:root {
    --sky-50:  #f0f9ff;
    --sky-100: #e0f2fe;
    --sky-200: #bae6fd;
    --sky-400: #38bdf8;
    --sky-500: #0ea5e9;
    --sky-600: #0284c7;
    --sky-700: #0369a1;
    --ink:     #0f172a;
    --muted:   #64748b;
    --bg:      #ffffff;
    --bg-alt:  #f7fbff;
    --border:  #e2e8f0;
    --radius:  14px;
    --shadow:  0 6px 24px rgba(2, 132, 199, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--ink);
    background: var(--bg);
    line-height: 1.6;
}
a { color: var(--sky-600); text-decoration: none; }
a:hover { color: var(--sky-700); }
.container { max-width: 1080px; margin: 0 auto; padding: 0 20px; }
.muted { color: var(--muted); }

/* Navbar */
.navbar {
    position: sticky; top: 0; z-index: 50;
    background: rgba(255,255,255,0.85);
    backdrop-filter: saturate(180%) blur(10px);
    border-bottom: 1px solid var(--border);
}
.nav-wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-weight: 700; color: var(--ink); letter-spacing: -0.2px; }
.nav-list { display: flex; gap: 22px; list-style: none; margin: 0; padding: 0; }
.nav-list a { color: var(--ink); font-size: 14px; font-weight: 500; }
.nav-list a:hover { color: var(--sky-600); }
.nav-toggle {
    display: none; background: none; border: 0; font-size: 24px; color: var(--ink); cursor: pointer;
}

/* Hero */
.hero {
    background: linear-gradient(180deg, var(--sky-50) 0%, #ffffff 100%);
    padding: 80px 0 60px;
}
.hero-wrap { display: grid; grid-template-columns: 1.3fr 1fr; gap: 40px; align-items: center; }
.badge {
    display: inline-block; padding: 6px 12px; border-radius: 999px;
    background: var(--sky-100); color: var(--sky-700); font-size: 13px; font-weight: 600;
}
.hero h1 {
    font-size: clamp(32px, 5vw, 52px);
    margin: 16px 0 8px;
    letter-spacing: -1px;
    color: var(--ink);
}
.tagline { font-size: 20px; font-style: italic; color: var(--sky-600); margin: 0 0 16px; font-weight: 500; }
.lead { font-size: 17px; color: var(--muted); max-width: 540px; }
.hero-actions { margin-top: 24px; display: flex; gap: 12px; flex-wrap: wrap; }

.btn {
    display: inline-block; padding: 12px 22px; border-radius: 10px;
    font-weight: 600; font-size: 15px; transition: transform .15s ease, box-shadow .15s ease;
    border: 1px solid transparent; cursor: pointer;
}
.btn-primary { background: var(--sky-500); color: #fff; box-shadow: var(--shadow); }
.btn-primary:hover { background: var(--sky-600); color: #fff; transform: translateY(-1px); }
.btn-ghost { background: #fff; color: var(--sky-700); border-color: var(--sky-200); }
.btn-ghost:hover { background: var(--sky-50); color: var(--sky-700); }

.hero-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
    position: relative;
}
.hero-card h3 { margin: 0 0 14px; font-size: 16px; color: var(--ink); }
.status-dot {
    position: absolute; top: 22px; right: 22px;
    width: 10px; height: 10px; border-radius: 50%; background: #22c55e;
    box-shadow: 0 0 0 4px rgba(34,197,94,.18);
}
.status-list { list-style: none; padding: 0; margin: 0; }
.status-list li {
    display: flex; justify-content: space-between; padding: 10px 0;
    border-bottom: 1px dashed var(--border); font-size: 14px;
}
.status-list li:last-child { border-bottom: 0; }
.status-list .ok { color: #16a34a; }

/* Sections */
.section { padding: 72px 0; }
.section-alt { background: var(--bg-alt); }
.section-title {
    font-size: 28px; margin: 0 0 32px; letter-spacing: -0.5px;
    position: relative; padding-bottom: 10px;
}
.section-title::after {
    content: ""; position: absolute; left: 0; bottom: 0;
    width: 48px; height: 3px; background: var(--sky-500); border-radius: 3px;
}
.sub-title { font-size: 16px; margin: 0 0 12px; color: var(--sky-700); }

