-year {

    color: var(--text-tertiary);

    font-size: 14px;
}


.timeline-content h3 {

    margin-bottom: 8px;

    font-size: 20px;
}


.timeline-content p {

    max-width: 600px;

    color: var(--text-secondary);

    font-size: 15px;
}


/* =========================================
   Contact
========================================= */

.contact-layout {

    display: grid;

    grid-template-columns:
        1fr
        1fr;

    gap: 1px;
}


.contact-card,
.social-card {

    min-height: 360px;

    padding: 40px;

    background: var(--surface);

    border: 1px solid var(--border-light);
}


.contact-icon {

    width: 46px;
    height: 46px;

    display: flex;

    align-items: center;
    justify-content: center;

    border: 1px solid var(--border);

    border-radius: 12px;

    font-size: 20px;

    margin-bottom: 35px;
}


.contact-card h2,
.social-card h2 {

    margin-bottom: 12px;

    font-size: 28px;
}


.contact-card p,
.social-card > p {

    color: var(--text-secondary);

    margin-bottom: 24px;
}


.text-link {

    color: var(--accent);

    font-size: 14px;
}


.text-link:hover {
    text-decoration: underline;
}


/* =========================================
   Social
========================================= */

.social-list {

    margin-top: 35px;

    display: grid;

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

    gap: 10px;
}


.social-item {

    display: flex;

    align-items: center;

    gap: 12px;

    padding: 12px;

    border: 1px solid var(--border-light);

    border-radius: 9px;

    color: var(--text-secondary);

    transition:
        background var(--transition-fast),
        border-color var(--transition-fast),
        color var(--transition-fast);
}


.social-item:hover {

    background: var(--surface-soft);

    border-color: var(--border);

    color: var(--text-primary);
}


.social-icon {

    width: 32px;
    height: 32px;

    display: flex;

    align-items: center;
    justify-content: center;

    border: 1px solid var(--border);

    border-radius: 8px;

    font-size: 13px;

    font-weight: 600;

    background: var(--surface);
}


/* =========================================
   Footer
========================================= */

.site-footer {

    border-top: 1px solid var(--border-light);
}


.footer-inner {

    width: min(
        calc(100% - 48px),
        var(--max-width)
    );

    min-height: 72px;

    margin: auto;

    display: flex;

    align-items: center;

    justify-content: space-between;

    gap: 20px;

    color: var(--text-tertiary);

    font-size: 12px;
}


/* =========================================
   Scroll Reveal
========================================= */

.reveal {

    opacity: 0;

    transform: translateY(22px);

    transition:
        opacity 700ms ease,
        transform 700ms ease;
}


.page-section.active .reveal {

    opacity: 1;

    transform: translateY(0);
}


.page-section.active
.reveal:nth-child(2) {

    transition-delay: 80ms;
}


.page-section.active
.reveal:nth-child(3) {

    transition-delay: 140ms;
}


.page-section.active
.reveal:nth-child(4) {

    transition-delay: 200ms;
}


/* =========================================
   Responsive
========================================= */

@media (max-width: 900px) {

    .hero {

        grid-template-columns: 1fr;

        gap: 50px;

        padding: 80px 0;

        text-align: center;
    }


    .hero-content {

        display: flex;

        flex-direction: column;

        align-items: center;
    }


    .hero-description {
        max-width: 600px;
    }


    .hero-avatar-wrapper {

        order: -1;
    }


    .avatar-ring {

        width: 240px;
    }


    .feature-grid {

        grid-template-columns: 1fr;
    }


    .about-layout {

        grid-template-columns: 1fr;

        gap: 60px;
    }


    .about-profile {

        display: flex;

        align-items: center;

        gap: 24px;
    }


    .about-avatar {

        width: 120px;
        height: 120px;

        margin: 0;
    }


    .contact-layout {

        grid-template-columns: 1fr;
    }

}


@media (max-width: 680px) {

    .navbar {

        width: min(
            calc(100% - 32px),
            var(--max-width)
        );
    }


    .nav-links {
        display: none;
    }


    .mobile-menu-button {
        display: block;
    }


    .hero,
    .section-block,
    .inner-page,
    .contact-page {

        width: min(
            calc(100% - 32px),
            var(--max-width)
        );
    }


    .hero {

        min-height: auto;

        padding: 100px 0 80px;
    }


    .hero-title {

        font-size: 48px;
    }


    .hero-description {

        font-size: 17px;
    }


    .hero-actions {

        width: 100%;

        flex-direction: column;
    }


    .primary-button,
    .secondary-button {

        width: 100%;
    }


    .section-block {

        padding: 80px 0;
    }


    .section-heading {

        margin-bottom: 40px;
    }


    .section-heading h2 {

        font-size: 40px;
    }


    .page-title {

        padding: 60px 0;
    }


    .page-title h1 {

        font-size: 52px;
    }


    .about-profile {

        flex-direction: column;

        align-items: flex-start;
    }


    .timeline-item {

        grid-template-columns: 1fr;

        gap: 8px;
    }


    .contact-card,
    .social-card {

        padding: 28px;

        min-height: auto;
    }


    .social-list {

        grid-template-columns: 1fr;
    }


    .footer-inner {

        width: calc(100% - 32px);

        padding: 20px 0;

        flex-direction: column;

        align-items: flex-start;
    }

}


/* =========================================
   Reduced Motion
========================================= */

@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {

        scroll-behavior: auto !important;

        animation-duration: 0.01ms !important;

        animation-iteration-count: 1 !important;

        transition-duration: 0.01ms !important;
    }

}