/* ═══════════════════════════════════════════════════
   자율주행 엔지니어 포트폴리오
   Wide-Block · Seamless Dark · Hover-Only Glow
   ═══════════════════════════════════════════════════ */

/* ── Design Tokens ───────────────────────────────── */
:root {
    --bg: #0a0c10;
    --surface: #111419;
    --surface-hover: #161920;
    --border: #1b1e26;
    --border-glow: rgba(0, 210, 255, 0.4);
    --border-glow-green: rgba(52, 211, 153, 0.35);

    --text: #bfc5ce;
    --heading: #edf0f5;
    --muted: #555d6a;

    --cyan: #00d2ff;
    --green: #34d399;
    --cyan-bg: rgba(0, 210, 255, 0.06);
    --green-bg: rgba(52, 211, 153, 0.06);

    --font: 'Inter', system-ui, -apple-system, sans-serif;
    --mono: 'Fira Code', 'Consolas', monospace;
    --max-w: 820px;
    --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Reset ───────────────────────────────────────── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 68px; }

body {
    font-family: var(--font);
    color: var(--text);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;

    /* Seamless dark bg + faint grid */
    background:
        linear-gradient(rgba(255,255,255,0.018) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.018) 1px, transparent 1px),
        var(--bg);
    background-size: 60px 60px, 60px 60px, 100% 100%;
    background-attachment: fixed;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

.container {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 24px;
}

/* ── Buttons ─────────────────────────────────────── */
.btn-fill, .btn-line {
    display: inline-block;
    padding: 10px 24px;
    border-radius: 6px;
    font-family: var(--font);
    font-size: 0.88rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s var(--ease);
    border: none;
}

.btn-fill {
    background: var(--cyan);
    color: var(--bg);
}
.btn-fill:hover {
    box-shadow: 0 0 18px rgba(0, 210, 255, 0.3);
    transform: translateY(-1px);
}

.btn-line {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text);
}
.btn-line:hover {
    border-color: var(--cyan);
    color: var(--cyan);
}

/* ── Reveal ──────────────────────────────────────── */
.reveal {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* ═══════════════════════════════════════════════════
   NAVBAR
   ═══════════════════════════════════════════════════ */
#navbar {
    position: fixed;
    top: 0; left: 0; width: 100%;
    z-index: 1000;
    background: rgba(10,12,16,0.72);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid transparent;
    transition: border-color 0.3s, background 0.3s;
}
#navbar.scrolled {
    border-bottom-color: var(--border);
    background: rgba(10,12,16,0.92);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 58px;
}

.nav-logo {
    font-family: var(--mono);
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--heading);
}
.bracket { color: var(--cyan); }

.nav-links {
    display: flex;
    align-items: center;
    gap: 4px;
}
.nav-links a {
    padding: 5px 12px;
    border-radius: 5px;
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--muted);
    transition: color 0.2s, background 0.2s;
}
.nav-links a:hover {
    color: var(--heading);
    background: rgba(255,255,255,0.04);
}
.nav-contact {
    border: 1px solid var(--border) !important;
    color: var(--heading) !important;
}
.nav-contact:hover {
    border-color: var(--cyan) !important;
    color: var(--cyan) !important;
}

/* Mobile toggle */
.menu-btn {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 1001;
}
.menu-btn span {
    width: 20px; height: 2px;
    background: var(--heading);
    border-radius: 1px;
    transition: all 0.25s var(--ease);
}
.menu-btn.open span:nth-child(1) { transform: rotate(45deg) translate(4px,4px); }
.menu-btn.open span:nth-child(2) { opacity: 0; }
.menu-btn.open span:nth-child(3) { transform: rotate(-45deg) translate(4px,-4px); }

/* ═══════════════════════════════════════════════════
   HERO – taller padding, not 100vh
   ═══════════════════════════════════════════════════ */
#hero {
    padding: 160px 0 100px;
}

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

.hero-pre {
    font-family: var(--mono);
    font-size: 0.85rem;
    color: var(--cyan);
    margin-bottom: 10px;
}

.hero-name {
    font-size: clamp(2.4rem, 5.5vw, 3.6rem);
    font-weight: 900;
    color: var(--heading);
    line-height: 1.05;
    margin-bottom: 10px;
}
.dot { color: var(--cyan); }

.hero-title {
    font-size: clamp(1rem, 2.3vw, 1.25rem);
    font-weight: 500;
    color: var(--muted);
    margin-bottom: 18px;
}

.hero-sub {
    font-size: 0.95rem;
    color: var(--muted);
    line-height: 1.75;
    margin-bottom: 32px;
}

.hero-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

/* ═══════════════════════════════════════════════════
   SECTIONS – compact padding
   ═══════════════════════════════════════════════════ */
section:not(#hero) { padding: 80px 0; }
footer { padding: 80px 0 0; }

/* Section header */
.sec-head {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 36px;
}
.sec-num {
    font-family: var(--mono);
    font-size: 0.82rem;
    color: var(--cyan);
}
.sec-head h2 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--heading);
    white-space: nowrap;
}
.sec-rule {
    flex: 1;
    height: 1px;
    background: var(--border);
    max-width: 200px;
}

/* ═══════════════════════════════════════════════════
   ABOUT
   ═══════════════════════════════════════════════════ */
.about-body {
    display: grid;
    grid-template-columns: 1.6fr 1fr;
    gap: 32px;
    align-items: start;
}

.about-text p {
    font-size: 0.94rem;
    margin-bottom: 14px;
    line-height: 1.8;
}
.about-text strong {
    color: var(--heading);
    font-weight: 600;
}

