:root {
    --bg: #f4f4f5;
    --surface: #ffffff;
    --text: #1a1a1a;
    --muted: #6b7280;
    --accent: #2563eb;
    --accent-light: #dbeafe;
    --border: #e5e7eb;
    --radius: 10px;
    --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0a0a0a;
        --surface: #141414;
        --text: #e5e5e5;
        --muted: #9ca3af;
        --accent: #60a5fa;
        --accent-light: #1e3a5f;
        --border: #252525;
        --shadow: 0 1px 3px rgba(0,0,0,0.3), 0 1px 2px rgba(0,0,0,0.2);
    }
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    font-size: 15px;
}

/* Nav */
nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(10px);
    background: rgba(255,255,255,0.85);
}

@media (prefers-color-scheme: dark) {
    nav {
        background: rgba(20,20,20,0.85);
    }
}

.nav-inner {
    max-width: 720px;
    margin: 0 auto;
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--accent);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

.nav-links a {
    color: var(--muted);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 500;
    transition: color 0.2s;
}

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

/* Container */
.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 2rem 1.5rem 3rem;
}

/* Header */
header {
    margin-bottom: 1.5rem;
}

.header-content {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.avatar {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent), #7c3aed);
    color: white;
    font-weight: 700;
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.subtitle {
    color: var(--muted);
    font-size: 1rem;
    margin-top: 0.1rem;
}

.header-meta {
    margin-top: 0.4rem;
    font-size: 0.85rem;
    color: var(--muted);
}

.status {
    color: #16a34a;
}

.sep {
    margin: 0 0.4rem;
}

.contact {
    margin-top: 0.6rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: var(--accent);
    color: white;
    text-decoration: none;
    padding: 0.4rem 0.9rem;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 500;
    transition: opacity 0.2s;
}

.btn:hover {
    opacity: 0.85;
}

/* Cards */
.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-bottom: 1rem;
    box-shadow: var(--shadow);
}

.card.highlight {
    border-left: 3px solid var(--accent);
}

h2 {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--muted);
    margin-bottom: 1rem;
}

/* Skills */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.25rem;
}

.skill-category h4 {
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.skills {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    list-style: none;
}

.skills li {
    background: var(--accent-light);
    color: var(--accent);
    padding: 0.25rem 0.6rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 1.5rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 5px;
    top: 8px;
    bottom: 8px;
    width: 2px;
    background: var(--border);
    border-radius: 1px;
}

.timeline .entry {
    position: relative;
    margin-bottom: 1.5rem;
}

.timeline .entry:last-child {
    margin-bottom: 0;
}

.timeline-dot {
    position: absolute;
    left: -1.5rem;
    top: 6px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--surface);
    border: 2px solid var(--accent);
    z-index: 1;
}

.entry-content {
    padding-left: 0;
}

/* Entries */
.entry {
    margin-bottom: 1.25rem;
}

.entry:last-child {
    margin-bottom: 0;
}

.entry-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.entry-header h3 {
    font-size: 0.95rem;
    font-weight: 600;
}

.date {
    font-size: 0.8rem;
    color: var(--muted);
    white-space: nowrap;
    background: var(--bg);
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
}

.org {
    font-size: 0.85rem;
    color: var(--muted);
    margin-top: 0.15rem;
}

.detail {
    font-size: 0.85rem;
    margin-top: 0.25rem;
    color: var(--muted);
}

.entry ul {
    margin-top: 0.5rem;
    padding-left: 1.2rem;
}

.entry li {
    font-size: 0.85rem;
    margin-bottom: 0.2rem;
}

/* Two column */
.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1rem;
}

/* Languages */
.langs {
    list-style: none;
    padding: 0;
}

.langs li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.4rem 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.85rem;
}

.langs li:last-child {
    border-bottom: none;
}

.lang-level {
    font-size: 0.75rem;
    color: var(--muted);
    background: var(--bg);
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
}

/* Footer */
footer {
    margin-top: 2rem;
    text-align: center;
    font-size: 0.8rem;
    color: var(--muted);
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 1.5rem 1rem 2rem;
    }
    .header-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    .entry-header {
        flex-direction: column;
        gap: 0.2rem;
    }
    .two-col {
        grid-template-columns: 1fr;
    }
    .nav-links {
        gap: 1rem;
    }
    .skills-grid {
        grid-template-columns: 1fr;
    }
}