  We construct a minimal viable extension of the standard model (SM) with
classical scale symmetry. Its scalar sector contains a complex singlet in
addition to the SM Higgs doublet. The scale-invariant and CP-symmetric Higgs
potential generates radiative electroweak symmetry breaking a la
Coleman-Weinberg, and gives a natural solution to the hierarchy problem, free
from fine-tuning. Besides the 125GeV SM-like Higgs particle, it predicts a new
CP-even Higgs (serving as the pseudo-Nambu-Goldstone boson of scale symmetry
breaking) and a CP-odd scalar singlet (providing the dark matter candidate) at
weak scale. We systematically analyze experimental constraints from direct LHC
Higgs searches and electroweak precision tests, as well as theoretical bounds
from unitarity, triviality and vacuum stability. We demonstrate the viable
parameter space, and discuss implications for new Higgs and dark matter (DM)
searches at the upcoming LHC runs and for the on-going direct detections of DM.