/* About */
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 40px; }
.about-text { font-size: 16px; color: #334155; }
.skills { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 8px; }
.skills li {
    background: var(--sky-50); color: var(--sky-700);
    padding: 6px 12px; border-radius: 8px; font-size: 13px; font-weight: 500;
    border: 1px solid var(--sky-100);
}

/* Timeline */
.timeline { position: relative; padding-left: 24px; }
.timeline::before {
    content: ""; position: absolute; left: 6px; top: 6px; bottom: 6px;
    width: 2px; background: var(--sky-200);
}
.timeline-item { position: relative; margin-bottom: 28px; }
.timeline-dot {
    position: absolute; left: -24px; top: 6px;
    width: 14px; height: 14px; border-radius: 50%;
    background: var(--sky-500); border: 3px solid #fff;
    box-shadow: 0 0 0 2px var(--sky-200);
}
.timeline-body {
    background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
    padding: 18px 20px;
}
.timeline-head { display: flex; justify-content: space-between; flex-wrap: wrap; align-items: baseline; }
.timeline-head h3 { margin: 0; font-size: 17px; }
.period { color: var(--sky-600); font-size: 13px; font-weight: 600; }
.company { color: var(--muted); margin: 4px 0 8px; font-size: 14px; }

/* Cert grid */
.cert-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 16px; }
.cert-card {
    background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
    padding: 20px; transition: transform .15s ease, box-shadow .15s ease;
}
.cert-card:hover { transform: translateY(-2px); box-shadow: var(--shadow); border-color: var(--sky-200); }
.cert-card h3 { margin: 8px 0 4px; font-size: 15px; }
.cert-icon { font-size: 26px; }

/* Projects */
.project-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 18px; }
.project-card {
    background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
    padding: 22px; transition: transform .15s ease, box-shadow .15s ease;
}
.project-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: var(--sky-200); }
.project-card h3 { margin: 0 0 8px; font-size: 17px; color: var(--sky-700); }
.tags { margin-top: 12px; display: flex; flex-wrap: wrap; gap: 6px; }
.tag {
    background: var(--sky-100); color: var(--sky-700);
    font-size: 12px; padding: 3px 10px; border-radius: 999px; font-weight: 600;
}

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 40px; }
.contact-list { list-style: none; padding: 0; }
.contact-list li { padding: 8px 0; border-bottom: 1px dashed var(--border); font-size: 15px; }
.contact-form { display: flex; flex-direction: column; gap: 14px; }
.contact-form label { display: flex; flex-direction: column; gap: 6px; font-size: 14px; font-weight: 500; color: var(--ink); }
.contact-form input, .contact-form textarea {
    border: 1px solid var(--border); border-radius: 10px; padding: 11px 14px;
    font: inherit; color: var(--ink); background: #fff; outline: none;
    transition: border-color .15s ease, box-shadow .15s ease;
}
.contact-form input:focus, .contact-form textarea:focus {
    border-color: var(--sky-400); box-shadow: 0 0 0 3px rgba(56,189,248,.25);
}
.alert { padding: 12px 14px; border-radius: 10px; font-size: 14px; }
.alert.success { background: #ecfdf5; color: #047857; border: 1px solid #a7f3d0; }
.alert.error   { background: #fef2f2; color: #b91c1c; border: 1px solid #fecaca; }

/* Footer */
.footer { background: var(--ink); color: #cbd5e1; padding: 24px 0; }
.footer-wrap { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px; }
.footer p { margin: 0; font-size: 14px; }

/* Mobile */
@media (max-width: 820px) {
    .hero-wrap, .about-grid, .contact-grid { grid-template-columns: 1fr; }
    .nav-list { display: none; }
    .nav-toggle { display: block; }
    .nav-list.open {
        display: flex; position: absolute; top: 64px; left: 0; right: 0;
        flex-direction: column; gap: 0; background: #fff;
        border-bottom: 1px solid var(--border);
    }
    .nav-list.open li { padding: 14px 20px; border-top: 1px solid var(--border); }
    .section { padding: 56px 0; }
}