:root {
    --bg: #06090e;
    --amber: #ffaa00;
    --green: #00ff66;
    --text: #e2e8f0;
    --font: 'Fira Code', monospace;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body { background: var(--bg); color: var(--text); font-family: var(--font); overflow: hidden; height: 100vh; }

.nav { padding: 2.5rem 4rem; display: flex; justify-content: space-between; border-bottom: 1px solid rgba(255,170,0,0.3); }
.logo { color: var(--amber); font-weight: 700; font-size: 1.4rem; }
.qkd { color: var(--green); font-size: 0.85rem; }

.hero { height: calc(100vh - 90px); display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center; padding: 0 2rem; }
h1 { font-size: 3.2rem; color: var(--amber); margin-bottom: 1.5rem; max-width: 850px; }
p { font-size: 1.1rem; color: #94a3b8; max-width: 600px; margin-bottom: 2.5rem; }

.btn-cipher { background: transparent; border: 1px solid var(--amber); color: var(--amber); padding: 1rem 2.5rem; font-family: var(--font); font-size: 0.95rem; cursor: pointer; transition: 0.3s; }
.btn-cipher:hover { background: var(--amber); color: #000; box-shadow: 0 0 25px rgba(255,170,0,0.6); }

.output { margin-top: 2rem; font-size: 1rem; color: var(--green); letter-spacing: 2px; }