:root {
    --primary: #6366f1;
    --accent: #10b981;
    --danger: #ef4444;
    --bg: #0b0f1a;
    --glass: rgba(22, 30, 46, 0.8);
    --border: rgba(255, 255, 255, 0.08);
}

* { box-sizing: border-box; transition: all 0.2s ease; }

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg);
    color: #cbd5e1;
    margin: 0;
    line-height: 1.6;
}

.background-glow {
    position: fixed;
    top: -150px;
    left: -150px;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 70%);
    z-index: -1;
}

header {
    padding: 80px 20px 40px;
    text-align: center;
}

.logo {
    font-size: 2.5rem;
    font-weight: 800;
    color: #fff;
    letter-spacing: -1.5px;
}

.logo span { color: var(--primary); }

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

.grid-layout {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 25px;
    margin-bottom: 25px;
}

.glass {
    background: var(--glass);
    backdrop-filter: blur(15px);
    border: 1px solid var(--border);
    border-radius: 24px;
    padding: 30px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.3);
}

/* Typografie v textu */
.text-content h2 { color: #fff; margin-bottom: 25px; font-size: 1.8rem; }
.text-content h4 { color: var(--primary); margin: 20px 0 10px; font-size: 1.1rem; text-transform: uppercase; letter-spacing: 1px; }
.text-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.divider { border: 0; border-top: 1px solid var(--border); margin: 30px 0; }

/* Klávesnice a Displej */
.display-container {
    background: rgba(0,0,0,0.5);
    padding: 30px;
    border-radius: 20px;
    margin-bottom: 30px;
    text-align: center;
    border: 1px inset var(--border);
}

.display-main { font-size: 2.2rem; font-weight: 700; color: var(--primary); font-family: monospace; }

.keypad { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; }

.key {
    background: rgba(255,255,255,0.03);
    border: 1px solid var(--border);
    color: #fff;
    padding: 22px;
    border-radius: 16px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
}

.key:hover { background: var(--primary); transform: translateY(-3px); box-shadow: 0 10px 20px rgba(99,102,241,0.3); }

.action-ok { background: var(--primary); border: none; }
.action-c { color: var(--danger); }

/* Ostatní prvky */
.tag { background: rgba(99, 102, 241, 0.1); color: var(--primary); padding: 5px 12px; border-radius: 6px; font-size: 0.75rem; font-weight: 700;  margin: 5px; }
.stat-row { display: flex; justify-content: space-between; padding: 12px 0; border-bottom: 1px solid var(--border); }
.stat-value { color: var(--accent); font-weight: 700; }

pre { background: #05070a; padding: 25px; border-radius: 15px; font-size: 0.9rem; overflow-x: auto; border: 1px solid var(--border); }
.comment { color: #5c6370; font-style: italic; }
.keyword { color: #c678dd; }
.str { color: #98c379; }

footer { text-align: center; padding: 60px; font-size: 0.8rem; color: #475569; }

@media (max-width: 850px) {
    .grid-layout, .text-grid { grid-template-columns: 1fr; }
}