:root {
    --bg-dark: #09090e;
    --bg-panel: #151522;
    --neon-blue: #00f3ff;
    --neon-purple: #bc13fe;
    --text-main: #e0e0e0;
    --text-muted: #8892b0;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
header {
    background: rgba(21, 21, 34, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 243, 255, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 50px;
}

.logo {
    font-family: 'Orbitron', sans-serif;
    font-size: 22px;
    font-weight: 900;
    letter-spacing: 2px;
}

.logo span { color: var(--neon-blue); text-shadow: 0 0 10px var(--neon-blue); }

nav ul { display: flex; list-style: none; gap: 20px; }

nav a {
    color: var(--text-main);
    text-decoration: none;
    font-family: 'Orbitron', sans-serif;
    font-size: 13px;
    cursor: pointer;
    padding: 8px 15px;
    transition: 0.3s;
}

nav a.active, nav a:hover { color: var(--neon-blue); text-shadow: 0 0 5px var(--neon-blue); }

/* Main */
main { margin-top: 120px; padding: 0 50px 50px; flex-grow: 1; }

.tab-content { display: none; animation: slideUp 0.4s ease-out; }
.tab-content.active { display: block; }

@keyframes slideUp {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 40px;
    margin-bottom: 25px;
    background: linear-gradient(90deg, var(--neon-blue), var(--neon-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.grid-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.card {
    background: var(--bg-panel);
    padding: 25px;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: 0.3s;
}

.card:hover {
    border-color: var(--neon-blue);
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.4);
}

.btn {
    background: transparent;
    color: var(--neon-blue);
    border: 1px solid var(--neon-blue);
    padding: 10px 20px;
    font-family: 'Orbitron', sans-serif;
    font-size: 12px;
    cursor: pointer;
    margin-top: 15px;
    transition: 0.3s;
}

.btn:hover { background: var(--neon-blue); color: #000; box-shadow: 0 0 15px var(--neon-blue); }

.btn-purple { color: var(--neon-purple); border-color: var(--neon-purple); }
.btn-purple:hover { background: var(--neon-purple); color: #fff; box-shadow: 0 0 15px var(--neon-purple); }

/* Calculadora */
.calc-container {
    background: var(--bg-panel);
    padding: 30px;
    max-width: 500px;
    border-radius: 15px;
    border-top: 3px solid var(--neon-purple);
}

.input-group { margin-bottom: 15px; }
.input-group label { display: block; font-size: 12px; margin-bottom: 5px; color: var(--text-muted); }
.input-group input {
    width: 100%;
    background: #000;
    border: 1px solid #333;
    padding: 12px;
    color: #fff;
    border-radius: 5px;
}

#calc-result {
    margin-top: 20px;
    padding: 15px;
    background: rgba(0, 243, 255, 0.1);
    display: none;
    border-radius: 5px;
}

footer { text-align: center; padding: 20px; font-size: 12px; color: var(--text-muted); }