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

:root {
    --bg: #fafaf9;
    --surface: #ffffff;
    --text: #1a1a1a;
    --text-muted: #5b5b5b;
    --text-soft: #7a7a7a;
    --border: #e6e6e6;
    --border-strong: #d4d4d4;
    --accent: #1a1a1a;
    --link: #1a1a1a;
    --link-hover: #5b5b5b;
    --header-h: 64px;
    --sidebar-w: 280px;
    --content-max: 760px;
    --transition: 180ms ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI",
        Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.65;
    color: var(--text);
    background-color: var(--bg);
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

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

a {
    color: var(--link);
    text-decoration: none;
    border-bottom: 1px solid var(--border-strong);
    transition: color var(--transition), border-color var(--transition);
}

a:hover {
    color: var(--link-hover);
    border-bottom-color: var(--text);
}

p {
    color: var(--text-muted);
    margin-bottom: 16px;
}

strong {
    color: var(--text);
    font-weight: 600;
}

/* ---------- Header ---------- */
.main-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-h);
    background-color: rgba(250, 250, 249, 0.85);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    display: flex;
    align-items: center;
    padding: 0 32px;
}

.header-content {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.main-header h1 {
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--text);
}

.header-nav {
    display: flex;
    gap: 28px;
}

.header-nav a {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    border-bottom: none;
    position: relative;
}

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

.header-nav a::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -6px;
    height: 1.5px;
    background: var(--text);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition);
}

.header-nav a:hover::after {
    transform: scaleX(1);
}

/* ---------- Sidebar ---------- */
.sidebar {
    position: fixed;
    left: 0;
    top: var(--header-h);
    width: var(--sidebar-w);
    height: calc(100vh - var(--header-h));
    background-color: var(--bg);
    border-right: 1px solid var(--border);
    overflow-y: auto;
    z-index: 999;
}

.sidebar-content {
    padding: 40px 32px;
}

.profile-photo {
    text-align: center;
    margin-bottom: 24px;
}

.profile-photo img {
    width: 160px;
    height: 160px;
    border-radius: 50%;
    object-fit: cover;
    border: 1px solid var(--border);
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.06);
}

.sidebar h2 {
    text-align: center;
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 8px;
    letter-spacing: -0.01em;
}

.sidebar-title {
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 4px;
    line-height: 1.5;
}

.sidebar-middle {
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 16px;
    line-height: 1.5;
}

.sidebar-location {
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-soft);
    margin-bottom: 28px;
    line-height: 1.7;
}

.sidebar-links {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.sidebar-links a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-radius: 6px;
    border-bottom: none;
}

.sidebar-links a img {
    width: 18px;
    height: 18px;
    opacity: 0.65;
    transition: opacity var(--transition);
}

.sidebar-links a:hover {
    color: var(--text);
    background-color: rgba(0, 0, 0, 0.04);
}

.sidebar-links a:hover img {
    opacity: 1;
}

/* ---------- Main content ---------- */
.main-content {
    margin-left: var(--sidebar-w);
    margin-top: var(--header-h);
    padding: 64px 56px 80px;
    max-width: calc(var(--sidebar-w) + var(--content-max) + 112px);
}

/* ---------- Intro ---------- */
.intro-section {
    margin-bottom: 56px;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.02em;
    line-height: 1.2;
    margin-bottom: 8px;
}

.page-subtitle {
    color: var(--text-soft);
    font-size: 0.95rem;
    margin-bottom: 24px;
}

code {
    font-family: "SF Mono", Menlo, Consolas, Monaco, monospace;
    font-size: 0.88em;
    background-color: rgba(0, 0, 0, 0.05);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--text);
}

.tagline {
    margin-bottom: 24px;
}

.tagline p {
    font-size: 0.85rem;
    color: var(--text-soft);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin: 0;
}

.tagline em {
    color: var(--text-muted);
    font-style: normal;
    text-transform: none;
    letter-spacing: 0;
}

.intro-section p {
    font-size: 1.02rem;
    line-height: 1.75;
    color: var(--text);
    text-align: left;
    margin-bottom: 18px;
}

/* ---------- Section base ---------- */
.section {
    margin: 64px 0;
    scroll-margin-top: calc(var(--header-h) + 24px);
}

h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text);
    letter-spacing: -0.01em;
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
}

h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    margin: 24px 0 10px;
    letter-spacing: -0.005em;
}

/* ---------- Project cards ---------- */
.project {
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px 28px;
    margin-bottom: 20px;
    transition: transform var(--transition), box-shadow var(--transition),
        border-color var(--transition);
}

.project:hover {
    transform: translateY(-1px);
    border-color: var(--border-strong);
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.05);
}

.project-title {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 4px;
    letter-spacing: -0.005em;
}

.project-meta {
    color: var(--text-soft);
    font-size: 0.82rem;
    margin-bottom: 8px;
}

.project-tech {
    color: var(--text-muted);
    font-size: 0.85rem;
    font-style: italic;
    margin-bottom: 12px;
}

.project p {
    font-size: 0.92rem;
    line-height: 1.65;
    margin-bottom: 14px;
}

.project-links {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 4px;
}

.project-links a {
    display: inline-block;
    padding: 6px 14px;
    font-size: 0.82rem;
    color: var(--text);
    background-color: transparent;
    border: 1px solid var(--border-strong);
    border-radius: 999px;
    transition: all var(--transition);
}

.project-links a:hover {
    background-color: var(--text);
    color: var(--surface);
    border-color: var(--text);
}

/* ---------- Footer ---------- */
.footer {
    margin-top: 72px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-soft);
    font-size: 0.85rem;
}

.footer p {
    color: var(--text-soft);
    margin-bottom: 6px;
}

.footer a {
    color: var(--text-muted);
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
    :root {
        --sidebar-w: 240px;
    }

    .main-content {
        padding: 56px 40px 72px;
    }
}

@media (max-width: 768px) {
    .header-nav {
        gap: 18px;
    }

    .header-nav a {
        font-size: 0.85rem;
    }

    .sidebar {
        position: static;
        width: 100%;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }

    .sidebar-content {
        padding: 32px 24px;
    }

    .profile-photo img {
        width: 140px;
        height: 140px;
    }

    .sidebar-links {
        max-width: 320px;
        margin: 0 auto;
    }

    .main-content {
        margin-left: 0;
        padding: 40px 24px 64px;
    }
}

@media (max-width: 480px) {
    .main-header {
        padding: 0 20px;
    }

    .main-header h1 {
        font-size: 0.95rem;
    }

    .header-nav {
        gap: 14px;
    }

    .header-nav a {
        font-size: 0.8rem;
    }

    .main-content {
        padding: 32px 20px 56px;
    }

    .project {
        padding: 20px;
    }

    h2 {
        font-size: 1.3rem;
    }
}