.interest-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.interest-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 18px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--cyan);
    transition: border-color 0.35s var(--ease), box-shadow 0.35s var(--ease);
}
.interest-item:hover {
    border-color: var(--border-glow);
    box-shadow: 0 0 16px rgba(0,210,255,0.06);
}
.interest-item span {
    font-family: var(--mono);
    font-size: 0.82rem;
    color: var(--heading);
    font-weight: 500;
}

/* ═══════════════════════════════════════════════════
   TECH STACK
   ═══════════════════════════════════════════════════ */
.tech-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.tech-block {
    padding: 22px 20px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    transition: border-color 0.35s var(--ease), box-shadow 0.35s var(--ease);
}
.tech-block:hover {
    border-color: var(--border-glow);
    box-shadow: 0 0 16px rgba(0,210,255,0.06);
}

.tech-block h3 {
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--heading);
    margin-bottom: 12px;
}

.tags { display: flex; flex-wrap: wrap; gap: 6px; }
.tags span {
    font-family: var(--mono);
    font-size: 0.72rem;
    padding: 4px 10px;
    border-radius: 4px;
    background: var(--cyan-bg);
    border: 1px solid rgba(0,210,255,0.1);
    color: var(--cyan);
}

/* ═══════════════════════════════════════════════════
   PROJECTS – wide horizontal cards
   ═══════════════════════════════════════════════════ */
.proj-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.proj-card {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto auto;
    gap: 0 28px;
    padding: 28px 26px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    transition: border-color 0.4s var(--ease), box-shadow 0.4s var(--ease), transform 0.35s var(--ease);
}

.proj-card:hover {
    border-color: var(--border-glow-green);
    box-shadow: 0 0 22px rgba(52,211,153,0.06), 0 0 44px rgba(52,211,153,0.03);
    transform: translateY(-2px);
}

/* Card internal layout */
.proj-top {
    grid-column: 1 / -1;
    margin-bottom: 12px;
}

.proj-label {
    font-family: var(--mono);
    font-size: 0.66rem;
    color: var(--green);
    text-transform: uppercase;
    letter-spacing: 1px;
    display: block;
    margin-bottom: 6px;
}

.proj-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--heading);
}

.proj-desc {
    font-size: 0.88rem;
    line-height: 1.65;
    margin-bottom: 14px;
}

.proj-result {
    border-left: 2px solid var(--cyan);
    padding: 10px 14px;
    background: rgba(0,210,255,0.02);
    border-radius: 0 6px 6px 0;
    margin-bottom: 14px;
}
.result-tag {
    font-family: var(--mono);
    font-size: 0.64rem;
    color: var(--cyan);
    text-transform: uppercase;
    letter-spacing: 0.6px;
    display: block;
    margin-bottom: 3px;
}
.proj-result p {
    font-size: 0.82rem;
    color: var(--muted);
    line-height: 1.55;
}

.proj-tags { display: flex; flex-wrap: wrap; gap: 5px; grid-column: 1 / -1; }
.proj-tags span {
    font-family: var(--mono);
    font-size: 0.68rem;
    padding: 3px 9px;
    border-radius: 3px;
    background: var(--green-bg);
    border: 1px solid rgba(52,211,153,0.12);
    color: var(--green);
}

/* ═══════════════════════════════════════════════════
   FOOTER / CONTACT
   ═══════════════════════════════════════════════════ */
.footer-inner {
    text-align: center;
    padding-bottom: 48px;
}
.footer-inner .sec-num { display: block; margin-bottom: 8px; }
.footer-inner h2 {
    font-size: 2rem;
    font-weight: 800;
    color: var(--heading);
    margin-bottom: 14px;
}
.footer-inner p {
    color: var(--muted);
    font-size: 0.95rem;
    line-height: 1.7;
    max-width: 380px;
    margin: 0 auto 24px;
}

.footer-bar {
    border-top: 1px solid var(--border);
    padding: 20px 24px;
    text-align: center;
}
.footer-bar p {
    font-size: 0.76rem;
    color: var(--muted);
}
.footer-bar strong { color: var(--heading); font-weight: 600; }

/* ═══════════════════════════════════════════════════
   RESPONSIVE
   ═══════════════════════════════════════════════════ */
@media (max-width: 700px) {
    #hero { padding: 130px 0 72px; }
    section:not(#hero) { padding: 56px 0; }

    .menu-btn { display: flex; }

    .nav-links {
        position: fixed;
        top: 0; right: -100%;
        width: 68%; max-width: 260px;
        height: 100vh;
        background: rgba(10,12,16,0.97);
        backdrop-filter: blur(14px);
        flex-direction: column;
        justify-content: center;
        gap: 6px;
        padding: 24px;
        transition: right 0.3s var(--ease);
        border-left: 1px solid var(--border);
    }
    .nav-links.open { right: 0; }
    .nav-links a { font-size: 0.95rem; padding: 10px 14px; width: 100%; }

    .hero-name { font-size: 2rem; }
    .hero-sub br { display: none; }
    .hero-actions { flex-direction: column; }
    .hero-actions .btn-fill,
    .hero-actions .btn-line { text-align: center; }

    .about-body { grid-template-columns: 1fr; gap: 20px; }
    .tech-row { grid-template-columns: 1fr; gap: 10px; }

    .proj-card {
        grid-template-columns: 1fr;
        gap: 0;
    }
}

@media (min-width: 701px) and (max-width: 900px) {
    .tech-row { grid-template-columns: repeat(2, 1fr); }
    #tech-focus { grid-column: span 2; }
}