:root {
    --primary: #007bff;
    --secondary: #6c757d;
    --success: #28a745;
    --danger: #dc3545;
    --dark: #343a40;
    --light: #f8f9fa;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

.container {
    padding: 20px;
    max-width: 600px;
    margin: 0 auto;
}

.card {
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.btn {
    display: block;
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    text-align: center;
    text-decoration: none;
    margin-top: 10px;
}

.btn-primary { background: var(--primary); color: white; }
.btn-success { background: var(--success); color: white; }
.btn-danger { background: var(--danger); color: white; }

input, select {
    width: 100%;
    padding: 12px;
    margin: 8px 0;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
}

.header {
    background: var(--primary);
    color: white;
    padding: 15px;
    text-align: center;
    font-size: 20px;
    font-weight: bold;
}

/* Utilidades PWA */
.install-prompt {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background: white;
    padding: 15px;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
    z-index: 1000;
}