:root {
    --bg: #12171d;
    --bg-panel: #171d24;
    --bg-code: #10141a;
    --border: #232b34;
    --text: #d9e1e6;
    --text-dim: #71808d;
    --cyan: #00ADD8;
    --cyan-bright: #5DC9E2;
    --gold: #FDDD00;
    --comment: #5c6a76;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: 'JetBrains Mono', monospace;
    font-size: 15px;
    line-height: 1.75;
}

::selection {
    background: rgba(0, 173, 216, 0.28);
}

/* ---------- Top bar: pkg.go.dev-style header ---------- */
.topbar {
    background: linear-gradient(180deg, #00ADD8, #0092b8);
    padding: 0 24px;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 1px 0 rgba(0, 0, 0, 0.15);
}

.topbar-inner {
    max-width: 1040px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 14px;
    height: 56px;
}

.gopher {
    flex: none;
}

.breadcrumb {
    font-family: 'Inter', sans-serif;
    font-size: 14.5px;
    color: #eafbff;
    font-weight: 500;
}

.breadcrumb b {
    color: #fff;
}

.topbar-tabs {
    margin-left: auto;
    display: flex;
    gap: 22px;
    font-family: 'Inter', sans-serif;
    font-size: 13.5px;
}

.topbar-tabs a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    padding: 4px 2px;
    border-bottom: 2px solid transparent;
    transition: border-color .15s, color .15s;
}

.topbar-tabs a:hover, .topbar-tabs a.active {
    color: #fff;
    border-bottom-color: var(--gold);
}

@media (max-width: 640px) {
    .topbar-inner {
        gap: 10px;
    }

    .breadcrumb {
        font-size: 13px;
    }
}

/* ---------- Layout ---------- */
.app {
    display: grid;
    grid-template-columns: 200px 1fr;
    max-width: 1040px;
    margin: 0 auto;
}

.sidebar {
    padding: 28px 0;
    position: sticky;
    top: 56px;
    height: calc(100vh - 56px);
}

.sidebar-title {
    color: var(--text-dim);
    font-family: 'Inter', sans-serif;
    font-size: 11px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    padding: 0 20px 10px;
}

.file {
    display: flex;
    align-items: center;
    gap: 9px;
    padding: 7px 20px;
    color: var(--text-dim);
    text-decoration: none;
    font-size: 13.5px;
    border-left: 2px solid transparent;
    cursor: pointer;
    transition: background .15s, color .15s;
}

.file:hover {
    background: rgba(0, 173, 216, 0.06);
    color: var(--text);
}

.file.active {
    color: #fff;
    background: rgba(0, 173, 216, 0.1);
    border-left: 2px solid var(--cyan);
}

.file-icon {
    color: var(--gold);
    font-size: 12px;
}

.editor {
    padding: 40px 40px 100px 32px;
    min-width: 0;
}

@media (max-width: 720px) {
    .app {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: sticky;
        top: 56px;
        height: auto;
        display: flex;
        align-items: center;
        gap: 4px;
        padding: 8px 12px;
        background: var(--bg-panel);
        border-bottom: 1px solid var(--border);
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        scrollbar-width: none;
        z-index: 90;
    }

    .sidebar::-webkit-scrollbar {
        display: none;
    }

    .sidebar-title {
        display: none;
    }

    .file {
        flex: none;
        padding: 8px 14px;
        border-left: none;
        border-bottom: 2px solid transparent;
        white-space: nowrap;
    }

    .file.active {
        border-left: none;
        border-bottom: 2px solid var(--cyan);
    }

    .editor {
        padding: 24px 16px 60px;
    }
}

@media (max-width: 400px) {
    body {
        font-size: 14px;
    }

    .editor {
        padding: 20px 12px 50px;
    }
}

section {
    margin-bottom: 60px;
    scroll-margin-top: 70px;
}

@media (max-width: 720px) {
    section {
        margin-bottom: 36px;
        scroll-margin-top: 116px;
    }
}

.codebox {
    background: var(--bg-code);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 18px 20px;
    overflow-x: auto;
}

.code-line {
    display: flex;
    white-space: pre;
}

.ln {
    width: 28px;
    flex: none;
    color: #333c46;
    text-align: right;
    padding-right: 14px;
    user-select: none;
    font-size: 12.5px;
}

.code-content {
    flex: 1;
    min-width: 0;
}

@media (max-width: 640px) {
    .codebox {
        padding: 14px 12px;
        font-size: 13px;
        border-radius: 6px;
    }

    .code-line {
        white-space: pre-wrap;
        word-break: break-word;
    }

    .ln {
        width: 20px;
        padding-right: 8px;
    }
}

.kw {
    color: var(--cyan-bright);
}

.str {
    color: var(--gold);
}

.fn {
    color: #7fd9f0;
}

.type {
    color: #8fd6c4;
}

.c {
    color: var(--comment);
    font-style: italic;
}

.plain {
    color: var(--text);
}

/* ---------- Hero ---------- */
.hero-title {
    font-family: 'Inter', sans-serif;
    font-size: clamp(30px, 4vw, 44px);
    font-weight: 700;
    color: #fff;
    margin: 22px 0 4px;
}

.hero-role {
    font-family: 'Inter', sans-serif;
    color: var(--cyan-bright);
    font-size: 16.5px;
    margin-bottom: 4px;
}

.cursor {
    display: inline-block;
    width: 9px;
    height: 1.1em;
    background: var(--gold);
    vertical-align: text-bottom;
    animation: blink 1s steps(1) infinite;
    margin-left: 3px;
}

@keyframes blink {
    50% {
        opacity: 0;
    }
}

/* ---------- Doc comment ---------- */
.doc-comment {
    color: var(--comment);
    font-style: italic;
}

.doc-text {
    font-family: 'Inter', sans-serif;
    color: var(--text);
    font-size: 15px;
    max-width: 620px;
    margin-top: 16px;
}

/* ---------- Skills ---------- */
.skill-block {
    margin-bottom: 22px;
}

.skill-comment {
    color: var(--comment);
    font-style: italic;
    font-size: 13.5px;
    margin-bottom: 4px;
}

/* ---------- Contact ---------- */
a.link {
    color: var(--gold);
    text-decoration: none;
    border-bottom: 1px dashed rgba(253, 221, 0, 0.4);
}

a.link:hover {
    color: #fff;
    border-bottom-color: #fff;
}

footer {
    color: var(--text-dim);
    font-size: 12.5px;
    padding: 24px 40px 40px 32px;
    max-width: 1040px;
    margin: 0 auto;
}